searching ��
for ��
memory
Searching for Melllory
The Brain, the Mind, and the Past
DANIEL L. SCHACTER ... BasicBooks A DIVIJIQO'I of ,-b.rpcrCo![;nsPlob.'is«n
For III)' /l/OI1ier, H(/f(;et
Copynght 0 1996by D�lIiel L. Sch�cter. Published by l3aslcBooks. A DI"isian ofH;IrperCollms Pubhshen.lnc. All nghts reserved. PTinted III Ihe Unl1C"d SUtCS ofArnenca. No p�rt of Ihls book m�y be reproduced 111 �ny manner wh�t:socver without WTII
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Great is the power of memory, a fearful thing, 0 my God, a deep and boundless manifoldness; and tlus dung is the !lund, and this am I myself. -Augustine, 771c COIifessiOlls � Saim AI/gusril/c
"I know it can'r've bee" like that, but that's what I
remember." -Pat Barker, Regel/erarioll
As I used to say to Illy clients, "Memory is life," -Saul Bellow, ?1IC Bellarosa Cmmcaioll
CONTENTS
AckllOl4Iledgmcflls
Xl
Il1troductioll Memory's Fragile Power
1
ONE On Remembering "A Telescope Poimed at Time"
15
TWO Building Memories E/lcoditl.� a"d Retrievil1g tile
THREE FOUR
Prescl/( and the Past
39
Of Time and Autobiography
72
Reflections in
Curved Mirror
a
l\1emory Distortioll
98
FIVE Vanishing Traces Amllesia alld the
Bmill
SIX The Hidden World of Implicit Memory
134 161
,x
Contents
x
SEVEN
Emotional Memories
192
"V1Je1I tIle Past Persists EIGHT
Islands in the Fog
218
PS)lcllOgCtlic A"lIIcsia NINE The Memory Wars
Seeldllg Trl/tll ;11 the Lillc TEN
Stories of Elders
of Fire
248 280
Notes
309
Bibliography
350
II/dex
387
ACK N OWLEDGM E N T S
THE SEEDS
OF THIS BOOK
were sown in 1975, when I worked
as a research assistant for Dr. Herben Crovirz at a Veterans Adminis tration Hospital in Durham, North Carolina. There I tested brain damaged patients who were utterly incapable of remembering new information for more rhan a few seconds. One man conversed easily when we fIrst met and seclllcd more or less likt: anyone elsc. But when I left the room and returned several minutes later, he had totally for gotten we had ever met. Startled and imngued by such dramatic dis orders, I developed a deep and enduring imerest in mClllory that I have pursued for the past two decades. 1 have had llIuch help along the way. Herb Crovitz ignited Illy
intercst in memory, and Endel Tulving nurtured it during my years in graduate school and ever since. I have been fortunate to work closely with many fine psychologists and neuroscientists during the past nvo decades. For their contributions to research described in this book, I am indebted to Marilyn Albert, Nat Alpert, Barbara Church, Lynn Cooper, Tim Curran, Elizabeth Gilsky, Peter Graf, joannc Harbluk, john KihlstfOm, Bill Milberg, Morris Moscovitch, Mary jo Nissen, Michael Polster, Scon Rauch, Eric Reirnan, Cary Savage, Endel Tulv ing, Anne Uecker, Mieke VerfaelJie, and Paul Wang-to name only some of my collaborators. I have received pointers and advice con cerning phenomena and issues addressed in these pages from numer ous colleagues, including Steve Ceci, Mary Harvey, jake jabobs, Eric Kandel, Michellc
Leichtman, Elizabeth
Lofl'lls, jallles McGaugh,
R.ichard McNally, Roddy Roediger, and Larry Squire. The members
A c know i c d gm en t s
XII
A c k n owl edgll1 e n t s
X111
of the memory working group in Harvard's Mind/Brain/Behavior
imeiJigence, helping to improve the final product significantly. Linda
initiative-Emory i:hown, Joseph Coyle, Jordan Fieldman, Gerald
Carbone kept finding ways to help me communicate more dearly :tnd
Fischbach. Jerry Green, Jerome Kagan, Elaine Sc arry, and L1wrence
Sullivan-have helped me to think through issues addressed in this book during numerous stimulating discussions. I am especially grate ful to colleagues and studentS who provided perceptive COllllllentS on
succinctly, even when this project intruded on her ea rly days of moth erhood; I greatly appreciate her cOlllmitment. M y greatest debt is (0 my family, Susan, Hannah, and Emily, the SOllrce of my most vital memories.
variolls drafts of the entire manuscript: Laird Cermak, T i m Curran, Stephen Kosslyn, Wilma Koutstaal, Ken Norman, Kevin Ochsner, and Robin R_osenberg. For tracking down references aU over the Boston area, I thank Gayle BessenotT and Lissa Galluccio, and for keeping track of the ever-increasing bibliography, I am grateful to Mara Gross and Kim Nelson. Maura Wog-Ill provided helpful advice concerning pragmatic aspects of this endeavor. My wife. Susan McGlynn, not only provided useful feedback on the evolving manuscript, but also put lip with too many occasions whell my need to wrire just one more page
kept me from f amily duties. Her love and support throughout this project have helped me more than she can imagine.
I am fortunate that my research has been supported by various pub lic and priv:l[e :lgencies, and I am deeply grateful to all of them: Air Force Office for Scientific Research, Connaught Foundation,Charles A. Dana Foundation, McDonnell-Pew Program in Cogllltive Neuro science, Nalioll:l.i Institute on Aging, National Institute of Neurolog ical Diseases and Stroke, National Institute of Mental Health, and Nat ural Sciences and Engineering Research Council ofCamda. Much of that research has involved people with shattered ll"lcrnories. I am espe cially thankful for
all
the time and effort
their f:unilies during participation
in
expen
our research p rojects. To protect
their privacy. I have used fictitious names or initials for patients who took part in my studies, and have also changed some background information about them. Although Ihis book is primarily about the scientific study of mem ory, I have al�o drawn on the inspiration of artists. In th e course of acquiring a coiJection of :tl"tworks in which memory is :t
ccntr;ll
theme, I have been unfailingly i mpre ssed by the dedic:ttion and
humanity that so many artists bring to their work. I am graleful thai they have allowed me to share their creations and tell their stories. At Dasic Dooks. I have been fortunate to work wilh a number of skilled professionals. Jo Ann Miller, now with John Wiley and Sons, provided wise counsel and in sigh tful editorial guidanc e from the inception of this book until
near
its end. Susan Rabiner stepped in
during the latter phases of the project with grace, enthusiasm, and
INTRODUCTION
Memory's Fragile Power
IN GAIHUEl GARCiA MARQUEZ'S epic novel OlleJ-Jll11dredYcars if Solilllde, a strange plague invades the small village of Macondo, causing the inhabitants to lose aspect� of their memories. The symp� tOIllS develop in stages. Each vlllagcr loses lhe abiljty to call up child hood recollections, then the names and fUllctions of objects, later the identity of other people, and finally "even the awareness of his own being." A silversmith, frightem:d when he c:mnot come up with the word mlllil to describe the tool he has always worked wllh, frantically goes about placing written labels 011 every item in his home. Inspired by the method's seeming sticcess,Jose Arcadia Buendia ateempts to label ever ything in the village: He .. ,marked the animals and plants: WlI\gOilf, pig, hf'll,
(fISSflIlII,
(a[
adiwlI, /}(mil/W, Little by little, srudying the lIlunite possibilities of loss of memory, he realized that the day might come when things would be recognized by their inscriptions but that no one would remember their lise. Then he was more explicit.
.
.
. TIlis is the
ww.
She must be milked ellery lIIonlillg so tlwr she will pmduce milk, fwd rhe milk I/HIS! be boiled ill order to be mixCl/ witll cwee to make Ci?fTee alld milk.' Distressed at the thought of a life of endless labeling, Buendia makes a heroic last anempt to save the memory or the villagers: he
1
In t r o duction
Searching Jor M e m o r y
2
3
tries t o develop a memory machine that will store written entries of
Like other biologically based capabilities, memory is generally well
all the experiences and knowledge accumulated in each person's life.
adapted to such everyday demands of life, because it has evolved over
After devising founeen thousand entries for the machine, mercifully.
countless generations ill rcsponsc LO the pressures of natura] selection.
Buendia is freed frolll this nightmare by a stranger who cures him of
A foraging anima] who can remember locations where food has been
the plague. With a cure comes the full restoration of his memory. Only
found has an important survival advantage over a competitor with less
then does he recognize the stranger as an old and dear friend.
accurare recall; an inhabitant of the jungle who can reCOb"llizc quickly
The novel dramatizes a world withom memory: a world in which
the signs of a dangerous predator stands a better chance of e�cape than
even close friends and family members seem like str,l.I1gcrs; a world in
a competiror with slower or foggier recognition processes. Indeed, we
which symbolic fOfms of communication arc useless, and Illost of the
can guess that Illany features of memory survived the rigors of evolu
tasks 011 which society depends cannot be performed; and, perhaps
tion precisely because they helped animals and people survive and
most [eUingl}',
a world in which reproduce; any memory system that consistently produced scrioliSour dissense of pe
self-awareness is stripped away. The narrator in Saul Bellow's TIle &1-
tortions would not be likely to survive m:lIly generations.' W hile fir
iamsil Comll,cti()/I, who runs a memory-improvement institute, SUIllS it
from perfect at meeting all human needs, ollr own memory systems
up for his clients: ;'Melllory is lifc."�
do a remarkably good job of handling the staggering variety of
Yct, except for those annoying moments when merl'lory f,1.ils or
demands we place upon them.
when somcone we know is afflicted with memory loss, most of us are
Yct memory's reputation has been tarnished lately. We hear disturb
barely aware thaI just about cverythmg we do or say depends on the
ing reports of f.lse traumatic memories in therapy patients. We read
smooth :lI1d efficient operalion of our memory systems. Stop and
stt3nge stories of people who vividly recall alien abductions. And we
think for a moment abollt what is involved in just one simple task:
learn that scientists have comc up with simple ways to induce some
arranging to mcet a friend at a restaurant. For starters, you mUSt be
of us to remember clearly evenlS that never happened!
able to bring to mind your friend's name and phone number 3S \vell 3S
Docs this suggest that as accurate as memory is in most situa
the informacion needed to r.:xecute the call. Then you must lise your
tions, it is less consistently reliablc than we once believed i t to be?
memory of voices to identify the person who answers the phone 3S
Or that its reliability is conditional. highly accurate in some situa
your friend. Throughout, to hold up your end of the conversation and
tions or under some conditions-perhaps when our well-being or
to understand what is being said to you, YOll must constantly access an
even our survival is at stake-but less so in other circulllstances? Or
internal dictionary of words, sounds, meanings, and syntax. At some
that it is highly reliable in allowing u� to rccall a general sketch of
poim you must search through memories of visits to restaurants, or
moments from the past, but much less reliable in its recall of spe
recommendations of new ones, in order to determine which restau
cific detail?
rant wOlild be a good choice. You IllUSt be able to call up details of
We've all had firsthand experience with memory's imperfections. I
your fricnd's personality, special interests, and anything elsc that will
once asked a colleJbrtlc how long it had been since he shaved his
contribute to harmony and avoid provocation or confrontation. Later,
beard. He replied in bewilderment that he hJd always been c1ean
you must caU upon knowledge and skills that remind you how to get
shaven. Each of us had perfect confidence in hi� own memory, yet the
physically (i'om here to there. Finally, yOll must be fully aware of whal
two were in conflict. Likewise, all of liS have had the uncomfortable
else is going on in your life so that yOLl do not schedule the meeting
experience of being unable to pull up a word or a name we oncc
for a lime when you already have something planned.
knew well, failing to recognize a f,1.CC that ollght to seem familiar, or
We perform these feats of memory naturally, even dlOugh the tasks
drawing a blank when a friend reminds us of something we suppos
require the virtually perfect operation of memory-retrieval systems
edly did together. Why is it, we Illay ask, that trying to remember Lhe
with processes so complex that even the most advanced computer
past is sometimes like.! trying to caplllre a darting phanlOlIl? Is this evi
would not be able to carry Ollt the assib'1llllem
dence of the imperfection of evolution? Or, rather, of the side effects
as we do. Now consider that we rely on these systems to perform sim
of its advantages? Imagine having immediate access to everything you
ilar feats coundess times each and every day of our lives.
ever knew or experienced. Is protection from the chaos that would
as e
S e a rdrrfl.� f o r .\lemofy
In trodu c t i o n
result the pncr.: we pay for the occasional inability lO retrieve infor
and forgetting for more than one hundred years. I�or Illuch of this
4
marion wc need or want at the moment?
5
time, progress has been slow, but the study o( memory has undergone
Researchers studying memory have begull to grapple in earnest
dramatic changes during the past couple of decades, some even revo
with these and other equaUy intriguing questions about how we
lutionary. Most important, we h:lVe now come to believe that mCIll
remember the past. For example, to study emorion, researchers often
ory is not a single or unitary faculty of the mind, as was long assullled.
ask their subjcCls to call up rhe saddest or happiest moment of their
Instead, it is composed of a variety of distinct and dissociable processes
lives. Remarkably, it has been observed that the aCt of remembering
and systems. Each system depends on a particular cOllstcllanon of net
sad episodes C;1I1 bring people to tears within lnQIllCnfS, and n."lllcm bering happy incidents
Gill
induce an almost immedi:ltc sense of r.:b
tioll. Why does memory have sllch power in our lives?'
works in the brain (hat involve different which plays a highly specialized role within the system. New break throughs in brain imaging allow us to see, for thc first time, how these specific parts of the brain contribute to different
To begin to answer the questions I've raised, we must first try to understand what memory is. Twenty years ago, when I first entered the field of memory research. it was fashionable for cognitivt! psy chologists co compare memorit.!S to computer ftles thlt are pbccd in storage and pulled om when needed. Dack theil, nobody thought that the sHldy of memory should include the subjective experience of rt'membering.\Vc now bclie\'e with some degree of certainty that our memories are not just bits of data that we coldly score and retrien', cornpllterlike. Artists and writers. of course, have long been aware of the import:ll1ce of subjective experience in memory, ;lnd I am often struck by their pre�ciellt commentS about what memory has me:lIlt co them in their creative work. For instance. in Matthew Sradler's novel umdsct1/JC: .\lem0'1� the story's protagonist, Maxwell Kosegartcn, starts to paint a landscape he saw sev eral years earlier. The painting develops slowly, over time.
as
Ma:.:well
retrieves and c:\l)lores his memory again and af,>:Iin. A� he paints, he con fi-onts the discrepancy bc[\'.'ccl1 the view of memory as a static repro duction and what his own experience is telling him. I-Ie writes:
if Illy memory ought to be an accur:ue replica of the original expe rience, if that was so, my p ..inting was hopcll.!ssly maccurate. It was
In this book I identify and discuss different enlble us to hold information for brief periods o( time, to learn skills and acquire habits, to recognize evcryday objects, to retain conceptu31 information, and to recollect specific evcms. Acting in concert, thest! memory systcms allow us [Q accomplish the tasks of our day-to-day lives while also supplying our intellect and emotions with ideas and feelings from the past that allow us to act with purpose and live rich emotional lives. But memory involves morc than JUSt our rcmelll br:mcc of things past. As we h:we come to learn that memory is not one single thing, we've opened up a whole new world of implicit. nonconscious memory that underlies our abilities to carry out efo f rt lessly such tasks as riding a bicycle or playing a piano, without having to direct each movemem consciously every time we attempt the t:l�k. Many of us chink of this type of memory as being stOred in our fin gers, but new research is uncovering that specific brain systems are involved in the non conscious effectS We now know enough about how memories are stored and retrieved [Q demolish another long-standing myth: that memories are passive or literal recordings of realiry. Many of us still see our memo . ries as a series of f 1mily pictures srored in the photo album of our minds. Yet it is now clear that we do not store Judglnent-free snapshots
a bad painting of a fuzzy memory. But [ preferred to think th:lt
of our past experiences but rather hold on to the meaning, sense, and
memory is never frozen, nor should it be. My painting was a suc
emotions these experiences provided us. Although serious errors and
cessful rendering of the dynamiC memory that had simply begun
distortions occur relatively inCrequently, they furnish significant clues
with the orlgmal ewnt.., . My painting. I figurl.!d. was so vcry
abollt how we remember the past because they arise from, and pro
accurate III its depiction of this memory th:lt it would inevitably
vide a window on, somc of the fundamental properties of our mem
look wrong when compared to the original model.' Philosophers and writers have sought to penetrate memory's I11Ys teries for centuries. and scienti�{S have struggled with remembering
ory systems. One especially important such property is that we cannot separate our memories of the ongoing events of our lives from what has hap pened to tiS previously. Imagine that for a set time period, two people
6
Sl'llfr/dtlg for Melllory
Intro d u c t i o n
7
were tied together so thal each could witness only whar the other saw,
tOols to bear on undersranding baffiing cases of amnesia. Clinicians
rcad on1y what the other read, learn only what the other learned, and
interested in memory loss drew increasingly on the techniques and
have only the emotional experiences the other experienced. Unless
theories developed by cognitive psychologists, and used new methods
these tWO people WCfC identical personalities with identical pam, their rncl\\ories of the tiH1C period could be vastly different. Wilat has hap
(or visualizing (he brain, Stich as magnetic resonance imaging (MRI), to provide precise characterizations of br. lin danuge in tht'ir patients.
pened to
At the same time, neuroscience made stunning progress, facilitated by
LIS
in the past dctt.!rrnines what we take OUt of our daily
encounters in life; memories arc records of how we have experienced
technical breakthroughs that allowed increasingly refined explorations
events, not replicas of the evellts themselves. Expcricnces 3rc encoded
of the brain and by the development of powcrful new theories using
by brain networks whose connections have already been shaped by
neural networks. More and more neuroscientists bCbran to relate their
previous encounters with the world. This preexisting knowledge powerfully influences how we encode and store new memories, thus
thc past few years, ncw functional neuroimaging techniques, stich as
fmdings with rats and monkeys to human memory. And during just
contributing to the nature, tex(Ure, and quality of wha( we will recall
positron emission tomography (PET scanning), have allowcd us to see
of the m01l1!.:llt.
the brain in action while people remember. Cognitive psychologists,
Not surpri�ingly, these insights and others have taught us much
clinicians, and neuroscientists are all now contributing to pathbreak
about the vulnerability of memory-why Ollr recollections are some
ing neuroimaging research that is providing a novel window on mem
times pr!.:disposed to corruption by suggestive influences, and how we
ory and brain. A synthesis has emerged during the past tWO decades
sometimes distort the past for no illmlcdiately apparent reaSOH. And
that is exciting and vast in scope.
we are beginning [0 unde�tand why some memories have the power
I decided to write this book because I believe it is time to tell the
to induce us to cry, to laugh. or [0 tremble. We are still far from being
talc from the perspective of someone who has been part of it. For
able to say that we have a complete picture of how human memory
much of my career I have attempted to link cognitive psychology,
works. but after centuries with little Sllccess, we are starfing to fmd
clinical observations, and neuroscience into a cohesive approach to
places for many pieces of the puzzle.
understanding memory. I-I ere I try to paint the big picture of mem
One reason for the emerging synthesis is that students of the brain and the lnind, after years of going separate ways, have C0111C together [0
ory as I have come to sec it. tlut my goal in writing this book goes beyond describing the ncw
develop an integrated approach that has transformed the study of
synthesis in memory research and relating SOllie of my own discover
Illemory: cognitive neuroscience. A mere two decades ago, the study
ies and ideas, to include consideration of a puzzle that many of these
of memory was carried out by separate tribes of cognitive psycholo
findings highlight. Memory, that complex and lIsually reliable asset,
gistS, clinicians, and neuroscientjsl�. Cognitive psychologists studied
can sometimes dcceive liS badly. Yet even though memory can be
memory in the laboratory, but showed scant interest in the world of
highly elusive in sOllle situations and dead wrong in others, it still
memory outside the lab and little or none in the brain. Clinicians-psychologists.
neurologists,
and
forms the foundation for our lllosr strongly held beliefS about our
psychiatrists
selves. A head-injury patient I once interviewed who had lost Illany
described fascinating disorders of meTllory, but were unfamiliar with
treasured memories felt that he had also lost his sense of self. He
thl.! elegant techniques llsed by cognitive psychologists to dissect
became so obsessed with the Illissing pages of his past that he could
meillory. Neuroscientists studied memory by removing particular
think or talk of little clse.
parts of animals' brains and then observmg the efe f cts. hardly noticed the findings and ideas of cognitive psychologists or clinicians.
"I can't review my life," he kept telling mc. This important duality-memory's many limitations on the one hand and its pcrvasive influencc on the other--is at the heart of thjs
In the 19805, cognitive psychologists began to emerge from the
book because it is central to understanding how the past shapes the
confines of the laboratory. Some swdied memory in everyday life,
present. I refer to it as fragile power, and it has afft'cted increasing
adding a new richness to their work. Others began to test patients
numbers of us in recent years. An intense controversy has exploded in
with memory disorders, bringing their vast arsenal of experimental
therapy settings. courtrooms, and the popular mcdia as people clailn,
111(rodUClion
Srarchi"g for Ml'lIIory
8
with passionate cOllviction, to have recovered long lost memories of sexual abuse during childhood. Are some of these allc�,.ations based 011 illusory "memories" created, rather than uncovered, in psychotherapy? We have also seen a steady parade of child care workers and others
9
in sOl11e of this re<;carch and will report the latest developments from the cutting edge of an exciting frontier. Chapter
3 examines how we construct our autobiographies from
fr3gmel1ts of experience that change over time. We wiU see that melll
cOllvicted for abusing young children. Did these children really expe
ories are not stored in any single 10c:Jtion in the brain, as some
rience the horrors they report, or did repeated questioning create
researchers used to believe, nor are they distributed throughout the
memories of events that never occurred?
emire bra1l1, as others contended. Different parts of the brain hold 011
Memory's fragile power is evident in other sectors of society, too.
to different aspects of an experience, whIch arc in turn linked together
As the aging population lives longer, more and morc families are
by a special memory system hidden deep within the inner recesses of
f cted by afe Here, the devastating progression of memory disorder highlights bQ(h
help in cases of A memory will our brains. New conceptions of autobiographical increase the corresponding us to make sense of what happened to a brain-damaged man haunted
our extraordinary dependence on memory and itS remarkable sensi
by a delusional memory that he is still fighting World War II, and pro
tivity to changes in brain function. And in perhaps the IllOSt poignant
vide insights imo the experiences of a novelist who told the story of
example of all, fifty ye:1fS after the horrors of the Nazi killing grounds,
her life to a dying daughter.
so-called revisionist groups have attempted to recast society's collec
How accur:lte are the tales we tell about our lives? In chapter 4, I
tive memory of the Holocaust by disnllssmg the recollections of sur
explore the relation between memory and reality and consider what
vivors and questioning the mountains of factual evidence and footage
happens when the connection between the twO is severed. Accumu
of the most despicable event of modern timcs.
lating evidence suggests (hat we are usually correct about the general
These examples remind us that trying to understand memory's
character of our pasts. bur are susceptible to various kinds of biases and
fragile power IS not JUSt an exercise in intellecrual curiosity; it IS also
distortions when we recount specific experiences. We are especially
essenri;ll for understanding some of the most compelling issues of our
prone to misremembering the source of ollr memories.:ls in the story
times. In this book I relate insight�. these and other important manifestations of memory in our day-to
I relate of a woman who confused a man she had seen on television from modern m with the man who had raped her. Studies of patients with neurologi
d:!y lives. Chapter 1 examines subjective experiences of remembering.
cal damage have begun to reveal what parts of the brain allow us to
It was once believed that remembering a past experience is merely a matter of bringing to mind a stored record of the event, but recent research has overturned this persisting myth. We will see how even the
SOrt out memories of actual events from f.1rltasies or imaginings. We have also learned importanr lessons frolll brain-d:Jlllaged adults who have lost large chunks of their pasts----some becallse they cannot
seemingly simple act of calling to mind a memory of a particular past
form new memories, others because they can't retrieve old ones. In
experience-what you did last Saturday night or where you went on
chapter 5 we will see that studies of th
your first date-is constructcd from influences operating in the pres
an idea with profound implications: memory is not a self-comamed
ent as well as from information you have stored about the past.
entity, as many researchers once believed, but instead depends on a
In chapter
2 I explain some of the fundamental processes that give
variety of different syStems in the bram.
rise to ollr memories. I will show how understanding the nature of
The study of amnesic p3tiellts has also helped to opcn up the pre
encoding can help us to fathom the spectacular feats of memory of a
viously hiddcn world of implici, memory--when past experiences
long-distance runner who could recall long strings of digitS and an autistic savant who had an extraordinary ability to remember visual
unconsciously inRut'nce our perceptions, thougiltS, and actions. When I first began doing research. psychologists studied explio·, memor), for
patterns bUl little else. I will illustrate the complexities of the retrieval
recent experienccs by asking people deliberately to recall or recognize
process when I introduce a brain-damaged boy who could recall his
words or orher materials they had been shown a few minutes earlier.
recent experiences through writing but not talking. And we will see
l3ut in the early 19805, a series of stunning experimentS showed that
how PET scanning studies arc beginning to alter our thinking about
people can be influenced by recent experiences even when they �Irc
how the brain accomplishes encoding and retrieval. I have taken part
unable to recall or recognize them explicitly. As we will see in chap-
11
Selnciliug for Memory
Introduction
rer 6, brain-damaged patients who lack explicit memory for recent events nonetheless rctam implicit memory for them. Most of us know little about implicit memory, because it operates outside Ollf aware ness. But it is a pervasive influence in all our lives, and I will show how it affects everyday situations involving legal battles over intellectual property and disputes about plagiarized ideas.6 The power of memory is most forcefully illustrated by the pro found effects of emotionally traumatic events, which I explore in chapter 7. I introduce llleTl and women who have experienced terri ble traumas that they could never forget: narrowly escaping a life threatening fire, years of abuse in a Nazi concentration camp, or tcrrifying wartime incidents. And I discuss how recent discovcnes in neuroscience have begun to illuminate the underpinnings of these potent recollections. Yet even though traumatic events are generally better remembered than ordinary experiences, these memories, like more mundane ones, are complex constructions-not literal record ings of reality. Emotional trauma does not, however, always lead to VIvid recall; sometimes emotionally intense e>.:pericnces result in far-reaching anUleSlas. Chapter 8 considers mystifying cases of psychogenic amne sia, such as a young man who suddenly lost nearly aU of his personal past after a psychological trauma. I examine what happens when peo ple develop amnesia for shocking events, like a murderer who forgets committing a brutal crime. I also consider the controversial phellomenon of multiple personality, now referred to as dissociative identity disorder. Docs this disorder provide an important window on mem ory and identity? Or, as skeptics claim, arc multiple personalities now observed so frequently that we must question their validity? Having studied patients with dissociated identities, I agree with the critics that dubious diagnosis and treatment are serious problems, but I do not believe that all such cases can be explained in this way. I will discuss some of these perplexing cases in light of recent discoveries about the effects of stress-related hormones on the brain. Questions concerning traunn and amnesia are central to the bitter debate over repressed memories of childhood sexual abuse, which I examine III chapter 9. This controversy is often thought of as a winner-take-all b::tttle royal between advocates of recovered memories and proponents of false memories. I believe that we need to step back from lhe rhetoric, and recognize that thIS is an unfortunate oversim plification of an issue with many intermingled parts that need to be disentangled. Although it is likely that some therapists have helped to
create illusory memories of abuse, it also seems clear that some recov ered memories are accurate. I conclude by considering what happens to memory as we age. We have learned that cell loss in some parts of the brain that are crucial for memory is either trivial or nonexistent, and that different kinds of memory are affected differently by aging. We have promismg leads about what parts of the brain are hit hardest by aging and new insights into what this means for memory. Evcn as I write these words, my own research group and others are carrying out studies of aging mem ory with PET scans that are providing a direct window on memory and the aging brain that has ncver been previously available. Looking at memory in older individuals, I hope to show, offers valuable insights into the nature of memory's fragile power.
10
Science is typically more concerned with understanding mechanisTlls than with appreciating personal meanings, but to fathom memory's fragile power we must pay attention to both. Thus I delve 1I1to the personal stories of patients who have developed amnesia as a conse quence of neurological or psychological trauma, and I tell of writers and artists whose lives have been affected to an unusual degree by attempts to recapture their pasts or by traumatic memories. I also make use of artworks that focus on the nature or filllction of memory. AU art relies on memory in a general sense---v -e ery work of art is affected, directly or indirectly, by the personal experiences or the artist-but some artists have made the explor
FIGURE
1
FIGURE 2
Catherine McCarthy, "Children in the Wood," 1992. 40 x 60". Dip tych, oil, and varnish on canvas. Nielsen GaUery, Boston. The artist, shown as a young girl, clutches a ribbon th:n trovcls through a d3rk
�pacc. connecting her to a hardy visible frogment of a young boy's kg at the tOP of the canvas. It i�
3
partial image of her
bmd1('T, who di!.'d unexpectedly
when he was young. The ribbon seems to symbolize the power of emorioml lllemoril'S that persist
fmm the past and still tie the artist to her brother. She itself contains a �!.'ries of faint pic
also surrounds herself with a white oval that
tures. perhaps memories from McCarthy's childhood. A couple of the images are recugnizable: an isolated tdephone pole and a locomotive cngmc. Others are little more th31l formless blurs. testaments to childhood episodes that remain beyond the grasp of conSCIous recollection. Next to the oval is barely visible text fmm a fa\"Orite childhood fairy tale, " Children
n1
the Wood." The
words in the story are blurred :lI1d vciled, like nllKh else from the distant past.
Christel DiUbohner, "Excursions VI," 1993. 8� x 5 x 2X" . Seeds, wax, and tar in box. Courtesy of t.he artist. Dillbohner makes �xtclIsivc usc of old and discarded objeclS as visual symbols of memory, such as this tatlered c.1se standing open 011 its side. One insidt· panel holds fragments of objects-a ladder. a filter. and rwo seeds-whereas the other cOIlt.1im a thin layer of paper and a filmy wax. Matcnalizing from a tear in the paper, like 3 memory emerging into consciousness. is a ghostly yet affecting old photograph of Dillbohner's brother. who died :tt 3n early age. l3y encasing the mt':lTlory-ladcn photo and the object remains imide tht': case. the artlst alludes to fragmentary but compelling mcmorll;'S that we with
liS.
all carry
ONE
O N R E M E M B E R I NG
" A Te l e s c o p e P o i n t e d a t T i m e "
" My F I R S T L O O K at the Boston G:lrdcn was 52 years ago and it wasn't Jove at fm;t sight," the BostO/1 Globe sportswriter Will McDon
ough commented on the venerable arena before its closing in 1995. "To me, the place always has been a dump and 1 can't wait to get rid of Ie Hut not the memories. Those belong to me," McDonough went on [0 recount some of his IllOSt vivid recollections of the famed bUIld ing: the time that pipes burst during a hockey game, flooding the
stands with water; the day that a little-known man named Chuck Cooper became the first black plaYl'r ever to participate in a National Basketball Association game; and the All-Star contest that was placed in jeopardy because basketball pbyers threatened to strike. Although the Boston Garden will be reduced to rubble, McDonough still has his memories. and he probably always will. He is nOt alone. The Bost()/I Globe headline seated: " After 66 years the Boston Garden soon Will be gone, but what will remain with LIS forever arc the Illemories."! Occasions stich as the closing of the 1305ton Garden underscore lil:lt
we carry in our minds the remains of distam expericncl�s that tie us to the past in a special way. Places that have long ceased to exist and people who have disappeared from our lives continue to survive in Our recolleceions, sometimes as ghostlike phantoms we can barely fathom and sometimes as crystal-clear portrait..� with all the vibrancy of the here and now. Our memories belong to us. They are uniquely Ours, not quite like those of anybody else. We feel lhis way in part 15
17
S e a rc/ring Jor MrmMy
O n R t' m e m b e r i n g
episodes because our memories arc roared in the ongoing series of read the \Vc lives. and incidents that uniquely constinnc our everyday ill morning paper, stroll in the park, or talk with a friend, and we are some way changed, transiently or perhaps permanently, by the expe
rance looked, o r how much you enjoyed dancing to tlilles yOll had not
16
rience. We go through an immense number of distillct cpi�odes dur ing a lifelime, but we call explicitly remember on ly a sllIa!! (raction of them. As the narrator in Saul Oellow's T1,e Bell(/rosa Cont/faiol! says whell asked about a long past event that he docs not recall, "Lady, this
heard since you were young. We are constantly making usc of informanon acqUired in the past. In order [Q type these sentL'nces into my computer, I 1llU',r retrieve words and grammatical rules that J learned long ago, yet [ do not have any sub jective experience of"rcmeillbering" them. Every time yOIl start your car and begin to drive, YOll are calling on knowledgt, and skills yOli acquired years earlier, but you do not feel as though you are revisiting
is one of a trillion incidents in a life like mine. Why should I recollect
your past. As we will scc, these lise" of the past call on [wo of the brain's
Our subjective sense of remembering the past is such a familiar and
r.1cl'u:!1 knowledge, and procedural memory, which allows us to learn skills
. ,"I ".
m;uor memory systems: semami( memory, which contains conceptual and
(requem part of our inner lives that we may fail to see any need to
and acquire habits. Uut there is something spl�cial about the subjective
examine it. When I ask you to recall what you did last Saturday night,
experience of explicitly remembering past incidents that separates it
it may take a few seconds for you to generate a memory, but before
from other uses of mcmory, something tl1:lt i� often overlooked i n sci
long you are probably reexperit'llcing some aspects ofth:1I evening.As
cntific analyses that portray memory as a device for storing and retriev
you think back, YOll may feel as though YOll are shining a spotlight on
ing information. In order to be experienced as a memory. the retrieved
images. sounds. and emotions that arc slumbering somewhere in the
information Illust be recollected in the comext of a particubr time and
vast storehouse of memory. As innocent and plausible as this idea may
pl:!ce and with some reference to oneselfas a participant in the episode.
seem, however, it is fundamentally misleading. Our experience of
The psychologist Endel Tulving has argued th:!t this kind of remem
remembering an event docs. of course, pardy depend on information
bering depcnds on a special system called episodic "'C"IO'1� which allows
about the evem that has been stored in our brains. But there are other
us explicitly to rec:!ll the personal incidents that uniquely defme our
contributors to the subjective sense of remembering, and to appreci
livt's. Any analysis of episodic memory must consider the subjective
ate memory's fragile power we will need to understand them.
experience of the person who does the remembering, referrcd [Q by Tulving as the remi'lIIum'r. Stressing the mtill1ate rclatiomhip between lhe rcmemberer and the remembered, Tulving observt'S that: "The par
E X P E R I E N C I N G T H E PAST The Rcmemberer
ticular stlte of consciomness that characterizes the expericilce of remembering includes the rememberers belief that the memory is a more or less true replica of the original event, even if only a fragmented
Cognitive scientists cOll1ll1only speak of human memory as a kind of
and hazy one, as well ,IS (he belief that the event is part of his own past.
information-processing device-a computer that stores, retaim, and
Remembering, for the rememberer, is mental tnne travel, a sort of reliv
retrie\'es information. Although this sort of analob'Y docs capture some
ing of something that happened in the past."l
of memory's important properties, it leaves no ro01l1 for the subjective
The idea of remembering as " mental ti111e travel" highlights some
experience of remembering incidents and episodes from our pasts.Try
thing that is truly remarkable: as rememberers, we can free ourselves
to remember {he most recent wedding you attended. Sights and
from the immediate conStraints of time and space, reexperiencing the
sOllnds from the event probably come [Q mind, as well as (he names
past and projecting our�clves into the future dt will. What we ordinar
and f.1ce" of people who were there. 13m there is more [Q the experi
ily think of as an exotic feat that could be accomplished only in sci
ence than merely retrieving differem kinds of information: there is
encc fiction is something we all engage in each and every day of our
also a conviction that this episode is part of your personal history.
lives.Try to remember, for lIlstance, the following three events: a clllld
related to events that camc before and have occurred since. You may
hood birthday party; an incident from your first job; and the last thing
remember thinb'S that you thought or felt as the bride and groom
you did before you WCIl{ to bed last night. Withlll a matter of seconds,
spoke their vows, your surprise at how well or poorly an old acquain-
yOll have revisited parts of your past that are �eparated by years-
Seare/d"l! Jor A l e m a r ),
18
FIGURE 1 . 1
perhaps decadcs--and YOli did not need any (:mcy equipment to make this jourm:y in time. Visual artists ha\'e created evocative depictions of the subjective experiences of the rcmcmherer. For exaillple. in the nineteenth cen tury, portrait painters showed people engaged in introspective :lets of remembering, and conveyed the poignancy of their rccollective expe riences through emotion-filled (.1ci:-1I expressions, supporting context, and titles suggestive of charged memories. A modern work that spcaks eloquently
to
the nature of the relllembcrcr's experience is "Looking
for Yesterday," by the Massachusens artist Candace Walters. (See fig ure 1 . 1 .) A young woman's partial figure emerges from a suspended picture frame, eyes gazing into a distance that is nO[ visible
to
the
viewer. She seems to be engaged in an emotion-filled act of remem bering. The woman hovers betwccn two realities, pardy in the fraille and p:lrtly Olit of it-perhaps a metaphor for the remembercr's simul taneous existence in past and pn.."Sent. Another comemporary work, New York artist Nancy Goldring's " The Traveler Renlcmbers: l3eigescape" (see figure 1 .2), also evokes the remcmberer's dual existence in past and present. Artistic depictions of the rellH.:lllberer are suggestive and even provocative. But scientist� who study memory have only lately begun to study subjective experiences of remclnbering. For much of this century, the study of memory-like that of othn areas of psychol ogy-adhcred to the tenets of behaviorism. which held that subjec tive mental experience is nOt a proper domain for scientific study. Then came the rise of cognitive psychology during the 1 9605 and 1 9705, driven by an information-processing metaphor in which sub jective experiences of relllembering had no place. Philosophas offered eloquent introspective accounts of what remembering is like, but scicnti<;[s generally ignored them.' When Tulving wrote about subjective experiences of lhe remelllberer more than a dCC
ow, acclllllulating scientific
(('search is st:lrting to tell a surprising story about the inner world of the rememberer. one that violates our intuitions about [he sources of the experiences we explicitly remember every day of our lives.
Candace Wahers "Looking for Yesterday," t 992. I I x 8W'. Oil stick and collage on papcr. Clark Gallery, Lincoln, Massachusctts. ,
�
The title o rhis wo�k su ests a search for the past. and a tear rolling down � t e woman s check I llplles that the past can nevt'r be fully recaptured The � . PI�C C reflects W:lltl'rs S OW 11 attempts 10 reml'm bcr eventS and feelings from . cl ll l hood �ull1rners spent III rural Virginia. She paints a fragment of the coun trySide behmd the young woman, a tanta li zing yet elusive piece of the past that he rell1.ell�be�r seeks to find. "My roOtS an: Southern," t h e anist comments. .�y paumng IS de,·oted to the memory ofporch swings and fioaung suns. My . . \\�rk IS an esc;l.pe lIno tlllle travel, a splfltu a[ journey and �limpsc into somethlllg more.'"
�
�
M E M ORY ' S P O I N T O F V I E W
Try again to remember the most recent wedding you attended. Once you have fixed :l �cenc in your mind, :lsk yourself the following
�
21
On Remembering
FIGURE 1 . 2
quescions: Do you sec yourself in the scene? Or do you sec the scene through your eyes, as if you were there and looking ourward, so that YOLI yourself are nOt :1I1 object in the scene? Chances arc (har you will remember the wedding in the laner format, from a perspective simi lar to the one you had during the original event. Now try to remem ber back to your first day in kindergarten. Chances are that yotl will sec yourself in the memory this time. These two modes of remembering are referred to as
field
and
obSl'rllcr memories, respectively. Sigmund Freud, one of the first to write about the field/observer distinction, believed that it held impor tant implications for his psychoanalytic theories. Freud comended that observer memories-which we view as a detached observer--'JTC necessarily altered versions of the original episode, because our initial perception of an event takes place frolll a field perspective. Noting the frequency of the observer perspective in his patients' childhood recol lections, Freud believed that he had strong evidence for the recon structive nature of early memories.' The first serious investigation of field and obscrver memories was reported in 1 983 by (he cognitive psychologists Georgia Nigro and Ulric Neisser. They asked people to remember various situations, such as "watching a horror movie" or " being in an accident or near 1987. 1 5 Nancy Goldring, "The Traveler Remembers: Beigescape," York. 18". Ektacolor print. Jayne H. Daum GaUery, New
x
m ntal time Goldring gives visual form to the idea that remembering involves � . IInagl'S. a travel. In the piece, which combitH..'S drawlIlg and photographic in JI1 act woman (the traveler) gaze� om a window, appan:lltly engaged . ing grtdhke intersect figures, ghostly of n collectio the her. Behind . ollection and places structures. and a dreamy landscape aTe visual allusions to the people as fragmen tary eXlstlllg currently travels. her during ered encount she has
o� r� c
images in memory.
accident," and queried them about their recollections. The majority of recollections were classified as field memories, but a significant minority (over 40 percent) were classified as observer memories. We tend to see ourselves as actors in the older memories (much as Freud maintained), whereas wc tend to reexperience morc recent memo ries from something like the original perspective. Nigro and Neisser then asked some people to remember events from their personal past while foclising on the feelings associated with each episode, and asked others to remember events while focusing on the objective circumstances surrounding the remembered episodes. Remarkably, people experienced more field memories when focusing on feelings, whereas they experienced mon: observer memories when focusing on objective circumstances. Think about this result in rela tion to our wedding example. It implies that if I ask you to foclls 011 "objective circumstances" (who attended, what they wore), you would be more likely to experience an observer memory, whereas if I ask yOtl to foclls on how yOll felt, you would be more likely to exp!.!ri encc a field memory. This means that an important part of your rec ollectiw experience-whether or l10t you see yoursdf;ls a participant in a remembered event-is, [Q a large extent, constructed or invented
Sel'Tdtillg
22
O n Rem cmbering
Jar M e m Q r y
way you remember an event at the nme of attempted recall. The at the time that you attempt to depends on your purposes and goals g the act of remcmbcring.7 recall it. You help to paint its picture dUTin experiences from diffcr In a more recent study. people recollected as field or observer mem Cill times in their lives and classified them intensity of the original ories; then they l'scim3red the emotional they fdt as they recol on experience and the intensity of the emoo memories, some people were lected it. When asked again to recall the ver point of view. These peo wid to switch from the flCld to the obser e was less emotional than they pk now s:lid that the original experienc experienced less emotional had indicated earlier, and also that they than they had earlier. There intensity during the act of remembering was adopted on the twO was little change when the same perspective hed from observt::r to field. occasions, or when perspective was switc to our wedding memory. Think about these fmdings in relation remember lhe wedding, you Suppose that when I first asked you to and groom sharing their first experienced a field memory or the bride of happiness at the time, dance. YOll rcmembered feeling a great deal ced the event. If I ask you and you feIe the S;1I11e way as you reexperien the field perspective, your now to recollect the experience again from d I ask you to try to recol feelings will be similar. Dut suppose instea an observer memory: that is, lect the bride and groom's first dance as perhaps sitting at your table with you as a participant in the memory, The findings that I JUSt Aoor. as you watch the couple on the dance ience the memory as less considered suggest that you will now exper and you will experience your cnlotionally intense than you did before, yOli did before. This sur current level of emotional arousal as less than suggests that the emotional prising, even startling, observation again least in part. by the way in intemity of a memory is determined, at mbering the episode. And which you, the relllemberer, go about reme may sometimes arise frolll the emotions th:lt yOll attribute to the past memory in the prcsellt. the way in which yOll �et Ollt to retrieve a
23
YOll saw her last, at a silllibr faillily occasion. The person next to her strikes you as familiar, but, much to your consternation, yOll cannot recall his nal11(', what he does, or where you might have seen him before. You are absolutely certain that you know him, but as he extends his hand, all you can do is hope thac he will identify himself. And he does: i t is the groom's friend Bill, wholll YOll Illet at a party ovcr a year earlier. We have all had slIbjecc1ve expniences similar to these at different tinlL'S i n our lives. Somerimes we recall our personal past by recollect ing a wealth of information abollt a person or place. other times by just knowing th:lt someone or somcthing is familiar. Psychologists have begun to explorc these two forllls of subjective experience, which :lre referred to as relllelllberill� and Im()JI!ill,ii the past. Several stud ies have shown that rec:lll of vi�lIal information about the physical set ting or context of' (In evt'nt is crucial to having
a
"remember"
expenencc. Jn one, college studenLS wt.!re given a beeper that sounded unpredictably several times a day. Each time the beeper went off, they recorded what was happening (except when it sounded at inoppor tune times). When the students were later asked to remember these events. the episodes they recalled 1Il0St accurately and confidently included Visual images of what had occurred during the episode. The subjecrive sense of remembering almost invariably involvt'd some sort of visual reexperiencing of an evenl.' Why does retric\·ing visual images tend to make us feel strongly (hat we are remembering a real event? Part of the reason is that some of the same brain regions are involved ill both visual imagery and visual perception. In Since we usually rely on these areas to perceive the external world, it should not be surprising that when we usc them CO creale visual images. the images Illay feel likt.! the mental residue of acwal events. These observations have an imporram implication: cre ating Visual images Inay lead liS to believe th:lt we are remembering an event even whell the illcident never happened.ll By appreciating that subjective experiences of relTlclTlbering are enhanced when we conjure up visual images, we can better under�tand incidents in which
R E M E M B E R I N G A N D K N OW I N G T H E PA S T Re(Urn again to our wedding episode. The first person you cncounter at the reception is your dear Aunt Helen, whom you have not seen for SOllie time. You immediately recognize the aging ('lce, remember her name and identity, and recall [hat it has been exactly three years since
people appe:lr co be recalling horrific events th:1t never occurred. Though it is clearly important, visual reexperiencing is probably not the sole basis of the subjective sense of remembering. We arc also likely to feel that we are remembering something from the past when we can recall associations and ideas that occurred to us during the ini tial episode. For example, a recent article by a distinguished philoso pher discusses at length some ideas about memory and conscious
Scare/Ii"t Jor M e m o r y
24
experience. As I read the article, I made many mental notes about points where I agreed with the analysis and points where I disagreed. If YOli now ask me abollt lhe article. that I clearly
remember having
1 can state with full confide,�ce 1 do not have any speClfic
read it. But
visual images of exactly where I was when I read it, what the article looked like, and so forth. I remember having read the article because I recall my specific thoughts and reactions to iell On the other hand, if we are distracted or preoccupied as an event unfolds. we may later have great djfficllity remembering the details of what happened, although we may still have a general memory of it. Knowing but not remembering can sometimes b� � Illbarrassing. I once attended a reception in my honor before glVlllg a lecture about memory to a large audience. I was introduced to numerous people at the reception, all the while preoccupied with mentally rehearsing my talk. I n the midst of a conversation with several peo ple, I extended my hand and introduced myself to a woman who had , JUSt joined the group. She seemed f.·uniliar, and I thought I Imght know her from somewhere. As the woman grasped my hand, she looked vexed and reminded me that we had met just a few minutes before! I had registered enough about her to "know" that she was familiar, but not enough to "remember" the specific moment when I first Illet her. The tlritish psychologists John Gardiner and Alan Parkin h:lVe recently reported something similar in the laboratory. Some partic ipants in their experiment paid full attention to faces th:u were pre sented for study; others divided their attention between studying the faces and carrying out another task. Dividing attention reduced the likelihood that people later "remembered" having seen a face, but it had no elTect on the likelihood that they "knew" the face had been presented. Other evidence from the laboratory shows that when a word is flashed lOO quickly to sec clearly, it can lead people to say that they "know" the word was presented earlier-even though they did not consciously perceive the word when it was first presented. Ll Such findings help explain why you sometimes have the experience of encountering someone who is familiar without TCmembering who they arc: yOll Illay have been preoccupied with other concerns when you first met the person and not have made the associations and conneccions necessary to remember the per son's identity. It should be evident, then, that whether we "remember" a past inci dem or just "know" that it happened depends on how we attend to
O n R e m e mb e r i n g
?"
-,
the event in the first place and what kinds of information we can bring to mind when recalling it. But, as with field and observer mem ories, subjective experiences of remembering and knowing can also be influenced by how we go about retrieving a past event. In one sim ple experiment, people recalled previously studied words and then indicated whether they actually remembered them or simply knew the words had been on the study list . When people recalled the target
word on their OWII, without any external hints, they were likely to indicate that they remembered rhe word from the list. When given
cues or hints to help trigger their memory, people were marc likely to indicate that they knew that a word had been on the list. Once again, the recollective experience of the rememberer depends on the way in which a memory is tetrieved.H The experience of "just knowing" is rdated to another experience we are all acquainted with: the sense that a bit of information is on the " tip of our tongue" but we cannot retrieve i(. ln both experiences, we have a strong conviction dut we know or remember something, bur we are 110[ quite sure exactly what i t is. My own research and other studies suggest that the tip-of-the-tongue ex"erience arises in part because rhe rcmemberer can retrieve
some of the
desired infor
mation bur not enough to produce full recall.IS For example, if I ask you who was standing next to Aum Helen at that wedding, you may be unable to recalJ Bill's name. However, you might be able to remem ber what he looks like and that his name begins with "B."These tid bits may produce :1 strong sense that you will eventually recognize or retrieve the name. Bm new research has shown that there is another important source of the tip-of-the-tol1b'lle experience: one's familiarity with the him or cue that triggers the retrieval attempt i n the first place. A sense of . funiliariry with a retrieval clle can induce a strong-and often spuri ous-feeling of knowing. For example, when I clie YOll for Bill's name by asking who was next to Aunt Helen, YOllr f.1l1liliarity with your aunt may make you almost certain that you will be able to retrieve Bill's name-even though you may not in f.1Ct be able ro do SO.L� Here we have yet another example in which a feeling of memory depends as much on what is happening in the present as on what happened in the pase. A� argued by the cognitive psychologist Larry Jacoby, our subjec tive sense of remembering sometimes depends on theories or attribu tions we generate abollC why something seems f.uniliar or why an image or idea suddenly or easily pops to mind. If our goal is remelll-
to anribute feelings of famil bering a past event, we may hr.: inclined a judgment or solve a prob iarity to the past; if our goal is to nuke relative ease of the task at lem, we may attribute similar feclings [0 the why subjective experiences of hand. ru we will see, this is one reason . . " rClnembcring can some-ames be 11llStaken.
T H E P U L L O F T H E PA S T Three S t o r i e s To appreciate more fully the impact of subjective experience in mem
27
O n R e- m c m b e r i n g
Sea rtidllg fo r Mel/uHf
26
/
ory, I now turn to three stories in which reexperiencing the personal past took on an unusual, even overwhelming. significance. Marcel Proust and Franco Magnani both developed an intense and unrelent ing obsession with memory chac they explored through art. An aging Italian artist known by the initials GR came to an unusual apprecia tion of what it means to have a personal past when he lost his melll ory and then, almost miraculously, regained it.
trics known as petites made/ciues. After dipping a madeleine into rhe tea and imbibing the mixture, hI.! is overcoml.! by an unexpected, over whelming, and entirely mysterious sense of well-being. "Whence could it have come to me, this aU-powerful joy?" he asks. " I sensed that it was connected with the taste of the tca and the cake, but that it infi nitely transcended those savours, could not, indeed, be of the same nature. Where did it come from? What did it mean? How could I seize and apprehend it?"lY He tries to induce the experience again by tast ing sl.!veraJ mort' mouthfuls of the potent mixture, but each experi ence is weaker than the previolls one, leading him to conclude that the basis of the effect " lies not in the cup but in myself." He surmises that the tea and cake have somehow activated a past experienCt.!, and wonders whether he will be able to recall it consciously. Then
comes
the
extraordinary
instant when
rhe mystery is
resolved: "And suddenly the memory revealed itself. The taste was that of the litde crumb of madeleine which on Sunday mornings at . Combray [the fictional name of Proust's childhood townJ when I went to say good morning to her in her bedroom. my aunt Leonie used to give me, dipping it first in her own cup of rea." Marcel notes that he had never elsewhere encountered the combination of smells
Marcel Proust: b/IJolrmrary Memory No single work of literature is more closely associated with human memory than Marcel Proust's A la recllere"e du temps perdu (III Search of Lost Time). II The depth of Proust's obsession with recapturing the past is difficult to overstate. The eight volumes that constitute
A
fa recherche were written over a period of nearly fifteen
1908 and concluding several months before his death in November 1922. The entire treatise exceeds
years, beginning around
three thousand pages, most concerned in one way or another with personal recollections or meditations on the nature of memory. Proust may have become so single-minded because he had largely withdrawn frorn society by the time he began writing his opus. He confined himself to his room throughout much of the writing, suf fering from illness and exhaustion, and in so doing substituted a world of time for the world of space. But his obsession with the past also reflects Proust's passionate conviction that the truth of human experience could be grasped only through an understanding of memory and time. In the most dramatic memory-related incident of the novel, the narrator, Marcel, is visiting his mother, who serves him tea and pas-
and tastes that characterized the episode at his aunt's house, thus mak ing them uniquely effective cues for an elusive but powerful memory: ';But when from a long-distant past nothing subsists. after the people are dead, after the things are broken and scattered, taste and smell alone, morc fragile but more enduring. more immaterial, more persis tent, more faithful, remain poised for a long time, like souls, remem bering, waiting and hoping, amid the ruins of all che rest; and bear unflinchingly, in the tiny and almost impalpable drop of their essence, the vaSt structure of rccoUection." The momem when the madeleine memory revealed itself was the moment when the narrator saw that memory could be both fragile and powerful. Memories that can be elicited only by specific tastes and smells are fragile: they can easily disappear because there are few opportunities for them to surface. But those that survive are also cxcepcionally powerful: havmg remained dormam for long periods of time, the sudden appearance of seemingly lost experiences clIed by tastes or smeUs is a startling event. The madeleine episode also highlights that reexperiencing one's personal past sometimes depends on chance encounters with objects thac contain the keys to unlocking memories that might otherwise be hidden forever. But Marcel's recognition that iJlvo/muar)' recollections
29
St'lJ rc/,jPlg fo r Memory
On R e m e m b e r i n g
ds, and depend on rare con arc fleeting. lasting only several secon , leads him to alter the focus frontations with particular smells or sightS progresses. his quest for self of his quest for the past. As the novel the active, 11O/'lIIlary retrieval of understanding depends increasingly on role of voluntary recollection his past.lO !-Ie explores the self-defining novel in the series, Tillie in olle of the key scenes from the fmal Marcel has not se�n for Regailled. At a gathcrmg of old friends whom ities and co place them 1I1 the many years, he strains to recall their ident In so doing he achieves a syn context or his remembered experiences. his appreciation of his own thesis of past and present that heightens
artist who has relentlessly attempted to reCaptuTC old memories by
28
identity.
gies from the scicnce of Proust also draws on concept" and allalo memory, which he made optics to develop an analob"Y of time and rfect as it is) which seems to explicit in a 1922 letter. "The image (impe special sense," Proust wrote, me best suited to convey thc nature of that at time, for a telescope ren "is that of a telescope, a telescope pointed eye, :md I have tried to ders visiblc for us stars invisible to the naked phenomena, some of us render visible to the consciousness unconscio situated in the past:'ll which, having been entirely forgotten, are y. The experience of ProUSt further develops his optical analog not based merely on is nds, remembering a past episode, Proust conte Instead, a feeling of remem calling to mind a stored memory image. images: onc in the pres bering emerges from the comparison of two perception of the three ent and one in the past. Just as visual information frolll dIe tWO dimensional world depends 011 combining epends on combining infor eyes. perception in tinK�rel1lel1lbering--d renowned Proust scholar mation from the present and the past. The to make us sec time . . . R.oger Shattllck explains: " Proust set abom s unless the remembered Merely to remember something is meaningles present affording a view of image is combined with a moment in the memories must sec dou the same object or objects. Like Ollr eyes, our minds into a single height blc; these nvo images then converge in our rese:lrch by more than a cned reality."21 Foreshadowing scientific insight thal feelings of half-century, Proust achieved the penetrating en past and present. remembering result from a subtle interplay betwe .
preserving them in paim.lJ The target of Magnani's obsession is his childhood village of Pomita, located in the Italian hills of Castelvec chio, about 40 miles west of Florence. Magnani was born there in 1 934 and Ijved in the village on and off until 1 958, when he left for good. He set out to sec the world, settling seven years later in San Francisco. Shortly thereafter, he began suffering from a mysterious ill ness that left him feverish and delinous, throwing him into both phys ical and psychological turmoil. In the 1l11dsr of the illness, Magnani began to experience, on a nightly basis, vivid dreams of Pontito that combined a hallucinatory intensity with a wealth of minute detail that (Ir exceeded his waking recollections of the village. The force of the nocturnal vlsions inspired Magnani, who had never painted seriously before, to try to caprure his images with brush :md canvas. The extra ordinary images then exploded into his waking life as involuntary, intrusive recollections. Magnani completed his first canvas of Pontito in 1967 . Soon, his entire life focused on painting his memories of the village. "He often feels a great urgency to get the scene down on paper immediately," observes an acquaintance, Michael Pearce, "and has been known to leave a bar in mid-drink in order to begin a sketch."2• Magnani's fin ished works are exquisitely detailed paintings of the buildings, streets, and fields that he remembers frolll Pontito. They rarely include people anc! are typically characterized by a tranquil stillness that lends them a sort of timeless and magical quality. I n 1988, a San Francisco science museUIll, The Exploratorium, mounted an exhi bition of Magnani's work. Susan Schwanzenberg, a photographer at the museum, had journeyed to Pontito and photographed the scenes depicted in Magnani's paintinb'S, attempting to capture each one from the exact perspective indicated in the work. The Explorato rium exhibited the paintings juxtaposed with the photographs, and the resuits revealed that Magnani's memories were impressively, sometimes astonishingly, accurate. On the other hand, it is equally evident that Magmni has painted highly idealized pictures of the village, a kind of paradise lost in which the remembered world is more beautiful, symmetrical, and whole than the inevitably blem ished reality. (Sec figures 1 .3a and 1 .3b.)
Frat/co lvtagtllHli: ObscssitJ(' Memory The raw psychological power of memory that is so evident in Proust'S writinb'S is also illustrated vividly by the story of Franco Magnani, an
These observations fit with the neurologist Oliver Sacks's observa tion that Magnani's painted memories, though often startling in their accuracy, are fundamentally imaginative reconstructions-not slavish reproductions.lS
On
31
For Magnani, as for Proust, fixation on [he past spills over froll!
fiGURE 1 . 3 a: Franco Magnani, "Via Mozza, 1a casa del 1I0nl10 di Franco," 1987. 1 4 x lOW'. O il on IlWseUI11 board. Courtesy of the artist.
It e m c m b c r i n g
the making of art into just about every aspect of his life; he thinks or talks orlittle other than Pomito. His endless reminiscing has cost him many friends, and he rarely goes OLlt or travels. In short. he ha� been reduced to what Sacks calls "a sort of half existence in the
j
present.".!t. I experienced some of these qualities when ' visited M:lgnani in the summer of 1993 at his home outside San Francisco. I had not yet reached the from door of his house before noting the first signs of his obsession: a personalized ;'Pomito" license plate. and bricbvork n':l11iniscent of the building; depicted in his paintings. When Magnani emerged from his garage/studio, I saw a tan, thin man who looked to be in his mid to late forties, even though he was about to turn sixty. Magnani showed me how he was renovating his entire kitchen with cabinets, tiles, and closets to resemble those he remembers from Pan tito. !-Ie was working on the time-consuming projcct by himself, found it difficult to locate funds to support the ('xpensive renovations, and had lost the use of his kitchen inddinitely-yel hI,; beamed as he talked about lhe noble task he had undertaken. He sought to create a three-dimensional environment in which Pomito was transported out of the past so that it became part of the filllcrioning presem.n Telling Tlle about the paintings on the walls of his hOll1e, he virtually shouted out his reconections, finally easing back into the presem once the memory had run its course. The aura of thc past was so acute during these incidents that I had the sCl15e that I was witnessing a kind of rupture in time, ;lS if I had been there when Proust first casted the
b: Susan Schwartzenberg, Photograph of "Via Mozza, la casa del nonno di Franco." Co u rtesy of the artist. the le�gth and tnJectory of In M:agnani's p:aiming of his grandfather's home twO bll1ldll1b'" :md the st,I(Ue the stone p:ath, the structure that connects the s :Ind doors all doc that is part of It. and the pl:acement of individual window not seen for nearly thIrty ument remarbble memory for a place Magnam had It is also apparent that the years when he completed the work in 1987, But the flowerbed could not pailltll1g is highly rom:all tic :and contains distortions: paiming, nor could the lovely have been seen from the perspective used in rhe on the left wall of the rooftop above the statm'; the curved doorway shown IS a genen' sense of or(kr photograph IS ollutted from the palTltIng; :Ind there . 1Il the photograph. and even perfection in the painting that IS nO! present
madeleine. Magnani has returned to Pontiro on two occasions since the mliseUIlI exhibit. He W;lS surprised and disappointed by unpleasant changes (the village is now nearly uninhabited) and by deviations from his recollections. Yet he was also gratified and occ3sionally overwhelmed by the chance to see and couch the world chac had for so long existed only in memory and dream. Franco is still devoted ro the Pomito of old, an enterprise that has :llways been more than a purely personal indulgence of vivid recollections: he has sought to preserve the memory of Polltito for others, to cap ture his extraordinary recollections in a form that allows them to affect and enrich the lives and memories of many. " I t is a project that has no end," concludes Sacks, "can never be brought to a con clusion or completion."211
32
On Remember i n g
S e a rc h i ng fo r M e m o r y
given a local anesthetic, but remained alert throughout the procedure.
"CR": lvfemory Lost a"d Regailletl
As he was lying quietly
everyday life If Marcel Prollst sought his memories in the objects of that imposed and Franco Magnani found them in dreams and visions known in the themselves on him, a sixty-seven-ycar-old Italian man d into "a plunge rarily medical litcrature by the initials GR was involun er, GR wa world that had no past. A poct, painter, and art review he awoke on the deeply immersed in various cultural projects when . state of nund. morning of March 19, 1 992, in a profoundly confused speaking. Most He could not Illove his right arm and had difflculry cv�n st p his of ries memo � and was frighteningly, CR had no specific bram where l, uncertain about his identity. He was rushed to a hospita ed the left thal scans showed that he had suffered a stroke that damag
�
amus of his brain.
bcr his occu As days and weeks passcd, CR still cou1d nor remem could not recall pation. He did not recognize his own paintings. He h able to rec g Thoug . the subjects of the books he had been writing ber anythmg nize and nalllc his wife and children, he could not remcm art exhibitions about them. GR was shown photographs of himself at any ofir.Th e for y memor no and other salient events, but hc profcsscd un�allliliar city of Milan, which he had known well, seemcd cntirely from hiS life. C R to him. He could not recollect any specific incidents e amnesia, in retroxrad call was suffering from what ncuropsychologists that occurred whjch people have problems remcmbering experiences or psycho prior to a strokc. head injury. or some other physiological day-to-day g, ongoin logical trauma. GR also had poor memory for .:N experiences, what neuropsychologists call 1llllcmgrat/c (1III11csia of well sense his s, month for ed As his amnesia continued unabat his about ss hopele being evaporated. "GR felt deeply depressed, ion to paint amnesia to the poim that he could not fmd the inspirat s�, a� he "becau him, treated who gists again," cOlllmented the neurolo time IllS of most said, he 'had no more self to express.'" CR spent
�
facts about sleeping or in an inert state of apathy. When he was told some retain could CR past. the in who he was and what he had done not dge, knowle of them. But this was secondhand autobiographical statelllents genuine memory. Though it enabled Crt to make a few dge knowle d acquire his erized about his past, he disparagingly charact remem "true of himself as " relearned," lacking entirely a sense of brance."
33
an irregular About a year after his stroke. C R showed signs of ker. He was heartbeal, so his physicians decided to implant a pacema
011
the operating table, CR fclt some discom
(art as the surgeon prepared his chest for the pacemaker. Then, in :1 stunning instant, GR clearly remembered that he had experienced a virtually identical situ;uion some twenty-five years earlier when he had undergone an operation for a hernia. Within a few seconds, he remembered other aspects of the earlier operation. Soon his head was swimming in a roiling sea of memories, as his past life came back to him in
a
torrent of images and thoughts. Overwhelmed by what he
tt:rmed a "catharsis" of remelnbering, GR could do litde but talk abom his past for the next several days. His memories. at first chaotic, soon rearranged themselves into a sensible chronology. As he sorted through and made sense of this vaSt array of incidents from different points in time, GR eventually came to feel like the self that had existed before his stroke. CR's story is almost without precedent. Retrograde amnesia IS a common consequence of bnin damage, and sometimes old memo ries that are seemingly lost gradually return to patients as they recover from head injuries or other medical conditions. Blit it is extraordinary for someone to lose his entire personal past and then recover it all in an instant, as a result of a single clle that happens to match a specific memory. Not all of CR.'s memory problems evaporated-he contin ues to have great difficulty remembering ongoing events-but he has his past back, and with it a sense of self. Just as the madeleines trig gered a torrent of childhood remembrances in Proust's novel, some aspect of what Crt felt or thought as the surgeon worked on his chesl reminded him of a distant event that opened the Aoodgates to the past. The neurologists who reported CR's memory recovery called it the "petites madelt:ines phenomenon." .)O Nobody knows why recalling a single event in this way would restore GR's memory for the rest of his past. His neurologists suggest that brain damage might have temporarily distorted the neuronal net works in which personal memories were stored, otTering the analo!,,), of a compact disc that has become stretched into the shape of all egg and is thus unreadable by retrieval systems. Somehow, they suggest, the successful recall of a single event serves to "re-set" the distorted net works imo their normal form. However it happened, it was only after he pieced together the bewildering aSSOrtment of memories that he experienced as his alone that CR once a!,'3in felt th:u he had a self to express.J! With their telescopes poimed at time-Proust and Magnani for
S('arr/ling JOT Memory
On R e m e rnb t: r i n g
years, GR for several extraordinary days----l-a l three men magnified the
question: Is a computer that passes a Turing te<;t also comciollsly aware
34
self-defining role of memory. They make visible what is perhaps less apparent in, bur no less characteristic of, the rest of us: our sense of ourselves depends crucially on the subjective experience of remem bering our pasts.
\
ARE C O MPUTERS R E M E M B E R E R S ? The stories of Proust, Magnani, and Crt would be virtually incom prehensible without acknowledging the subjective side of f'Clnembcr ing. The experience of remembering is what makes the everyday manifestations of episodic memory that we all know-the experience of1l1cmal time travel-a distinctly and perhaps uniquely human activ icy. Clearly, the ability merely to store :l.Ild retrieve information is 110[ a unique feature of the human mind, or even of living organisms. Every time we type on our personal computer, we interact with a for midable memory system.}! Cognitive scientists have pursued an analogy berween human and computer memory at the level of software: the instructions, programs, and rourines that are executed either by cells in our brains or silicon chips and wires in a computer. Many cognitive scientistS see the human mind as a paTlicubr kind of computing device. and they assume that if they understood the rules by which the mind operates, they could program a compmer to mimic it cxacdy. Could a com puter engage in mental time travel, revisiting and reexperiencing the past, the way we do? Could a computer ever feci that a memory "bclonb os" to it, as Will McDonough feels that his recollections of the 13ost0I1 Garden belong to him? This question is closely related to a more elementary one: Are com pmers, in principle, capable of any form of conscious experience?This issue is typically broached with reference to the notion of a "Turing test," which stems from the work of the great British [nathelllatician Alan Turing.ll A Turing test is a hypothetical situation in which an observer asks questions of twO respondents�one human and one computer, but disguised so that the observer does not know which is which. If the observer is unable to determine, by relentless probing, which is which, then the computer passes the Turing test, Many pro ponents of artificial intelligence (AI) have contended that when a computer passes a Turing test, it must be granted the ability to think like a human. For our purposes, let's grant this claim and ask a further
35
of its thoughts in a way that is sirnilar to, or even remotely resembles, conscious awareness in a human being? Proponents of '\trong A[," who take the view that some day soon computers will exhibit all human mental abilities, answer the ques tion with
a
resounding ycs ..JO Some philosophers do, too. For instance,
Daniel Dennett argues that human consciousness is produced by the operation of something like a computer progranl, what he calls a "virtual machine" that is installed and implemented in the parallel hardware of the human brain: " [If] all the phenomena of human con sciousness are explicable as 'just' the activity of a vinual l11achine real ized in the :mronolllically adjustable connections of the human brain, then, in principle, a suitably 'programmed' robol, a silicon based computer brain, would be conscious, would have a self."» [f Dennett's robot is gr:1I1ted comciousness and self, then it should probably also be gr:111tcd full rights to subjective experiences of remembering and the ability to engage in memal time travel. Den nett's vision is reminiscent of the fictional worlds depicted by slIch writers as \Villiam Gibson in
!Yellromall(Cr and joll/IIIY Mllemollic,
where humans and computers plug into a com mOil cyberspact...'"-a mental highway systenl in which information moves from mind to mind and the subjective experiences of humans and computers merge imperceptibly inco each other. The idea that human consciousness is
a
software package that ju�t
happens to be installed in brain cells is seductive, but this kind of analysis has also elicited incisive criticisms from philosophers and sci entists who believe that it is naive..l6 [f a computing robot cannot achieve rudimentary consciousness, then it is hard to see how it could ever engage in subjective experiences of remembering, or have the feeling that memories " belong" to it. The debate over computer consciousness can help us to sharpen our ideas about exactly what kind of evidence we need before con cluding that ml)' act of memory involves a conscious experience of remembering. [n experiments [ have mentioned, fOI" example, when a perSOIl says that she either "remembers" an item or simply "knows" it, the experimenter is willing to take these statements as reflections of the quality of her recollective experience. It would be simple to program a computer to make these two kinds of responses in a sim ulated memory experiment, but nobody would want to argue on that basis that the computer remembers some items and knows oth ers in the same subjective sense tbat people do. What would it take
36 FIGURE 1 . 4
to COIIVII1Ce us that it docs? Is there a Turing test for recollcctivc experience? In R.idley Scon's movie Blade RUllller, computer technology and biocnglllccnng conspire to produce a spl:cics of "replic:tl1ts" that seelll human in virtually all respects. Rachel is a newly developed
•
expcrimcmal replicanr that has been implanted with a rich set of
t
memories that provide her with a personal past. a past so compelling that she is unaware of her nonhuman status. Deckard, whose job is to perform a kind of Turing test w weed out wayward replicams, awak ens her to reality by reeling olT a series of Rachel"s most personal childhood memories and informing her that "those aren't your II1cllloric5; they'n.· somebody else's." But Rachel's emotional reactions to these memories, as indicated by her tears, f,1.cial expression, and tOne of voice, arc inte nse. Deckard is thus convinced that the melll ories do in �OTlle sense belong to her, and so concludt."s that she should be allowed to live as a human. Rachel has, in eITect passed a ,
Turing test for rccollective experience: Deckard cannot distinguish this replic:lllt's subjective re�ponse to her memories from that of a person beca\lse Rachel shows the full subjective force of memory's power. The depth of subjective experience Rachel displays is the hall mark of explicit remembering in people. Hecause this is slich an inte gral part of human remembering. compelling evidence of intense subjective experience is what it would take for most of liS to be con vinced that a computer docs indeed remember in the same sense that we do.11 The neurobiologist Gerald Edelman has argued that the richness of human recollective experience " cannot be adequately represented by
Richard E. Schaffer, "The Color of Memory," 1988. 22 x 30". Mixed media on paper. Courtesy of the artist. Richard Schaffer.
:111
Arizona artist who employs visual symbols to express
ideas about memory. provides a fitting summary reflc:ction on the rrlationship bcp,veen computer memory and human memory in his multimedia collage,
" The Color of Memory:' The left side of the pit'ct' contJ.ins an actual Aoppy disk along with various forms of computer code and digital readout; the right
the impoverished language of computer science-'storage: 'retrieval:
sidc consists of a series of fragrncmary Images, alluding (Q the visual informa
·input.' 'ourpuc '\!i I agree with hjm. As, Edelman emphasizes and we
tion that i� such an important part of human rt,collectivt' c:-.:pcriellce. In the
will see in later chapters, subjective ex periences of remembering arc
COntext of the preceding discussion, Schaffer's piece suggcsrs-and I strongly
"
closely linked with particular systems and networks in the brain. Con sequently, I a111 skeptical that software that is not grounded in (his bio logical substrate will ever h3ve the experience of r�visiting its past.(See figure 1 .4.) By looking at the end product of memory, the recollective experi ence o( the rememberer, I have been attempting to bring to the fore ground some of the
key manifestations of memory's power in
psychological life. Bm to fathom the narure and (unction of explicit remembering mort." deeply, we need to stan at the beginning of the memory process and work our way through again to the end. The
concur--that the computer is a rctricver of information bur nOt a rememberer of experien ces. Whether the gtllf that separatt'S tht' two is entirely and forever impassable remains to be
�ccn.
38
S e a re/ring for M e m o r y
�
lOugh subjective sense of pastness that makes our memor cs feel as t1. of br1l'1k the they belong to liS, that drove Proust and Magnam to to obsession, and thal made CR feci that he once again had a self mem l 11tllna� of eature f express is a fundamcmal and perhaps singular ory. We need to understand llIorc about the underlying procc,ses that
TWO
make [he experience possible.
BUI L D I N G M E M O R I E S Encoding and Retrieving the Present and the Past
O N E O F M Y FAVORITE I'LACES is the Musellm of Modern Art in
midtowll M:.mh:m:m . A native New Yorker, I have made regular pil grimages [0 this Inceca of arc since high school days, and h:lVC come ro regard many of the paIntings there as wise and familiar old friends. Like close friends. howewT, they cannot always be there when you wam them. More than once I have rerurned to a tlVorite spot, eagerly anticipating another look at an esteemed painting by de Chirico, I-Iopper, or Klee, only to learn that it was away on extended loan. Although the painting's absence is disappointing, I som�times attempt to make up for it by conducting an informal study of my own mem ory for the piece: What objects and people does the painting include, and how arc they located relat.ive to one another? How big is (he work? What arc the dominant colors and importam themes? I can check the accuracy of my answers by locating a reproduction in (he Illuseum shop. The French artist Sophie Calle wondered what aspects of a paint ing linger in the memories of viewers who are familiar with it. To fllld Out, she conducted a kind of naturalistic memory experiment with an artistic twist. Calle asked a cross section of Illuseum personnel to describe their recollections ofs�ver31 paintings that had been removed from their uSLIal locations at the Musellm of Modern Art. She pro39
40
cceded to create a " memory ghost" for each Illlssmg paintmg-- exhibiting the exact words lIsed by tbe museum workers to describe their recollections of (he piece. The most striking outcome was the sheer variety of recollections that her inquiry elicited. Some people recalled only an isolated color or object; others remembered at length subtle nuances of fOfm, space, people, and things. Calle's observations imply that different people retain and recollect very different aspects of their everyday ellvironments. Why would this be so? Scientists agree that the brain docs not operate like a camera or a copying machine. Theil what aspects of reality do remain jnJJ�� ory once an episode has concluded? These kinds of quesnons have dogged every philosopher, psychologist, and neurosciemist who has thought seriously aboul the nature of remembering and forgening. Throughout much of the history of scholarly thinking about melll ory, dating back to the Greeks, people have approached these ques tions by adopting a spatial metaphor of the mind. The Greek philosophers held that memory is li.ke a wax tablet on which experi ences are imprinted, perhaps forever; centuries later, Sigmund Freud and William James bmh conjectured that memories arc like objects placed in roOIllS of a house. One pundit compared memory to a garb:1ge can that cont:1ins :1 random assortment of objects.1 The cognitive psychologist Ulric Neisser called the idea that faith ful copies of experience are kept in the mind, only to reappear again at some later time prerty much in their original form, the "reappear :lI1ce hypothesis." Neisser proposed instead that only bits and pieces of incoming d:lt"a are represented in memory. These retained fragments of experience in turn provide a basis for reconstructing a past event, much as a paleontologist is able to reconstruct a dinosaur from frag ments of bone. "Om of a few stored bone chip<' reflected Neisser, "we remember a dinosaur."� A visual analogue of Neisser's reflections is found in the work of the Israeli artist Eran Shakilli:�. Shakine has explored his personal past by making: colbged paintings in which fragments of old phoLOgraphs and text are submerged in layers of milky white paint as exemplified by his painting "Hadas5.1h" (fib'tlre 2.1). Shakine struggles with the secming paradox that our sense of self, the foundation of our psycho logical existence, depends crucially on thcse fragmentary and often elusive remJlants of experience. What we believe about ourselves is determined by what we remember about our pasts. If memory worked like a video recorder, allowing us to replay the past in exact detail, we could check our beliefs about ourselves against an objective
FIGURE 2 . 1
Eran Shakine, "Hadassah," 1992. 12 x 16". Collage, oil, and varnish on plywood. Courtesy of the artist.
a bardy perceptible family photograph refer to cill' arti�['s personal history that now exist only as hazy birs
S�li?pt'ts of old buildings and ddterenr stages
m
and pieces of rncrnory.
42
B uilding Memories
Searc/liug Jor Memor y
record of what happened in
Ollf lives. We must make do instead with
the bits and pieces of the past that memory grants liS.
43
Short-term memories last for only seconds. Nowadays, researchers believe that such temporary records depend on a speci3lized system.
The general idea that memories 3rc built from fragments of expe
called I/J(lrki/Z,� memory, that holds small amounts of information for
fience can help liS understand key aspects of the remcll1berer's fecol
brief time periods, as in dIe backward recall task you JUSt performed.
lective experience, as well as memory distortions and effects of
Everyone is familiar with the operation of working memory from
implicit memory, to be discussed in the coming chapters. For now, it
experiences in day-to-day life. Imagine that you need to look up a
is important (0 understand something more ahoU( how the fragments
friend's number in the phone book. YOll find the nUlllber, then walk
are constructed and reconstructed.
across the room to make the call, aU the while madly repeating the digits to yourself as rapidly as you can. If you arc diStracted for even a moment during your walk to the phone, you will need to consult the
B U B B L E S P. A N D T H E NATURE O F E N C O D I N G
book again; if you punch in the number successfully, you will proba bly forget it almost immediately. Why are such memories so fleeting?
Oubbles p , a professional gambler from Philadelphia, spends virtually
Pan of the answer is that working memory depends on a different
all his time making bees: shooting craps at local gaming clubs, dealing
network of brain structures than long-term memory systems do.
cards in illegal poker games, attempting to come tip with new systems
Some patients with damage to the inlier part of the temporal lobes in
to beat the numbers. He is not a highly educated man-Bubbles
the center of the brain have little or no difficulty rctaining a string of
claims to have read only two books in his entire lift.--but he is capa
digits for several seconds, yet they have great difficulty forming and
ble of certain feats of memory that are well beyond the abilities of
explicitly remembering more enduring memories. Other patients
even the mOSt erudite Ph.D-s. Most people have difficulty recalling in
who have suffered damage to a specific part of the parietal lobe on the
correct order a string of more than seven digits immediately after see
cortical surface can form long-term memories but cannot hold and
ing or hearing thelll. When the task is to repeat them backward, moSt
repeat back a string of digits. They lack a specific part of working
people remember even fewer digits. But Bubbles P"s digit memory is
memory, known as the p/lO/Z% xiral looJ', that most of us rely on when
equally spectacular in either direction.] To appreciate his ability,
we need to hold a small amount oflinguistic information in mind for
inspen each of the digits at the end of this sentence for one second
sevef".1i seconds.'
each, then look away from the page and immediately try (0 recall them in reverse order: 43902641 974935483256.
This is where the concept of encoding comes in. By relying 011
1 suspect that by the
your phonological loop to repeat a phone number madly to yourself.
8, 4, or 5, you were already h:lV
yOli encode it only superficially. To establish a durable memory,
ing problems going any further, and I would be willing to place a bet
incoming information must be encoded Illuch more thoroughly, or
0, much less all the way back to [he begin
deeply, by associating it meaninbrfilily with knowledge that already
time you worked your way back to [hat nobody made it to
ning. Bubbles P., however, can rattle off in correct backward order
cxis[.� in memory. You must do more than simply recycle the infor
every one of the twenty numbers in this sequence and similar ones.
mation in the phonological loop. Suppose that instead ofjust repeat
How does he do it? Has he simply been gifted with an extraordinary,
ing the phone
perhaps photographic, memory?
attempt to make the Ilumber meaningflli i n some way. For example,
The answer likely resides in the same process that contributes to
nlllllber-555-6024-to yourself ovcr :lIld over, YOll
if you play golf (as I do), you might encode the Humber by thinking
constructing fragments of experience. Psychologists refer to it as an
that
555 is the yardage of a par-5 hole and that 6024 is the length of
eucollillg process-a procedure for transforming something a person
a relatively short I S-hole course. You have now carried out a deep
sees, hears, thinks, or feels into a memory. Encoding can be thought
encoding and should be able to remember the information Illuch
of as a special way of paying attention to ongoing events that has a
longer and more accuf"Jtely than if you merely repeat it. This is
major impact on subsequcnt memory for them. Psychologists first recognized the importance of encoding processes during debates about short-term memory that raged in the I 960s.
known in (he psychological lircr:lrurc as a "depth of processing" effect.s The same SOrt of effect is probably at work in cases like that of
45
Scarr/lin,!! Jor M e m o r y
UUllding Memories
l:3l1bbles I� Bubbles is knowledgeable about numbers and seems able
rience suggeSlS that something that is meaningful will be more easily
to segregate effortlessly a long string of them into llleaningful unitS or
remembered than something that is nor. nut it turns out that only a
chunks. Rather than frantically recycling them, as most of us do, l:3ub
certain kind of semantic encoding promotes high levels of memory
bles lIses the �kilJ he has developed with Ilumbers through years of
performance-an eJll/,orativc encoding operation that allows yOll to
gambling to link incoming digits to knowledge already in his mem
integrate new information with what you already know. For example,
ory. Bubbles does not ha\'e a generally extraordinary memory: his
if I induce you ro encode olle of our study list words by posing the
memory for words, faces, objectS, and locations-anything ocht'r th:m
question, " I s shirt a type of insect?" you must pay attention to the
numbers-is no better than average.
meaning of the word in order to provide the correct answer. As YOll formulate a response to this question, however, you do not 1I1tegr:lte the target word with your preexisting knowledge of shirts-that is,
ElabomtiJlf Ellcodil1g Memory rcse:archers have tried (0 devise special techniques to gain control over the encoding operations chat a person performs, and
you do nm carry out an effective elaboration of the word shirt. If I test you after you have answered chis kind of orienting question, you will show surprisingly poor memory for whether the word sll;rl was on the list.'
these operations have played a crucial role in the unfolding story of
In our everyday lives, memory is a natural, perhaps automatic, by
memory and amnesia research during the past twenty years.· Suppose
product of the manner in which we chink about an unfolding episode.
I tell you that an hour from now, I will test your ability to recall the
If we want to improve our chances of remembering an incident or
following words: Roor, car, tree, cake, shirt, Rower, Clip. gras..'i, dog, table.
learning a fact, we need to make sllre that we carry out elaborative
You might try to remember the words by cmUlIring lip visual images,
encoding by reRecting on the information and relating it to other
by simply repeating the word.� again and again, or by making up a
things we already know. Laboratory studies have shown that simply
story that connects the words (0 one another. As long as I leave you
intending to remember something is unlikely to be helpful, unless we
to your own devices, I cannot le:trll much about how encoding
translate that intention into an effective elaborative encoding. For
processes influence memory. I need to come up with some way of
example, when preparing for an exam, a good student may make a
controlling how you think about the to-be-remembered items.
special effort to form meaningful memal associations among the snady
Memory researchers have �olved rhis problem by usmg what is
materials, whereas the same student may not bother engaging in such
known as an orienting task. Instead of allowing people to memorize
elaborative encoding if she is not going to be tested. In my earlier
the target items in ;Illy manner they please, an orienting cask guides
example, carrying our the orienting task-answering the question, "Is
encoding by requir1llg a person ro answer a specific question about
shirl a type of clothing?" -ensllTes th:H you have already made effec
the target. For example, I could induce you to carry Out a decp.
tive use of elaborative encoding processes; "trying to remember" adds
semantic encoding of target words by asking for a yes or no answer to
nothing beyond that.
questions such as, .. Is shirr a type of clothing?" You cannot answer this
The issue can be turned around, too: most experiences that we
question accur:ltcly without thinking about the meaning of the word
recall effortlessly from OUT daY-IO-day existence-yesterday's impor
shirt. To induce you to engage in shallow, nonscrnantic encoding of
tant lunch date, the big party last weekend, last year's Slllnmer vaca
the word. I could ask you 10 answer a question such as, "Does shirl
tion-are noc initially encoded with any particular intention co
contain Illore vowels or more consonants?" You c;m llnSWer this ques
remember them. Occasionally, the apparent significance of an event
tion easily without atcending to the meaning of the word. If I later test
may prompt us CO make a special effort to encode it deeply. However,
yOllr ability to recollect sllin and other words on rhe list, I can be fairly
day-to-day existence would be precarious and probably unmanage
confident that you will be able to recall or recognize mallY of the
able if we had CO make an intentional effort to encode each and every
words that you encoded semantically and few of the words that you
episode from our daily lives in order to be able to recollect it later.
encoded nonselnantically. This finding may not seem particularly surprising; everyday expe-
Instead, a kind of natural selection drives us. What we already know shapes what we select and encode; things that arc meaningful to us
D u i l d i ng M e m o r ies
S e a re/dliS for .\le""JrY
.6
�ponc:meollsly elicit the kind of elaborations that promote later recall. Our memory systems afC built so that we are likely
(0
remember what
47
table, which brought to mind the person who had been sitting there. He accomplished this fcat by using a system of mnemonics he had
is IllOSt important to liS. Carrying out a deep, elaborative encoding influences not only the quantity of what can be remembered but also the quality of our rec
developed known as the method of
loci,
which became famous in
ancient Greece after this incident. The method involves encoding
ollc<.:tive experience. As [ noted in chapter 1 , when we meet a new
information into melllory by conjuring up vivid mental ilnages and
person and encode inform:lt'ion elaboratively, we arc more likely later
Inentally placing them in familiar locations. Later, at the time of
(0 "remember"
the episode; if we do not elaborate, we are more likely
attempted recall, one consults the locations, just as Simonides did. IO If,
"just know" that the person seems familiar. Elaborative encoding is
for example, you wanted to remember to buy becr, potato chips, and
a critical and perhaps necessary ingredient of our ability to remember
toothpaste, you could usc rooms in your home as locations, and imag
in rich and vivid detail what has happened to us in the pasL-
ine your bedroom afloat in beer. your kitchen stuffed from top to bot
(0
:1
tom with bags of potato chips, and your living room slathered with
downside, too: if we do not orry out elaborative encoding, wt' will be
toothpaste. Upon arriving at the store, you could then take a mental
left with impovt,;Ti�hed recollections. Experiment� have showll chat
walk around your house and "see" what is in each room.
But the dependence of explicit memory on elaboration has
peoplc are surprisingly poor at remembering what is 011 the front and
Modern practitioncrs usc the method of loci and other, related
back of a penny, despite seeing and handling pennies all the time.9 It
imagery techniques to perform such feats as remembering all the
is likely, however, that we encode the features of a penny quite super
names and numbers listed in good-sized telephone books. These
ficially, because using pennies in everyday life requires only that we
accomplishments are nothing new, however. Greek orators used
notice the general shape and color of the coin. The encoding process
mnelllonics to memorize speeches of extraordinary length, and
can halt once we have extracted the necessary information; there is no
Roman generals used them to remember the !lallles of tens of thou
need to carry out a more elaborate analysis of the coin. In this exam
sands of men in their cOlllllland. During the Middle Ages, scholastics
ple, wc are behaving like experimental volumeers who perform shal
used mnemonics to aid in the learning of interminable religious
low or superficial orienting tasks, and later recall little or nothing of
tomes. In f:lct, throughout the Middle Ages, mnemonics played a
what they have seen. If wc operate on automatic pilot much of the
major role in society, exerting a large mAuence on :lrtistic and reli
tillle and do not reflect on our environment and our experiences, we
gious life.ll
may pay a price by retaining only sketchy memories of where wc have
By the fifteenth and sixteenth centuries, Simonides' relatively sim pic method of loci had been superseded by increasingly baroque
been and what we have done.
·'memory theaters" that were conceived and drawn by some of Europe's most inventive minds. These intricare and sometimes beauti
Ellcodillg
ami Mt/elllot/ir Devices
ful strucrures consisted of hundreds of locations, each contain1ng ideas and precepts thal were frequently mystical. Learning all the locations
Elaborative encoding is a critical componem of virtually a l l pop
and precepts in a memory theater-into which one could later men
ular memory-improvement techniques. The oldest example of a
tally deposit new to-be-remembered informarion-was it�elf an ardu
memory-improvement strategy is visual imagery mnell1onics, first
ous, sometimes impossible task. The excesses of mnemonic systems
developed by the Greek orator Simonides in
477
U.C.
As the story
eventually created a backlash against them.12
goes, Simonides, a poer, was called to recite verse at a large banquet.
My central point is that the core cognitive act of visual imagery
During the course of the evening, he was unexpectedly summoned
mnemollics--creating an image and linking it to a mental location
outside to meet two young men; the moment he left, the roof of the
is a form of deep, elaborative encoding. Mnemonic techniques pro
banquet hall collapsed, crushing and mutilating beyond recognition
duce rich and detailed cncodings that are rightly linked to preexisting
all the guests. Simonides became a hero because he was able to
knowledge, yet are distinctively different frolll other items in memory.
reconstruct the guest liq by ilnagining each locatio II around the
It also seems likely, in light of llly earlier discll�sion ahom the impor-
.8
S e a rd,jug Jor Mem o , >,
B u i l d i n g M e m o r i es
.9
tanee o f visual reexperiencing in consciolls recollection. rh:u the
revealed the same effect: experts' level of recall greatl)' exceeds that of
visual format of imagery mnemonics enhances its usefulness as an aid
novices for meaninbrful configurations of information within their
Elaborative cllcoding has also turned out to be important in cases
arrangements of thc same information or for information outside
of Illnemonists like nubbles I� Psychologists at Carnegie Mellon
their dOlllain.!� Building lip the extensive knowledge base that is required to suppOrt the supermemory of a skilled expert does not occur overnight. 111 a
to explicit remembering. I)
domain of experrise, hut it is no better than novices for random
University wanted to dcterminc whether ordinary people could be trained to remember morc than seven or so digits after a single expo sure. They invited two average undergraduates to the laborarory for daily sessions in which they were presented with. and ancrnprcd to recall, strings of digits. For the first several weeks of training, nothing much happened. One of the students then ceased training. but rhe other, known by the initials SF, persisted. Soon thereafter, his digit span began to rise systematically, and then spectacularly. After sevcral months of training, S F could recall over eighty digits in correct order after being exposed to them only once. Did the training strengthen a general-purpose memory muscle? Could :m)'one achieve a similar feat just by engaging in memory exer cises? Clearly not. SF's remarkable accomplishmentS owe to his use of elaborative encoding. At about the time when his digit span began to improve, SF hit on a technique for carrying out elaborative analyses of incoming digit strings. He was a runner on the college track team, and called on his detailed knowledge of the meaning and significance of running times ill order to encode the otherwise meaningless digitS. For example, he nl.ight code the string
4125 as a "four minute, twelve
and one half second mile, not bad for me on :t windy day." The growth of his digit span tracked the increasing sophistication of his elaborative strategies. Yet SF's memory had not improved in any gen eral sense. When asked at the end of training to recall scrings of leners, SF could manage no more dun about seven. U Chess masters, toO, can exhibit phenomenal memory for the loca tions of chess pieces on a board. After just :t single five-second expo sure to a board from an actual game, imernational mastcrs ill one study remembered the locations of nearly all twenty-fIve pieces, whereas novices could remember the locations of oilly about four pieces. Moreover, it did not matter whether the masters knew that their memory for the board would be tested later; they performed just as well when they glanced at the board with no intention to remember it. OUt when the masters were shown a board consisting of randomly arranged pieces that did not represent a meaningful game situation. rhey could remember no more than the novices. Later studies of high level experts in bridge and electronics, among other fields, have
range of fields, it takes about ten year.; of extensive smdy. practicc, and preparation to achit've an internationally recognized level of expertise. The knowledge base that is built during that decade provides the basis for a highly refined and powenul form of elaborative encoding that
enables experts to pick our key information efficiently and to imbue it with meaning by integrating it with preexisting knowledge. This idea helps to explain how expcril!nccd actors melnorize lcnb'thy scripts. Recent studies have shown rh:lt rather thall anempting rote memoriz.ation, actor.; analyze scripts for clues to the motivations and gO:lls of their charaners;
memory is a natllr:tJ by-product of this ebborarive encoding. As one actor put it. '"I don'( really lIIemorize. There s i no effort involved . . . it JUSt happens. all(' d:ty early 011, I know the lines." An actor's search for the deep meanings in a script often involves extended analyses of the exact words used by a character, which in turn promores verbatim recall
of precisely what was s;lid, not just the general gist of it. I. The concept of elaborative encoding might even help explain some ofthe strange rncmory :Ibcrrations ill people known as amistic savants. These individual� h:wc low IQs and poor social skills that make it dif
ficult for them to function in everyday life. Yet, as excmplified by Dustin Hoffman\ character in the popular movie R..aill .\fall, they may
have spectacular memory capacities. One boy known by the initials )0 received a diagnosis of autism when he was five years old. He had become socially withdrawn and started to make biz.arre squawking noises and rocking movementS by the age of three. His language
development lagged behind other chiJdren of the same age.17 l3ut )D's parcIHS also noticed that he possessed i�olated pockets of extraordinary visual memory. Without being able to rcad, four-year old)D could spell out words with his play blocks that had appeared briefly on a TV screen. On family trips, )D remembered the exact
roUte rhey had taken previously and became extremely upset if rhe driver deviated even slightly from it. His parentS also noticed that )D had an uncanny ability to perform tasks that reqtllre complex visual
analysis. While still young, he could assemble a five hundred-picce jig saw puzzle in abol!( two minutes!
Sl'arc/lill�� JOT Jlcm
50
The psychologist Lynn Waterhouse tested JD when he was eiglueen years old. His vocabulary \vas still at the level of a six-year-old's, but on intdligence test'> that require copying complex figure'l with a set of blocks or rct:.lining visual memory for the location ofan object.JD scored phenomenally high. Like nubbles I� and SF, however, jD's exceptional melllory is limited. For IIlSt:lI1CC, he has a hard tillle remembering faces, not to mention words. He can effortlessly elaborate 011 and remcrnbcr visu;li panerns, but cannOt elaborate on or remember Hluch {·Ise.
FIGURE 2 . 2
'111(' MuseulI1 lim
The notion of ebbor.nion also provides imeresting perspectives on the recollections of the Musi.'ul11 of Modern An personnel in the proj ect I mcmiollcd earlier. Several of them were asked to recall the Magritte painting, "The Menaced Assassin." (See figure 2.2.) Their memory reportS are revealing: 1 : There's a lot of pink Aesh, red blood. guys in black. The back ground is blue with French ironwork on the balcony, the bedroom is beigc. but the only striking color is that blood painted red that looks like kctchup. 2: It's a painting with a smooth surface, an easy one to spot check. It is approximately five fect high and seven feet long. It i� framed in a plain, dark, walnut-stained molding, something auStere. I never liked iL l don't like stories in painting. I don't like trying to figure them oul. That's why J never gave it any rime.
It has a film noir sort of feel, a mystery novel look to it. The puzzle is there. YOli have all thosc little clues that will probably lead YOll nowhere: there arc men dressed in dark coats, and black bowler hats, the way Albert Finney was dressed in .\llmler 011 rhe Oriem Express, placed in a room with a dead body. In the cellter, the one who seems to be the perpetrator is lifting the needle of a phonograph. Two wcird . looking individuals are hiding to rhe side. There is a f1ce looking from the balcony, almosr like a SUIl 011 the horizon. And, when you look at her carefully, you realize that the towel probably conceals a decapit:lted head, 3:
4:
I think it'sjusl a TlUlrder scene. Men in dark suits, a pale woman
and dashes of red blood. That's a.1I I remember. '8
Rene Magritte, "The Menaced Assassin," 1926. 59X" x 6 ' 4W'. Oil on canvas. The Museum of Modern Art, New York. Kay Sage Tanguy Fund. Photograph © 1996 The Museum of Modern Art, New York.
Sophic Calle, an arrist, queried museum personnel about their recollections of Magritte's palilting, and elicited a wide variety of memories. (See page SO.)
Srarcli i llR Jor iHem o r y
FIGURE 2 . 3
Based Oil what they recollected, I feel I can make reasonably con-
#4 probably belongs lO a security guard or other nonprofessional staff, as does # I , which focuses solely on the physical features of the painting. Comment #2, 6dl'IH guesses about their identities: cOlluncnt
which describes the work's exaci measurements and properties of its frame, likely comes from someone charged with maintaining the painting. And the thematically rich set of memories in
#3
no doubt
belong to a cumlOr or similar an profeSSIOnal. The rationale for these educated guesses is simple. What people remember aboO{ a painting is heavily influenced by how they think about or encode it, and exactly which aspects of a paiming are elaborated depends on what kind of knowledge is already available in one's long-term memory. Encoding and remembering are virtually inseparable. Hut the close relationship between the two can sometimes cause problems in our everyday lives. We remember only what we have encoded, and what we encode depends on who we an..'-Our past experiences, knowl edge, and needs all have a powerful inftuenCl' on what we TCtam. This is one reason why nvo different people can sometimes have radically divergent recollections of the same event.(See figure
2.3.)
S C A N N I N G THE M I N D Encoding Processes and the Brain
Memory i s part of the br:lin's attempt to Impose order 011 the envi ronm ent.19 [n n:celll years, new insights into the brain substrates of
Jerry Coker, "The Memory Tree Man,"
1993. 1 5
x
I(YJ,
x
I". Mixed
media on found meraJ. Marion Harris GaUery, Simsbury, Connecticut. Coker is
� self-tauglu
maker of masks who uSeS scrap metal and other every
elaborative encoding have emerged from studies that lise powerful
day 1l13tenals
new functional neuroimaging techniques-tools that allow scien
hood. In "The Memory Tree Man" the metal face is that of a migrant worker
tists to observe the activity of particular brain regions while people perform tasks designcd to tap perception, languagc, memory, or other cognitive processes. The most advanced of these brain scan ning techniques is known as positron elllission tomography (PET). I n a PET study, an experimental volunteer lies in a supine position, and the scanner forms a doughnut-shaped ring around the person's head. When the scanm'r is turned 011, it provides a precise reading of blood flow in localized brain regions.2Q The general rationale
10
traveling with
create expressive faces of people
[l{' remembers from his child
�i s family �n rural Arkans.1S. They carne upon the young Jerry
as hc was pJaYlllg .!lcar 1m grandfather·s apple tn'c. The r.1mily Slopped and stared 3t the tree WIth great interest. Seming what they wanted.Jerry asked the migrantS if they wished to pick some apples. They pulled OUt se\'eld.l bushels.
�
filled th m up. and happily chatted with Jerry about coming back the next day. Jerrys grandfather was nOlle too pleased. however, whell the worker duti
:lIl �y returned and demanded all the apples remaining on the tree.The migrant
IIlslsted that Jerry had told him he could pick all the apples he wisht·d. Bm
underlying PET scanning experiments is that when a brain region
Jerry sw re to hi grandfather that h e never prornised anything. Was one of the � � t\VO parties fibblllg? Or had they remembered [he event differt.'lltly? Jerry·s
is heavily involved in a cognitive task, it should become more
g dndfalher must have known something about how different people encode :
active, and hence require more blood uptake, than a region that is little involved or uninvolved in the task. A related technique, known as functional magnetic resonance imaging (functional MR.I), also
different aspecrs of the same t'Vent, because he camc (Q the wise conclusion that only the apple trce knew what had actually happened. He worked ou( an . equitable settlement between the boy and the worker, but he could not bridge the gulfberween Ihe twO different versions of the past that each maintained.21
54
55
S e a rching for M t m o r y
Uuilding Memories
FIGURE 2 . 4
blood Row) in the frontal lobes, the vast region of cortex that occu pies the forepart of the brain. (Sec figure 2.4.) Blood Row increases associated with elaborative encoding were seen in a restricted area in tilt! lower front part of the left frontal lobe (the left inferior prefrontal cortex), and the same or similar regions have been activated in other PET cxperimen�� that also require people to carry our deep or elab orative analyses. These results have been confirmed recently in a sep arate experiment using functional M it ! . In addition, patients who have suffered damage to t hese frontal regions often have encoding problems: they fail to organize and categorize new information as it comes into memory. The left inferior prefrontal cortex plays an importa n t role in "deep" or elaborative processing.lJ Evidence showing frontal lobe involvement in encoding operations indicates that the cognitive processes identified by memory researchers can be related to specific regions of the brain. Further information concerning how the brain encodes incoming information comes from studies of event-related potemials. or ER.PS---electrical waveforms in the brain that are elicited by specific sights. sounds, or other stimuli. Deep encoding processes arc reflected in a specific part of the ERP known as the ]>300, a bump in the electrical waveform that occurs about one-third of a second after a person is exposed to a word or some other external stimulus. When something unusual or highly dis tinctive occurs-like a loud, jolting sound in a Stream of quiet, soft lont's-the brain emits an especially large P300. This heightened elec trical aC[ivity reAects the extra processing that the brain devotes to novel. distinctive events. As you might expect, larger P30Qs during encoding tend to be associated with greater subsequent recalP' Encoding of novel events also involves a StructUTC f.1ll1iliar to mem ory researchers: the hippocampus. The hippocampus is a slnall, horse shoe-shaped structure tucked a,vay deep in the inner or medial parts of the temporal lobes (see figure 5.1). Memory researchers have focused on the hippocampus for the past several decades because research on bnin-injured patients suggested that damage to the hippocampus can produce a severe loss of memory for recent experiences. This conchl sion has been modified somewhat because of newer evidence, but there is no doubl that the hippocampus is one of se,reral anatomically related Structures that play an imporum role in explicit remembering. Some PET scanning studies have shown that the hippocampus becomes extremely active when people view pictures of certain scenes, like a rain forcst in South America or a mountain range in Tibet. A PET experiment that I conducted with several colleagues revealed
Motor rona
lobes, Each hemisphere of the cerebral cortex is divided into four major arc a lobN rontal f The re'. hemisphe one of surface shown in this view of the sllch in role-s t importan p\:Jy that egions r sub distinct vast territory consisting of :md memory, g n ki r wo retrieval, stnlegic processes as clabonlive encoding ri a p Ihe within Tt"giollS Specific 4). r te p a c (sec h re:call of source information aspects different of swrage: the in c participat lobes etal, occipita\. and tl'mporal coop or attributes oflong-tenn memories (see chapter 3).These cortical areas hip the s a such brain, the of sectors inner the in er-dte closely with structures ongoing our citly pl x e r i remembe to us allow to pocampus (sec figure 5.1), Ilrld experiences Rcprinted from E E. Bloom and A. UZCrsoll, Bmi", Mil/d, 1988). Co., Freeman H. Behavior, 2d ed. (NewYork:W .
.
mcasures changes in regional blood flow across different task con ditions. A group of rescarchers at the U n iversity ofToromo that incillded Fergus Craik, a primary developer of t.he depth of processing frame work, carried out PET scans while volunteers performed either a deep. elaborative encoding task or a shallow, nonclaboracive one.n To determine which brain regions are specifically activated by the ebbo rative encoding task, the researchers subtracted the estimates of blood Aow in the nonclaborative task from the estimates o f blood Row in the elaborative task. They observed a strong region of activation (high
57
B u i l d i n g: M c m o r i e s
56 activity in the hippocampus when people saw "impossible" shapes and
man proponent of the new theory, the controversial biologist Ernst
tried [0 classify them.HThcsc neuroimaging studies suggest chat part of
Haeckel. Semon received his Ph.D. and became a rising young profes
the encoding process involves a hippocampal response to novelty.
sor at the University ofJella, a major European center for evolutionary
When the hippocampus becomes active during a novel event, our
research. Then, in 1 897, he fell in love with the wife of an eminent col
attcmion is drawn [0 it. Then another network may kick in. involving
league, Maria Krehl, who eventually left her husband to live with
the left inferior frontal lobe, which makes available a wealth of seman
Semon. The two were vilified, Semon resigned his professorship, and
tic associations and knowlcdge--the stuff of elaborative encoding. Taken together, the behavioral and physiological evidence 1 have m:mhalcd highlights that memories of past expcnences are natural and
the pair moved to Munich, where they were married. Semon, work ing on his own as private scholar, developed a theory of memory. In 1 904, he published a monograph,
Die MIICfIIf',
that anempted ro
to some extent inevitable outcomes of the ways in which we think
unite the biological analysis of heredity with the psychological and
about and analyze the world. For bencr or worse, our recollections arc
physiological analysis of memory. Semon argued that heredity and
largely at the mercy of our elaborations; only those aspects o experi . cnce chat are targets of elaborative encoding processl:s have a hIgh like
reproduction could be thought of as Illl'lllory that preserves the effects of experience across generations. Nlllen/e, a terill Scmon created in
lihood of being remembered subsequently. These targets of elabor:ltion
allusion to the Greek goddess of memory, Mnemo�ylle, refers to a fun
arc the remains of experience chat populate our minds-the bone chips
damental process that he believed subserves both heredity and every
of the ctinosaur alluded to by Ulric Neisser, and the hazy bit� and pieces
day memory. He conceived it as an elemental elasticity of biological
of memory paimed by Emn Shakine. More extensive elaborations leave
tissue that allows tlle effects of experience to be preserved over time.
�
more bone chips in their wake, thus promoting rich recollections of
Semon distinguished three aspects or stages of Mneme that he
what we saw, felt, and thought during an episode.To a large extent, [hen,
deemed crucial (0 understanding both everyday memory and hered
our memoril..'S arc our elaborations. Or perhaps I should say that our
itary memory. Because he believed that ordinary language has too
memoril'S are built 011 our elaborations, because,
many potentially misleading connotations to be useful scientifically,
as
I will show, the
determinants of explicit fCmembering are not quite so simple.
Semon described the three stagc:s with terms of his own invention:
fllJ!rap/'y is Semon's term for encoding information into memory; cIIgftlll/ refers to the enduring change in the nervous system (the H I STORICAL INTE RLUDE
"memory trace") that conserves the dfectS of experience across time;
The Story of R i c h a r d S e m o n
and nphor)' is the process of activating or retrieving a memory. Semon's
unusual
terminology
and
his
emphasis
on
the
The swdy of mcmory, like that of any scientific endeavor, has a his
memory/heredity analogy elicited a tOrrent of disapproval from
tory full of pioneering figures whose achievements are recognized and
prominent experts of the time. Yet precisely because of this COIHrO
honored by researchers active in the field today. As a gr:ldu:ue student,
vt'rsy, his ideas about the operation of everyday memory tended to be
I became intrigued by Richard Semon, who played an unappreciated
overlooked. Only one reviewer of Oil' i\ll/cme, the American psychol
role in the history of memory research. My curiosity was sparked by
ogist Henry J. Wan, looked beyond the issues of heredity that so mes
tantalizing comments from some of the twentieth-celllury's moS{
ITll:rized biologists and picked out the single IllOSt irnportant aspect of
towering intellects, sllch as the philosopher Bertrand Russell and the
Semon's theory. "The mOst v;llmlble pan of the book is the concept
physicist Erwin Schrodinger, concerning the great value of his work.
of the ecphoric stimulus," rcAected Watt. "Howt'ver, Semon in his
Hardly anyone working on memory in 1 9 7 7 had heard of him, but I
at(empc to find something common in the reproduction of thc organ
soon discovered that his ideas were both original and important.2OI
ism and in the reproduction in the sense of memory, has lost sight of
Semon was born in Berlin in 1 859, the same year that Charles Dar win published
Origi/l of Species.
As a young man, Semon fell under the
his own objective (the discovery of the nature of the ecphoric stimu lus) and has gone astray."17
spell of this innovative approach to understanding e\'olution, and he
What exactly \vas Watt driving at? Psychologists at the time showed
went off to study at the University ofJena with the most famous Ger-
scant interest in memory-retrieval proce�ses. Most of them believed
58
Searlid".i! for Memory
B u i l d i n g Memories
that the likelihood o f remembering an experience i s determined entirely by the strength of associations rha[ arc formed when the information is initially encoded into memory. According to rhis view, if strong associations are fOfmed-because the information is partiClI brly vivid, or is repeated frequently enough-In emory will lacer be good: jf weak associations are formed, memory will I:ltcr be poor. Semon, in contrast, argued that memory does nOt depend solely on the strength of associations_ He camended that the likelihood of remembering also hinges 011 the ecphoric stimulus-the hint or cue that triggers recall-and how it is related to rhe engram, or memory trace, that was encoded initially. Watt realized that Semon had pin pointed a key aspect of memory that had been given short shrift, and wished tiut Semon h�d focused more extensively on it. In 1 909, Semon published
:1
book that must have made Watt exceed
ingly happy. Entitled Dil' Mllm,isrllw Etltpfindll11gclI (MI/clllir
Psyrl/()l�y),
it was eIHircly about everyday memory, leaving aside the contentious issues of heredity in Die !VII/ClUC. Semon elaborated his dteory of ecphory (retrieval processes) and applied it to a host of critical issues. Sadly for Semon, however. the new book aroused slight interest among researchers and had no detectable impact on the study of memory. Psy chologisrs had little use for Semon's iconoclastic views on retrieval processes; in fact, they misunderstood his ideas. In addition, Semon's sta tuS as a scientific isolate, withom prestigious institutional afriliations, did noc enhance his cause. He was accorded the same kind of treatment given to flat-earth theoristS, believers in perpetual-motion machines, and ocher cranks who exist at the fringL'S of science: he was ignored. In 1 9 1 8, Semon's wife died of cancer. Later that year, he placed a German flag on his wife's bed and shot himself through the heart. Despite his nagging despair ovcr the neglect of his work, Semon believed that his ideas would soon achieve widespread recognition among researchers. His hopes went largely unrealized, with the excep tion of one of his terminological inventions: the engram. The great neurosci�ntist Karl Lashley wrOte a paper in 1950 entitled "[n Search of the Engram," which Slll'1 nnarizes Lashley's unsuccessful attempts to find the engram (the representation of a memory in the br:lin) in any single, restricted location. Decause the paper became a classic in the field and comajns the first prominent invocation of the term f'IIgratlt, Illost scientistS have assumed that Lashley invented the word-and he did nOt even cite, much less discuss, Semon's prior use of the term. Engrams are the transient or enduring changes in our brains that result from encoding an �xpericnce. Neuroscientists believe (hat the
brain records
:1.11
59
event by strengthening the connections between
groups of neurons that participate in encoding the experience. A typ ical incident in our everyday lives consists of numerous sights, sounds, actions, and words. DitTerent areas of the br:lin an:llyze these varied aspects of an event. As a result, neurons in the different regions become morc strongly connected to one another. Th� new pattern of connenions constitutes the brain's record of the event: the engram. This idea \vas first suggested by the Can:ldi:m psychologist Donald Hebb. and has since been worked out in considerable detailZll Engrams are imporranr contributors to wh:n we subjectively experi ence as a memory of something that has happened to us. Bue, as we have seen, they are nm the only source of the subjective e;\:periellc� of remeJ11b�rillg. As you read th{.'Se words, there are thousands, maybe mil lions, of engrams in some form in your brain. These patterns of COllllec tions have the potential to enter awareness, to contribute to exphcit remembering under the right circumstances, but at any one instant most of them lie dormant. If I cue you by asking you to remember the most exciting high school sports evcnt YOll ever attended, a variety of engrams that only seconds ago were in a quiescent state become active as you sifi lhrough candidate experiences; if I ask you to remember what you ate the last time you had dinner at an Italian restaurant, a very different set of engrams enters into awareness. Had I not just posed these querit.'S to you, the relevan t engrams might have remained dormant for year.. Semon appreciated that, engrams bemg merely potential comribu lOrs to recollection, an ad�qllate accOllnt of memory depends on ullder5tandillg the influences that allow engrams to become manjfe.<;t in consciolls awareness: What properties of a cue allow it to "awaken" a dormant engram? Why arc some cues etTective in eliciting recollec tion whereas others arc not? Semon argued that any given memory could be elicited by just a few select cues-partS of the original expe rience that a person focused on at the time the experience occurred. Thus, only a fraction of the original evellt need be present in order to trigger recall of the entire episode. To recollect the IllOSt exciting hIgh school sportS event you ever attended, you need nOt r�instate all the cues that were present i1l1lially. Only a subset must be available, those that are closely relatcd to your encoding of the event. Your original encoding and elaboration of the event--say, a football game in which the quarterback made a series of miraculous plays to pull otT an unexpected victory-focused heaviy l on the role of the quarterback. Years later, the mere melHion of the quarterback's name, or even a glance at his f.1ce, may bring to your
61
SeMel/jug Jor Memory
B u i lding Memories
mind the game, the participants, and how your team WOll. Out if you
ber a painting in the museum that matches the description. I would be
do not encounter the critical ClICS, yOll will not recall the experience.
willing to predict that the cue "snake around woman" is more likely to
A friend Illay ask if you recall the time your tcam beat the school with
elicit a recollection of the Magritte painting from the first respondent
the young coach who went on to a career with a professional tcam.
than from the second, and that "wicked man shoors" is more likely to
60
You Illay be puzzled about what g.1l11C he is referring to, and have only
evoke a recollection from the second. The usefulness of the cue
a fuzzy recollection oEthe coach. But as soon as he says that il was the
depends on the nature of the initial encoding. and vice VefS.l.:lO
game in which your quarterback threw two long touchdown passes in
These conside�tions suggest chat the way we perceive and think about
the final minutes, you can retrieve the memory easily. Thus, if encod
an event plays a major role in determining what cues wi.l1 laler dicit rec
ing conditions are not adequately reinstated at the time of attempted
ollection of the experience. Dut it is not the literal similarity between
recall, retrieval will fail----even if an event has received extensive elab
encoding and retrieval conditions that is the crucial determinant of
orative encoding.
expicit l memory. Rather, what maners most is whether a retrieval cue fCinstates a person's subjective perception of an event, including whatever thoughts, fanta..�ies. or infercnCl.'S occurred at the time of encoding. What
Sell/Oil'S Legacy: Cue· Dcpclldellf lHelllory The contemporary researcher who has comributed Illost to under
do you think ofwhen you read the following sentence? The fish attacked the swimmer.
standing the relationship between encoding and retrieval is my former nlentor, Endel Tu lving. One of Tulving's most influential ideas is known
Most people infer that a shark is responsible for the attack. Experi
as the
ments have shown that if I later give you "shark" as a retrieval cue, you
ff1codillg spenfidr), prioriI'll',
which is sim..ilar in many respects to
Semon's theory. According to this principle, first advanced in the 1 970s,
will be more likely to remember this semence than i f ! give you "fish,"
the specific \Yay a person thinks about, or encodes, an evellt determines
even though "fish" was part of the original sentence. ';Shark" is an
what "gets into" the cngr.lm, and t1l!.! likelihood of Iatcr recaUing the
effective retrieval cue because it is more likely than "fish" co bring to
event depends on the extent to which a retrieval clle reinstates or
mind what you thought abom when you read the sentence.Jl
matches the original encoding. Explicit remembering always depends on the similarity or afiinity between encoding and retrieval processes.:I
The close relationship between encoding and retrieval can help us understand instances of remembering and forgetting in our everyday
A hypothetical study (what sciencists refer to as a thought experi
lives. R.ecently I spent a pleasant week with my family in San Diego.
l11em) with some of the material from Sophie Calle's artistic investi
enjoying a brief respite from the Boston winter. We passed a couple of
gation of memory will help illustrate the cemral notion at stake here.
happy afternoons, especially our two young daughters, at the San
Consider two more recolk:ctions of Magritte's "The Menaced Assas
Diego Zoo and SeaWorld. Bur I had visited both places on earlier
sin" that were reported by Museum of Modern Art personnel:
trips and wanted to see something new. So, on a misty Sunday morn ing, we trekked over to [he historic nineteenth-century Coronado
I : Large, awful. There's a pink boa around the neck of :l: naked woman lying on a table like :I: piece of lamb. That's all I remember.
2:
I remember clothed men standing around a woman who is not
only nude but dead, as if she was a sacrifice in the middle of the roolll. Your eyes go immediately to her. \Vhat I remember mOSt is tbe blood COining out of her mouth and the assassin. He just looks evil. In Illy imaginary experiment, I probe each person's memory by pro viding brief descriptive cues and asking him or her co try to remem-
Hotel, located 011 a penillSulajust off the San Diego coast-As we drove over the lengthy bridge that connects the peninsula to lhe mainland, my wife described the size and beauty of the hote.l and noted that our guidebook said that it was tbe fIrst hotel to usc electric lights. I had no previous image of or knowledge about the Coronado, and eagerly anticipated seeing it. When we pulled up in front of the hotel, I was not disappointed: it is an enormous and glorious ('xample of Victorian architecture. The lobby is graced with magnificent, deep brown wood and elegant fur niture. Behind the lobby there is a tr.lnqllil cOllrryard. As we entered
63
Building Memories
62
it, I was suddenly gripped by an unexpected but compelling: convic
shallow encoding, and you will have a hard time later remembering
tion: I had once stood in this vcry courtyard, conversing with partic
that 1 showed you the word brain. YOll would be much more likely to
ipants at a scientific conference. I remembered clearly tbat several of
recall that r showed you bTl/iII if you had carned out a deep encoding
us were discussing my impending move to Harvard University. In a
(such as, think of three important functions th:H a brain performs). But
matter of seconds. I recalled that I had stayed at the Coronado Hotel
if I ask you to remember a word that rhymes with traill, you will be
a little more than fOllr years earlier. As I stood in the courtyard with
more likely to remember bmill after shallow than deep encoding!.I.I
my wife and children, I was able [Q remember which room I had stayed in and various other incidents from that earlier visit. Why wasn't I reminded of the previous trip when we drove over the
All else being equal, elaborative encoding yields higher levels of explicit memory than nonelaborative encoding. probably because a rich and elaborate encoding is accessible to a broad range of retrieval
bridge, when Illy wife described the hotel, or when I saw the impos
cues, whereas a shallow, more impoverished encoding can be elicited
ing structure and lovely lobby with my OWJl eyes? Why did it t:lkc the
only by a few perfectly matched cues. Consider twO bachelors who
sight of the courtyard to trigger the memory? I had encoded that trip
arc seeking spouses. One of them, a doctor, has a broad range of cul
to San Diego as the " conference before my move to Harvard." I was
tural and recreational interests; he is potentially attractive to many dif
not particularly focllsed on the name of the hotd, its historic status, or
ferent kinds of women. The olher is entirely consumed by his work
the Victorian architecture. I was preoccupied with all that I had to
on high-energy particle physics, and would consider as a mate only
accomplish in the two weeks before moving. During breaks between
another similarly devoted particle physicist. The second bachelor will
conference sessions, informal groups gathered in the courtyard, and
have many fewer chances to locate a good match than the first, but if
everybody I spoke with seemed to want to hear about Illy move. The
he is fortunate enough to find one, the physicist C;1Il be at least as
courtyard was an effective retrieval cue-it brought to mind my initial
happy as the doctor. Similarly. an elaborative encoding affords many
encoding of the trip--whereas the other features were not.
more opportunities to "meet" the right retrieval cue than a shallow
Our OW11 statCS of mind can also serve as valuable cues for remem
encoding, and thus increases the chances of successful retrieval; but if
bering. When people drink alcohol or smoke marijuana during the
the right cue is encollntered, a shallow encoding can yield compara
encoding phase of a memory experiment, they later have difliculty
ble or even higher levels of recall.
remembering what they encoded-but they recall more when they
One happy implication of this analysis is that when elaborative
are later given similar doses of alcohol or marijuana. This is known as
encoding has been carried om, and the right cue is available at the
s((It('·dcpClldcllt retrieval, and it has been observed across a wide range of
time of attempted retrieval, memory can achieve extremely high lev
drugs, dosages, and experimental materials. Inducing the same imoxi
els of accuracy. In one experiment. people were given the daunting
cated state helps to re-create more fully the state of mind that prt:
load of
vailed at the rime of encoding; the improved match between encoding
extensive elaborative encodings. and were later given retrieval cues
and retrieval conditions benefitS memory.l.l The exquisite interdependence between encoding and retTieval
600 words to study. They were also induced to carry om
that reinstated those encodings. Shortly after seeing the people recalled over
600 words,
90 percent of them.}.!
suggests some important qualifications to points I IHade earlier con
Because our understanding of ourselves is so dependent on what
cerning elaborative encoding and e:-.:plicit remembering. Recall the
we can remcmber of the past, it is troubling to realize thal successful
fundamental finding fTOm depth of processing studies: when we
recall depends heavily on the availability of appropriate retrieval cues.
enb>age in deep, elaborative encoding of an event, we arc later likely to
Such dependence implies that we may be oblivious to parts of our
remember that event weU; when we engage in shaUow, superficial
pasts because we fail to encounter hints or cues that trigger dormant
encoding, we will later remember the incident mllch less weU . l t turns
memories. This Illay be one reason why encountering acquaintances
out, however, that superficialJy encoded events can be remembered
we have not seen for years is often such an affecting experience: our
more accurately than deeply encoded events when people are given
old friends provide us with cues and reminders that are difficult to
retrieval cues lhal match exacrly a shallow encoding. Suppose I ask
generate on our OWI1, and that allow us to recollect incidents we
you to think of a word that rhymes with braill. You have carried out a
would ordinarily fail to remember.
64
B u i l d i n g M e lll o r i e s
Searching Jo r AI/ e m o r y
In his relentless quest for self-understanding, the narratOr i n Marcel Proust's novel confronted the disturbing reality that his ability to
65
recount most of his life prior to the operation. but he had great diffi culty remembering his ongoing, day-to-day expcrienc{.'S.
recapture the past depended on finding retrieval cues that could
Curiously, however, Neil performed reasonably well at school,
unleash the torrents of memory that he sought. He ultimately came
especially in Eng-lish and m:lthematics. The psychologistS who tested
to realize that he could nOt allow his menta] time travels to depend
his memory wondered how he managed to do so well. To find out,
solely on chance encounters with smells and tastes, and so he instead
chey asked him some questions about an audiotaped book he had
pursued the past by actively seeking out cues and hints that would
been studying, Cider ulilll Rosie, by Laurie Lee. He remembered noth
help him [0 remember. NJ of us share Proust's problem: [Q understand
ing. Noting Neil's frustration, and realizing that his class performance
bener who we are, we mUSt somehow generate or find cues that aUow
was based on written responses, the examiner asked Neil to write
us [0 remember things that might otherwise remain dormant or sim
down his answers, beginning with anything that he could recall from
ply fade away. We saw how in the case of patient GR, encollntering
the book. After a while he wrote: "BloodshQ[ Geranium windows
the right retrieval cue (a medical procedure similar (0 one he had had
Cider with Rosie Oranium smell of damp pepper and mushroom growth." "What have I written?" he then asked, unable to read his
before) allowed hUll to regain his seemingly lost personal past. We must not, howevcr, confuse these ideas with the norian that all
own handwriting but able to speak normally. The examiner, who was
experiences arc recorded somewhere in our brains, only awaiting the
familiar with the book, immediately recognized that the phrases came
appropriate retrieval cue to be brought il1(O awareness. While con
direcdy from it� pages,
trolled research has demonstrated over and over that cues and
Intrigued by Neil's ability to write down information that he could
reminders can lead to recall of experiences that have seemingly disap
nOt express orally, the examim'r asked whether Neil could write any
peared, it does not necessarily follow that all e:":l'eriences are preserved
thing about incidents related to his hospitalization some two years ear
and potentially recallable. Sometimes we forget because the right cues
lier, which he had been unable to remember when asked to talk about
are not available, but it is also likely that sometimes we forget because
them. "A man had Gangrene," he wrote, correctly recalling the ailment
the relevant engrams have weakened or become blurred.»
of another man in the ambulance that brought Neil to the hospital.
R_etri('val cues are a bit like the portable metal detectors that scav
Neil's parents asked him to write down the names of the children
engers sometimes use to try CO recover coins on a beach. If coins are
in his class. He produced a long list. which turned out to be accurate.
hidden somewhere beneath the sands, then the scavenger needs the
When his mother asked him what had happened at school that day,
detector (0 find them. But if no coins remain in the sand, then even the
Neil wrote, "Mum I saw tulips on the way hOllle."This was the first
most powerful detector will turn tip nothing. Our brains include some
time in two years that Neil had been able to relate to his mother a
beaches with hidden coins and others that are barren. Like the scavenger
memory of something that had happened to him in her absence. Neil's parents equipped him with a small notebook, and he began
seeking money, \ve do not know before searching which are which.
to communicate reb'lilarly abom incidents in his everyday life. Yet he remained unable to recount these episodes or:lily. When he wrotc them down, Neil was ullable to read them, and often expressed sur
NEIL
prise when someone told him what he had written. After an after
R e t r i ev a l P r o c e s s e s a n d the B r a i n
1988, a
noon's excursion to several r,'lIlliliar locations, Neil was unable to
fourteen-year-old English boy named Neil began radiation
remember anything when asked. But when cold to write down what
trcatment for a tumor hidden deep within the recesses of his brain.
had happened, he provided a succinct. and accurate, summary of the
Neil had been a normal child uncil the expanding tumor began to
afternoon's activities: " We went to the museum, and we had some
interfere with his vision and memory and to create a host of other
pizza. Then we came back, we went onto the Beach and we looked at
mcdical problems. Chemotherapy was eventually successful, but
the sea. Then we came home."
In
eil
suffered heavy cognitive losses. He was virtualJy unable to read and
This case is unprecedented in the annals of psychology, psychiatry,
could no longer Ilame common objects on sight. Neil was able to
or neurology..l6 Neil's tUnlor did damage his brain, including some
66
Dudding Memories
S c a rf/rj"g for M e m o r ),
67
structures that are known (0 be imporr3m for memory. But nothing
that regions of left inferior fromal cortex appear to be particularly
about the condition ofillS brain provides specific clues to how or why
active during encoding processes. In contrast, as Endel Tulving has
he could retrieve recent episodic memories through writing but not
shown, PET studies of memory for words, sentences, faces, and other
speaking.
materials consistently reveal that specific regions toward the front of
There are other indications that the brain uses different systems for
the right frontal cortex are especially active during e"l'licit retrieval of
retrieving written and spoken information. The neuropsychologist
episodic memories-more active than the corresponding left frontal
Alfonso Caramaua has described two patients who suffered strokes in
regions.-tQ Of course, merely observing that a region is active during
differem regions ofche left hemisphere that are usually associated with
retrieval does nor indicate exactly what role it plays in the retrieval
language impairments. Both patients subsequently had special prob
process. For example, if the right frontal regions that have been :lcti
lems producing English verbs (they could produce nouns normally).
vated during PET studies constitute a retrieval system that is neces
One patient had problems writing verbs but not saying them, whereas
sary for recalling all episodic memories, then damage to right frontal
the other had problems saying verbs but nOt writing them.)1
regions should cause a devastating impairment of explicit retrieval;
Caramazza's fmdings still leave us a long way from understanding
such patients should have grdve difficulties recalling past cvenrs. How
how Neil could recall his recent experiences through writing but not
ever, studies that have included patients with right frontal damage typ
speaking:. Out these strange cases of disruptions of retrieval raise ques
ically fail to show generalized impairments of explicit remembering.
tions that are essential to understanding memory: Exactly how does
But these patients can exhibit sOllle memory difficulties, such as prob
the retrieval process work? What goes on in my mind/brain that
lems in remembermg which of two events occurred more fecencly,
a!Jows the cue "What did YOll do during your sumiller vacation?" to evoke III me the subjective experience of remembering beautiful sun
and some arc also susceptible to fascinating memory distortions. These . impairments, which I consider later, may be caused by fluiry retrieval
lit days of hiking and swimming at Lake Tahoe? We do not understand
processes.
precisely how the retrieval process works, but some dues art' begin ning to emerge.J8
In 1992, neuroscientist Larry Squire and colleagues reported a PET study of explicit retrieval that showed activation of the hippocampus,
One critically important idea is that the brain engages in an act of
which we have already seen plays a role in encoding novel experi
"construction" during the retrieval process. The idea is well illustrated
el1ces. �l Given that both the hippocampus and the frontal lobes can
by neurologi.st Antonio Oamasio's theory of how the brain remem
become active when people arc instructed to remember recent events.
bers. As I elaborate in the next chapter, Darnasio and mhers have
it is natural to ask what role each structure plays in the retrieval
argued that there is no single location or area in the brain that COI1-
process. A recent PET study I carried OUt with colleagues suggests that
tains the engr:lI11 of a particular past experience. Posterior regions of
they play rather different roles. Think about what is involved when I
the cortex that are concerned with perceptual analysis hold on to
ask you to recall what you did last Saturday night. Attempting to
fragmentS of sensory experienc(,-bits and pieces of sights and sounds
retrieve th:\t memory involves a r:lir amOllnt of mental work. YOll
from everyday episodes. Various mher regions of the brain, which
engage in search strategies and try to come up with cues. sllch as gen
Damasio calls convergence zones, comain codcs that bind sensory
erating names of people you might have seen or where you Illight
fragmcnts to olle another and 10 preexisting knowledge, thereby con
have gone. The mental effort that you expend is an important part of
stituting complex records of past encodings. Oall1asio suggests that
the retrieval process. But there is also the moment when you actually
remembering occurs when signals from convergence zones trigger the
remember the event: you recall that you went to the movies and saw
simultaneolls :lctivatioll of sensory fragments that were once linked
a thriller that kept yOll on the edge of your seat. TillS subjective rcc
together. The retrieved memory is a temporary cOllStelJation of activ
ollcctive experience is, of course, an essential pan of the retrieval
ity in several distinct brain regions-a construction with many con
process. When a brain area becomes active during a memory-retrieval
tributors. :t9
task, it cOllld reAect eicht'r the mental effort associated with trying to
New information reg-drding brain systems involved in memory
remember or the recollective experience associated with successful
retrieval has been provided by PET scanning studies. I noted earlier
remembering. We designed our PET study to discmangle these twO
Se(lrdli llg Jor M e m o r Jl
68
Building M emories
aspects of retrieval. Our results show that increased blood flow in the frontal lobes during explicit retrieval refh:cts primarily the mental effort involved in searching memory. However, silllply trying to remember all event is not enough to activate the hippocampus. Increased blood flow in the hippocampus seems to reflect some aspect of the subjective experience associated with remembering the event.'� In line with cht.'Sc findinb "S, the neuropsychologist Morris Moscovitch proposed that hippocampal and frontal systems may be involved in two different kinds of retrieval processes. One of them, referred to as associalillf retrieval, is an 3moll1aric reminding process that depends on the hippocampus and related medial temporal lobe Structures. Associative retrieval occurs when a cue automatically triggers an expe rience of remembering. Everyone is familiar with this sort of experi ence: hearing a f.worite song reminds you of where you were when you first heard it; you tell a new acquaintance that she reminds you of an old friend; seeing a cue word in a memory experiment easily
69
system damage leads to severe memory loss for recent experiences, whereas frontal system damage typically does not. When the auto matic retrieval system is dysfunctional, the interrogations of the strate gic system WIll be fruitless, and it will be difficult to recall recent events. However, if the strategic retrieval process is impaired and the automatic retrieval process is intact. it should still be possible to remember reasonably well in the presence of appropriate reminders or cues. Deficits will be restricted largely to those situations in which effonful, strategic search is required-and this is a reasonably accurate description of what happens in many cases of frontal system damage. The power of modern ncuroimaging techniques raises the possibil ity that we may, in rhe nor tOO distant future, learn enough about brain mechanisms of memory retrieval to be able to illuminate the disordlT that rendered Neil mute about experiences that he could describe onjy when a pencil was placed in his hand.
brings to mind the word that was paired with it during the study episode. The other retrieval process, which is referred (0 as
e.fforifll/ or
strategic retrieVtli, involves a slow, deliberate search of memory and depends on regions of prefrontal cortex-perhaps most critically. the right frontal regions that have been activated during explicit retrieval in PET studies.o When I asked you to remember what you did last Saturday night, you relied on the strategic retrieval process to generate hints and cues, which you used in turn to "interrogate" the automatic retrieval process. If the frontal system generates a cue that has a match in mem ory. the medial t.emporal system will automatically "spit out" an engram that combines with the cue. Without the aid of the frontal sys tem, the medial temporal system must simply "wait" for an appropri ate cue to come along and make contact with a stored engram. As we wilJ sec in chapter 3, the medial temporal region works cooperatively with regions toward the rear of the bram where engrams :1Tt� stOred, including areas in the parietal and occipital cortices, forming distrib uted networks that aHow liS to encode and recall our recent experi ences. Indeed, our PET study TCwaled blood flow increases in specific pam of the occipital and parietal lobes during recall, perhaps reflcct ing the dynamic interaction between mcdial temporal srruclUres and cortical regions that results in the construction of a memory. Out we will also see that the medial temporal region is not necessary for retrieving experiences from the distant past. These ideas help to make sense of the fact that medial temporal
C O N S T RU C T I N G M E M O R I E S T h e Role o f t h e R e t r i eval Environ m e n t Findings and ideas concerning brain mechanisms of retrieval are absolutely crucial to undtTstanding memory's fragile power. But it is still important to develop an adequate conceptualization of retrieval at the psychological level. How are we to think about what is retrieved when we recall a past experience? Does the act of retTleval simply serve to activate, or bring into conscious a\varencss, a dormant memory? Suppose, for example, that I provide a retrieval cue such as "tell me about last year's Thanksgiving dinner:' It Illay take you a few seconds to recollect where it occurred and who was there, but by the timc you reach the end of this sentence there is a good chance that YOll will recall some of the basic information. How did this subjective experi ence of remembering come about? The simplest account is that the clle somehow activated a dormant engram of the event, and that your subjective experience of fCmcmbering the event, however mcom plete, is a straightforward reAcaion of the information that had been quiescent in your mind: a lightbulb that had been turned off i s sud denly turned 011. But memory retrieval is nOt so simple. I have already suggested an alternative possibility, rooted in
eisser's analogy that retrieving a
memory is like reconstructing a dinosaur from fragments of bone. For
13 u i l d i u g M e m o r i e s
S e a rcll i tlg for iHe m o r y
70
71
the paleontologist, the bone chips that are recovered on an archeo
that people reported contained little infonnation about the event they
logical dig and the dinosaur that is ultimately reconstructed from
were trying to recall (the speaker's tone of voice) but were greatly
not the same thing; the full-blown dinosaur IS constructed
influenced by the properties of the retrieval clie that we gave them
them
3TC
by combining the bone chips with ocher available fragments, in accor
(the positive or negative facial expression) .44
dance with gcncr:d knowledge of how the complete dinosaur should
There have been few other attempts to examine how the proper
appear. Similarly, for the rememberer, rhe cngranl (the stored frag
ties of a retrieval cue contribute to our subj ective experiences of
mems of an episode) and the memory (the subjective experience of
remembering. This is likely attributable to what Tulving has called the
recollecting a pasl event) are not the same thing. The stored fragments
"overpowering influence" of the traditional theory that a memory is
contribute to the consciolls experience of remembering, but they are
simply an activated engr
only part of it. Another important component is the rctneval cue
one-to-one correspondence between a bit of information stored
itself. Although it is often aSSlllned that a retrieval cue merely arouses
somewhere in our brain and the conscious experience of a memory
or activates a memory that is slumbering in the recesses of the brair1,
that results fro m activating this bit of information is so intuitively
I have hmted at an alternative_: the eue combines with the engram to
compelling th
yield a new, emergent entity�the recollective experience of the
tists who study memory and theorize about it are lTlcreasingly skepti
remenlberer-th;lt differs from either ofits constituents. This idea was
cal of this idea.
intinuted in some of Proust's writings, in which memories emerge
For example, one of the most influential approaches to thinking
from comparing and combining a present sensation with a past one,
about memory in recent years, known as connectiolllsrn, has aban
much as stereoscopic vision emerges from combining information
doned the idea that a memory is an activated picture of a past event.
from the two eyes.
Connectionist or neural network models are based on the principle
If all a retneval cue did was to activate a dormant memory, some findings I have considered would not make much sense: recalling an
that the brain stores engrams by increasing the strength of connections between different neurons that participate !Il encoding an experience.
event from an "observer" perspective Jfter recalling the same event frorn a "field" perspective leads people to say that the event seems less
become stronger, and this specific pattern of brain activity constitutes
When we encode an experience, connections between active neurons
emotiollJl than when they first recalled it; the feeling of knowing that an unrecal1cd bit of information is on the tip of the tongue is often an l!1usion produced by a (lmiliar retrieval cue; and the experience of
IS similar enough to a previously encoded pattern, remembering will
" remembering" a past event, as opposed to "just knowing" that it occurred, is lessened when melllory is prompted with certain kinds of
activated engram, however. It is a unique pattern that emerges from
retrieval cues. Once we acknowledge that a retrieval cue combines with the engram in order to yield a subjective experience that we call
work combines information in the present environment with patterns
the engram. Later, as we try to remember the experience, a retrieval cue will induce another pattern of activity in the brain. I f this pattern occur. The "memory" in a neural network model is not simply an the pooled contributions of the clle and the engram. A neural net
a lnelllory, we can begin to make sense of these apparent puzzles. A recent swdy from Illy laboratory provides evidence that the
is what the network remembers. The same conclusion applies to peo
properties of a retrieval cue can influence what we recall about the
ple. When we remember, we complete a pattern with the best match
past. College students looked at photos of people and heard them
available in memory; we do not shine a spodight on a stored picture.�
that have been stored in the pase, and the resulting mixture of the two
speak in either a pleasant or an irritating tone of voice. Later, they saw
The idea that a memory is an emergent property of the cue and the
the photos again and tried to recall the person's tone of voice. When
engram is difficult to accept. We must leave behind our familiar pre
students saw a f:'lce with a bit of a smile, they tended to say that the
conceptions if we are to understand how we convert the fragmentary
person had previously spoken in a pleasant tone of voice; when they
remains of experience into the autobiographical narratives that endure
saw a face with a slight scowl, they tended to say that the person had
over time and constitute the stories of our lives.
spoken 111 an unpleasant tone. In (let, there was no relationship between facial expression and tone of voice. Thus, the "memories"
O f T i m e and A u t o b i o g r a p h y
73
the past and often shape the future. Mildred Howard acknowledges this relationship by commemorating distant events with aged object�. She appreciates that our understanding of who we are and who we
THREE
will become depends on memories that may fade, change, or even strengthen as time inexorably passes. And it is from tillS ongoing dynamic betwecn timc and memory that our autobiographies-the stories we tell about our lives-are born. We cannot hope to under stand memory's fr.lgile power without examining what happens to memory as time passes, and considering how we translate the residues of experience that persist across time illlo tales of who we are.
OF TIME AND AUT O B I O G R A P H Y
T H E R E C E D I N G PA S T III the first cxpl.!rimental analysis of reTlll.!l1lbering and forgetting ever reported. an epoch-making study by the German psychologist
T H E ARTIST
M I 1. D R E D
HOWARD likes to relate visual stories
about her family. Her parents moved theiT growing family from Texas
(0 California at the beginning of World War Ii. Mildred, the youngest often children, was the only one born in California. Growing up, she listened intendy (0 the stories of her parents, brothers, sisters, ;Ul�)(S, and uncles about theiT trials and adventures in the Texas countryside. She was especially moved by the cales of her elderly Aunt Mildred, a reposilOry of family lore who mesmerized her young niece with col orful renditions of past events. In "Rose (Rooseveh)" (figure 3 . 1 ) the artist invites us to imagine one of Aunt Mildred's storics by reprinting a photograph from her family albunl on an old window franH! and providing us with hints of the underlying narrative. Mildred Howard was enthralled by the oral history of her family but sometimcs felt a twinge ofjealousy that she had not been there herself to witness the escapades that she heard abollt. Perhaps this is one reason she has worked for ycars to capture in pictures the faded yet vital recollections of family stories that date back to beforc her birth. "The sepia-toned images of handsome men and women in their Sunday best," notes one observer about Howards work, "speak of f.1.lnily pride dimmed through the passage of time and diminished memory."l The distant, almost translucent quality that characterizes some of the old Jllel� lO des is communicatcd effectively in "Caney Creek" (figure 3.2). TlIlle and memory are inextricably interwoven; memories always refer to
Hermann Ebbinghaus ill
1 885, lengthening the delay between
encoding and retrieval produced dramatic increases in forgetting. Ebbinghaus, who servcd as his own and only subject, set about melllorizing long lists of nonsense syllables. He then carefully tested himself at different times after learning. Ebbinghaus remcmbered progressively less at each of the six delays thar he llsed, ranging from one hour to one month. The rate of forgetting was relatively rapid at the early delays and slowed down at later oncs. Ebbinghaus forgot a great deal between a one-hour delay and a nine-hour delay. whereas he lost relatively little between a one�day delay and a [wo day delay. Many later researchers have al�o found that the rate of for gening is slowed down by the passage of (il11e.2 Psychologists have more recently investigated how memory for everyday personal experiences is influenced by the passage oftil11c. lo the early 1970s the psychologist Herbert Crovitz rediscovered and refined a method for studying memories of real-life experiences that had been described by the nineteenth-centlllY Uritish SCIentist Sir Francis Galton. The method, now comlllon.ly referred to as the Crovitz procedure, is simple. Think of a spccific memory from any time in your life that comes to mind first when yOll are given the word
tahlr.
Once yOll have retrieved a memory, do your best to assign
a date to it. Now try the same procedure using the cue word
/wrl,
and
then do it one more time with thc cue word rIIl/. In Crovitz's experiments. people retrieved memories from many
different points in their lives. ranging from a few minutes prior to the 72
FIGURE 3 . 2
FIGURE 3 . 1
Mildred Howard. "Caney Creek," 1991 . 21 x 24 x 6". Mixed media on window frame. Nielsen Gallery, Boston.
I
Three f.1int figl1rc�-ntel11bcn of the artist's t:lmily in rural Texas-fade likt· blurs into a receding background. A window frallIe scarred by peeling paim and cTacked surf.lees surrounds their image. further hcighu-ning the sense of an old memory Tav:lged by rime. Six empty bottles ofcream soda stand in front of the figures. For How.ml. these empty \'essels evoke images ofa rousing f.1111ily get-together or of conversations with brothers and sisten on a hot after noon.
Mildred Howard, "Rose (Roosevelt)," 1992. 28 x
18 x 2 " . Mixed
media on window frame. Gallery Paule Anglim, San Francisco.
Two well-dressed young men surround a miniature window-wnhin-a-window contaJlling a photo of th� artist's Aunt Mi l dred in her younger diys. Are these two young suiwrs who vied for Aunt Mildred's affectio ns? R.e!ltives who
participatN\ with Aunt Mildred in SOllle unportant or mysteriOus bit of fam ily Imtory? We don't know the particulars, but we can guess that It is an ab�orbing talc.
Searching Jar Mell/Qry
O f T i m e a n d A u t o b i ography
experiment to the eJriy years of childhood. H e found that the more
four percent of psychologists chose the first option. This conclusion
76
reCCil! time periods yielded the Illost memories, the more distant tillle periods (he fe\\'e�L (When I tried the experimcnr mysetf, I remem bered leaving some papers on a cable for a colleague a week earlier; dislocating my fmgcr playing baseball as a child; and running w catch a taxi in New York City sever.11 months earlier.) The drop-otT in reported memories was steepest in the recent time periods and morc gradual in the remOte time periods.\ Despite a few deviations. the general rule that memories hecome grJdually less accessible with the passage of tillle holds in lllallY situa tions. It is sometimes surprising bow much we may forget when a suf fiCient amount of time has passed. For example, survey researchers interviewed
590 people who were known to haw been injured in an
automobile accident during the preceding year. Almost everyone who was illtervie\ved withill three months of the accident remembered this disrurbing evem (fewer than -l- percent did not report it). nut
27 per
cent of people interviewed between nine and twelve months after the accidenr failed to report it. "The obvious reason for this trend," the authors of the study conunent, "is a decreased ability co recall the occurrence of a motor vehicle accident as rhe time between the date of the accident and the date of interview increases.'" Why is the passage of time associated with decreasing memory? As time passes, we encode and store new experiences that interfere with our ability to recall previous ones. I can remember what 1 h:ld for breakfast today, but not what I had for breakfast on this day a year ago, . because J have had many breakflsts since then that interfere with my ability CO pick out any single one from the crowd, Interfering events of this kind Illay give rise to an increasingly fuzzy or blurred engram as time passes.� Many researchers would agree that blurring or even loss of information from the engr.un plays a role in the pervasive for gerting that afflicts us all. Bm some have contcnded that no informa tion is ever lost frorn 1l1�ll1ory-that all experienced events cxist somewhere in the mind, pretty rnuch in their original form, simply awaiting the right cue to elicit them. The memory researchers Elizabeth and Geoffrey Loftus asked psy chologiSts to choose between two theories of forgetting. One theory holds that everything that happens is permanently stored in the mind, so that details we cannot rernember at a particular time could eventu ally be recovered wi III the right technique. The other theory holds that sOllie experiences may be permanently lost from memory, and would never be able to be recovered by special techniques. Eighty-
77
might appear to be justified by evidence I considered earlier con cerning the importance of retrieval cues in remembering. It is likely, for instance, that many people who forgOt about their motor vehicle accident... after a year could be induced to remember the event if given a specific retrieval cue, such as a detailed description of the circulll stances surrounding the accident. But as
J intimated in the previolls
chapter, there arc problems with the idea that all experiences are kept forever in some dark corner of the brain.' The idea received seemingly strong support from the oft-described brain-stimulation studies conducted by the Canadian neurosurgeon Wilder Penfield during the 1 9505. In the Loftus and Loftus survey, psychologists frequently pointed to Penfield's work as crucial evidence favoring the idea that all experiences are permanently stored in the mind. Penfield's observations were certainly dramatic. Prior to oper ating on patients who required brain surgery, Penfield carefully placed an electrode on the surface of the exposed temporal lobe. The patient was fully conscious as Penfield turned on an electrical current. Some times he elicited surprising memories of seemingly long-forgotten events, "Yes, sir, I thjnk I heard a mother calling her little boy somc where," reported onc patient. "It scemed to be something that hap pened years ago." Another patient exclaimed, ·'Yes. Doctor, yes. Doctor! Now I hear people laughing-my friends in South Africa." When a�ked if he could recognize them, the patient replied, "Yes, they are two cOllsins, Bessie and Ann Wheliaw,"1 To Penfield, such examples revealed a lasting record of experiences in the brain:"1t is clear that the neuronal action that accompanies each succeeding state of consciousness leaves its permanent imprint on the brain."8 If we could just figure out a way to fmel the unchanging neural imprims that our brains preserve forever, Penfield thought, we could remember or cven relive cverything we have ever experienced. Maybe the passing of time docs not, after all, erode or crase the brain's recordings of past events; it might merely wreak havoc with our abil ity to replay our dusty old records. Although the idea has an undeniable appeal-it leaves open Ihe possibility that we could aU achieve Proust's and Magnani's dreams of recapturing the past fully-many psychologists and neuroscientists now concur (hat Penfield's results provide little support for this rather romantic proposition. Only 40 of the
520 patients who received tem
poral lobe stimulations reported any memal experiences that could be interpreted as memories. Even more important, Penfield failed to doc-
78
S e n r c " j ll� faT J"'e m ,, , >,
Ulllcnt whether his patients' experiences were memories of actual past incidents or Illere fantasies or hallucinations.9 In a more recc!nt investigation, French researchers described similar mental experiences in patients with temporal lobe epilepsy. What the researchers called the "dreamy state" was either evoked by electrical stimulation in the vicinity of the temporal lobes or occurred sponta neously during the aura that precedes a seizure. Patients sometimes reported the experience of remembering, but they tended to recall generic scenes rather than specific evcms. " ) saw before my eyes the house of a friend in my grandmother'S village," said one patient. "then it disappeared and I saw rhe house in Brittany whert' I spend my sum mer vacations." " I was ill my kitchell, in front of the sink, dressed as usual," reported another. Still other patients described strange feelings of dej:l Vll, such 3S one who related ;' ltlhe impreSSIOn of having already done what I am in the process of doing; it seems to me that I have already lived through the entire situation; with a feeling of strangeness and often of fear."IQ It is important that these subjective feelinb1S of remembering result from electrical activity in temporal lobe structures because this region of the brain plays a paramount role in memory. But,just as in Penfield's studies, the patients' reports provide no indi cation of a permanent record of specific memories that is impervious to
the p:lssage of time. The idea that all experiences are recorded forever, requiring only a
Proust;an taste, sight, or smell to come dancing into consciousness, can never be disproved on purely psychological grounds. Even jfwe show that a person cannot remember an experience in response (0 a wide variery of retrieval cues, it is always possible that some other cue would result in sudden recall . And there is no question rh;lt providing cues, or reinstating the physical or mental context that prevailed dur ing an experience, sometimes does lead to recall of seemingly lost experiences. However, neurobiolo,;ical research with invertebrate organisms has shown that the neur.1i changes that underlie some sim ple forms of memory can weaken and even disappear over time. Nobody has yet demonstrated that the same thing happens ill mam mals. (jut this kind of finding suggests that as time passes. there may be a diminution in the strength of connections among neurons that represent particular experiences. At a biological level, some engrams might literally fade away over [ilne. 11 The two extreme positions abom the causes of forgetting-that it occurs either because an engram has disappeared from stonge or because a fully intact engram is merely imccessible :It thc momcnt
O f T i m e and A u t O b i ography
79
. owing to retrieval f1iluT(.-3re too ' simplistic. Rather than ar,;uing about wheth r or not all experienc es are preserved forever, we need � t? refine ou Ideas about why forge tting occurs. It seems likely that as � tll11e passes, IIlterference from new expe riences makes it progressively . morc dif ficult to a retrieval cue that elicits an increasing ly blurred engram. The cogllltive psychologist Marigold Linton conducted a we11-known study of her own mem ory that confirms this poill t. She wrote rief d�scriptions. every day, concerning at least two specific events III her hfe; she then tested her memory for random samples of these events at sever.II points jn time . The study had been undl'r way for fourteen years when Linton repo rted on it in 1 986. She notes that for about a year after the occurrence of an episode, it " em be accessed readily-with virtual1y any cue."12 How ever, as Illore time ebpses, and t e eng am becomes more blurry, the range of cues that elicits a spe : Cific episode progressively narrows. This means that wilen we sud denly and unexpectedly recover a seem ingly forgotten memory, it may be because we have luckily stum bled upon a retrieval Cllt' that matches up perfectly with a faded or blurred engram. When I visired a summer camp wher e I worked as a w:lieer rwenty . five years eathe r, I drove by a Spot on the lake that olTer s a lovely view back toward the camp. As I was looking out from my car, I suddenly remembered when several friends and I visited (hat exact spot-the . only other ttltle I had ever been to that part of the lake. I hadn't thought about the incident for a quart cr-cemury. and I could not recall exactly what we had been doin g or who else was there. Gut I am pretry certain there are few jf any cues other rh:1Il the sight of the camp across the lake that would have led me to recall this hazy mem o')'.
fi'��
?
�
�
These cons derations also lead to anoth er important implication for th: relati. onship between the retrieval cue and the engralll. All things elll� equal, when Illelnory is probed soon after an event, the engram IS a nch source of information and may even be the dominant con tributor to recol1ective experience. Relat ively little retrieval inforrnJ ti�n is needed to elicit the appropriate engram, and the retrieval cue w!ll play a more or less minor role in shaping the subjective experi ence of remembering. I f I ask you to reITlelnber what you did JUSt before you picked up this book, you probably will not have a prob lem recalling the incident. , need not provide you with extensive cues to elicit he memory, and your recol lection of the event would prob � . ably be slIllIl ar regardless of how I clle you. The s.1me is often true of favorite past episodes that we have recounted frequently: we tel1 the
�)
80
S e a rc h i ng fM M e m o r y
same story over and over again, regardless o f which panicular cues elicit it. However, the nature of the cue-engram relationship is likely to be quite differem for episodes from the distant past that we have not recounted many times. Now that the engram of the event is a more impoverished source of information, considerable cueing may be needed to elicit memory for the episode, and the properties of the retrieval cue itself may figure quite prominently in shaping rhe remembcrer's recollective experience. If, for example, I ask you to rec ollect events that transpired at your Thanksgiving dinner of six years ago, you will need a variety of retrieval cues in order to remember explicicly much of what happened. Now the quality of your recollec tive experience may indeed depend sib'11ificantly on precisely which cues arc used to trigger recollection. Suppose, for instance. you recall that six Thanksgivings ago, your old friend George flew in for the hol iday; you attempt to cue additional recollections by thinking about him. Suppose further that in the intervening years, you and George had a serious disagreement and you 110 longer feel as warm lOward him as you once did. These properties are now incorporated into your permanent knowledge of George, and they may play a role in shaping your memories of what happened at that Thanksgiving dinner. You Illay be inclined to recollect that he made a disparaging remark or that he behaved inappropriately, even though the engram of the event contains only vague information about what occurred. Because the engram is so impoverished, fecollective experience may be deter mined more heavily by salient properties of the cue, which itself has stored associuions and meanings in memory. Weakening and blurring of engrams over time is, on the face of it, an unpleasant reality of memory. It is frustrating, even disturbing, to realize that past experiences are constantly slipping away from us, some rapidly and others imperceptibly. But we would be far worse ofT" if we did not forget. In Jorge Luis Borges's jarring story "Funes, the MemoriollS," a young man remembers the tiniest details of all that has happened to him. He remembers every leaf of every tree he has ever secn and every separate occasion on which he has seen them: "1 have more memories in myself alone than aU men have had since lhe world was a world." But the price of perfect retention is high: Funes's mind is so cluttered with precise memories that he is incapable of general izing from one cxperience to anQ[her. He has difficulty fathoming why a dog he encounters has the same name at one moment as it has a minute later. "To think is to forget a difference, to abstract," Borges
O f T i m e and A u t o b i ography
81
reminds us. Years after Borges wrote this story, the Russian neuropsy chologist Alexander Luria described a Illuch-celebrated nmelllonist Shereshevskii, who was Plab'tlcd by Funes's fictional problem: he overwhelmed by detailed but useless recollections of trivial informa tion and events. He could reCOUllt without error long lists of names, numbers, and JUSt about anything else th;u Luria presented to him. This served hilll weU in his job as a newspaper reporter, because he didn't have to write things down.Yet when he read a story or listened to other people, he recalled endless details without understanding much of what he read or heard. And like FUlles, he had great difficulty grasping abstract concepts. lJ Forgetting, though often frustrating, is an adaptive feature of our memories. We don't need to remcmber everything that has ever hap pened to us: engrams that we never usc arc probably best forgonen. The cOb'Tlirive psychologist John Anderson has argued convincingly that forgetting memories over time is an cconomical response to the demands placed on memory by the environment in which we live.We are better ofT" forgetting trivial experiences than clogging our minds with each and every ongoing event, just in case we might want to remember one of those incidents someday. \' But we do need to form an accurate picture of the general features of our world, and it turm Out that we are reasonably adept at doing so. Our recollections of the general COntours of Ollr pasts arc oftell reasonably accurate. Perhaps paradoxicalJ)', if we, like Funes or Shercshevskii, were constantly over whelmed by detailed memories of every page from our pasts, we would be left without a coherent story to tdL
\��
HYPERM NESIA AND C O N S O L IDATION D o M e m o r i e s Ever S t r e n g t h e n o v e r T i m e ?
Though forgetting has adaptive features, time is still an enemy of memory. We forget Ollr experienccs--somerimes rapidly, sometimes slowly-as the delay between encoding and ret.rieval increases. But memory doesn't always fade over time. Consider a curioliS phenom enon that psychologists call "ypcnllllcsill. When people arc shown a bunch of pictures, for example. and arc later given a series of tests in which they try ab"din and again to recall the pictures, the overall per centage of correct answers increases on each lest, even though more and more time has passed since the original encoding episode. If one group of people Iud taken a single test at a shorr delay and another
Starcldng for M e m o r y
82
O f T i m e and A u t o b i o g r a p h y
. roup had taken a single tcst at a long delay, there's no question that eople tested at the long delay would remember less than peo�lc . tested at the short delay. But when people arc tested agalll and ag�lI1, recalling the pictures on each test seems to minimize forgettmg
�
bccween one tcst and the next. This active rehearsal also promotes recovery of pictures that people failed to recall initially, perhaps because the rcmcmbl'rcrs generate new retrieval cues on Ia[e� tests that dredge up previously imcccssible engrams. Th� net result IS that . memory seems to improve, not decay. over til11t'. LikeWise, psycholo gists and neurobiologists have dis�ovcrcd that some eng.r:.IIlls appear (� . . become Illore resistant to forgctnng as {lme passes. SCiennsts use the terlll coflSo/idmiml to refer to this seemingly paradoxical state of . aif,irs.ls The concept of consolidation has had a long and somewhat con troversial history in the psychology and neurobiolo�;y of mel�lory. Many contemp0r:\ry researchers distinguish betwcen two quite dlffcrcm types of memory consolidation.
. . One type of consolidation operates over nme penocis of �econds or . minutes' it convertS immediate or short-term melllones mto more
� long-term memories.The ability to perform .this s�ort-term
endurin
consolidation is often interrupted when people 5UStalll senouS head
injuries. Fo!lowing stich injuries, they are almost invariabl� unable to . . remember the accident Itself or the few 1ll1llutes precedmg It, and they virtually never recover these memories. The events just prior to an accide l ;t may be registered and entered into short-term or working
memory, bm they never gain entry into the long-term system. Some
years ago enterprising rcsearcl�e�s :�ccoll1p:lIlied a college foo �bal1 team to their weekly games. :l11t1Clpatlng that players would occasloll . ally suffer concussions. When there was a particularly hard hu " known in football as a ding"--one of the researchers would rush out ontO the field to interview the dazed player. One senior filllback car ried the ball into the heart of the defensive line, was dinged, and then stumbled back to the huddle. When queried thirty seconds after the ding, the player thought he was in high school but still corr�ctl y. " recalled that his team had just executed a play called a 32-dlve.
�
Twenty minutes later, he regained his orientation, but I ad no mem ory of his injury or the 32-dive play. All of the dmged pla�ers responded similarly: they initi'll1y remembered the play that had Just been nlll, but rninutes later had no idea what had happened to them or what play had been run. \�
.
. Neurobiologists have studied this short-term consohdatlon process
83
extensively in rats, mice, fruit Aies, and even in simpler organisms such as lhe invertebrate sea slug Aplysia. This tillY organism has an extremely simple nervous system thal consist.� of only abom 20,000 neurons (compared to approximately 100 biUion neurons ill the human hrdin). When the experimenter applies an unpleasant stimulus to its tail, the tiny slug withdrdws its gill. BUl it is quickly sensitized to the unwelcome stimulation, becoming increasingly adept at with drawing its giU :lI1d making other defensive responses. Eric Kandel and colleagues have observed that following exposure to just one noxious event, Aplysia exhibits these enhanced withdrawal responses for sev eral minutes-bur then they diS
decades. That is, some engrams appear to become more resistant to disruption by brain injury as the years pass. Patients with memory dis orders from damage to structures hidden deep within the temporal lobes provide evidence for this kind of consolidation. These amnesic patients have problems remembering everyday e,Xperiences that take place afier the onset of their brain damage (anterograde amnesia). Most of them also have problems remcmbenng f.,cts and events from periods of rime prior to the brain damage (retrogr:.lde amnesia). In SOme cases, patients have gre:lt diffi culty remembering experiences from relatively recent time periods and less difficulty. sometimes none at ali, remembering experiences from the distant past. This temporal
Sl'tJrddll.l1 for .\lemor)'
84
O f T i m e and A u t o b i o g r a p h y
�
85
gradient was first noticed i n the nineteenth century by the Frenc . psychologist Theodule R.ihot, and is thus known today as l"ltbot S
chunks of their pasts. For example, when Squire gave amnesic patients
Law.'A
their lives, the patientS recalled as many experiences from childhood
Memory loss in head-il�lIred survivors of accidents often obeys
cue words and asked them to remember epIsodes from anytime in as people who have no memory problems. But amnesics were less
l"libot's Law. In addition to forgetting permanently the accident itself
likely to remember experiences that occurred after childhood.XlThus,
and the minutes preceding it, slich people may temporarily lose mell1-
there is no single estimate of how long it takes for a memory to
ories of recent days, weeks, and months, while retaining memories of
become fully consolidated.
the distant past. This Illay be because some memories arc subject to a
One particularly fascinating, and sad, story of retrograde amnesia
long-term consolidation process that allows thelll to become more
involves a famous scientist who became amnesic after years of pro
resistant to disruption over time.
longed alcohol abuse. Lengthy alcoholism sometimes results in thi
During the 1970s and 1980s, rt.."seaTchen. reached simila� conch� stans using carefully constructed tests. The neuropsychologlsts M rl . . Iyn Albert and Nelson Butters constructed a " famous faces test, 1Il . which patients identity pictures of people who became (;11ll0US at dIf
�
amine deficiencies that wreak havoc with a part of the brain known as the diencephalon, which is closely connected with the medial tem p?�al lobe. This cO �ldition is known as Korsakoff's syndrome, in recog llIuon of Sergei KorsakotT, the nineteenth-century ll... ussiall
ferent times during the past fifty years, such as Charles Lindbergh,
psychiatrist who first described it. The amnesic scientist, now known
Joseph McCarthy, and Oliver North. Some amnesic patients who took
in the literature by the initials PZ, was sufficiently famous that he had
this test had great difftculty identifying faces from the recent past, but
written an autobiography. Nelson Butters and Laird Cermak tested
little trouble identifying faces from the distant past. But since many
I)Z's memory for some of the experiences described in his autobiog
people who became famolls in the distant past are still talked about
raphy, with the certain knowledge that he once remembered them in
today, the test may not provide a pure measure of memOty for remote events. Larry Squire overcame this problem by developing a test that
rich detail. ResultS of the study were clear-cm: PZ remembered accu rately most childhood events, but he could not remember any of {hI;:
used television programs that remained on the air for only a single
episodes in his autobiography from the last twenty years of his life; he
season, reasoning that people would not be likely to learn about such . programs af[(:r they had been broadcast. He fOUl that the amnesIc . � patients had special problems remembenng teleVIsIOn progr:-ms f�TlI recent time periods. This fmdillg was particularly clear-cut III studl�s
�
of psychiatric patients who developed temporary retrograde :ll�lI1eSla aftcr undergoing electroconvulsive therapy (ECT) for rehef of
showed gradually decreasing memory accuracy from the middle period of his life on.l! Studies of nonhuman animals have recently begun to provide important new information about retrograde amnesia. If a person who sutTers :l head injury in 1995 no longer recognizes the f.1ce of Oliver North, we do not know how well she would have recognized the face
intractable depression. Prior to ECT. these patients possessed more
prior to the accident. But in animal studies, researchers can carefuUy
accurate memory for television programs from recent periods than
control how well an animal encodes and retains a particular memory,
from more remote periods-just like the normal control group. After
and then make a brain lesion either days. weeks, or months after ini
ECT, however, they had trouble remembering programs tIut aired a
tial learning. If memories consolidate over time, and the medial tem
year or tWO prior to ECT, even though they had no problems rernem bering programs frolll more remote time periods.'�
poral egion plays an i11lportam role in the consolJdation process, then � . a medIal temporal leslOll should have relatively little effect when it i s
Squire and others have also shown that patients With perm�nent . memory problems that result from damage to structures III the mner
it is made soon after learning. This is exactly what has been observed
partS of the temporal lobes, including the hippocampus, are bener able
in experiments using monkeys and rats.Z2
made long after initial learning and a llluch more drastic effect when
to remember experiences from the distant past th:Hl from the recent
These observations all converge on the conclusion that it takes
past. On some tests, like recalling television programs, patients have problems remembering only the year or twO preceding the onset of
some time after initial encoding for a memory to become fully cstab . lashed or organized in the brain. At thc level of brain systems, Squire
their amnesia; 011 other tests, their memory problems cover larger
and others have contended that the hippocampus and related struc-
Sear£!riug for Me m o r y
O f T i lllt! a n d A u t o b i o g r a p h y
tores i n the medial temporal region play a role i n memory consolida
can be thought of as a critical convergence zone for assembling explicit memories. Many researchers believe that the medial temporal region
86
tion, though for only a limited tillle after an event occurs. Lon�-terll1 storage of memories appears to occur in cortical networks outside � he
medial temporal regioll, with different cortical networks representing different kinds of information. For instance, storage of visual memo
�
ries depends on networks in the occipital lobes and the ower or i� fe rior parts of the temporal lobes, which are essential for vIsual processing. (See figure 2.4.) PatientS with lesions to a structure � t the junction of the occipital and temporal lobes, known as the fus,for1l1 , gyrus, have great difficulty recognizing faces of people who are fanll1, iar to {hem. and may also have problems recognizing other kmds of visual objecu. Antonio O:nmlsio and his colleagues described a sixty five-year-old woman. EH, who suffered damage in the occipital/tem poral region of both hemispheres as a result of a st� ke. She co� ld identify a face as a "face," but was unable to recoglllze the s�eclflc faces of her friends, relatives, husband. and daughter; she even failed to recognize her own f:lce in a mirror, despite realizing that it must be
87
comains a kind of index that "points to" the locations of different kinds f ormati011 that are stored in separate cortical regions.The index is of in
needed ro keep track of all of the sights, sounds, and thoughts that wgether comprise an episode, until the engram can be held together by direct connections between the cortical regions themselves. Then the index contained in the medial temporal region is no longer neces sary in order to recall the episode. An important implication of this view of memory storage is that no single picture in the mind corre
sponds to a memory of last year's Thanksgiving dinner, or of seemg your dear old Aunt Helen at a family wedding. What comes to mind when you remember slIch events is something like a giam jigsaw puz zle, assembled fro m many constituents in response to a cue. The medial
temporal region contains instructions that specifY how to a.ssemble cllC puzzle; eventually, the instructions are shifted over to conical regions that contain all the component pieces of the.: puzzle.!4
heTS.Yet EH had intact visual acuity, norlllal intelligence, full ability to
At the psychological level, long-term consolidation occur.; in part
use and understand language, and could identifY people easily when
because people talk about and think about their past experiences; the
she heard their voices. She also had difficulties recognizing her own
older a memory, the greater the opportunity for such post-event
house, car, and clothes, even though she could identify each generi
rehearsal. Perhaps thinking and talking about a past experience promote
cally as a house. a car, or dothes. EH's lesion prevented her from
the direct connections between conical storage areas that evcllUially
retrieving specific visual mcmories of unique objects.
. . In contrast, damage to other cortical regions impairs dIfferent kmcls
allow them to assemble the jigs..1w puzzle that constitutes an event. Once an experience has been repeatedly TCtrieved, it becomes cOl1soli
of knowledge. Patients with parietal damage forget once-familiar spa
cl ued and no longer depends on the integrity of the medial temporal
tial layouts and have difficulty navigating routes that they used to . travel with ease. R.ecent PET scanning studies have shown that pan
st.ructures. The idca that [he medial temporal region works coopera
etal regions become especially active when people remember the
term memory has been formalized in a recent neural network model
location of objects. Long-term memory for the sound of a word
developed byJames McClelland and colleagues. They developed a com
tively with cortical storage areas to achieve a fully consolidated long
depends on networks that involve a part of the telliporal lobes in the
puter simulation tl1:lt docs a good job of Inimicking the f.1Cl that retro
left cerebral hemisphere known as Wernicke's area. After damage to
grade amnesia tends to affect recent 11lt'lllories more than distant ones ..!';
this region of the brain, patients are unable to make Illuch sense of
Nobody knows exactly what changes in the brain correspond to
spoken language :md often speak a bewildering kind of gibberish.1J . Explicit memories for past episode'S typically include many different
long-term memory consolidation. We do know, however, that neurons i n the brain arc capable of rearranging themselves over time. In one
kinds of infor mation: visual, auditory, spatial, verbal, and so forth. As I
panicularly striking recent experilllcllt, adult cats were partially
mentioned in the last chapter, Oalllasio has proposed that different
blinded by lesions to retinas ofborh eyes. Specific visual areas in their
kinds of information arc linked together in "convergence zones" that
brains no longer responded when lights or objects appeared in panic
bind together fragments of perceptual experience. Oamasio envisages a
ular locations. Yet nine months later, some of these areas beb'lll to
series of convergence zones operating at different levels, binding visual
respond again to visual stimulation. A gradual reorb'lnization had
features into representations of faces. for instance, or binding face rep
occurred, involving new connections among neurons. Perhaps some
resentations to other kinds of information. The medial temporal region
thing similar occurs in long-term consolidation, with the gradual
O f Time a n d A u t o b i o g raphy
Setlrc/rins Jor Mem o ry
88 development
of new
connections
helping
to
make
repeatedly
rehearsed memories more resistant to forgctting.:!6 Recent research also points to another player in the consolidation
89
of her own if she ever awoke again, Allende tried to infuse her with mcmories. "Listen, Paub," she wrote in the opening line of Pallia, a memoir of the frightening illness,
"I am going to tell you a story, so
process: sleep. Over a decade ago. the neuroscientist Jonat.han Winson
that when you wake up you will not feel so lost." She then relates
hypothesized that memories become consolidated dUTing sleep, par
experiences that she shared with Paula, divulges personal secrets that
ticularly during the rapid eye movement (REM) stage when we
her daughter never knew about, and imparts family legends about
dream IllOSt frequently and intensely. Winson's idea was lhat during
ancestors from past generatiolls. AlIende attempted to break through
sleep, when the brain is not so preoccupied by the continual barrage
the curtain of siknce that isolated Paula by piecing fragments of her
of external stimulation that occurs during waking, it works through
autobiography into a coherem whole for her lifeless daughter. "In the
the experiences of the day, discarding the trivial and saving the signif
long silent hOllrs," Allende reRected, "I am trampled by memories, all
icant.
happening in one instant, as if my entire life were a single, unfath
Winson's ideas recently received support fTOm electrophysiological recordings in rats suggesting that during sleep, the hippocampus "plays
omable image. The child and girl
I was, the woman I am, the old
woman I shall be, are all water in the same rushing lorrent. My mem
ally be scored permanently. This could be an lTllportant part ofche role
ory is like a Mexican mural in which all times are si1l1ultaneous."!!i . Isabel Allende tells her story eloquently. And the f'lCt that her own
that the hippocampus plays in consolidating new memories. Sleep
alHobiography is so closely interleaved with her daughter's illness
researchers have long observed that dreams often contain remnants of
lends it a special poignancy. BlIt in Illany respects, Allende's remem
back" a rccent experience to areas of the cortex where it will eventu
recent experiences. It now seems likely that as we sleep, our brains are
bered autobiography is a lot like everybody else's recollections of their
working hard to save the experiences that we Will carry around with
livcs: a complex tapestry that includes memories of specific moments
for much of our lives. Memory consolidation during sleep is likely
and more general recollections of larger chunks of time. She recollects
lIS
influenced by what we think about and talk about while awake. The
what the stars looked like when she was a young girl in La Paz. She
important events in our Jives that we o[[ell review during waking 1.11:IY . be frequently "replayed" during sleep. Experienc(."S that receive lade
recalls a scary and confusing sexual encounter on a beach when she
attention during waking probably receive fewer nocturnal playbacks, paving the way for forgetting. Our conscious activities during waking probably conspire with unconscious happenings during sleep w shape and sculpt the stOries that we tell about our lives.Z7
was eight years old. She remembers what it \vas like to live in Lebanon during the t 9505. And she recounts hundreds of other incidents, peo ple. and lessons from her life as she sits at Paula's bedside. Despite the complexity of personal memories, our autobiographi cal recollections also contain a good deal of underlying structure. Although memories of what has happened in the past may seem like a formless variety of snapshots and stories, many researchers distin
REMEMBERING THE EXPERIENCES O F A LIFETIME
guish among different levels of autobiographical knowledge. Various terms have been proposed to describe these levels, but
I will adhere to
lhe distinctions suggested by two pioneers in autobiographical mem
In December 1 99 1 , the writer Isabel Allende attended a party in
ory research, Marrin Conway and David Rubin.liI They postulate
Madrid to launch her latest novel. As she was explaining to guests
three kinds of autobiographical knowledge that are arranged h.ierar
how she had come to write the book, Allende received disturbing
chically. The highest lewl of the hierarchy contains lifetime periods:
news: her twenry-seven-year-old daughter Paula had been rushed to
lengthy segmellts of life that are measured in years or decades, say,
the hospital. Paula and her family had known for several years that she
going to college, living ill Arizona, or working at a particular place.
had inherited a rare metabolic disorder, porphyria, and now the dis
The middle of the hierarchy includes general events: extended, COI11-
ease caused her to lapse into a coma. Allende stayed at Paula's bedside
posite episodes that arc measured in days, weeks, or months, such as
for the year that she remained comatose before dying. Powerless co
going to football games during freshman year, vacationing at the
awaken her daughter, and unsure whether Paula would have any past
Grand Canyon, or the first professional stint yOll had. The bottom of
90
the hierarchy is populated by event-specific knowledge: individual episodes th:lt arc measured in seconds, minutes. or hours, such as the big fight that ended rhe final football game of rhe season, the moment yOll first laid eyes 011 the Grand Canyon, or the time you arrived for a HH:cting unprepared. When people tell the stories of their lives, all three kinds afknowl edge arc usually present and interleaved. Isabel Allende.: talks in global terms about the lifetime period when she resided in Lebanon. Embedded within this lifetime period, she imparts many recollections of what ' have termed general events. She recalls, for insr:mce, rcpeated trips [Q the sOllks-cr,Hllped and winding alleyways filled with shops that sell every kind of food imaginable. "I can srill smell those mar kets!"she recalls. "All the aromas of the planet wafted through those twisting streets, a melange of exotic vapors." Allende recollects how "[ mlerchants came out to meet their customers and nearly dragged them inside those Ali Baba caves glutted with treasures." Here Allende is not remembering a specific episode in a particular time and place; she is extracting features and themes that arc common to many episodes, and hence is remembering a general event. But she can also proceed further down the hierarchy :lnd rec:lll event-specific knowl edge. Thus, as she continues her recollection of markets in Lebanon, she remembers a particubr shopping trip in which her mother pre vailed llpon her to buy cloth for a wedding dress at bargain pnces. even though young Isabel had no marriage prospects in sight. " We left the baz:lar with meters and meters of white, silk-cmbroidered organza," Allende remembers. " besides sevcral tablecloths for Illy hope chest and a carved wooden screen that has survived three decades, countless moves, and exile."J(l Controlled studies have revealed thal each of lhe three kinds of autobiographical knowledge serves different functions, and Illay even be mediated by different underlying brain systems. Gener-II events appear to be the natural entry points into our autobiographical mem aries. When people are asked abollt expr.:riences from their pasts, they prefer to describe their expericnces at the level of the general event. People tend to say, " I really enjoyed going to basketball games during high school," rather chan saying where they went to high school or recollecting a specific incident from a particular game.ll General events may enjoy this privileged status because they accrue the benefits of repetition. One reason it is easy for m e to remember the first course I taught to Harvard undergraduates is thal I taught many sessions of the c1as.s. during the semester. I have a harder time
Of T i m e a n d A u tobiography
91
recalling specific episodes from particular classes because they occurred only once. Remember that in Marigold Linton's study of her own experiences, she found that up to about a year after a specific event her memory was quite accurate. but b('yolld a year this event specific knowledge bebran to lose individuating detail, and particular episodes began to merge imo one another-they became general events. The fate of Linton's memorir.:s suggests that losses at the event specific level can be turned into "gains" at the general-event level. This can help us to understand why we tend to ;'enter" Ollr pasts at the level of the general evene. General events capture a good deal of the dis tinctive flavor of our pasts. and arc readily accessible because they have been sttengthened through repetition. The lifetime period scrves a different function. If I asked you to recall experiences from anytime in your life, my guess is that yOll would not produce any lifetime periods, such as "when I weJ1[ to high school."This information is so general that it does not convey much about your autobiography. Howevcr, you might have started your search by generating a lifetime period and then retrieving a general event from that time. Lifetime periods help us to find general-event knowledge and event-specific knowledge; they provide the skeletal structure of our amobiographical l11emories.n These considerations led Conway and Rubin to an important pro posal about the nature of 3utobiographical lllelllories, onc that echoes ideas I developed earlier. They contend that there is no single repre sentation or engram stored in melllory that has a one-tO-one rela tionship with the mental experience of recollecting one's past. Instead, such experiences arc always constructed by combining bits of infor mation from each of the three levels of autobiographical knowledge. Just :lS memories for individual cvt"nts resemble Jigs..1w puzzles that are assembled from many pieces, so do the stories of our lives. This idea is illuminated by a bizarre variation of retrograde amne sia. In 1 993, the British researchers John Hodges and Rosalecn McCarthy dr.:scribed :l sixty-seven-year-old patient idemified as PS who suffered a stroke in the thalamus, a structure that is often dam aged in cases of amnesia. PS had great difficulty remembering ongo ing events. He was also unable to remember just about everything that had happened to him before his stroke---except for one period in his life. PS insisted that he was temporarily on Icave from the navy dur ing World War II. He believed with great intensity that he was still in the midst of active navy service and that it would soon be time for him to return to his ship. The patient recalled a fcw scattered
92
Of T i m e and Autobiography
Searrh jtlg fM M e m o r ),
93
fragmems o f knowledge about other parts o f his life, but his under
carved a\vay [rom one another, we begin to appreciate that a great deal
standing of himself was dominated by the delusional conviction thac
of structure and complexity lurk beneath the surf.,ce of Ollr normally
he was living ne:lrly a half-century in the past.
seamless recollections of the multitude of occurrcnces from our pasrs.
PS's bewildering fate illustrates what happens when differem levels
What we experience as an autobiographical memory is constructed
of autobiographical knowledge are pulled apart from one anorher. PS
[rom knowledge of lifetime periods, general evellts, and specific
could recall a few gem:ral events but hardly any event-specific knowl
episodes. When we put all this information together, we start to tell
edge. It is unlikely that these memories were obliterated; nobody has
the searies of our lives. Isabel Allende clearly appreciated the con
ever hypothesized that the thalamus is a seat of memory storage.
structive nature of autobiographical remembering as she laid out the
Remember that Gil. who also developed all1ne�ia as a result of dam
tale of her life to her gravely ill daughter. "My life is created as I nar
age [0 the thalamus, eventually recovered his past. Moreover, PS had
rate," she wrote, "and my memory grows stronger with writing."
nOt sustained any damage to the conical areas that I have suggested
Looking ahead to a time when Paula would awaken-a rime that
are the repositories of our permanent (consolidated) engrams. l:3ll( the
never came-Allende imagined that the twO of them could join
thalamus is a key switching station that connects systems in the front
together in the task of memory construction. "When you wake up we
and back of the brain. Hodges and McCarthy suggested that PS's
will have months, maybe years, to piece together the broken fragments
knowledge of past events had become disconnected frolll retrieval sys
of your past; bener yet, we can invent memories that fit your fan
tems in the frontal lobes that ordinarily allow access to ic.l'
tasies."3<
This disconnection hypothesis alone, however, docs not explain
Psychologists have come to recobrnize that the complex mixtures of
PS's persiSting delusion. PS also sulTered from a specific disruption at
personal knowledge that we retain about the past are wovcn together
tbe highest level of autobiographical knowledge-the lifetime period.
to form life stories and personal myths. These arc the biographies of
The knowledge that we all possess abom specific past periods in our
self that provide narrative continuity between past and ftHure--a set
lives is usually turned off, or inhibited, unless we engage in an act of
of memories that form the core of personal identity. The psychologist
recollection that temporarily activates ie. I know, for instance, that I
Dan McAdams. one of the most energetic developers of the hypoth
went to college in North Carolina during the I 970s, but this lifetime
esis that life stories play a crucial role in cognition and behavior,
period knowledge normally rests in a quiescent state. The knowledge
emphasizes that these high-level memories, too, are COllsrructions:
becomes active when I turn my attention to that period of my life, but it does 1I0t lead me to believe that I am now living in the North
The unfolding drama of life is revealed more by the telling chan by
Carolina of the 1970s, and it will surely settle back into a deactivated
the actual events told. Stories are not merely "chronicles," like a sec
state once I move on to thinking abollt other things. In PS, however,
retary's minutes of a meeting. written to report exactly what tran
the neural representation of thc lifetime period "when I served in the
spired and at what time. Stories are less about (,cts and more about
navy during World War JI" seems to have become continuously and irreV('rsibly turned all. He is trapped in the world of nlvy service dur ing the 1 9 -105 because damage to his thalamus somehow tripped a switch that he is unable to shut off. Part of the reason PS actually believes th:lt he is living in the 19405 may be that his w;mime service constitutes an especially significant part of his life. I also suspect that he has formed this pathological belief because the abnormally acti vated lifetime-period knowledge is CUt off from other memories. Unable to remember much of anything else about his past, PS cannot escape the persistellf conviction that he will soon be returning to his ship. When differem components of autobiographical knowledge arc
meanings. In the subjective and embeHished telling of the past, the past is constructed-history is made.» If our memories are always constructed and occasionally distOrted, might our most basic beliefs about our lives and our selves be fun damentally erroneous? If the construction of our autobiographies is like a jigsaw puzzle assembled from a multitude of concrihurors, and is influenced by large doses of our present needs and desires, then might we oflen be blind to the fundamental truths of our lives? The novelist Reynolds Price, reflecting back on his past, wished that his parents had taken more photographs and recorded more of what happened in order to help him overcome creeping uncertainties
Setl ,ddll�
JO'
O f T i m c and A u to b i ography
Melllo, >,
thc look about the reliability of his own memories. "I think I recall bitter and and tOne of many of those mOlllenlS of laughter, pain, ce longing," muses rice, adding parenthetically that "the confiden
P
the that I do recall them, with a good deal of truthfulness, lies near contin fOOl of my hold on sanity and on the work 1 do." Out, Price ues, " an elementary understanding of the shaping force of memory to requires me to grant that I may in fact be anything from fuzzy as of think lying to badly wrong on every stich instance of what I vital rccall." .)(,
Price is well aware that autobiographical memories are complex conStructions. But this need not mean that we live in a world of wholly to fabricated, self-serving fantasies. There are, in fact, good reasons un f are lives our of believe that our memories for the bro3d contours one damentally accurate. Sometimes specific events that are recalled by
s member of a family are forgotten by others, and sometimes member dif events general and s of the same family remember specific incident of a fercntly. My younger brothcr, Ken, for example, has no memory
hot June night when we wcm to a Yankees baseball game as kids and he cried when the Yankees lost. I recall the game clearly. He remem bers incidenlS involving a pet dog th3t I don't remember. These dis ily crepancies probably reflect differences in how deeply various fam brave they tations members encoded the events initially, what tnterpre
t en they later thought and talked abollt them. Ken them, and how of had primary responsibility for the dog in our family, and thought and I talked about incidents involving the dog much more frequently than
did. We went to the Yankee game for my birthd.'lY, which made it espe it cially distinctive for me. Ken usually cried when the Yankees lost, so
was JUSt one of many similar incidents for rum. In contrast, when adults retrospectively assess the general character of more extended time periods in their pasts, they are usually fairly accuratc. My brother and I havc similar recollections of how our par
ents got along with each other, the things we enjoyed doing as kids, and wh:lt Ollr grandparents and other relatives were like. Our experi ence secms to be typical, because research has shown that siblings'
memories of the general qualities of their family lives during child hood usually mesh.p Interestingly, cognitive psychologists who have demonstrated distor tions and inaccuracies in memories for single episodes have reached a similar conclusion. The cognitive psychologist Craig Darclay con ducted a study of college students' memories for everyday evelllS in which the srudents recorded in diaries brief descriptions of memorable
95
things that happened in their lives just after they occurred. One stu dem wrote: " I went shopping downtown looking for an anniversary present for my parents, but couldn't find a thing. I get so frustrated
when I can't find what I w:.II1t." Barclay later tested the students' mem orics for these events, at delays ranging from several months to two years. Sometimes hc showed them a primed version of an actual diary
emry and asked them to say whether this was exactly what they had . written down. Other times dC'scriptions had been changed in small respeclS, sllch as: "I went shopping downtown. I must have gone to ten
stores before giving lip and going home. I get so frustrated when r can't find what I want." As time passed, students were increasingly likely to say that these changed descriptions were exactly what they had writ ten O\vn months earlier. Less often, students falsely recognized . descnpnons that were taken from another studel1{'s diary. Overall, stu dents retamed the general meaning of their experiences, even though they were wrong about many particulars. "It is IlOt the case," Barclay
�
�oTlclud�d, " that the meaning around which autobiographical memory
IS
orgaruzed is a complete fabrication of life events. There is a funda mental integrity to onc's aLUobiographical recollections.""
It i s certainly troubling to confrom the possibility that our life sto ries could be subject to profound distortion, because in the final an alysis the memories that give rise to these stories are all that stay . with us from cradle to grave. Thcy tic liS to the places we have been and the people we have known. There is even a sense in which one person's autobiographical memories allow olher people to achieve a degree of immortality. The Argentina-born artist Diana Gonzalez Gandolfi conveys this ilnportam message in her paiming "Memory Weaves the Echoes" (figure 3.3). Inspired by the poctry of Nobel lau reate Pablo Neruda, she eventually came to terms with the death of close personal friends by appreciating that thcy cont.inue to exist as echoes in her memory. Her painting juxtaposes images of these ghoslS from the past wirh a solitary hanger and piece of cloth, physical reminders of an absent persoll. Memory's echoes assumed
enormous importance for Isabel Allende. Reflecting 011 her daughter's ordeal, Allende recalled what her grandfarher once told her: "Dcath does not exist; people only die when we forget them." Allende recognizes that Paula continues to
live on in her own autobiographical recollections of their shared past: " It is wonderful what mcmory does. You can remember how some one smelled, YOll can remember the tone of their voice, and re-create the person to carry inside you." Paula, too, appreciatcd this essential
O f T i m e a n d A u to b i o g r a p h y
97
function of memory. Knowing that porphyria might claim her life prematurely, Paula wrote a sealed letter to her f.1.lI1ily. Her mother could not bear to open that leucr for many momhs, but when she
FIGURE 3 . 3
did, she found comforting words that recognized the power of mem ory: "I know yOll will rcnu.;lllber me, and as long as you do, I will be with yoU."'9
," 1990. 26� Diana Gonzalez Gandolfi, "Memory Weaves the Echoes . Bostoll , Gallery Beck l Randal er. polym and 33W'. Oil, wax,
x
of the artist, who The ghostly flgllres in this paiming r�fer to deceased friends . memory now exist oilly as echoes in
R. e n e c t i o n s i n 3 C u r ved M i rror
99
shoot a Jewish lawyer. This witness easily picked out Walus's face from a series of photos. " 1 witi never forget that face," he stated confidt.·mly. "This is the £lce lof a man] who killed an innocent man whose only crime was that he was a Jew." Based on such eyewitness identifications,
FOUR.
Walus was convicted of war crimes and his U.S. citizenship was revoked. When WalliS'S case was appealed, a different story emerged. Searches of German war records failed to turn tip any record of a Frank Walus, or anyone with a similar name. A Polish war crimes commission had no record of any WallIS. Perhaps most important, WalliS was able to
REFLECTIONS I N
substantiate with documents and witnesses his wartime alibi: he had been scm to Bavaria, where he performed forced labor on farms.
A C U RV E D M I R RO R
Wartime photographs of Walus on a Bavarian f.1.TIlI-which looked so different from his 1 978 appearance that the judge in WallIS'S first
Memory D istortion
trial suspected chat it was somebody else in the photo-were matched to another, indisputable photograph of Walus as a civilian guard in the American occupation. The appe:lls court overturned the conviction, but left open the possibility that WalliS could be retried. (He never
I S A B E L A L L E N D E came to regard her memories as close friends. providing comfort and continuity during the c� urse o f P� llla's illn� ss. The psychologist Shlolllo Breznitz. in reflectmg on 1m tcr� l lIlg , wartime experiences of hiding from the NazIs, felt somethJng s1I111br: , , " The ftelds of memory are unbounded. Locations are thelT servants,
f\
and time is theif playground. As we travel through life it is hard to fmd a truer friend,"l JUSt as we can generally trust our c1os� friends, we can usually rdy on our memories. Yet even the best � f frten s may occa sionally deceive us, and memory, toO, can sometllncs t� lck � s at the very moment when we want to believe it most. When d'� tornons �nd
�
illusions of remembering do occur, these Illlstakes provIde reveahng clues abom the naUlre of memory's fragile power. and also illustrate dramatically that Ollr day-to-day lives can be turned upside down by wh;l{ we believe about the past. Frank W:llus learned about memory distortion the hard way. I n 1978, he was tried on charges that he had been a Nazi war criminal. Several witnesses identified him as a Gestapo monster who had ter rorized civilians in the Polish towns of Cz�tOchowa and Kielce between 1939 and 1 943. One man recalled seeing WalliS kill tWO chil dren and their mother. Another told of a time that Walus entered his house and brutalized hjs father; lhe same man recalled seeing W31us
was.) ';The United States District Court admitted that a serious rnis t:lke had been made," observes the psychologist Willcl1l Wagenaar, who has provided an informative slllllm:uy of what happened to Walus; "that Frank Walus was not the criminal that witnesses knew from
35 years ago, and that Walus should receive compensation."
Wagenaar suggests that the misidentifications occurred because Walus as an older man strongly resembled the true Nazi criminal at a younger age. Wagenaar also points out silnilariries between the WalliS story and the more widely known case of Cleveland auto worker John Dem janjuk. He was accllsed and convicted of being Ivan the Terrible, a heinous Nazi war criminal who terrorized Jews at the Treblinka con centration camp. Demjanjuk was sentenced to death and deported to Israel, when: he served nearly eight years in prison before the Israeli Supreme Court overturned his conviction. The court found reaSOn to believe that the true Ivan nught have been one Iv;m Marchenko, who had vanished Once the war ended. Wagenaar served as a defense expert for Demjanjuk, and his detailed analysis of the case, published in 1 988, aft.er Den�anjllk had been convicted. raises serious questions about the k.inds of questioning and identification procedures that led people to recognize DC ll lj a njuk as Ivan. Leading questions were used, photo . lineups were sometimes constructed improperly, and f1ilures to posi tively identify Den�anjuk as Ivan were overlooked. There is no ques-
98
100
S e a rc h i ng for .Hr m o ry
Reflections i n
tion that Ivan existed and perpetrated evil deeds, but the Israeli Supreme Court found many reasons [0 doubt the reliability of eye witness ldentifications that portrayed DCJlljanj uk as the monster of Trcblinka.l Incidents such as these arc frightening reminders of memory's fal libility. Bm they arc hardly surprising to psychiatrists and psycholo gists, who have long been aware of the vulnerabilities of human memory. Much has been written about Sigmund Freud's ideas con cerning his p;\tienrs' recollections of childhood sexual trauma. He ini tiaUy accepted such reports, often obtained with the use of hypnosis, as veridical recollections. Hut after
1897 he viewed rhem as falltasy
based confabulations, thereby exhibiting some of the same confusion concerning recovered memories of childhood sexual trauma that exists today. Some have contended that this change of view arose from careful analysis and rethinking of his clinical observations; others have suggested that Freud, shunned by his colleagues for accepting his patients' stories of sexual abuse. lacked the necessary cou�a�� to believe what he heard; and still others have argued that Freud 1I11ually coerced his patiellts into generating stories of abuse in order to con firm his own theories regarding the role of early sexual trauma in psy chopathology.1 Whatever the reason for his change of view, Freud came to focus increasingly on the role of distortion in memory. In a classic
his classic
a
C u r v e d M i r ro r
101
1932 monograph, Remembering. Participants i n Bartlett's
experiments listened to an old Indian legend entitled "The War of the Ghosts," and later retold the story on several occasions. Bartlett found that people rarely recalled all the events i n the scory accurately; they often remembered occurrences that made general sense or fit their expectations of what should have happened, but were not part of the original story. Hartlett also observed that the recollections of his par ticipants changed, sometimes substantially, across multiple retellings of the story. Bartlett concluded that memories are imaginative recon structions of past events. He argued that the experience of remem bering is shaped as mllch by the rememberer's "attitude" -expectatiolls and general knowledge regarding what should have happened and what could have happened-as by the content of specific past events. � While it is easy to agree that recol1ections are sometimes distorted, and even easier to see that this bas enormous social implications and consequences, understanding the foibles of memory poses a formida ble challenge. To lInravei these mysteries, I will attempt to illuminate the murky twilight zone where memory and reality grope for each other, usually coupling mccly but sometimes yidding strange concoc tions that have the power [0 change lives drastically and forever.
1899
paper titled "Screen Memories," Freud argued that the visual i�ages that we bring to mind when recollecting early childhood cxpenences are not pictures of reality; they :Irc distortions or screens that allow us to avoid (1.cing what really happened. Freud's central idea here-that conscious recollections are inevitably distorted by a person's wishes, desires, and unconscious conflicts-became a core assumption of all psychoanalysis. A major go:1i of analysis, according to Freud, is [Q uncover the "true" reality hidden behind the screen memory. Freud likened the psychoanalyst to an archeologist, working back through ever more distant Iayt.:rs and strat:l in order CO excavate the original traces and remains of remote eventS. 13m Freud never specified how co separate out the layers of discortion from the hidden core of truth! Freud's opinions were limited by the fact that he could not know what had actually happened during his patientS' childhoods. To draw firm conclusions about the accuracy of a memory, we need to have an objective record of the remembered event. The British psychologist Sir Frederic Barden solved this problem by conducting controlled studies of how people recall complex events, which he described in
THE P E R I L S O F P R I O R KNOWLED G E E n c o di n g a n d D i s t o r t i o n We live in relativistic times, and the idea that people construct cheir own subjective realities finds ready acceptance among many people. Yec most of us arc not easily willing co part with the assumption that there is a shared external reality chat is at least partly knowable through memory. The assumption is fundamental to many of society'S institutions, such as our legal and educational systems, and it also underlies our truSt in autobiographical memory as a bJsis for self understanding. Even when a person's memory (or some aspect of external reality seems to be mistaken, he or she Illay be accurately remembering what was encoded into memory. Eyewitness misidentifications sometimes arise becallse of li mita tions on what is encoded. More than two decades ago, eyewitness tes timony led to the arrests of Lawrence Berson for several rapes and George Morales for robbery. Later, a man named Richard Carbone confessed [Q all of these crimes. It was the great misfortune of the
Scarch i ng Jor Melli "'>,
102
R e fl e c t i o n s i n a C u r v e d M i r r o r
103
unjusrly arrested men that each shared several salient fearures i n COIll
ily and effortlessly generally helps our cognitive lives run smoothly
mon with Carbone: all were about the same age, wore similar kinds of
and efficiently. When wc enter a restaurant, for example, we already
glasses, mamtained small dark mustaches, wore dark curly hair of about
know a great deal about the gcneral sequence of events that will
the sarne length, and had similarly shaped faces. Suppose that an eye
unfold, from being seated to leaving a tip; when we go to a concert,
witness had encoded those features of Carbone's appearance that were
other knowledge structures become active that lead us to expect that
shared with Berson and Morales, but little or nothl!lg else. By identi
quite a different series of events will occur. Yet precisely because our
fying a picture of BerSOI1 or Morales as the face of the person he saw
past knowledge of situations and event sequences is aaivated contin
commit a crime, the eyewitness would accurately reflect what he had
ually and effortlessly, we may be unaware that inferences based on this
ongmally encoded. But because distinguishing Carbone from Berson
knowledge sometimcs imperceptibly creep into our encodings-and
and MoraIl�s reqUlres llIore specific information than he had encoded,
our memories-of external cvems.9
the eyewitness would be tragically wrong.6 The encoding process can also add information to memory that
There is a good chance that you can experience a memory distor tion of this SOrt yourself by paying careful attention to the following
later results in distorted recollection. For instance, verbally describing
series of words: candy. sour, sugar, bitter, good, taste, tooth, nice, honey,
a (lce,
soda, chocolate, hean, cake, eat, and pie. Turn away from the page now
:1
color, or even
:1
taste of wine can impair subsequent recogni
tion when an imprecise verbal description overrides a more precise
and take a minute or so to write down all the words you
nonverbal memory.7 And knowledge about what we expect to happen
ber from tillS list.
em
remem
can become illcorporated into a new memory, even when the
Now take the following test. Consider the three words printed in
expected event did not occur. Our memories can be distorted by the
italics at the end of this sentence and, without looking back to the
same pool of preexisting knowledge that usually aids out ability to
previous paragraph, try to remember whether they appeared on the
sweer. Think
acquire and retneve new information. As an examplc, imagine the
list that I just presented: taste, pOilll,
following scenario. You arc at a baseball game on a warm and sunny
answers, consider whether you actually remember seeing each word
carefully about your
afternoon, comfortably watching the action from front-row seats. The
on the list, and assess how confident you are in your memory. Many
home team has men on first base and third base, and there IS one our.
people who study this set of words confidently recall that sweet was on
The pitcher thro\vs thc ball over the plate and the batter hits it on the
the list-but it was not. The psychologISts Hemy L. Roediger and
grollnd to the shortstop, who fields the ball and attempts to execute a
Kathleen McDermott have even shown that people not only believe
double-play. The runner from third scores.
that sweet WJS on the list but claim to remember it vividly.lO
If you do not know much about baseball, you probably imagined
I have carried out demonstrations with audiences containing nearly
the events pretty much as described, perhaps filling in a stadium full
a thousand people, and successfully induced 80-90 percent of them to
of enthusiastic fans or creating hometown uniforms for the players.
claim erroneously that I had read the word
slIIeet aloud
a minute ear
But if you are a true baseball aficionado, you may well have noticed
lier. Why are people so easily fooled? Presentation of so many strong
something that was not stated in lhe passage: because the runner on
associ;Hes of
third base scored, the batter must have been safe at first. If the batte.r
things" in your mind.You may then rernernber this categorical knowl
sweet
m.ight activate the general category of "sweet
had been out at first-that is, if the double-play had been successful
edge on subsequent tests. A related possibility is that at the time of
then the inning would have ended and the runner on third could not
study, one or some of the presented words may trigger slIIeef as an asso
have scored. When baseball experts in an experiment were presented
ciate. Later, on recall and recognition tests, people have difficulty
a story like tim one, they often insisted that the passage contamed the
remembering whether sweet was actually presented on the list or
sentence "The batter was safe at firsr." People who knew little about
whether they merely thought of the word during list presentation
baseball were not fooled into making this Inistake. The experts were
[n eithet of these scenarios, (ll5e recognition of SU!£e1 reflects gen
the victims of their own extensive knowledge about baseball, which
erally accurate retention of the gist or meaning of the word list. Con
infiltrated theif encoding of the story.�
sistent with (his idea, when I performed the "sweet" experiment wilh
The fact that our general knowledge of the world is activated eas-
a group of amnesic patient.�. they had difficulty remembering the
Sl'tudd/lg Jor Memory
It e n e c t i ol1s i n a C u r v e d M i rror
words that were actually on the list. a s would b e expected from
remembered. Covered by a shield of scales, the frightenmg monster
104
patients with impairmentS of explicit memory. But they also made many fewer f.1.lsc recognitions of SIvt'cf than did people with intact memories. This is because the amnesic patients did nOt successfully encode and retain the gist of the stuclied words. False recognition of slIIeef
requires accurate retention of the general meaning of the words
on the target list, which in curn depends on the hippocampus and other medial temporal lobe structures that arc damaged in 311mcsic patients. Consistent with this idea, in a PET study just completed as this book went to press, my colleagues and I found that medial teJll poral lobe regions dose to the left hippocampus became active dur ing both "true" recognition of previously studied words and false recognition of nonstudied associ:ues such as
sweet.
In contrast, areas in
the tcmporal and pariecal lobes that store information about the sound of a word were active when people recognized words they had actu ally heard during the study phase of the experiment-but not when they falsely recognized nonpresentcd words such as swcet. !!
Clearly. then, encoding processes can introduce a degree of distor tion into our memories. Prcexisting knowledge, which oftcn aids in the construction ofelaborative encodings, can sometim<.."S seep into and corrupt new memories. Such corrupting inAuenct::s turn Out to be a natural feature of many neural network models of memory. In such models, engrams are stored as patterns of activity that arc superimposed upon one another. Some of the individual "units," or parts of a pattern, may be involved in the storage of several different engrams. This means that new memories are inevitably influenced by old memories, which opens the door [0 distortion as a relatively common occurrence. In a neural network, a memory for any single episode will necessarily be affected, and perhaps altered, by memories of other episodes.11 We ear lier saw the benefits of a memory system that relies on prior knowl cdge when building new memories; now we have seen the costs.
105
lingered in the sky for several hours before speeding away in a flash. Arnold's memory of the giant dragon emerged gradually as he thought about his experience in the context of religious texts and precepts and as he rel:ued it to the widely held beliefs of his contelll poraries about the meaning and significance of dragons. In other words, Arnold probably did encoullter a large bird or creature of some sort on Ius trip, bur his final mell'lory took rime to construct from an assortment of cues and beliefS that saturated his retrieval environment. Arnold's written recollection of the dragon is not merely an acrivated engram of what happened during the trip. It is an imaginative inven tion that incorporates information from the present as Arnold tries to make sense of what happened in the past. Evenrually, Arnold gener ates a new interpretation of his original experience that fits with what current teaching says about the religiolls significance of dragons. ll Though few people nowadays remember seeing mile-long dragons Roating in the sky, there are modern examples of memory distortion that are perhaps not so differem from Arnold's. To understand Arnold's memory and the modern analogues of it, we will need to keep in mind the important k"Sson that a retrieval cue does not merely aW:lken a dor mant engram, and that the subjective e""perience of a mcmory does not simply reflect the propertie.� of an activated engram. As [ have already sugge.<;ccd, the cue and the engram compire to yield the subjective experience that wc call remembering. This analysis implies that when a person produces a subjectively compelling, bue demonstrably inaccu rate, memory report, we must examine the environment ill which retrieval occurs JUSt as carefully as the past events to which the memory refers. Arnold's retrieval environmem. full of texts and ideas about drag ons, drove him to remember an appropriately formed monster. In the twentieth-century psychology laboratory. distorted recollec tions sometimes resull from the \vay memory is probed or cued. For instance, some experiments have shown that the exact way a question about the past is worded can influence wh:u :1 person claims (0
C U E S THAT C O N F U S E R e t r i ev a l a n d D i s t o r t i o n In the year 1 030, a Bavarian monk named Arnold journeycd to Pan nonia on behalf of his abbot. Years later, Arnold wrote about his trip and recoulHed a remarkable event: cncountering a Rying dragon. The huge beast hovered in the air and spanned an enormous distance, as much as a mile. Its head alone was the size of a mountain, Arnold
remember. U DistOrting effects of present circumstances on past events can also occur when people are asked to make retrospective judg ments about attitudes and views they held in the past-what the psy chologist Robyn Dawes has dubbed "biases of retrospection:· For example, in a 1 973 study, people were asked to rate their attitudes toward five salient social issues: guaranteed jobs, rights of accused peo ple. aid to minorities, legalization of marijuana, and equality of Women. In 1982, many of lhese people were a�ked to make the same
106
R e fl e c t i o n s in a C u r v e d M i r r o r
Searclijng Jor JHe m o r y
107
racings; i n addition, they were asked to indicate what their attitudes
attempting to retrieve hazy or degraded engrams, and so it is particu
had been back in 1 973. Participants' recollections of their 1973 atti
larly important in the therapeutic comext. And therapists themselves
tudes wcre much more closely rel:Hcd to their current views than to
are powerful
their past views. The views chat people held i n 1973 had Jjttle (0 do
between the nvo (the transference) is a fundamental principle of psy
with how they remembered those views in 1982. Retrospective biases
choanalysis. These are probably some of the reasons why. as we will sec,
can occur over shorter tillle periods, too. In one experiment, for
people who have come to believe during therapy chat they have recov
figures for their patients; the intricate relationship
instance, people who heard a message extolling the virtues of tooth
ered "real" memories of sexual abuse almost invariably poillt to the
brushing remembered brushmg theiT teeth Illorc often during the
powerful influence of their therapists ill generating and maintaining
preceding two weeks than people who heard a message that deni
the distorted recollectiol1.A lherapist is a Tll;uor part ora retrieval envi
grated toothbrushing. Such recall biases may be one reason why peo
ronment that helps to shape what a patient believes about the past.
ple who take part in ineffective self-help programs often still believe
The same sort of considerations apply to another interpen;onal sit
they have made sibrnificam gains. For instance, studcnts who partici
uation that often involves an attempt to recover degraded engrams of
pated in a study skills improvement program rated their skill level
fleeting or distant experiences: hypnosis. Hypnosis is a social process in
before beginning the program and thcll tried to recall their initial rat
which the suggestions and cues provided by the hypnotist guide the
ings after completing it. They remembered their initial skill ratings as
hypnotized individual through an imaginative, rolc-pbying activity.
bcing lower than they actually wcrc, whereas students who were pm
Not everyone is responsive to a hypnotist's suggeStions. But those who
on a waiting list showed no such bias. Having put Illuch effort into
are, referred to in the professional literature as "high-hypnotizable sub
the program, participants justified the investment by TCvising their rec
jects," are vulnerable to creating illusory memories when givell sug
ollections of thc past in line with their presem needs and belief.s.I�
gestions.l1 Nevertheless. the misbegotten image of a hypnotized person
Clinicians and therapists have also recognized that the retrieval envi
at the mercy of a kind of psychological truth serum, having no choice
ronment can influence how the past is reconstructed. In his trencham
but to reveal past secrets that are hidden in the reces.�es of the uncon
monograph Narrative Trl/III and J-Jistorim/ Tnlfl!, the psychoanalyst Don
scious mind, is a powerful and enduring one. A Florida jury convicted
ald Spence rejects Freud's idea that the analyst is a kind of archeologist
a man named Joseph Spaz.i:mo of the 1 973 murder of an Orlando
who attempt... to excavate the patient's "true" memories from the scat
nun;e. A judge sentenced Spaziano to death. The state's case against
tered debris of the past. " More than we realized," Spence comends, "[he
Spaziano W'.lS based almost entirely 011 the testilllollY of Anthony Dil
past is continuously being reconstructed in the analytic process:'
isio, sixteen yean; old at the time, who recalled that Spaziano had
Spence appreciates that the am.lyst is :I critical component of the retrieval setting who helps determil1(.'-not merely uncover--the form
shown him the dead body at a dUl1lp site. The jury did not know, how . ever, that Dilisio f'liled to recall this incident until he was hypnotized.
and content of the patient's memories. The words and phrases used by
"All we are there for is to bring out the truth." said Joe D. McCawley,
the analyst do not merely "wake up" or "activate" a slumbering mem
who hypnotized DiJisio and believes that reputable hypnotists do nOt
ory; they may shape what the patient recalls and inRuence the patient's
create false memories: "When hypnosis is properly used, you JUSt get
subjective experience of remembering, :IS he seeks to unlock part.� of
the truth." Ironically, several yean; after Spaziano's conviction, and too
the past that arc IllOSt relevant to understanding the present. A thera
late to influence it, the Florida SUprcI'l'H! Court ruled lh;H hypnotically
pist who responds with great interest to an isolated image or a vaguc
refreshed testimony is not reliable enough [0 admit in court. However,
feeling may lead a patient to construct a memory on the basis of what
an impassioned June 1 995 article by Spaziano's lawyer published in an
may or may nOt be the remains of a long past experience. I.
Orlando newspaper motivated Florida governor L'lwtoll Chiles to
These concerns arc amplified when we consider that in psycho analysiS (and other fOfms of intensive psychotherapy) . patients struggle to recover loS{ experiences that are typically not accessible to conscious recollection. The retrieval environment likely plays
gram a temporary stay of execucion. Anthony Dilisio now says that he never went to the dump with Spaziano and never saw the body.11 Despite the claims of practitioners. controlled studies suggest that
especially
hypnosis docs nothing to enhance the accuracy of memory retrieval.
important role in molding recollective experience when one is
'Ilstead, hypnosis creates a retrieval environment that increases a per-
:l.Il
108
Refl e c t i o n s i ll a C u rved M i r ror
Sl'du h i llg JOT ,\lelllo,)'
109
son's willingness to call just about allY memal experience a '"memory."
curious phenomenon in April 199.3, when a Pro/llli"c documentary
Sometimes hypnotized people do bring forth accurate memories, but
concerning recovered memories of sexual abuse showed a hypnotized
they're just as likely to produce illusory oncs-and there is no reliable
woman in the act of recalling her brutal death in a past life. The
way co cdJ the difference between the two. Experiments have also
woman, referred to as Dawn, had experienced unexplained stomach
shown th:lt hypnosis heightens a persoll's subjective confidence in the
problems all her life. As she drifted backward in time under hypnosis,
veracity of tbe memories produced, without a corresponding increase
Dawn, a therapist, remembered that she had been sbshed to death by
in accuracy. Importantly, hypnosis increases the vividness of visual
soldiers i n the flfSt century A.D. "When I was actually being killed, I
imagery that people experience. and hypnotized subjects may some
had made this decision not to scream, to die with digniry. The screams
times misinterpret their vivid mental imagery as a Slife sign that they
were JUSt trapped. The terror was trapped in my body. I think that's
are remembering a past event.'� The idea chat hypnosis is associated with distorted memory call be
what the sick to Illy stomach has always been about." Another woman all
the show recalh.'d that a babysitter who molested her had been a
traced back at least to Freud's work with hypnotically induced mem
mistreated servant in a past life. The siner, she believed, had finally
ory retrieval in the late nineteenth century. In his early work, Freud
extracted revenge by abusing her centuries Iacer.
used hypnosis 3S a tool for uncovering his patients' traumatic experi
These weird recollections probably resule from the expectations of
ences trorn childhood, which often involved sexual abuse by an adult.
both hypnotist and therapist, and also reflect the demonstrated capabil
Out as noted earlier. he lawr became convinced that the.: memories his
iry of bypnosis to lead people to believc that all manner of imaginative
patientS reponed under hypnosis were frequeml)' confabulated, and
experiences are memories. In fact, experiments have shown thac when
soon abandoned the usc of hypnosis in therapy.
people are regressed to "pasr lives," they tend to remember whatever
Fn.'ud·s skeptical view of hypnotic lllellloTie.:s has been further sup
the hypnotist suggests. The same kind of explanation applies to the
ported by expenments showing that hypnotized individuals can be led
recent rash of people who have claimed with great conviction that
to '·reme.:l1lber" event.� that did not occur but were suggested to them
they remember being abducted and tortured by high-tech aliens. Not
by a hypnotist. In one scudy. for eX:llllple, approxlmacely half the hyp
surprisingly, these claims almost invariably emerge under hypnosis.2l
notized subjects later reported a f,1.lse memory created by the hypno
Although it sometimes elicits recollections of events that never hap
tist's suggestion that they had been awakened by loud noises several
pened, hypnosis is by no means neceSS<1.ry to cre:lte illusory memories.
nights earlier. Many of them insisted that they had heard the noises
Recent research suggests that false recollections of relatively complex
even after being informed that the hypnotist had suggested them. ''I'm
experiences can be created even without a formal hypnotic induction.
pretry certain I heard them," said one. "As a matter of f,1.ct I'm pretty
In wlm has become a well-known study, Elizabeth Loftus asked pairs of
damned certain. I'm positive I heard these noises," More recent stud
siblings to "remember the time that . . ." The study focused on child
ies of hypnotic "pseudomemories" have.: shown that they occur fre
hood experiences of being lost, with the critical twist that some of the
quently in highly hypnotizable people even when no formal hypnotic
events in question never occurred. One sibling (who had been briefed
induction is used. The tendency to produce illusory melllories in hyp
by the experimenter) described a relatively detailed but false recollec
notic contexts is closely rebt.ed to a person's hypnotizability, and also
tion of a time when the other sibling had been lost; the latter sibling was
to the quality of the n:: trieval environment. When expcrimcntal par
asked to describe his recollection of the experience. In the best-known
ticipants feel strong social pressure to produce memories, they tend to
example from the.: scudy, fourteen-year-old Chris was told at length by
re.:C:11I events that never occurred. Fewer illusory memories are
his older brother Jim about the time the five-year-old Chris got lost ill
reported when the rapport between hypnotist and subjectS is poor.
a shopping mall and was found, crying, by a kindly old man. Loftus
when people are provided incentives to distinguish carefully between
probed Chris's memory of the experience for several days after Jim's
real and IllIaginary events, or when they are led to believe that they
recollnting of it. Chris responded by providing a detailed memory of
will remain able to make such distinctions even when hypnotized.lO
the experience. He related that he fclt "so scared that I would never see
Other experiments have shown that hypnotized subjects can con
Illy family again," recalled "the man asking mc if I was lost," remem
fidently remember past lives. The nation's anemion was dr:lwn to this
bered that the old man wore a "flannel shirt," and recollected that his
St'af(/Ji Il,� Jar "'lemOTY
R e fl e c t i o n s in a C u r v e d M i r r o r
1l100her had told him "never to do that again."22 Loftus found that fOll[
after several interviews and retrieval attempts, implying that repeatedly
1 10
111
of the five people who panicipated in her experiment (three children
thinking about the evCIlt increased participants' confidence that it
and twO adults) related memories of events that nc\'er occurred.
actually happened. Experiments have shown that simply repeating a
Do the participants really believe that these false eventS occurred, or
false statement over and over leads people to believe that it is true.
arc they merely complying with the social dCllland� of the test situation?
Likewise, when we repeatedly think or (alk about a past experience,
And how do we know for sure that Chris or others wcrc Ilot once actu
we tend to become increasingly confidt,nt that we
ally lost' in a shopping mall? These possibilities cannot be ruled out, but
accurately. Sometimes we are accurate when we recoum frequently
Loftus's basic findings have been confirmed III an independent srudy by
discussed experiences. Out we
Ira Hyman and his colleagues. They obtained information from college
about frequently rehearsed experiences that we remember inaccll
studCllls' parents about various things that had happened to their chil
r.ltely. Retrieving an experience repeatedly can make us feel certain
dren when they wcre young. The experimenters queried the students
that we are correct when we are plalllly wrong The tenuous correla . tion between a person's accuracy and confidence is especially relevant
about ;lctual as well as f..bricated events: an overnight hospitalization for an ear infection: a birthday party with pizla and a clown; spilling punch
to eyewitness testimony. Witnesses who rehearse their teStimollY again
at a wcdding reception; evacuating :l grocery score when sprinklers went
and again in interviews with police officers and attorneys may
oft: and causing an accident by releasing a parking brake when left alone
become extremely confident :.bout what they say-even when they
in a car. Although student" tended nor to remember any of these imag
are incorrect. This consequence of rehearsal is especially important
ined events when first questioned. after several interviews approximately
because numerous studies have shown that juries arc powerfully inAu
20 to 30 percent of the_Ill brcnerated f.,lse recollections. In follow-up
ellced by confident eyewitnesses.2'
studies. Hyman has confirmed these findings and discovered that
All these effectS ofretrieving and rehearsing memories are illustrated
instructions to imagine a fictitious evem n i crease the likelihood that
in one of the most politically significant cases of memory-based testi
people wiU come up with a f..lse memory. Hyman also reports that peo
mony from recent decades: John Dean's recollections of conversations
ple who attain high test scores 011 scales that measure viv1dncss of
with rlichard Nixon about the cover-lip of the burglary at the Water
imagery, responsiveness to suggestions, and lapses in :mentioll and mem
gate Hotel, which led to the demise of Nixon's presidency. Dean's tes timony concerning his conversations with Nixon, Robert Haldenlan,
ory are especially ikely l to creatc false memories.:!} If wc hold the traditional view th3t memories are simply activated
and other principals com:lins highly detailed, seemingly verbatim
engrams, these findings are puzzling: Why should people report expe
memories of exactly who said what in particular conversations. The
riences when there is no engram that corresponds to that cxperience?
level of detail in Dean's recollections is so extraordinary that he came
Uut when we consider rh,1t the retrieval environmem contribmes to
to be known as the hUlllan tape recorder. When Nixon's �eCTCt tapes of
the constructioll of a memory. these fllldings become comprehensi
Oval Office conversations were made public, it became clear that
ble. In both the lost-in-the-shopping-mall study and Hyman's exper
Dean's memories were not terribly accurate. The psychologist Ulric
imelltS. the retrieval environment
from
Neisser, after comparing Dean's testimony and the actual record of the
normally trustworthy sources who have provided speciftc infonnation
conversations, concluded that Dean nrely if ever recalled the verbatim
COl15ists of infonnation
about a seelnillgly credible experience. Under these conditions, some
Content of a conversation. Despite IllS confident presentation, Deall
relllemberers may interpret any subjective sensations elicited by the
often ("iJed to recall correctly even the general gist of a conversation.
cue-vague feelings offamiliarity, fragmentS of other possibly relevant
I n a crucial meeting with Nixon and H3ldeHl,m on September 1 5 ,
experiences. perhaps even dreams or f.,ntasies that arc not recognized
1973. for instance, Dean recalled that Nixon made comments indicat
as sllch-as signs of an a\vakening engram. Once the process is initi
ing his full knowledge of the Watergate cover-up. Dean remembered
ated, it is just a short step for these reJ11cmberers to do what I have
many specific details from the beginning of that meeting:
suggested that all rememberers normally do: knit together the relevant frab'111entS and feelings into a coherent narrative or story. It is also note\vorthy thal false recollections emerged Illost clearly
The President asked me to sit down. Both Illen appeared to be in very good spirits and Illy reception
was
very warm and cordial. The
1 12
Srar(lIillg fo r Mem o ry
FIGURE 4 . 1
President then told me that Bob--referrillg to Haldeman-had
kept him posted on my handling of the Watergate case. The Presi dent told me I had done a good job and he appreciated how difli cult a t:lsk it had been and the President
was
pleased that the case
had stopped with Liddy. I responded that I could not take credit
because others had done much more difficult thinb'S than I had done. As the President discussed the present status of the situation I told him that all I had been able to do
W;J.S
to contain the case and
;J.SSlst in keeping it out of the White House. In reality, Nixon had nOt asked Dean to sit down, did not say that Haldeman had kept him posted, did not teU Dean that he had done a good job, and made no mention of Gordon Liddy. Nor did Dean say anything about not taking credit. Dean was corren, however, that Nixon revealed knowledge of the cover-up in this conversa lion; he recalled accurately general themes and points that were repeated ag;lin and again in different episodes and conversations. According to Neisscr, "what seems to be specific in his memory actually depends on repeated episodes, rehearsed presentations, or overal l illlpressions."2� The conflicting testimony of eyewitnesses in other high-profile cases reminds us th:u Dean is not an aberration. When Clarence Thomas and Anita Hill told radically differem tales of wh:u had hap pened between them years before Thomas's 1 9 9 1 confirmation hear ing for ;l scat on che Supreme Court, many people assumed that one of them had to be lying. Is it possible th;lt both were remembering the past as accurately as they could, a past that had been shaped for each of them in different WdYS by how they thought ahom their interac tions after they occurred?
In the 0.J. Simpson case, many were left scratching their heads when Simpson's housekeeper testified that his infamous white Bronco had not moved from its spot all evening, yet Simpson's limousine driver tcs tified that he had no memory of seeing the car when he arrived late that evening. Had each of them been so well rehearsed by defense and prosecution attorneys that both believed they were telling the truth?"" The an of retrieving selected memorics by thinking about thcm to ourselves and talking about them with ochers helps to consolidate long-term engrams. Out when we rehearse indccurate information, which may have infiltrated our recollections during attempts to fill gaps in fragmentary engrams, we may unwittingly creare misraken though strongly held-beliefs about the past. (See figure 4. 1 .)
Cheryl Calleri, "Fugitive Memory III," 1992. I S x 12 x S " . Photo graphic construction. Rut.h Bachofner Gallery, Los Angeles. Calleri attempts to cOllvey visually [he idea [hat memorie s change ovt.·r time by mounting a vintage �hotograph in front o f :l. curwd mirror. R.eflected by . Ihe cUn'ed ImHor: the sll�glc: photograph i� lransformed into a double im ge a
that C OI1Vf:Y� the ullprcsslon that I1ll�mories are in a state of Aux. ·'Fugitive Memory III··. shows an ephemeral double image ofa nim�(eclHh-cent ur)' tin type. Calleri"s ambIguous images allude to the ongoing procCSSC!i that serve 10 shape sculpt-alld distort-many of our recollections. ,
S e a r f l l i "J
1 [4
for M e m o r y
THE WOMAN WHO M I S T O O K A PSYCHOLOGIST F O R A RAPIST
R e fl e c t i o n s i n
a
115
C lI r ved M i r r o r
In cbssic studies on eyewitness memory by Elizabeth Loftus and her colleagues, people viewed slides in which a car is involved in an
T h e Va g a r i e s o f S o u r c e M e m o r y
accident after coming to a halt at a stop
ign. After witnessing the
Donald Thompson has devoted the better part of his lif� to the study
stopped at the stop sign?" and others were asked a quesrion comain
s
event, somc people were asked, "What happened to the car after it
of human memory. A native Australian, he elnigrated to Canada in the
ing a misleading suggestion: " What happened to the car after it
late 1960s to study with Endel Tulving. Thompson collaborated with . Tulving in a series of f1Tl10US experiments that led to the eJlcOllifiX speci
stoppcd at the yield sign?" Later, everyone was asked whether the car
ficity p rilldph': the inAuential idea that the specific manner ill which
asked the misleading question tended to remember having seen a
we encode an event determines what retrieval cues wiU later help us
yield sign. Loftus argued that the misleading suggestion had effectively
remember it. After obtaini ng his Ph.D., Thompson returned to Aus
wiped out these individuals' memories of the stop sign.21
had come ro a halt at a stop sign or a yield sign. People who had been
tralia and cominued his studies, focusing mOSt intensively on issues
Important scientific results tend to gener;ue a Aurry of subsequent
concerning memory distortion and eyewitness identification. He tes
research that helps to refine and alter Ollr lInderstanding of the initial
tified frequently as ;1Il expert witness in legal cases that involved eye
Outcome, and Loftus's finding was no exception. Various studies have
witness recollections.
shown that misleading information docs not' diminate the original
One can imagine how Thompson must have felt, then. when
memory; when people are given appropriate tests, it is possible [Q
authorities informed hlln that he was going to be questioned about a
demonstrate th:H the original mc mory stil1 exists. Dm there is mount
rape because he matched almost perfectly the victim's memory of the
ing evidence that participants in such experiments often sutTer scrious
rapist. Although bewildered by the bizarre accusation, Thompson was
source memory problems: they have difficulty recollecting wherher
fortunate because he had an airtight alibi.Just before the rape occurred,
they acwally saw the yield sign or just heard about it later. In one par
Thompson was doing an interview on live television-ironically, he
ticularly striking experill1cm, participants were specifically informed
was dl.."Scribing how people can improve their ability to remember
that all the information in the postevent narrative was bogus
yet
-
f..ces-and he could not possibly have been at the scene of the crime
when tested a week later, some of them insisted that this information
when the rape occurred. When it came to light that the victim had
had been part of the original event! Their source melllories had failed:
been watching Thompson on television prior to the rape and had
they no longer remembered what was in the postcvenr narrative and
apparently confused her memory of hilll from the television screen
wh;n was in the original scene.19
with hn memory of the rapist, Thompson was releasc.!d immediately.
The cognitive psychologist L.ury Jacoby devised a clever procedure
A number of similar cases have been reported. Each time, witnesses
that also illustrates how failures of source memory can lead to memory
offered erroneous identifications of perpetrators because they h:ld
distortion. Consider the following mllles: Sebastian WeisdorC Roger
encountered the accused outside the context of the crime. They later
Bannister, Valerie Marsh, Minnie Pearl, and Adrian Marr. Do any of
failed to remember when and where they h:.d seen the person, while
them belong to famolls people? The track star Roger Bannjster and the
retaining a strong sense of familiarity toward him.n
entertainer Minnie Pr.:arl may ring a bell. but the others probably do not
These dramatic instances of distorted remembering demonstrate that
(they are not famolls) . In Jacoby's experiment, people hardly ever claimed
accurate recollection often depends critically on our ability to recall pre
that a noni:1mous !lame such as Sebastian \Veisdorf was f.1T1l0US when
cisely when and where an event occurred, a process I will refer to as soulre
they were tested immediately afier exposure to the nonfamous names.
ml:tIr()()'. The rape victim correctly remembered due she had seen Thompson's face before, but was mistaken regarding the soulre of her rec
But when tested a day later. they often claimed that Sebastian W<:isdorf . \vas the name of a famous person. Once again, a f.ilure of sollrce mem
oileccion. l{ccent research shows clearly that source memory is extremely
ory is (he likely culprit: with the delay, people forgot that they had
f.tlliblc. and that tliluT'l's to remember the correct source of acquired
encountered Sebastian WeisdOlf in the study list, but still felt that they
information are responsible for various kinds of errors and distortions in
knew the name. Jacoby claimed-with tongue planted firmly in cheek
eyewitness recollections and other aspects of everyday memory.
that he had shown that it s i indeed possible to become famous overnight,»
R e fl e c t i o n s i n a C u r ved M i rror
1 16
1 17
Social psychologists have indeed docllm('med that when people
The ability (Q recollect source information lies at {he he:l.rt of our ability co distinguish memories from fantasies and other products of
forget the source of their knowledge. beliefs can be unduly inAuenced
our imagination. Have you eVer planned to carry Ou( a simple activity,
by the statements of people who lack credibility. Suppose, for exam
such as mailing a lener, and later had difficulty recollecting whether
ple, that Professor Jones. a self-professed memory expert. tells YOll that
yOll had actually dOlle it or simply thought about doing it? In an
it is possible to remember events that occur during the first weeks of
attempt to convince yourself (hat you indeed put the letter in the mail.
life. But you also learn thatJoncs's Ph.D. is a fakt: and that he has never
you may desperately tTy to r('member some aspect of the conrext in
had any formal training in memory research. YOLI will be inclined to
which you carried Ollt the activity. If, for example. you can specifically
dismiss his claims :lbollt memories of inf.·lIlcy, bur a week !:Iter you are
recall that the mailbox was stuffed full of letters when you opened it.
more likely to accept them because YOll may have forgotten that he i...
you can cOllifonably conclude that you did mail the letter. If, however.
a
you are unable to recall any source information whatsoever, chen yOli
because SOCial psychologists have also demonstrated convincingly that
noncredible source. Such
findings :Ire particularly worrisome
people are generally biased in the direction of believing new infor
arc likely to continue to fret over what you did or did not do. Laboratory studies conducted by the cognitive psychologisl Marcia
mation. For example, Daniel Gi lbert and his colleagues have shown
Johnson and her coJ1eagues have shown that our ability to distinguish
pt�opJe Staterllents including made-up words-such as " A bilicar is a
memory from imag ination hinges on the recall of source information.
spear"-that are arbitrarily designated
Memories of external occurrences typically contain perceptual details
finds that when people forgct whether the statement was designated
about the context or setting of an event, whereas memories of inter nal events (such :is thoughts and fantasies) typically contain liccJe con
as true or false, they show a bias to caU it tflle. It requires a good deal . of effort, Gilbert reports. to muster tht.: critical f'lCllities to "unbdieve"
textual information. When we C:innot recall anything specific about
new information. Failures of source memory. then, open the door to
context or setting, we lose an important basis for determining
the formation of 1I11\V'.Irramed and possibly dangerous belielS..l.l
whethcr a "rear' external event occurred, and hence we are quite StlS
as
eitht'r true or f:'lise. Gilbert
Remembering when something happened is also an important part
ceptiblt: to memory distortions. Conversely, if an imagined or fanta
of source memory. If I ask you to try to remember what YOll did on
sized evem does contain a wealth of details about the context and
July
setting of an event. we will be inclined to believe that it is a real mem
to the events of that day. At best, you may be able to narrow down the
16, 199-1, it is extremely unlikely that you can obtain direct access
ory of all actual event. Later in the chapter, I will discuss how these
range of possibilities ("I was vacationing on Cape Cod ill the mjddle
considerations assumed paramount importance in the celebrated case
of July that year, so I prob:lbly spent some of the day on the beach"),
of Paul Ingram, whose " memories" of unlikely evems turned life
and you might be able to draw on other kinds of illforlllation to sug gest further hypotheses ("The calendar says that July 1 6 was a Satur
upside-down for many members of a small Washington town." The relative fragility of source memory 11lay have import:H1t social
day that year, and I think that we spem one of Ollr Saturday afternoons
implications in everyday life. We live in a media-saturated environ
011 the Cape visiting Provincetown"). Yet you :llll1ost surely cannot
mcnt in which we are constantly encountering news, gossip, and
silllply "look up" the dare the way you could look it up in your
rumors from sources that vary widely
appolJ1tmem book for that year.
in
credibility. If, for instance,
YOll are waiting in a checkout line in the supermarket and notice
a
The reconstructive Ilature of memory for time is underscored by
tabloid containing an ugly stOry that illlpeaches the honesty or fidelity
various i1Jusions and distOrtions. II One cOlllmon distOrtion is known
ofa public figure. you may be inclined to dismiss it because you main
as a
tain little f:lith in the reliability of the source. But what if several
during calendar year 1993. Can you recall the date and the tillle of day
sc(/Ie dJea.
Try to remember a visit that you made to a 1l1llSeml'1
months later yOli arc engaged in conversation about the honesty of
of the visit? You l11a)' remember correctly that you went to the
public figures, and you remember the negative Story but no longer
museum
recall the exact source? You may be inclined to stake more belief in
was
the StOry than is warranted because you fail to remember that yOllr
were recorded in memory, it would be impossible (0 Tllisremember
information was acquired from a dubious source.
the date by several months but still remember the eX3n time of day.
III
the evening, while at the same time recalling that the visit
in June when it was actually in AUb'1ISt. If a litel'31 record of time
SrI/rei/its.'! for .�,/I {' m o r y
R. e O e c t i O Il S i n .. C u r v e d M i r ror
The (:let that such scale effecrs occur implies that people infer and
memory. I n addition, the injury also caused extensive dam l in expicit
reconstruct time of occurrence on the basis of other kinds of retrieved
age to his fmmal lobes.
118
119
information, slIch as physical setting. For example, you may recollect
Gene was a polite, quiet, and cooperative young man who seemed
that it was dark when you left the museum, which allows you to infer
entirely normal in most respects-cxcept for his nearly total inability
chat you visited the museum in the evening. You Illay also recall that
to remember his past experiences explicitly. To find out whether he
you were wearing light clothes because of the heat, but this tells you
could learn any new facts, a female assistant and 1 took turns telling
only that the visit occurred during sllllllll crtime. Unless you can recall
him bit.� of trivia that we made up. sllch as "Uob Hope's father was a
some other salient information that allows reconstruction of the date
fireman," or Jane Fonda's favorite breakfast food is oatmeaL" A
(for example. thaI the visit W
minute or two later, one of us would ask him, ;'What job did Bob
'
are likely co make errors-perhaps large ones-when attempting to
Hope's father h;lve?" or "What does Jane Fonda like to cat for break
assign a date to the episode.
f:lst?" Surprisingly, Gene could occasionally provide the correct
P�oplc also make systematic errors whe.n trying to recall the dates
answers to Ollr questions I was truly startled, however, when I asked
of well-known public events, tending to estimate that extremely
him to tell me how he knew the facts. Gene cOll'iistently claimed
important and salient evenrs occurred more recently than less impor tant events that occurred at about the same time.l4 The errors that people make when trying to remember the �xact tillle of events, or other k.inds of source information. highlight a m:�or
.
either that he had just made a lucky guess or that he had come across the fact in a newspaper ur heard it on the radio-he never remem bered that my assistant or I had told him the specific t:lcts JUSt a minute or so earlier!
vulncr.lbility of our explicit memories. The sights. sounds, and meanings
Gene exhibited a form of mcmory t:lilun: known as source amne
of everyday experience are nO[ always all bundled up together into a
sia: he could learn a new fact, but had no memory for the source of his
single package. When we lose source information but rcrain some aspect
knowledge.'» He behaved much as you or I luigiu if we wcre asked to
of an experience--like the face of an attacker or the sense of familiar ity with a nalll(..'-we cast about in our minds in an attempt to figure
indicate how we know that Paris is the capital of france. We do not remember exactly wherc or when wc learned this fact. but we can
out why we have a feeling of knowing or remembering. If we are lucky,
infer that it \vas probably in elementary school or perhaps through
our erroneous gUes5<.'S arc benign; nobody suffers much if I come to
reading an encyclopedia. Gene's case is striking bccause his source
i a famous person. Dut when the stakes believe that Sebastian Weisdorf s
amnesia occurred almost immediately aft('r he learned the fact; for nor
are higher, the vagaril-'S of source memory can lead to disaster.
mal adults, source amnesia is observed only with much longer delays. We found that most of the other memory-impaired patienl$ we tested also showed source amnesia to greater or lesser degrees. Patients
M E M O RY D I S T O RT I O N A N D T H E B R A I N S o u r c e A m n e s i a a n d C o n fa b u l a t i o n
who were particularly susceptible to source amnesia tended to havc signs of damage to the frontal lobes, whereas patients who were less susceptible to source amnesia h:ld few signs of frontal lobe damage.
Some o f the most dramatic failures of source memory arc seen in
Subsequent research has confirm ed that patients whose damage is
brain-cbm aged patient$. 1 had the chance to observe such failures
restricted to specific regions of the frontal lobes, and are not globally difficulty
remembering source information.
when ca rrying out my own studies of memory and amnesia in the
amnesic, have great
early 1 9805. I sought to determine whether patienl$ with explicit
Patients with restricted frontal lobe damage also have problems
Tllem ory
deficits could learn any new facts, and if so, whether thl!Y
remembering tempor:11 information, such as which of two events
could remember when and where they acquired the facts. One of the
came first, or the order in which a sequence of items was presented.
first patients 1 tested was a young man who had been involved in a
These observations indicate that the frontal lobes play an import.lllt
1lI00orcycie accidl!nt several years earlier. The patient, whom I will
role in allowing us to remember when and where ollr past experi
refer to as Gene, had suffered a serious head injury that damaged the
ences occurred, and thus form a critical part of the episodic memory
hippocampus and other medial temporal lobe areas that are implicated
system.J6
120
R e fl e c t i o n s i n a C u r v e d M i r ro r
In certain cases of frontal lobe damage, failures of source mCJllory arc accompanied by extensive and even bizarre confabulations-falsc recollections of events that did not occur and, i n some instances, could not have occurred. Confabulations frequently involve distortions in rcmembering the time of past events. The neuropsychologist Morris Moscovitch described a case in which a sixty-one-year-old man with widespn:ad frontal lobe damage insisted that he had bcen married for just four months when he had been married to the same woman for over thirty years. He recalled correctly that he and his wife had four children, spontaneously addinbr-apparently with some bughter- "Not bad for four months." When asked about the ages of his chil dren, he noted that the eldcst was thirty-two and the youngcst twenty-two. How could onc produce these children in four months? The patient had a ready response: "They're adopted.'·J? Such confabulations arc often subjectively compelling, as illustrated by a patient who was asked to say whether he actually "remembered" the pcrsonal cxperiences that he reportcd or he just "kncw" that these
121
did o n a Thursd:IY night six weeks ago. Associative retrieval is often oper:ltive in confabul;lting patients: all kinds of experiences automat ically spring to mind i n response to environmental cues. Strategic retrieval, on the other hand, may be totally incapacitated. This means that the patients do !lOt make the efforts necessary to figure out exactly when or where their recalled expe.:riences occurred. Their minds are filled with all kinds of mnemonic AOt&1111 and jetsam-fr;lg Illents of experiencc that are not anchored to a proper time and place, and thus enter into peculiar alliances and marriages with onc another. Thc result is a jumbled life story that is confusing to friends and rel atives, if not to the patients themselves. Conf.1bulating patients tend to be una\vare that their recollections are often distorted. For these patients, the truth of their recalled pasts is as compelling as i t i s for anybody else. Because they are.: often amnesic for recent experiences, however, attempts to implore them to stOp conf.1bubting art:: quickly forgotten and thus gencrally ullsuccessful.40
experienc(.'S had happened to him. The patient consistently said that he remembered the experiences, both when his memories were accu rate and when they were confabulations that contained gross errors in temporal dating..l
.
•
Confabulation is also related to the distinction between aSSOCiative retrieval and stratcgic retrieval that 1 discussed in chapter 2. AssodariVt' r('fr"flled is an involuntary form of remembering that is triggered auto matically by an object or what somebody says: it is epitomized by the kind of vivid recollections that imposed themselves Oil Marcel Proust. S/ra/e.i!ic rctricl!al is more laborious and voluntary-the kind of retrieval that you would undertake if I asked you to try to reme.:mber what you
REMEMBERING PHANTOMS F a l s e R e c o gn i t i o n a n d t h e R i g h t F r o n t a l L o b e I n the spring of 1994, I gave an informal presemation onc morning to a weekly meeting of fellow Illemory researchers at the Veter:lns Administration Medical Cemer in DoslOn. I was trying Ollt some ideas ahollt the role of the right frontal lobe in memory retrieval. ideas that had been stimulated in part by PET scanning studies that suggested an important role for the right frontal lobe i n explicit retrieval. One of my colleagues mentioned thac he had just come across a patient who might be of imerest to me. The patient, a man in his sixties whom I will call Frank, had suffered a serious stroke that produced extensi\'e damage to hjs right frontal lobe, but spared all other parts of his brain. Frank had been a successful lawyer during his working life, and retained I'nany of his cognitive skills. If you had no knowledge of his condition and spent several hours with Frank, chanccs are that you would not suspcct that anything was amiss. He is a pleasant, coopcrJ tive man who behaves appropriately, can recall recent and distant past events, and converses easily. Yet large sectors of his right frontal lobe had been destroyed. What had this damage done (0 his memory? To try to find out, my colleagues and J gave Fr:lnk a simple test of recognition memory." Frank studied a list of familiar words, and a few minutes later saw old words frolll the list and new words that had not
1 22
S e a r c h i llg for l\< 'I r m o r )1
Il. c fl e c t i o n s i n
a
C u r ve d M i r r o r
123
appeared on the list. We instructed Frank to indicate which words
As long as a word or picture was generally similar to thc items that had
wcre old and willch were new. I n addition, we told Frank that he
appeared in the study list, Frank was willing to claim he remembered it.
should say whether he actually had a specific recollection of h:lVing
l then seeing a When Frank saw cOlllmon words during the study ist,
studied the word earlier ("remember"), or whelher he thought that
common word during the recognition test.-...v ....e en one that had 110[ been
the word had appeared earlier because it just seemed £1111iliar to him
on the study list-was enough to make him feel th:n he had seen the
("know"). We compared Frank's performance to a control group who
word earlier in the experiment. \Vhen Frank saw nonsense \vords 011 the
were about his age and h:ld a similar educational background.
study list, then seeing a nonsense word on the test--old or new-ehcited
Frank's responses to previously studied words were relatively nor
a feeling of remembermg. However, Frank did not make false recof,Tfli
mal; he made about the same number of "remember" and "know"
tions to pictures of animals because tht.-'Y were drastically different from
judgments as peopk in the control group did. But when we examined
anything he had seen during the study phase of the experiment.
Frank's responses to new, nonstudied words, we quickly noted some
These observations Illay remind you of the distinction that I drew
thing lInusllal: Frank claimed to "remember" that nearly 40 percent of
between two different levels of knowledge that can be accessed when
the new words had appeared on the list! People in the: control group
people attempt to remember past episodes: general-event knowledge
rarely indicated that new words had appeared on the list, and when
and event-specific knowledge. Recall that general events refer to
they did, they nearly always said that they Hkncw" that the word had
extended eplsodl:s, such as going to a movie, whereas evellt-speciflc
been shown earlier; they hardly ever said that they "remembered" see
knowledge refers to particular episodes that arc nested within the
ing a new word, In a series of S11111iar experiments, we found that
general event, such as buying popcorn or being surprised by the end
Frank frequently claimed that he "remembered" sounds, nonsense syl
of a film. In a memory experiment of the kind that we conducWd
lables, and pictures that had never been presented to him. People in
with Frank, the gener:ll event might be seeing a lISt of words or see
the control group almost never said that they remembered items that
ing some pictures of objects, whereas event-specific knowledge would
had not been presellted. Frank's problem was also evident even in casual cOllversation. When
rl:fer to memory for the specific items th:lt were presented during the experiment. Frank
appeared
to
be
inappropriately
responding
1 Illet Frank for the first time, at his downtown apartment, I asked him
"remember" 011 the basis of general-event tnfonnation, rather than
whether he h.Jd ever seen me before. Yes, he responded, he '·recalled"
event-specific knowledge.
that I had tested him at my office. Why did Frank claim to remember
Our findings and ideas provide clues regarding the functions that
me? And why would he claim to remember that words, sounds, or
are ordinarily subservcd by the frontal regions tlut arc damaged in
nonsense syllables that had not been presenred in an e:,Xperiment had,
Fr:lnk. The hypothesis that frontal regions are specifically involved in
in fact, been shown to him? There are: a number of possibilities, but
e£fortful or stI
our research with Frank poimed in one direction.
strategIC retrieval were disrupted in Frank, then he may have become
We obtained an important lead from an experiment in which we
"stuck" at the general-event level, f,1.illllg to engage in the effonflli
figured out how to stop Frank's r:llse recollections. We showed him
search that is necessary to detl:rnune whether a specific word or pic
some pictures of common objccts, such as a chair or a shirt. and later
ture had been shown to hinL Frank seemed unwilling or unable to
asked him whether he recognized thosc objects; we also asked him
carry out the 11ICntaJ work necessary to detenn11'le whether a partic
about pictures of other imnilllate objects that had not been prcsented
ular mcntal experience should be called a "memory."
earlier. The catch was th:lt we also tested him on pictures of animals.
This interpretation meshes well with the results of recent PET
Would Frank claim that he remembered seeing pictures of alllmals,
scanning studies. The frontal lobes become active when people engage
even though 110 animals at all had appeared on the list? The answer
in the mental work involved in trying to recall a past event. The dam
was a resounding no. Frank almost never said that he remembered see
age that Frank suffered to his right frontal lobe made it difficult for
ing a picture of an animal, yet he insisted that he rCJl1ernbered seeing
him to put forth the saine kind of effort during retrieval. The result
many inannnate objects that had not been prescnted earlier.
was that Frank became too easily satisfied that he had "remembered"
We now had some insight into the basis of Frank's false recollections.
when there was only a f,1.11Ii1y resemblance between a word or a pic-
Sl'llrtilillg for J\fc m o ry
Refl e c t i o n s in a C u rved M i r ror
ture :md something he had seen earlier. Likewise, Frank's " memory"
fant3stic claillls abollt preposterous events. One preschooler, for exam
12-4
" I? -,
for having met me before was probably rooted in reality. An aduh male
ple, recalled diving into a lake to rescue a companion ITom the
psychologist had once tested him, but Frank Illisrakenly took this as
dlltches of attacking sharks that had been released into the waters, and
evidence that the two of liS were old acquainr.mces.
another child " remembered" an incident involving an alien spaceship.
Frank's false recognitions :Ire also illurmnated by evidence from
Nonetheless, the children's reports of abuse led to the conviction and
Jr.,
who ran the preschool, and
"split br:lin" patients, whose left and right cerebral hemispheres have
imprisonmenc of Roben Kelly,
been surgically disconnected from each other. The two hemispheres
' Kathryn Dawn Wilson, a young mother who worked there..
no longer communicate with each other, so researchers can present
.In another case with many similar features, Margaret Kelly . Mlchaels, a nventy-slx-year-old teacher at the Wee Care Nursery . School If} New Jersey, was accused of various horrendous act�:
information separately to each one. Recent studies have demonstrated that the left hemisphere often f.1.lsely recognizes novel pictures or words that are similar to ones it has been shown rec(�ntly. Hut the right hemisphere claims to remember only those pictures or words that match exactly the ones it was ShOWll. The left hemisphere seems to make infert.!llccs and associations that render it sllsceptible to memory disLOrtion, whereas the right hemisphere retains a less embellished and more veridical representation. Frank h:ld sustained damage to his right hemisphere, so he probably relied heavily on the left hemisphere when making recognition decisions, (hus making him vulnerable to remembering things that never happen�d.·2
urine and eat h�r feces, alld to have raped and assaulted these chil dren with knives, forks, spoons, and Lego blocks. She was accused of performing these aCl� during school hours over a period of seven months. NOlle of the alleged acu were noticed by staff or reponed
all
them."s
Despite the absence of physical evidence and the curious circum
�
Some of che most striking and socially significant evidl.:llce for source amnesia and confabulation comes from recent studies of young chil dren. The fallibility of children's memory has become a hot topic recently, largely because of the cricical role that young children's t�s timony plays in cases of alleged sexual :Ibuse. Public and media :men episodes involving
preschools, where teachers and professionals have been accllscd-and sometimes convictcd-of carrying out lewd and often grotesque sex ual acts")
FrOlIl/ill£' in July 1 993. The
show tracked the progress of a court case in the small
parents. No parent noticed signs of strange
bcha\'lor or gennal soreness in their children, or smdled urine or
stance that nobo y at the preschool ever noticed or reponed inap . propTlafC behaVior, the preschoolers' memories of abuse wcrc
S o urce A m n e s i a and the P re s c h o o l
cion ro sllch questions has been imellSe in
�heir
�
by ch ldn:n to feces
THE C O N FABULATED MOUSETRAP
One poignam instance was broadcast by
Kelly Michads was said to have licked peanut butter off children's genitals, played the piano while nude. made children drink her
onh Carolina
town of Edenton. Several members of the Little Rascals preschool staff, including young women who were mothers themselves, were accused of sexually abusing children at the preschool. The charges were based on the children's recollection of being abused and of wit nessing sexual acts between staff members. But the children were sub ject to highly suggestive questioning, and their allegations included
cOllvincing t'nough to lead to the conviction of Kelly Michaels on over one hundred COUllts of sexual abuse against twenty children. Although sentenced to a forty-seven-year prison term, Michaels's cOI�vic[ion was ovenu�ned on appeal after she spcnr five years in jail. As 111 the North Carolma case, the New Jersey preschoolers were sub ject to highly suggestive and relentless question.ing by examiners who were convinced that abuse had occurred. The aCClisations and convictions in the North Carolina :lnd New Jersey cases wcre based on children's memories. Were the jurors cor rect to accept (he preschoolers' recollections of abuse? To what extent are children's memories subject to distortion and even outright COI1f.1.bularion? When should their (estilllony be bdiewd? These questions have vexed psychologists. soci31 workers, lawycrs�and p:lrelll';-for decades. Professional opinions have tended to polarize toward one of two extreme views. Some have argued that "children do not lie," that they are capable of 3ccurately recalling much of their pasts, and that they are no more susceptible to suggestive inAucncL'S than are adults.
1 26
Set/ reI/jug for M e m o r y
Others have claimed that young children are often unable to distin
R e fl e c t i o n s i n
a
C u r v e d M i rror
127
the source of their knowledge, they behaved as though the events had
guish between fanrasy and reality, are hypersuggestible, and are virtu
actually occurred. These confabulated mClllories were, howcver, con
ally incapable of offering cn:dible testilnony about past events. In a
vincing to the children . Evcn when told th:n the mousetrap incident
scholarly review of nearly a century's worth of research, Stephen Ceci
and othcr imaginary episodes never happened, some of the children
and Maggie Bruck took an intermediate position: young children
insisted to their parents that these episodes must have occurred
oftcil are more suggestible and prone to distortion than older children
because they were so sure that they remembered them.
and adults, btl[ under the right circumstances they call accurately recall many aspects of their past experienccs.06
The psychologist Michelle Leichtm:m collaborated with CeC! on a study that showed how some children could be led to rnisremember
Recent research has shown convincingly that yOllng children often
an innocuous everyday event. A stranger n:1111ed Sam Stone paid a
have great difficulty remembering source information, which in turn
two-minute visit to a preschool. Sam walked around the classroom,
renders them vulnerable to false recollections. It has also been estab
sald heUo to a teacher, who introduced him to the children, COIll
lished that suggestive questioning can have devastating effects on the
mented that the story being read to the children was a favorite of his,
accuracy of somc preschool children's memories. Ceci and his collab
and left. in subsequent interviews concerning Sam's visit, some chil
orators have provided some of the most dramatic fmdinb'S:7 In one
dren were asked Illisleading questions :Ibollt his behavior. "Remember
experiment, for instance, they asked preschool children about some
the time that Sam Stone visited your classroom and spillcd chocolate
everyday events that had actually occurred. Dut they also inquired
on that white teddy bear?" an imervlcwer asked these preschoolers;
about other incidents that, according to the children's parents, had
"did he do it on purpose or was it an accident?" The interviewer also
never happened. For instance, they asked children to recollect the time
asked whcther Sam was being silly or angry when he Tipped a book.
that they " [g]ot a finger caught in a mousetrap and had to go to the
Sam never spilled or ripped anything during his visit. Bur when
hospital to get the trap ofT." An interviewer asked the children to think
probed ten weeks later about their memories for the episode, over 50
hard about the events by attempting to visualize them; the procedurc
percent of three- and four-year-olds said that Sam had spilled choco
was carried out once a week for ten weeks. Finally, the interviewcr
late on a teddy bear or ripped a book. About one-tlmd of the three
probed the children's memories: "Tell me jfthis ever happened to you:
and four-year-olds claimed that they actually remembered seeing Sam
Did you ever get your finger caught in a mousctrap and have to go to
commit these acts. One three-year-old girl, for instance, recalled that
the hospital to get the trap ofF'
"[hJe . . . he when my teacher said 'be careful with the dollies,' and
Ceci and colleagues observed that over half {he children produced
he . . . he put it lip. Then the dollies, some, some of them ripped off."
"memories" of at least olle of the made-up mcidents. These false recol
The interviewer asked why some of the dollies ripped. "Because he
lections were typically complex narrarives that contained rich and
was throwing them up and down," the little girl explained, "and he was
detailed information about numerous a.spects of the imaginary episodes.
trying to catch it." Did Sam Stone do anything else, the mterviewer
One little boy, for example, recalled that the trouble all began when his
wondered? "Then he got a book and throwed it up,"
the girl
brother tried to wrestle a toy from him: "My brother Colin was trying
answered, "and then olle of the pages ripped off." "Really?" asked the
to get Blowtorch [an action figureJ from ille, ;lnd I wouldn't let him
interviewer. "How did he rip the page?" "When he was throwUlg it
take it from me, so he pushed me into the wood pile where the mouse
up." the little glrl reported. The same younb 'Ster also recaUed that "[h]e
trap was. And then my finger got caught in it. And thell we went to the
played with one of the toys, and said 'be carerul!' But he didn't be care
hospital, and my mommy, daddy, and Colin drove me there, to the hos
ful with the toys. Then he went into Housekeeping to play with the
pital in our van, because it was far away. And the doctor put a bandage
toy. And he throwed one of the toys in Housekeeping." Five- and six
on this finger."·A This child and others a.ppeared to be suffering from a type of source amnesia. The events in their narratives fclt familiar because they had
year-old children fared somewhat better than the younger children: JUSt under 40 percent said that Sam had done any lllisdeeds; only a few claimed dut they saw him do these things.
been thinking about them for weeks, but the children failed to
In contrast to these children, other preschoolers did not receive any
remember that they had imagined these episodes. Unable to recollect
misleading suggestions at aU. Hardly any or these three- and four-year-
R e f l e c t i o n s in a C u r ved M i r r o r
128
129
olds said that Sam had done anything ro a teddy bear or a book, and
One worrisome aspect of the findings reported by Ccci and col
none of the older children did. The boys and girls who had not been
leagues is that the f.1lse recollections of Inisled children are convinc
misled provided generally accurate accounts of Wh:H Sam had done.""
ing to knowledgeable adults. In both the Sam Stone study and the
As in the mousetrap study. impaired source memory is a likely con
mousetrap swdy. experts who viewed videotapes of children recount
tributor ro these instances of memory disrortion: some misled chil
ing their experiences failed to distinguish conf.1bulated stories from
dren confused whether they had actually seen Sam spill chocolate aU
accur:tte :tccounts of what actually did happen. Experienced memory
over a teddy bear or whether they had only been told about it. Then
researchers. therapists, and law enforcement professionals who all spe
they built an inaccurate story around the fragmellfS of information
cialize in working with children were stumped by the task of separat
that had been "implanted" during suggestive. questioning.
ing out true and f.1lse memories-even though these experts were
These observations sl1ggest that when an examiner imparfS mis
quite certain that they knew which children were remembering accll
leading or l!rroneoLls sliggestions ro a yOLlng child. she may no longer
rately :lI1d which were nolo Clearly, adult� who interview preschoolers
be able ro remember accurately what acrually happened. Conversely,
must take careful precautions (0 avoid inadvertent.ly creating distorted
in the absence of heavy-handed suggestive questioning. the recollec
recollections of events whose existence they merely suspeclo Bruck
tions of young children can be extremely accurate. These points arc
and Ceci have shown clearly that such precamions were sadly lacking
also borne out by Bruck and Ceci's observations of an everyday inci
in the Kelly Michaels prc$chool fiasco.
dem that is familiar to all preschoolers: visiting the doctor's office.Yl
Research with young children is consistent with the links I have
When a group of five-year-old children visHed their pediatrician for
emphasized among source amnesia, memory distortion, and frontal
a scheduled checkup. the pediatrician administered a physical exam,
lobe fimction. The evidence shows convincingly that preschool chil
an inoculation. and an oral pol.io vaccine; an assistant gave the child
dren can have problenL'i with source memory, problems that appear to
some tteats, read a stOry, and talked about a poster on the wall. A year
be closely linked with memory disfOrtion:;. Intriguingly, studies of the
later. children were questioned several rimes about the visit. Some
developing brain indicate that frontal regions are especially slow to
children were given misleading suggestions that the assistant had con
develop; they are probably not fully functional until near adolescence
ducted the exam and given the �hots, whereas the pediatrician had
and are definitely imlllature in preschool children. Likewise, behav
given (hem treats, read to them, and talked about the poster.The other
ioral research has shown th:n preschool children often carry Out cog
children received no Illisleading information. Over half of the chil
nitive tesfS in a manncr similar to adults with frontal lobe lesions. I
dren who received misleading questions incorporated the suggestions
reviewed this evidence in detail with two of Illy Harvard colleagues.
into their memories of what had happened. They now "remembered"
the developmental psychologists Jerome Kagan and Michelle Leicht
that the assistant had given them a shot. and added in other false
man. and we concluded that preschoolers' f.1lse recollections are partly
details. Some children. for instance, recalled that the assistant had
attributable
checked their cars and noses. Dut children who received no mi�lead . iug suggestions never generated f1lse recollcction�.
Although it is too simplistic to attribute all the memory disfOrtions
to
the
relative
illlmaturity
of their frontal
lobes.52
exhibited by young children to immature frontal functions, the idea
Likewi�e, other studies have shown that children who are not sub
llIay help us to go some way toward understanding why some chil
ject to suggestive questioning can remember everyday evenfS with
drt'n stubbornly insisted that Sam Stone soiled a teddy bear and oth
impressive accuracy. For instance. the cogllitive psychologist Robin
ers remembered the pain caused by a mousetrap that never harmed
Fivush and her colleagues found that three-year-old children recalled
them.
specific everyday events. slich as a family ouring to the circus or an air
The wnfabulations of young children and patients with frontal
plane trip. with considerable accuracy; indeed. they showed impressive
lobe damage provide striking evidence that a subjective experience of
levels of retention when queried about the events a year later. Fivush
retnl!lnbering can be simultaneously compelling and dead wrong. nut
also reports that preschool children do not routinely incorporat.e into
elaborate false recollections arc not the sole province of preschoolers
their own memories information about a past event that is simply
and frontal patients. They can sometimes turn up in the 1Il0St unlikely
mentioned to them by their mothers.51
settings.
130
S e a r(l!ing Jor Me m o ry
REMINISCENCES OF
A SHERIFF'S DEPUTY
I n the spring of 1993, TIlt' Nelli Yorker published a n article about a case of memory retrieval so strange that it stimulated the intense clITiosity of people who had never previously thought much abollt the work ings of human 11ICIllOTy. Provocatively tided "Remembering Satan," the artjcle centered on the story of P.nli Ingram, a forty-three-year old deputy in a Washington county sheriff's office whose eightccn and twcnty-two-ycar-old daughters had accused him of sexually abus ing them as childret1.�\ Ingram could not remember committing any abusive actS, and so initially denied the charges. Yet his d:lUghtcrs' memories were compelling enough to lead the local authorities to arrest him. Ingram continued to st:lte that he did not remember any abuse, but the arresting officers-his own colleagues-assured him that if he confessed he would be able to remember the incidents. Ingram belonged to :l fundamemalist Pentecostal church and was also encouraged by his paswr to remember the alleged events. After sever-II hours of questioning and praying. he conceded that the :llleg:ltions were true. that he had probably repressed the memories, and that he was willing to sign a confession. As the questioning proceeded, the scope of the inquiry expanded, and the officers aggressively pursued their hunch that the abuse occurred in the context of a sat:mjc cult Involving several of Ingram's friends. Ingram again prayed with his pastor and began to recover the requested memories. He followed the officers' sugges tions to visualize his coconspirators and the acts they had per formed, and he was buoyed by assurances from his pastor that God would allow only true memories to enter his mind. When Ingram's daughters learned that their father had begun to describe saranic rit uals in connection with the alleged abuse, they began to recover their own memories of ghastly cult activities, including mass orgies and murders of babies. Soon enough, Ingram had confessed to engaging in all manner of s:nanic rituals, including animal sacrifice and murder. Ingram's recovered memories led to his own imprisonment and to the jailing of two alleged coconspiratOrs. BOth of these men vehe mently denied all charges. There was no external evidence that Ingram's daughters had ever been abused. nor was there an)' physical evidence ofl11urders and mutilations. And, to make matters even mud dier, the memories reported by the twO daughters frequently con flicted with one another. As he awaited a jury trial in prison, Ingralll
R.efl e c t i o n s in a C u r v e d M i rror
131
was interviewed by the social psychologist R..ichard O(�he, who asked Ingram to remember the time he had forced his son and one of his daughters to have sex in front of him. This evem was similar to oth ers that Ingram had been queried about, but it differed in an impor tant way: his daughter never claimed that it had occurred, and Ingram's son said that 110 such event had ever taken place.Yet Ingram$ response to OfShc's question followed a predictable pattern: he initially failed to recollect the episode, but after visualizing and praying on it, he recovered a vivid "memory" of the terrible act that he had ordered and witnessed. This jarring obscrv;nion does not show that all of Ingram's other "memories" are inaccurate, and there is no way to prove conclusively that OfShe's made-up event never actually happt·ned.s.I But assuming that this evem never did occur, Ofshe's observations indicate that Ingram is susceptible to f.1.lse recollections. Therefore, they also raise doubts about the validity of the other memories that Ingram recalled with his pastor's hdp. Eventually, the lack of external evidence for Illurders and sacrifices led to the dropping of cult-related charges against Ingram and his two friends. . Although Ingram's f1ith in his recollections had been shaken, he continued to believe that he had abused his daugluers and that he owed it to them to plead guilty. Ultimately, however, after taking more time to carefully think through what had happened, Ingram con cluded that none of his memories were real and proclaimed his inno cence. He ulIsuccessfi.Uy attempted to change his guilty plea, was �entenced to a twenty-year prison term, :md had two appeals denied during his first six years of imprisonmelll. With the widespread anen cion that followed the publication of the article and a book about the Ingram case, public sympathy for him increased. As of this writing, however, Ingram remains in jail. The case of Paul Ingram is riveting because the magnitude of the apparent memory distortion seems so immense: How could anyone misremember ghastly murders and sacrifices that apparently never occurred? Nobody knows for sure eX:lctly what did or did not hap pen [Q Paul Ingrain and his daughters, but some features of Ingram's case become comprehensible when we consider the importance of the retrieval environment, the role of imagery in recol1ective experi ence, effects of rehearsal 011 melllory, and the nature of source mem ory. The retrieval environment in which Ingr.un recovered his "memories" contained several cfllcial features: suggestive questioning by the arresting officers and assertions that he would remember his
Sf'arch ;,,:.: Jor IHc m o ry
132
R eflections i n a Curved Mirror
abusive acts if he confessed; their instructions to visualize the events he was trying to remember and to conjecture abOllt what happened; and his pastor's assurance that God would allow only real memories to enter his mind. These factors, mutually reinforcing one another, freely encouraged Ingram to generate the kind of"raw materials" that are likely to give rise to a subjective sense of remembering--vivid visual images-and provided Ingram both legal and moral assurance that the resulting mental experiences would be accurate memories of horrendous
events. Frequent
repetition
and
retriev:1I
probably
increased Ingram's willingness to believe that these experiences were true memones. Problems of source memory were largely "solved" for Ingram by the officers who asserted that confession would yield remembrance and by the pastor who offered assurances that God would let only genuine memories enter his mind. Ingram was thereby excused from grappling with the fundamental question tklt ought to have plagued him: Were the vivid images that came bursting into his consciousness recollections of events that had actually occurred, or were they merely products of current and past imaginings, thoughts, and fantasies? Unfettered by the need to analyze the sources of his subjectively com pelling mcntal experiences, Ingram was free to create a complex net work of evil acts, unspeakable rituals, and demonized individuals that confirmed the darkest suspicions of those who wished to expose-yet may have unwittingly helped to create-the hellish world that Ingram described. Tragedies like tbe Paul Ingram story or the Kelly Michaels case teach us that fr:lgility :lI1d power can coexist as salient attributes of memory because those aspects of memory that make it fragile-the role played by the retrieval environment in constructing subjective recollective
experience, the
susceptibility
of remembering to
postevent influences and change, and the evanescem nature of source memory-in no way diminish its power. The fr:lgility of memory is partly attributable to the fact that the seemingly str:ligh tforward task of remembering the what, where, and when of our past depends 011 subtle interactions among differ ent processes of which we are only dimly aware, and over which we have little control. But, as I emphasized at the outset of this chap ter, we mUSt keep in mind th:ll errors and distortions in remember ing, though startling when they occur, are far froHI the norm in our mnemonIC lives. Most of the time our memories reliably handle the
133
staggering variety of demands that our day-to-day activities place on them. I have already touched on some of the brain systems and processes that allow us to remember the events and themes that constitute our lives. To understand more fully the brain substrates of memory's fragile power, we need to take a longer look at the for eign and bewildering world of the amnesic syndrome.
Va n i s h i n g T r a c e s
135
allows us to recoUect specifiC incidents from our pasts; setllamic mem ory. the vast network of associations and concepts that underlies our general knowledge of the world; and procedl/mf memory, which allows
FIVE
us to learn skills and know how to do thinb'S. Spending time with Frederick, I started to see that he could help me study these memory systems in the everyday world. Golf became one of our favorite subjects. Frederick had been an :lVid golfer for thirty years. He still played from time to time, he said, although he could not remember any specific recent trips ro the golfcourse. I, [00, had long been all avid golfer, and always looked forward to talking
VAN I S H I N G T R A C E S
with Frederick abom Ollr mutual passion.
Amnesia and the Brain
a severe memory disorder? Frederick would need episodic memory to
What, r wondered, would a game of golf be like for someone with remember where he hit the ball and how many strokes he took on each hole. Words like par, birdie, and wedge would be meanmgless to him without semantic memory, as would the game's strategies and rules. And without procedural memory he cOlildn't make use of the
T H E A M N E S I A T H AT R E S U LT S from brain damage provid(."S an
skills he had acquired in the various facets of the game, such as driv
extraordinary window on many aspens of memory. It's also a fasci
ing and putting. Playing a couple of rounds of golf with Frederick, I
nating human story. I recall that the first time I Illet 3n engaging m�n
realized, could be a revealing narural laboratory in which to study the
in his mid-fifties named Frederick, nothing suggested that he W'3S 111
effects of memory loss.
any way remarkable. Frederick came to the Unit for MCI1l�ry isor clefS. which my colleagues and I established at the Ul1IverSity of
Frederick and one on a course that was new to him. 1 Frederick had
Toronto in 198 1. Its purpose \\I:IS to evaluate. investigate, and rehabil
never been a highly skilled player but had always been able to hold his
itate memory problems that arise :ls a consequence of brain injury and
own. which he did during both of the rounds we played. As far as I
disease.
could tell, his procedural memory for the golf skills he had acquired
I?
We played two rounds. one on a golf course that was familiar to
It did not take long for us to see that there was indeed something
many years earlier was intact. Frederick's semantic memory, toO,
wrong. terribly WTOng. with Frederick's memory. When we showed
appeared to be relatively unscathed: I carried a tape recorder with me
him words and pictures. he remembered little or nothing of them.
during bocll rounds, and every time Frederick used a term of golfjar
When I asked him how he had made his way to us for testing, he
gon, I recorded what it was and whether it was being appropriately
could not teU me. When I inquired about wh;n he had done the day
lIsed. His golf vocabulary was perfen: he spoke easily about birdies,
before, he looked at me with a blank stare. In view of these memory
doglegs, and finesse shots. Frederick also exhibited excellent retention
difficulties, I was not surprised to learn that Frederick had stopped
of the rules and strategies of golf: he knew that the player whose ball
working and that he led a quiet life with his wife. His physicians
is f.tnhesr frorn the hole plays first; he regularly chose appropriate
believed that he had entered the early stages ofAlzheimer's disease, the
clubs; did his best when putting to assess the slope of the green. Fred
devastating illness that often begins with memory loss and develops
erick's access to semantic knowledge abom the game was no differ
into a generalized deterioration of cognitive function.
Cnt, at least in any obvious way, from that of any othcr experienced
Back in the early
19805, I was starting to take seriously the idea that
memory is not a single thing. Laboratory evidence pointed tow� rd three differem long-term memory systems: episodic memory. which
golfer. But at one poim Fredcrick's ball was between my baU and the hole, and he marked it with a coin-a standard item of golf etiquette---then began walking off the green after I had completed my putt. He had
134
136
Sco rrid n.1! Jor A-Iemory
Van i s h i n g Traces
forgotten that he had marked his ball and noe yet putted himself. To
prompted him, Frederick couldn't muster more than a perplexed look
examine Frederick's episodic memory more �ys[ematically, I intro duced a simple manipulation: on half of the holes. I hit fmc and he hit second, so that he could inlllledi:nciy search for his ball: on the other
and an 111credulolls question, such as "Did
137
I really do that?" or "Did
that really happen?" When I picked up Frederick at his home to play our second round,
half, he hit fmc, thus creating a delay before he initiated his search.
about a week later, he warned lIle that h (' was not a very good player,
Frederick often found his ball in the first case, but almost newr found
lhat he had not been out on a golf course for several months, and that
it when the search was delayed. As long as he could hold his recollec
he might be a bit nervous since this was the first time he had ever
tion of the tec shot in shore-tefm or working memory, he generally
played with me. I did not have the heart to tell him the truth.
remembered the location of his ball. But either the passage of time or the interference created by watching me hit was sufficient to elimi nate his working memory of the ball's location. and he could nO( count on his long-term episodic memory. As we walked from each green to the next tee, I asked Frederick to recall his shots on the hole
MAKING AMNESICS The Machinery of Memory
we h:1d just completed. ;lgain testing his episodic memory. On most
Frederick's memory impairment, though unusually severe, i s typical of
holes, he could not recall any shots.
one of the Illost extensively studied consequ ( nccs of brain damage in '
A startling incidem occurred on the 1 0dl hole at the course Fred
all of neuropsycholog y: the amnesic syndrome. Modern research 011
erick h;ld played many times before. This hole requires that the tee
the amnesic syndrome was stimulated by pathbreaking observations
shot be hit over a creek, and Frederick was not sure whcther he would
made by the neurosurgeon William l:kecher Scoville and the neu
be able to execute a good enough shot to avoid ending up in the
ropsychologist Brenda Milner of a young man now known widely
water. Uut he hit one of his finest drives of the round, easily carrying
throughout psychology and neuroscience by the initials HM
the ball over the creek and setting up a relatively straightforward sec
arguably the single Illost important patient ever studied in neuropsy
ond shot to the green. Excited and impressed by his drive, Frederick
chology.! What makes him so special?
illlmediately began to think about his next shot: Could he rt':1ch the
I n 1953, Scoville operated on the twcnty-sevcn-ye:lr-old HM to
green with all 8-iron or would he be safer to lise a 7-iron? Could he
relieve seriolls, recurrent epileptic seizures. He f('llloved a constella
mamge to keep his approach shot out of the sand trap? Clearly, Fred
tion of structures tucked deep within the medial (inner) sectors of the
erick had carried out a deep, ebborative encoding of the tee-shot
temporal lobes 011 both sides of the brain, including most of the hip
episode.
pocampus, the amygdala, and some adjacent areas of temporal cOrlex
I then stepped up to the tee and hit my drive (carrying well over
(see figure 5 . 1 ) . HM's seizures diminished, leading to a general
the creek, I am pleased to report). As I walked off the tee and headed
improvement in his medical condition. Prior to the operation. his IQ
down the fairway, I glanced back over Illy shoulder to an unexpected
had measured 1 0 1 on the Wechsler Adult Intelligence Scak.�nearly
sight: Frederick was teeing up again and preparing to hit another
identical to the population mean of
drive. When I asked him what he was domg, he gave me a bemused
years after the operation, HM scored 1 1 2 . 'n just about :Ill respects, he
100. When he was test!.:d two
look and said rh:1t he. too, would like to play the hole and so he would
seelncd exactly like the preoperative
have to hit a tee shot. He had no memory of h:lving teed off a minute
he appeared entirely incapable of remembering anyd1ing th:1t hap
earlier, and no idea that he had managed to hit his drive over the
pened to him after the oper.Jtion.
creck.
HM. The sad exception was that
HM's amnesia quickly became apparem when he could not recog
After each round. Frederick and
I had drinks in (he clubhouse, and
nize members of the hospital staff he used to sec on a regular basis.
I asked him to recall whatever he could about the brame. Unable to
and \,",ould frequently forget when he had recently eaten a meal He
recall a single stroke or episode from the entire round, he instead
performed disastrously on the Wechsler Memory Scale. When a per
spoke in empty generalities, ruminating that "I hit some bad ones out
son scores about
there"
scale, most neuropsychologists classify that person as amnesic. After his
or " Couldn't really plitt today." No matter how much I
15
pointS lower on this test C'MQ") tl1:111 on the IQ
138
S l' a r c i l i l lg for M e m o r y
Va n i s h i n g Tra c e s
FIGURE S . t
ber informat.ion across a delay, amnesic patients' explicit memory for
1 39
ongoing t:xperienccs is devastated. _.,
. 0fI�' .� { "'PI"
"-••l�"wn
HM provided the first direct evidence that stru nures in the medial temporal lobe play an important role in memory. [n addition ro his severe anterograde anmesla (that is, inability to remember t:vents that occurred after the operation), H M also had some retrograde amne sia-he failed to recall events from several years preceding his opera tion. For instance, l-IM had forgotten about the death of a favorite uncle approximately three years earlier. Subst:quent research suggests that the pcriod of HM's rctrograde amnesia covers more than JUSt
,,'-'lil
three years prior ro the operation. When tested in the early ·1 980s , he
Op,;., '"
did not rem ember any speCIfic episodes that had taken place m the decade before his operation at age twenty-seven, but he remembered many episodes that occurred before his sixteenth birthday. This telll poral gradient provided imponam early suppOrt for the consolidation hypothesis discussed in chapter 3, which hold.s that the mcdia[ tem poral region is crucial to memory for
a
limited period of time after
initial encoding of an experienc e. Because HM had no difficulty recalli ng childhood experiences, the engrams for such memories pre sumab[y had become fixed or consolidated in the extensive cortical "
networks outside the medial temporal region that subserve long-term storage. Accordingly, his retrieval of such expe riences no longer
This figure allows us to look " through" the cerehral cortex and vicw some of the structures that occupy the inner regions of the brain. The hippocampus. parr of the limbic system, and the thalamus. parr of the diencephalon, both play important roles in explicit remembering. The amygdala. also part of the lim bic system. is critical for cIIIQlional mcmorics (see chapter 7). Tht, ccn:bellulll, part of the hindbrain, is prominently involved in proCCdurlJ memory (sec chapter 6). Reprinted from F. E. Bloom :ltld A. Lazerson, Bmi" , J\lli"d, lllld BeluwjoT, 2d ed. (New York: W H. Freeman Co .. 1988).
depended on an imact medial temporal lobe. In the years that followed thc publication of Scoville and Milner's pioneering observations, H M 's case was often cited to support the idea that memory for rect:llt events depends on the hippocampus, the
Sinal! seahorse-shlpcd structure th:lt is a critical component of the medial temporal lobe system. During the 1 9705, research crs who stud ied meillory in rats and other amnu.ls reported that lesi ons to the hip pocamp us produce Inarked deficits in an animal's memory for recent experiences, particularly for spatial layouts: These
operation, HM's MQ was 47 points lower than his IQ.)
observ:ltions
seemed to dovetail with HM's situation, but since the hippocampus
The surgical removal of HM's medial temporal structures had
was only one of several structures rcmovt:d from IllS med I al temporal
demolished his explicit memory of recem experiences while le3ving
lobc, his case could not dctermjne whether damage restricted to the
unscathed hiS general level of intelligence. Indeed, the key ro under
hippocampus c a uses severe amnesia .
st:lllding amnesic patit:nts like HM is realizing that their disorders are
[n
1986, Stuart Zola-Morgan, Lar ry Squire. and David Amaral
highly selective. Gcncr:ll intelligcnce, perceptual functions, language
described RJj, a p:Jtienr with damage restricted to the hippocampus.
comprehension and production, and various kinds of knowledge and
When he was fifey-two years old , RJ3 had undergone coronary artery
skills are an spared. Immediate or working memory is likt:wise uuim
bypass surgery and shortly afterward suffered an arterial tear that
pairt:d : when tested immediately, amnesi c patiems can remember just
caused a temporary loss of blood flow to rhe brain. This is known as
as many numbers as normal volunteers. But when required to rcmCll1-
ischemia, and is ofren produced by temporary loss of oxygen to the
Sl'll fCh illg Jor M e m o ry
Va n i s h i n g Tra c e s
brain as a resuh of cardiac arrest-a cOl11mon cause of amnesic syn
Brazil. Everything went well until New Year's Eve: " It was just before
dromes. A p
midnight," David relates. "The champagne was open and
field is especially sensitive to ischemia.
'thank God the eighties are nearly over.' Then I started getting chis
140
When RJ3 died, ill 1 983. Zola-Morgan and coUeagues carefully
headache that got worse and worse.'"
141
I thought
As the headache became
examined hi� brain and found damage only in the CA 1 field of the
increasingly unbearable, David became confilsed and sick, then fell
hippocampus. Other structures within the medial temporal lobe, as
into a coma. He did not fully regain consciousness until after he had
well as el�e\Vhere in the brain, were almost entirely unaffected. Hut
been Hown back to England. He woke up in a London hospital
ItJ:fs amnesia was not as severe as HM's memory loss, and Jill had
remembering virtually nothing about his past. He possessed little or
almost no retrograde amnesia. More recently, two patients have been
no memory for ongoing events, and was unable [Q speak or compre
described who also sustained significant damage only in the hip
hend what others said. Writtt'n words were meaningless strings ofiet
pocampus; their melnery impairments were generally similar to JU3's,
ters to him.
except th:u they had more extensive retrograde amnesias.J These
David had contracted a herpes simplex virus in Brazil that spared
observations indicate that damage to the hippocampus alone can pro
his right hemisphere but destroyed much of his left temporal lobe and
ducr.: a clinically significant memory loss. The kinds of profound
its connections to other regions of the left cerebral hcmjsphere. Con
amnesia observed in HM and Frederick may require damage to addi
sequently, his verbal rnemory and his ability to usc :l11d understand
tional medi:1i tempor:11 lobe structures.
language had been obliterated. Nellrologist� and neuropsychologists
This idea is supported by observations concerning a rare but dev
have known for over a century that language and verbal abilities are
astating neurological condition that often produces amnesia: herpes
heavily dependent on the left hemisphere, whereas nonverbal and spa
silllplex encephalitis. Herpes simplr.:x, a dangerous virus (hat is the pri
tial functions are more dependent on the right hemisphere. Memory
mary cause of encephalitis in Western societies, produces symptoms of
is simibrly bteralized. Patients with damage to th(· left hippocampus
infection lhat include high fever, vomiting, and severe headaches.
and medial temporal lobe tend to have difficulties explicitly remem
Unless trt'ated quickly, encephalitic infection can produce serious
bering verbal information but havc no problems remembering visual
brain damage. Structures throughout the medial temporal region are
designs and spatial locations. Patients with damagr.: to the right hip
particularly vulnerable to herpes simplex, perhaps because the IClI1pO
pocampus and medial temporal lobe tend to show the opposite pat
ral lobe is close to the poim at which the virus enters the brain, or
tern.9 In cases of global amnesia, like those of HM, 5S, Boswell, and
because the virus has a special affinity for the specific neurochemical
R.n, damage to both the len and right medial temporal regions results
and neuroimlllunological properties of the temporal lobe.6 Sadly for
in poor memory for both verbal and nonverbal information.
those infected, herpes simplex encephalitis call produce the son of
[Jut David Jane's right hemisphere was perfectly fine and, during
full-scale annihibtioll of explicit memory for recent experiences seen
the earliest days of recovery. while hi� state of consciousness was still
in HM and Frederick. One patient known in the amnesia literature as
rather hazy, he tried to paint again and found chat he could. When he
SS used to be a physicist who worked on laser technolob"Y before COI1-
returned home from the hospital and faced the excruciating task of
rracting encephalitis. SS 11:ls maint:J.ined :J.11 IQ of 136, but he forgets
learning to read, speak. and write again, he continued to paint with
most of his experiences after just a few minutes. Likewise, another
relative ease. His subject matter, however, had ch;lllged. Instead of
well-studied patient known as Boswell seems CO have no explicit
painting landscapes and temples, David felt irresistibly drawn toward
memory for reccm experiences despite generally imact cognitive
the high-tech nnages of his own br:lin that revealed dearly and dis
fUllctions.?
passionately the damage that had radically altered his melltal life. He
I recently encountered a particularly affecting case of encephali(is
embarked on a series ofpaintings of magnetic resonance image (MR.I)
induced amllesia involving a young British artist. David Jane, a
scans that showed with pinpoint precision the areas of llis left tempo
respected painter in his mid-thirties, had exhibited his pictures of
ral lobe that had been destroyed by (he herpes silllplex virus. But these
landscape forms and ancient Indian temples in Slllall London galleries.
paintings arc nOt merely slavish copies of the MR.I images; the artist
In 1989. he and his family decided to take a Christmas vacation in
has succeeded in creating novel and highly personal interpretations of
142
S t' llfc/!itlg for M e m o r y
FIGURE 5 . 2
his brain scans. His paintings convey a n eerie sense of how mind and memory arc exquisitely, perhaps frighteningly, dependent on the integrity of the brain, as exemplified by ';ReafTirmarioll
II" (figure
5.2). When J spoke with David Jane in early 1994, four years after the onset of his amnesia, his speech was still somewhat labored but he expressed unswerving determination to carry on with his art. David's new paincings had been shown publicly in 1 993, and they received glowing reviews. HI
David remarked, only
half�jokingly, that the
destruction of his left hemisphere seemed to free up the right side to cn.',lte more boldly than before his illness. But he is acutely aware of his memory problems, and still has difficulty reading and writing. Davids memory impairments are much broader than rhose observed in classical cases of amnesic syndromes; he lost much of his semantic knowledge, Among encephalitic patiel1t�, however, D:wid's case is not unique. When the virus spreads widely throughout the telllporal lobe, and particularly when it damages the front of the temporal lobe, patients can have great difficulty accessing general knowledge about familiar objects, places, or words. II
MOl/keys mId Memory With the relatively r::are exception of cases like RD, brain d::amagc in amnesic patients is not neady restricted to the struclllrcs that are of interest to memory researchers. Studying amnesia in animals, though, enables scientists interested in the brain systems that subserve meillory to make precise, experimentally controlled lesions to specific brain structures. In 1978, the neurosClencist Mortimer Mishkin of the National Institute of Mental Health made a major contribution to the analysis of brain and memory by producing an analogue of human amnesia in monkeys. Mishkin used a simple task in which the animals are shown
David Jane, "Reaffirmation n," 1992. 40
x
26", Oil on paper. Courtesy
of the artist. �leTl;' we sec Jane's in�erpret�tioll ora coronal section oran MRJ scan. Jmag me that you arc looklllg 3t the front of the brain toward the back. A coronal section depicts a top-to-bottom slic\." of the brain at a p:lrticular location in the
a small toy for several seconds. Shortly thereafter, the monkeys are
from-back plane. The standard radiological cOI1VCmiOIl is to show the left side
shown the same object, plus a new one. Whenever they choose the
011 th� right and the right side 011 the left. This paint"Jllg incorpo �tes thIS con�'elltlOn: the small circubr dark :lrea in the middle of the right . SIde of the p:ullUng represents the lesion that caused D;lVid's lo�s of memory
new one, the monkeys are givell a food reward. Once they learn the rules, monkeys can demonstrate recognition of what they were shown earlier by choosing the novel object, Mishkin observed that removing either the hippocampus or the neighboring amygdala had no effect on the monkeys' abilities to recognize which object had been pre�ented earlier. Bm removing bOll! structures led to a massive memory impair-
of the
�rain �
(dl.lnage are;Js ofthe bralll �ho\V up as dark SpOts on an Mit! scan).Tht· large . . . d1rk cavltles 111 the Iluddle of the pa11lting arc known as ventricles, which also �how up as dark regions on 3n M Fl l . The brain :lS depictcd in "Reatlir11lation II" �s a dangcrous. foreboding place, full of olmnous crevIces and fissures. Look Ing at th� pa�1l1ing, we can begin to appreciate the shadowy, foreign world of . encephalitIS-Induced amm.'Sia.
Sctlrcilillg Jor MClll o r y
Va n i s h i n g Tra c e s
!l1cm: rhe monkeys withom a hippoc3mpm and amygdala could learn the rules of the cask and perceive the objects clearly, bue they were just abom as forgetful as patient HM.12 Since rhe publication of Mishkin's pioneering study, there has been a grl:ar deal of research on memory in brain-Iesioned l11onkl:ys. It is now well established that damage to the amygdala alone does not pro duce a serious impairment of recognition memory (as I discuss in chapter 7, however, the amygdala does play a major role in memory for emotional experiences). 13m there has been a lengthy and often animated debate about whether damage to the hippocampus alone produces significant impairments of recognition. A nurnbcr of psy chologists and ncurobiologists have argued that the hippocampus is a key structure-perhaps 1111' key structurt.�underlying explicit mem ory for recent experiences in monkeys, humans, and other animals. In the c:lrly 1 970s, neuroscientists exploring the ceHular basis of mcmory discovered th:u electrical stimulation produces a long-lasting increase in the activity of synapses (the contact points between neurons) within the hippocampus. Called long-term potentiation, or LTI� this persisting effect of stimulation showed that hippocampal synapses can be altered by expericnce-a necessary property of any mell'lory sys tem in the brain. Although it has also been shown that other brain regions exhibit lTP. too, the initial discovery of LTP within the hip pocampus led many neuroscientists to focus intensively, almost exclu sively, on how this strUCtUfC contributes to memory. U While everyone agrees that the hippocampus plays a role in explicit memory, some havc comended that it is not involved in all aspeces of explicit recall and recognition. John O'Keefe and Lynn Nadel have argued that the hippocampus serves to create a mcntal map of the ellvironlllent, and is crucial to memory only when people or animals must rel'llclllber 1Ill! spaCial locations of objects and events. Recent experiments with monkeys indicate chat when recall of spatial loca tion is nOt specifically required, damage to the hippocampus alone produces a modest deficit of recognition memory that is 1110St evident when monkeys are tested after relatively long delays.'� Something seems to be amiss here. If damage to the amygdala alone produccs no memory deficit and damage to the hippocampus alone produces only a modest one, how can joint damage to the two struc tures yield profound amnesia? Using improved surgical techniques that allow researchers to make more precise lesions than was possible previousi)" Mishkin's group and a team headed by Zola-Morb>an and Squire have shown tha( severe deficits of recognition memory result
from damage to a duster of cortical structures in the Illcdial temporal lobe (the emorhinal, perirhinal. and par:lhippocampal cortices) that are adjacent to, and a major source of input for. rhe hippocampus and amygdala.'� Mishkin's early finding 11m joint damage to the hjp pocampus and amygdala causes amnesia resulted [rom inadvertent damage to adjacent cortical areas during surgery. The neweT findings are consistent with observations concerning human amnesia: some of the temporal cortex adjacent to the hippocampus and amygdala were removed in the severely amnesic patient HM, but such areas were not damaged in cases of milder amnesia such as Rll
144
145
Korsakoff's S)'tldrollle Taken together, studies of human patients and experiments with monkeys show convincingly that damage to the medial temporal lobe can cause amnesia. But the stOry of the brain and amnesia doesn't stop here, because bTain damage in some amnesic patienes is found pri mariJy outside the medial temporal region. For example, patients with Korsakoff's syndrome, who have a long-term history ofakohol abuse, show a profound loss of Illcmory for recent expeTiences that likely results from a thiamine deficiency sometimes linked to alcoholism. AlcoholisTll itself can lead to mild memory problems. but most alco holics do not develop a full-blown Korsakoff's syndrome and associ ated amnesia. If> The onset of Korsakoff's syndrome is u�ually accompanied by a transient episode in whjch the patient suddenly becomes disoriented and confused. While in this acute stage of the illness, a person's behav ior may change radically from one moment to the next. One Kor sakoff patient interviewed in 1959, for example. knew the year he was born and correctly figured out that he was sixty years old. The next minute, he insisted thar it was 1 928 and that he was still a young man. Another conceded that he had been all a hospital ward for two weeks, but IJunutes later laullched into :I talc of having gone to church and dinner \Yllh his doctor the previous Sunday. One patient denied being married when a psychologist asked her about the wedding ring she wore. Then she proceeded to "recall" three f.tbricated husbands. The next day, everything she talked abollt involved her real husband. l1 When thjs confusional state ends after several days or weeks, patients emeTge with a chronic and debilitating memory impairment. In addition to memory loss. Illost patients with Korsakoff's syndrome
Sea r c h i llg JOT M e m o ry
Va n i s h i n g T r a c e s
have cognitive and motivational problems-they tend to be cogni
medial tcmp0r:ll lobe or to the diencephalon. These two regions are
146
tiveiy apathetic and to show linle affect. The psychologist Howard G:mincr relates a conversation from the carly 1 970s with a typical Korsakoff patiem that illustrate's these qualities. When he encountered Mr. Q'Dolilldl on the ward of the Boston Veterans Administration Hospital, the p:ltient was Ripping through a mag:tzinc with a cover story on the explosive issue of the day: the Watergate cover-up. Asked
147
connected by :1 structure known as the fornix, which is a major om pUl pathway of the hippocampus. The interconnectedness of the rwo areas suggests that a brain network involving both the medial tempo ral and the diencephalic regions plays a key role in explicit memory, and that damage to structures in either the medial tempor:ll or dien cephalic components of the network may cause memory problems.l!1
what was in the magazine, Mr. O'Donnell responded, " Oh, politics
This idea fits well with the recent work on brain-lesioned monkeys
and all that. I don't fo llow it much."When Gardner asked specifically
that h:ls highlighted the import:lnce of the encorhin:ll :lIld adjacem
about Watergate, the patient remained indifferent: ;;Oh, I don't pay it
cortices in memory function. These ateas funnel inputs from earlier
much mind. I've been busy lately and haven't been keeping up." But
processing stations all over the brain that deal with difTerelH aspects of
surely, Gardner con(inued, you mllst have he:lrd of W:uergate. "Oh,
experiences-the sights, sounds, and smells that make lip everyday
yeah if you say so, Doctor," O'Donnell conceded, "but I don't have
episodes-to the hippocampus, amygdala, and their targets in the
any opinions about that sort of thing:' Could the patient say anything
diencephalon. Here, the inputs :Ire linked or bOllnd together to form
at :III about Watergate? " Oh, they got sonle stool pigeon, or something
engr:nns that underlie explicit memories for day-to-day episodes.
like that. It's all the same to me.""
Damage to the emorhinal region, then, should have grave conse
Despite a generally bland state of mind, Korsakoff patients, like
quences. If the emorhinal cortex is dysfullClional, thell the entire
other amnesic patients, achieve IQ scores in the normal range and
medial temporal-diencephalic network is sure to pay a heavy price,
generally 20 to 40 points higher than their MQs. In other words, their
because little information can enter the system.
motivational and COb>11itive deficits arc not suffici('m to explain their memory loss.
These considerations provide possibly important insights inco the devastating memory loss I witnessed during my twO rounds of golf with Frederick. Recall that he W".IS in the early stages of Alzheimer'.) disease. Severe memory impairment is one of the most COlll1110n early
Alllllesia lIlId rl,c D;CllfCplw/o/l Postmortem studies of Kors:lkofT patients' br:lins h:lve rcve:lled the
signs of the illm!ss; in some cases, amnesia may bl' the only major sign of pathology until the disease runs its inevitable course and produces a global deterioration of imelleclu:l1 function. There is now consider
presence of extensive d:lmage in a collection of subcortical struCtures
able evidence that the major pathological signs of Alzheimer's disease
known as the diencephalon. Two prominent components of the dien
(known as neuritic or amyloid plaques and neurofibrillary tangles) arc
cephalon :Ire the thalamus (an important switching station in the br:lin
initially concentr:lted ill the encorhiml cortex, as well as the hip
through which vinually all sensory input passes) and the mammillary
poc:llnpus.ll Frederick could perceive ongoing events during a round
bodies (a nucleus of cells located just below the thalamus; see figure
of golf, but those perceptions could nOt be transformed inco explicit
S . I ) . The thalamus, you may recall, was damaged in patient GR, who
memories because the critical input padnvay to hippocampal and
lo�t and bter recovered his emire past, and also in patient PS, who
diencephalic networks was probably ravaged by accumulating deposits
lived with the delusion that he would soon be sailing on a ship dur
of neural debris.
ing World War 11. KorsakotTpatients usually have abnormalities in both
Studies of human amnesia and dellH!lltia, together with findings of
the thalamus and the Illammillary bodies. Studies of the brains of some
memory impairment in monkeys, convey a profound lIleSS:lge: a
Korsakoff patiellts, using either MI't1 to visualize damaged tissue in
neural system within the medial temporal-diencephalic region carries
living patients or direct examination of pathology in postmortem
Ou( functions that arc vital to e�tablishing new explicit memories.
cases, have revealed abnormalities in the hippocampus :md other parts
This system allows us to link together the varied components of
of the medial temp0r:ll lobe as well.'9
everyday episodes into integrated records of experiences: what we see
The amnesic syndrome, then, can result from damage either to the
and what we hear, what we think and how we feel. Medial temporal-
Stare/rillS Jo r .\ltmory
Va n i s h i n g Traces
diencephalic structures arc thus essential to episodic memory, and th�y also contribute to the formation of new semantic memories. AmneSIC patients gener-illy have difficulty learning novel f:'lcts and vocabulary, . although with enough repetition some of them can acqUIre new semantic knowledge. And in addition to failing to recollect episodes in rich detail, they feel licde of the rudimentary sense of familiariry about recent events chat most of us experience routinely. For instance, in experiments that required participants to say whether they actually "remember" specific details of a recent event or just "know" that it seems familiar. amnesic patients made fewer remember and fewer know responses than peoplc with normal melllory fUllction.n Dam age to medial temporal and diencephalic structures dot:s not destroy all forms of memory: even amnesic and demented patienrs can be unconsciously influenced by ongoing experiences and can acquire new skills. Out these implicit melT10ries appear to be based on isolated slivers of information, rather than on the multimodal engrams that underlie explicit relm:mbering. Our ability to form explicit memories of day-to-day experiences is inextricably intertwined with the normal Row of information inro and out of the cluster of cells and synapses, hidden deep within the innermost regions of brain, that comprise the medial te.mporal-diencephal,c circuie.
these types of knowledge depends on the integrity of specific con stclbtions of underlying brain structures and processes. Gene helped teach me some of these lessons. He developed amne sia when he sustained a serious head injury during a 1 98 1 motorcy cle accident th:1C damaged large sectors of his frontal and temporal lobes, including his left hippocampus.l.lThirty years old al the time of the accident, Gene. like Frederick, is now unable to recall day-to-day experiences except for a few isolated new facts (see chapter 4). In addition to his anterograde amnesia. however, Gene also shows a remarkable fornl of retrograde amnesia. Unlike amnesic patients who obey R..ibot's Law, Gene is unable to recall a single specific episode from any time in his life. Asking Gene about his personal past is an almost unnerving expe rience. He is a quiet, polite. and affable young man who always tries his best to come up with answers to questions that are posed to him. But no amount of prompting or ctleing helps Gene recall specific past eventS, whether happy or 5.'ld. at school or at work, or including fam ily or friends. Even when detailed descriptions of dramatic events in hi� life are given to him-the tragic drowning of his brother, the derailment, near his house, of a train carrying lethal cheulicals that required 240,000 peoplt· to evacuate their homes for a week�Gene does not generate any episodic memories. Though he had bet:n an avid motorcyclist prior to his injury. Gene no longer remembers any of the numerous trips he had made Wilh his cycling buddies. or can he recall the frequent visit.� to bars he used to make with his friends. Whereas other amnesic patients usually can dredge up some episodes from the distant past, Gene remembers absolutely nothing. I-Ie looks at me with a puzzled expression, as if he understood that he should be able to provide a response to my questions. Gene appreciates that peo ple are generJlly able to recall specific incidents from their pasts. Sit ting quietly trying to come up with an episodic memory, he is apt to emit a nervous laugh-a sort of recognition chat it is strange, almost silly, that he cantlot come up with anything. Then there is usually a sigh of resignation as Gene acknowledges that nothing is going to cOllie to him. Within a couple of minutes, this incident, too, vanishes into the black hole of his episodic memory. A life without any episodic memory is psychologically barren-the mental equivalent of a bleak Siberian landscape. Nothing much hap pens in Gene's mind or in his life. He has few friends and lives quiedy at home with his parents. He performs many of the saille routine activities again and again. And just as his recollections of the past arc
WHEN THE PAST D I SAPPEARS Retrograde Amnesia a n d the Structure of Memory
We have already seen that patients with damage re�trictcd to the medial temporal lobes have retrograde amnesias that obey Ribot's Law: such patielltS can remember many experiences from the distant past but few from the reccnt past, juSt prior to their brain injuries. Dut . . I1UO when brain damage extends out�ide the medial temporal regIOn, areas of the cortex where engrams arc :lctu<111y stored or regions lhat are essential to retrieving memories, we sec much more extensive ret rograde amnesias that sometimes blanket nearly all of a patient's per sonal past. These retrograde amnesias underscore that our normally seamless awareness ofepisodes from our personal pastS and knowledge of the world masks a great deal of underlying complexity. Remem bering one's wedding depends Oil a diAerent brain network than knowing where a bar of soap can be found. Recognizing a submarint: requires differen! nellral machinery than recognizing l spider. Each of
149
Va n i s h i n g Tra c e s
Se/Jrc h i llg jor Mem o ry
ISO
151
dcvast:ncd, he thinks little abom the future. It does not occur to him
Though Gene's total loss of episodic memory is rdrc among amnesic
to make plans, and he has nothing to look forward to. If Gene were
patients, a few other patients are almost as badly impaired. The
told today that he would soon be going on a trip around the world,
encephalitic patient Boswell is unable to recall a single specific episode
he would forget this incident as quickly as any other.
&om any time in his life. SS, the ex-laser physicist who contracted her
But Gene knows some l hinbl'S about his past. He knows where he
pes simplex encephalitis, cannot recount specific episod('s from any
went to school and that he worked at a manufacturing plam for three
time in his life. \Vhen SS is asked about his past he does not respond
years prior to his head injury. He knows that he owned twO lllotOr
blankly, as Gene does. He can rcg:tle listeners with s[Qries aboul his
cycles and a car. that his family owns a Slllllmer cottage where
childhood and other times in his life. l3ut SS's reminiscences are lim
I�e h�s
spent Illany weekends, and what the names are of the students 111 his
ited to oft-told tales about the general characteristics ofjobs he held or
class photograph. Gene has also retained a good deal of nonpersonal
people he knew. \Vhen asked to ebborate on one of his stones, or to
semantic knowledge that he acquired prior to his accident. He can
provide information about the circlllllstances or settings of particubr
describe :'Iccllr:ltely and in detail each step lIlvolved in changing :'I flat
incidents, SS is at a loss: he c:'lnnOt embellish his general descriptions
tire, even though he cannOt recal l ever having changed one himself.
with additional contextual details. SS has, however, also retained a con
Gene can also name a number of former co-workers and correc tly
siderable amount of the technical knowledge he acquired before
identify sorne photographs and drawings of eq ipment fr� 111 the 1� 1an ufacturin� plant where he used to work. Even more lI11presslveiy,
becoming ill, and maintains a high level of vocabubry and general knowledge. He is able to recall ... nd recognize some famous people
Gene easily and correctly defines technical terms he learned 011 the
from the past, albeit fewer than healthy people of his age.n
u
job, such as
ke)'way s/rmrk, spiral mmrdrei,
and
srellite.
The kind of memory loss l!xperienced by Gene and SS shows that
Gene·s :ltHobiographical knowledge is akin to the nonpersonal
semantic memory can be partially preserved even when episodic
knowledge most of us have of other people's lives. I know, for insta�lCe.
Illemory is entirely dysfunctional. Traditionllly, psychologists have
that 11Iy father served on a warship in Italy, and I know many thmgs
defmed semantic memory as a network of associations and concepts
abom dlC neighborhood where my mother grew up because my par
that underlies our basic knowledge of the world-word meanings,
ents often talked to me about what happened to them in the past. l3ut
categories, facts and propositions, and the like. But the retrograde
I have no episodic recollections of the settings and circumstances of
amnesias I have just considered suggest th:'lt semantic memory also
their experiences. I can acquire all kinds of factual knowledge abollt
forms the basis for a good deal of personal, autobiographical knowl
another person's past withom h:wing any of the specific recollections
edge. Even Gene can provide S0111e autobiogr:lphical "facts" about
that belong only to that person. So, toO, with Gene: he knows thinb "S
general features of his prl'-accidelll autobiography. l3ecause he cannot
about p;lrtS of IllS autobiogr:lphy but does not remember specific pa�t
recollect any particular episodes, it is likely that everything he knows
episodes.
about his past is contained in semantic memory; Gene has a past, but
Interestingly, Gene can draw on this semantic knowledge when
it is strangely imperson:11.
asked questions about his current persol131ity and how it relates to what
This idea can be usefully linked to the distinction I discussed in
he W:-IS like before his head injury. Gene's friends and family agree that
previolls chapters among lifetime periods ("when I went to college"),
his personality h:ls changed sinct· his accident; he is now less active and
general events
otllgoing than he once WdS. To investigate Gene's knowledge of these
event-specific knowledge ("the big fight that ended the final footb:ll l
(
"
going to football b>ames during freshman year"), and
changes, Endel Tulving asked him and his mother to rate various
game o f the season"). Gene and SS have n o problem recalling lifetime
aspects of his pn:selll and past personal traits. The two gencr:llly agreed
period knowledge, and even show some knowledge of general events.
about the char:lCleristic features of Gene's previolls and current per
But neither has :lIly access to event-specific knowledge. Since Gene
sonalities. Despite an uner inlbility to remember a single episode of his
and SS have complete loss of episodic memory and panial loss of
OW11 behavior, Gene has managed to learn something about his new
semantic memory, perhaps lifetime periods and general events are part
traits. This is problbly because he is still capable of gradually accumu
of semantic memory, while event-specific knowledge is part of
lating semantic knowledge on the basis of repeated experienccs.l4
episodic memory and preserves the details ofindjvidual expericnces.lIfi
152
S e a r c h i ng for Mem(HY
Ncuropsychologisrs have described patients who are in some sense
Vanish i n g T r a c e s
153
Shallicc described four patiems with encephalitis who had great diffi
mirror images of Gene and SS: they can recall specific episodes from
culty identifying Itvmg things but easily identified most man-made
their lives, bur have lost much general knowledge of lhe world. For
objects. One patient, a forty-eight-year-old naval officer known by
instance, in a CJse of encep halitis descnbed by the Italian neurologist
the initials SHY, defined a wheelbarrow as an "object used by people
Ennio De Renzi, damage was largely confined to the from portion of
to take material about," a towel as "material used to dry people," ;md
the temporal lobe. a part of the brain that is important for semantic
a submarme as a "ship that goes underneath the sea." This same man
memory. This patient no longer knew the meanings of COlllmon
called a wasp a "bird that Aies," a crocus "rubbish material," and a spi
words, had forgonen virtually everything she once knew about his
der a "person looking for thmb'S; he was a spider for a nation or COUIl
torical cvcnts and famous people, and retained little knowledge of the
try." More recelltiy, other patients have been described who exhibit
basic attributes of animate and inaJ1lmace objects. She had difficulty
the opposite pattern: greater difficulty identifying inanimate objects
indicating the color of a mouse, and had no idea where soap would
than living things. And even finer-gr;lin distincdons between pre
ordinarily be found. Her semantic memory-the bedrock of our gen
served and impaired categories have been observed. The neurologist
eral knowledge of the world�\Vas horribly impaired. However, when
Amonio Damasio has described a patient who can recogmze tools but
asked about her wedding and honeymoon, her Lither's illness and
not clothes, and another who has little difficulty recognizing man
death. or other specific past episodes, she readi l y produced detaIled
made objects except for a terrible problem with musical instruments.2'I What accounts for these unusual impairments? Does the brain
and accurate recollections':'? A similar pattern has been seen in some elderly adults with a dis
orgalllze �elllantic knowledge along strictly categorical line�? Proba
order called "semantic dementia."These patients have difficulty nam
bly not. Damasio and others have suggested that apparent category
ing common objects, and have an impoverished vocabulary and poor
specific disorders arc related to the kinds of information that are used
comprehension of individual words. Over time, their semantic knowl
to identify panicular emities. We tend to distinguish among animals
edge of words, objects, and facts gradually dissolves. Although they still
and plants based on details of their Visual appearance, whereas we tend
have general categOrical knowledge-they can distingUish between
to distinguish among tools based on actions we perform when using
living and nonliving rhinb'S, for example-they retain little or no
them. Patients with problems recognizing objects 011 the basis of
knowledge about specific attributes of objects. One patient, for
appearance would therefore also tend to have particular difficulties
instance, was asked to identify a picture of a deer and responded, "Ani
recogmzing living things, whereas patients with problems recognizing
mal, gives milk, like sheep." Another was shown a picture of a violin
objects on the basis of functions would tend to have particular diffi
and responded, "Is it an instrument? I think it's made of metaL"These
culties recognizing such man-made objects as tools.
same patients can remember what they had for breakfast or where
A recent PET scanning study by Alex Martin and colleagues at the
they went on a recent vacation; their episodic memories arc preserved.
National Institute of Mental Health provides some insight into these
The semantic impairments in such patients resemble similar deficits
startling disorders. When healthy volunteers identified pictures of
that h;tve been documented in patients with Alzheimer's disease. BtH
either animals or tools during separate brain scans, areas in the lower
in Alzheimer's patients, disorders of semantic memory arc genera.11y
pans of the temporal lobes that participate in the perception of com
accompanied by severe deficits
episodic memory. Patients with
plex objects showed heightened aerivity (blood flow increases) com
semantic dementias are important because they Indicate that semantic
pared to control conditions. But when they Identified picrures of
memory can be seriously impaired even when episodic memory
tools, there was also mcreased blood flow in the left premotor cor
functions reasonably well.28
tex-an area that becomes extremely aerive when people simply
III
Semantic memory may sometimes break down in bizarre ways [hat
imagine rnoving their ha.nds to grasp an objecr. Identifying tools W:IS
provide important clues to how our general knowledge of the world
also associated with heightened activity i n a part of the left hemi
is represemed in the brain. I n some particularly intriguing cases,
sphere (rhe middle temporal gyrus) that is involved in producmg
patients lose only certain categories of knowledge. For example, i n
action words (such as write) . These results suggest that knowledge of
1 9 8 4 the British neuropsychologists Elizabeth Warrington and Tim
tools, but not of animals, depends 011 brain regions that represent
Illovements and actions: things people do when using tools. These areas of the brain are typically d:lln:l£ed in patients with problems naming man-made objects, wherca� regions toward the rcar of the brain that represent distinct visual features of complex stimuli tend to be damaged in patients with problems nanting living things. The peculiar category-�pecific impairments seen in some brain-damaged patients arise because distinct brain networks are responsible for knowledge of different properties of objects.:ltl When
functioning smoothly,
the brain
155
Va n i s h I n g T r a c e s
Sea rcllitlg for Memory
systcrl'lS
that
suppOrt
episodic and semantic memories allow us to recognize object.� ill the world, to tr:lvcI in time, and co cons{ruct our life stOries. Bur when they are disrupted by brain d:l.Ill:lgC. we are afforded a glimpse of the building blocks from which we build tht" tales of our past that confer coherence and lIle:ming on our day-to-day lives.
culties. His observation has been confirmed by many subsequent . . deSCriptions of patients with Korsakoff's syndrome. When Howard Gardner spoke to Mr. O'Donnell. he 6r:lve him several words to remember and asked him to recall them sev('fal minutes later. Mr. O'Donnell could not remember :my of tlwm.
"
I guess I wasn't paying
enough attention," reasoned Mr. O'Donnell. Gardner repeated the exercise, but the outcome was the same. "Sometimes I get preoccll pied," the patient explained. " My memory's fme, J think ."}l Korsakoff amnesics often overestim:lte how well they will pe,form 011 memory rem. Like Mr. O'Donnell, they believe their memory is jusr fine, so they think they will remember as much as anybody else. Simply telling the patients that they have a memory problem has lit de efTecr.H Patients who develop amnesia as a tesult of head injurie� are also often unaware, or only panly aware, of their memory prob lems, :ts arc patients who develop memory problems as :1 consequence of burst :tneurys1lls in the anterior communicating artery. The ante
EXPERIENCING AMNESIA A w a r e n e s s a n d U n a \\' a r e n e s s o f M e m o r y L o s s We have aU had the experience of forgetting a routine act we have just per(onned. [n the midst of a long drive on the in terstate, deeply immersed in ollr private reflections, we Illay suddenly realize th:n wc can't remember any of the sccl1l:ry for the past several miles. This kind of ":mmes1a" occurs because attention is required to form new
episodic memories, and when our anentional resources are consumed by internal thouglm and feelin&"S, there are few left over for dealing with the world outside. We can corn fort oursdves by attributing such lapses of memory to being on " alltomatic pilot," but what if life were always like that? When Frederick and I played golf, he sometimes failed to remelll ber a shot he had hit minutes before; when I told him about it, he was amazed and bewildered. Frederick knew he had a problem with his memory, but he did llot appreciate how f.1r-reaching it was. Within minutes, however, he would inv:lriably forget what he had forgot ten-another testimony to the depths of his memory disorder-and resume the enjoyable business of striking the ball. There is a kind of poetic justice at work for patients with amnesia: the impairment might mercifully serve a protective function by pre venting patients from becoming aware of the catastrophic nature of their memory loss. In
1 889,
Sergei Kor�akoff noted that his patients
expressed little awareness of, or concern about, their memory diffi-
rior communicating artery supplies blood to the basal forebrain. a subcortical structure that provides the medial temporal lobes with a chemjcal messenger, acetylcholine. that is important for memory function. This artery also supplies blood to a lower sector of the frontal lobes known :IS the orbiofrontal region. Patients who have suffered ruptured amerior conummicating artery aneurysms have great diffi culty recalling recently presented information, but unlike
other
amnesic patients. seem to possess relatively imace feelings of familiar ity: they can show normal recognition of recendy acqUIred informa . tion when asked to choose between familiar and unf1mjliar alternatives. Like patients with frontal lobe damage, they have prob lems generating useful retrieval str.ltegies, and they also freqm:ncly en6'<1ge in bizarre conf."lbularions without any a\\�lreness of how implausible their conconions arc.»
A man I call Eric became amnesic after a ruptured anterior C01l1Illunic:uing artery aneurysm. Eric desperaH'ly wished to return to his job as an architect and insisted that his memory was :15 good as ever. Any occasional memory lapses on his part were insignificant, he claimed, and certainly not serious enough to prevent him from returning to work. In [.1Ct, however, Eric had little or no explicit memory for recent events. My colleagues and [ asked him to predict how likely it would be for him to remember various everyday sirua tions-such as a telephone conversation with a fi'iend-either a few minutes or a few weeks later. Eric gave himself high marks. But when we asked Eric's wife to rate his memory, she thought he would be
Searr/'; II,e Jor M e m o r ),
Va n i s h i n g Traces
unable to remember any of the events we asked about after more than
These deficits arise because key fUllctions subserved by fromal
a few minutes. The data we gathered indicated that his wifc's assess
regions--strategic retrieval and monitoring-are impaired in patients
156
ment was extremely accurate and that his was woefully wrong.><
157
with this damage. It seems likely that impairments of these same func
Not att amnesic patients show such unawareness, however; some arc
tions contribute to these patients' diminished aWareness of deficit.
3Clltcty aware of their memory problems Olle m3n who became
Consider for a moment how an amnesic patient could becOll"le aware
amnesic after en ceph aliti s commemed: "There's nothing wrong with
of his deficit. Suppose a patient attempts to recall some recent expe rience, such as what he had for breakf:lst this Illorning, and f.1iis to
.
me physically, but memally things as they happen don't seem to impress themselves on illy mind." Another patient with extensive ver
remember anything-no memory of munching cornA:lkes in the
bal memory loss as a re�ulr of d:nnage (0 the diencephalon character
kitchen, eating eggs Benedict in a restaurant, or anything else. If he
ized
I will fCmember
realizes that a persOIl with normal memory would have no difficulty
something when I need to remember it." Patient HM has some
remembering such an episode, then he should become aware that
awareness of his memory loss, and has said that he feels as if he is con
something i s amiss with his memory.
his
problem
as "not
knowing whether
stantly waking up from a drealll. In his recent biography of HM, the
Frontal lobe damage could imerfere with this kind of on-line eval
writer Philip Hilts describes conversations in which HM confesses to
uation of memory in various ways. For example, a confabubting
being concerned about slipp ing up in front of others because of his
patient may produce erroneous memories when attempting to recall this morning's breakf.1st. Mistakenly remembering that he had eggs
amnesia. He once described his condition as
;'
ltJhe loss of memory,
but not of reality."ll
Denedict at a 6ncy restaurant when he ate cornflakes in the kitchen,
Patients who have been amnesic for a long time could, if [Old of
he would have no reason to suspect that he is amnesic. In fact, clini
their memory failures over and over, eventually learn that they have
cal and experimental observations have revealed that patients who
them. Dut awareness of memory loss also occurs in patiellts who sud
confabulate also tend to be unaware of their deficit.l$ However, chis is
denly develop a temporary anmcsic syndrome known as transient global amnesia. This condition usu ally laSts for mere hours, is typically observed in otherwise healthy dderly adults, and is probabl y produced by temporary blood blockages in the hippocampus and related medial temporal lobe structures. These patients have problems remembering ongoing experiences and may also be afflicted by varying amounts of
not invariably true, and some patients who arc unaware of their deficit . do not conf1bulate. Frontal damage in these cases may disrupt patients' ability to integrate their observations of their own memory failures with their knowledge that normal people do llot have such problenls. Damage to structures other than the frontal lobes can also lead
retrogtade amne.sia, ranging from the past couple of years to the past
patients to deny the existence of deficits that are readily apparent to
couplc of decades.l6
others, sLlch as paralysis of arllls or legs. It has long been observed that
Why are some amnesic patients acutely aware of their memory
patients who have suffered strokes in the parietal lobe of the right
problems while others vehemently deny them? Patients who are
hemisphere maintain that their paralyzed limbs (on the left side) are
aware of their deficits might be better able than those who aren't to
fUllctioning normally. The psychologist V. S. R.:Il11:lchandran has reported some intriguing memory aberrations in an elderly woman
remember that tbey forget." Dut this seems unlikely because even severely :Ullnesic patients are sometimes well aware of their problems. The key to solving this puzzle probably ltes in the vast territory of the frontal lobes. Amnesic patients with impaired awareness are gen
who sllstained a right p:lri etal stroke. 13M lost the usc of her left arlll. but denied that it was paralyzed. She rationalized her inability to move her ann by saying that she was tired that day or simply didn't feel like
crally characterized by signs of frontal pathology, whereas amnesic
lifting it. Ramachandran performed an unusual experiment with her:
patients with intact awareness typically show no signs of frontal
he irrigated BM's left car with cold \vater. For reasons lhat are not well
"
,
Illlpairment.}1
understood, when this procedure is performed, some patients tem
We have already seen that brain damage restricted [0 Lile frontal
porarily stop denying their paralysis. (It may be that the damaged right
lobes docs 1I0t produce a fiill-blown amnesic syndromc. But it is often associated with source anmesia, f.1lse recog11ltion. and confabulation.
hemisphere is somehow stimulated into action by dlC cold water treatment; the right hemisphere is more strongly connected to the left
Searching for H .. e m ar),
158
FIGURE 5 . 3
side of the body than to the right-thus applying cold water treat� ment to the right ear generally has no effecL) After this procedure, DM acknowledged that her lefi arm was paralyzed and even stated correctly that i t had been paralyzed for st:veral days. Thirty minutes aftt:r the treatment, she said the same thing. Eight hours later, how ever, when the effects had worn off, OM once again stated with con viction that she could move her arm. When one of Ramachandran's colleagues asked what the two doctors had done to ha that morning, liM remembered the irrig-dlion. At first she didn't remember what she had said when the doctors asked about her arm, but then she asserted, " 1 said my arllls were okay." Ramachandran suggests that OM had selectively repressed the part of her Illemory that was inconsistent with her present beliefs: "it would have been very difficult for her [0 dt:ny her present paralysis and yet Jdnllt the insight she had acquirt:d 8 hours earlier, while at the same time maintaining an integrated self." In some amnesic patients, a similar kind of selective forgetting might help to maintain lInawarc� ness of deficit.)') Although the plight of OM and other patientS suggests that impaired awareness of deficit is a mercy. it is often an obstacle to improving the quality of their lives. Amnesic patients who acknowl� cdge their deficits Illay structure their environments so �s to lessen the load on their memories, or they may use notebooks :lIld other reminders to achieve some independcllce in daily living. OUt patients who deny or minimize their deficits oftell rnaintain unrealistic expec� tations about what they can accomplish, and so are less likely to ben� efit from intervention and training..fO But there is one circumstance in which imp�ired awareness of deficit can be
�
blessing: when the ravages of A1zheimer's disease
destroy both cpisodic and semantic memory, thereby shattering a pcr� son's ability to comprehend thc world. Early in rhc course of the dis� case, many AJz.hcuner's patients maintain acute in�ight into their problell lS, whercas others minimize or deny their symptoms. For those who retain insight, the awareness of their memory loss can be as CTuslling as forgetting itself. Diana Friel McGowin, a Florida leb':ll scc retary and mother of three, was diagnosed with A1zheimcr's disease at the tllll1sllaDy young age of forty-fiw. She has written a harrowing account of her dawning awareness that somcthing was terribly wrong with her memory. An intelligent woman who at OIiC time possessed an IQ of 1 37, McGowin recounts the sheer terror of discovering that she could not remember where she lived. Unable to find her way
E. Stocpcl�Peckhall1, "Alzheimer's I," 1 983. 2 1 x 16". Mixed media collage. Courtesy of the artist. Stoept'l-Peckhalll's tribute to her father includes a handwriul'o a
Ilcwspaper
c. xccrp
t rrom
article concerning memory Joss in AlzlH.'illlers patielHs; hut her
. SCript qUIckly degenerates IIno gibberish,just as {he disease deStroys the mind. Pictures or people who are rragmented beyond recognltlOIl allude to loss of memory, :lIld a cracked Illlrror highlights the l'ventual loss or self-awareness. Footsteps in the snow-tract"S of someone rrom til(' past-rem1l1d us that an ultact person once inhabited the decnnated world of the Alzheimer's patient.
A vetled photo of the artISt's f.1ther durmg his healthy years provides an image of that once�norlllal persOIl.
S c a re/Illig fo r Memory
160
home, she told a guard at a park entrance that she was Iost and he . asked where she lived: ;' A cold chill enveloped me as I reahzed I could
�
not remember the name of my street. Tears began to flow dowll n y
C1lee'-l"!>." When
he asked what I}art of town she lived in, " 1 felt panic . wash over me anew as I searched my memory and found It blank ' ." �'
SIX
It is excruciating for family members to wimess a patient's p:tinful
�
awareness of his own vanishing mcmory. " Alzheimer's is the cruelc t . of diseases" acknowledges the writcr Glenn Collins, reAecung on 1m _ f.'Hher's str ggle with :I ruthlessly advancing d eJlle' tia. "What s bad is . _ the meanness of it. The knowledge of forgemng. I he frustration and
�l
�
�
confusion and sh:tme of forgening."�l As cognitive function deteriorates over a period of years, mosl
�
�
Alzheimer's patients become progressively les aware of the extent, r . . even the existence, of their deficit... r�ecent eVldencc mdlcates . that thiS
T H E H I D D E N WOR L D O F I M P L I C I T M E M O RY
�
dimming of awareness in Alzheimer's patients is accoll1�alli d by an increase in conf.'lbllbtions on memory tests and by a decline III frontal lobe function. However, signs of frontal dysfunction arc probably 110t , . a necessary precondition for unawareness of deficit: some AlzhclIners
scn�
parient<; who pctform reasonably well on behavi oral tests that are . sitive to fromal damage are largely unaware ofthclr probl ms.
� �zheLmers,
mC1l1?ry
In a moving visual memorial to ber father's battle with
. disease the artisl Ellen Stoepel-Peckham portrays the deterioration of
�
meL�lo y, lIlteliect, and awareness in her collage " Alzheimer's r' (figure
5 .3).
. The artist highlights that when the past vamshes as a
rr:
D E C I:. M B E R A F T E R N O O N S darken carly in Boston. For most peo
ple, this is one of the more depressing features of the New England wimcr. I don't mind it much, because dlC early eveninb"S allow me to enjoy the sunset from the wUldows of Illy office near the northern fringe of the Harvard campus. The stunning view of the entire Dos[Qn skylinc is especially lovely in the fading light of dusk on a winter after noon. At thc close of one such afternoon in Decembcr 1993, I took a much-needed break and gazed out the windows. But my pleasant
su1t 0f . :tmnesia and demt,ntia, so docs much of the person. AppreClanng tI e
reverie was interrupted by the ring of a telephone.
present and anticipating the futun; hinge on an ability to . cate with the past. When we lose the capKit)' to travel III orne, we are
the prestigious New York firm of Cravath, Swaine, and Moore. His
�
.COl1unul1I
cur loose from much of what anchors our sense of who we are and where we :tre headed. Yet even in the most profound cases of anmc sia, the past ncvcr fully telinquishes its grasp on the present. When cxplicit memory is destroyed, the past continues to affect the presellt through subde influcnces that operate outside of awareness. To und�r . . stand these influences. we JllUst plunge into the world of IInpilcH
memory.
Ol
The caller introduced himself as Rowan Wils I
,
�n
attorney with
firm had been representing the compmer giam 113M in � major law suit in which questions about memory seemed likely to play a role. I agreed to hear about the case and to consider becoming involved i n it. Wilson's first qucstion struck an immediate chord: Is it possible, he wanted to know, for a person to retrieve mforlllation from a past experience without being aware that he is relying on memory? Most of 111y scientific efforts for the past decade had been directed toward precisely that issue. I had been conducting experiments investigating what Illy colleagues and I can impli(il IIIelllo,y: when people are influ enced by a past experiencc without allY awareness that they arc rememberlllg.Yes, I responded, a person most definitely can make use of memory (or a past experience wilhout ;lny :IW;ln.:ness of remell1161
Sedrc/dtlg for M e m o r y
1 ('2
T h e H i d d e n World of I l11 p l i c L t M e m ory
bering. But why on earth would a n attorney have any interest i n knowing that?
163
During the past fifteen years, psychology and neuroscience have made 1I111l1ensc progress tOward answering those questions. I t i s no
This one had excellem reasons: parts of his case hinged on the via
exaggeration to say that research on implicit memory has revolution
bility of the idea that memory can be manifested without awareness
ized how we measure the effects of past experiences and how we
of remembering. Wilson's case emailed a dispute over imellecrual
think about the nature of Illcmory.l The path that. led to implicit
property: Who owns the rights to the ideas and knowledge that an
memory-both for me personally and for the field :IS a wholt"-can
employee develops in the courst" of performing his duties? Much
be traced back to events that unfolded some twO decades earlier in the
depended on the status of wchnical knowledge residing i n the head of
ancient town of Oxford.
an electrical engineer who had once worked at IBM. Peler Bonyhard. Beginning in
1 984, Bonyhard played a key role in
IBM's development
of a revolutionary new technology for reading information from a computer disk. He had helped to develop what is known in the indus
WHY D O A M N E S I C PATIENTS L E A R N ?
try a� an MR (magneto-resistive) head.This almost unimaginably tiny,
When I arrived in Oxford just after the New Year i n 1 978, i t was the
paper-thin device uses a magnetically based method for decoding
first time I had ever been to England. I was captivated immedi:nely by
information stored 011 a disk that allows computer manufacturers to
the impreSSive towas and intricate spires of All Soul's College, the
pack much more information on(O the disk than they could with pre
golden brown stones of the magnificent Bodleian library, and the nar
vious technolofD'. The technical and fmancial implications of MR
row stOne paths that lead to centuries-old stores and pubs. Enrolled as
head technology are cnormOllS, and Bonyhard was a valued IBM
a graduate srudent at the University of Toromo,
cmployee.l3ut his services were also coveted by others. In
1991
Bony
I had been blessed
with a stroke of good fortune: my supervisor, Endcl Tulving, had been
hard left IBM to join a rival company, Seagate. that specializes in man
awarded a visiting chair at Oxford for a year and
ufac{Uring disk driv(.'S and heads.
most of that year with him.
I would be spending
113M objected to the fact that Bonyhard was allowed to work on
Tulving had arranged for me to meet weekly with Professor
Mil... heads at Seagate. While at 113M, he had been exposed to a large
L.1wrence Weiskramz. one of the world's authoriti(."S on how the brain
arl'1OUllt of confidential, trade-secret information about the manufac
accomplishes perception and memory. Weiskramz and his colleague, the
ture and function of MIt hea(l�, information he had promised not to
London neuropsychologist Eliz:lbcth Warrington, had recently pub
disclose. 113M contended that because he was deeply involved in Sea
lished several articles about amnesic patients that intrigued and puzzled
gate's attempt to develop its own Mit head, it would be virtually
memory researchers. In their experiments, amnesics and a group of
impossible--despite his best intentions-for Bonyhard not to disclose
normal volullleers studied a list of common words, such
trade-secret information. This was the heart of Rowan Wilson's case
den. When shown �omc of these words several minutes later, together
as
rable or gar·
and the reason he was consulting me: he suspected that Bonyhard
with words that wcre nOt on the list, amncsic patients had great diffi
might unknowingly divulge trade-secret information in his new job.
culty remembering which had been on the list and which hadn't. No
Although I Ilcver had the opportunity to address the issues-IBM
surprise here: previolls scudies had already shown lhat amnesics have
�H1d Sea gate settled their dispute and llonyhard could no longer work
problems recob'Tlizing words from a recently presented study list. B u t
directly on the developmem of MR heads-the c,lse raises questions
Warrington and Weiskrantz gave another kind of I'ncmory test. They
that are central to understanding memory's fragile power: To what
provided the first three letters of a word. such as tab--- or g:lT--,
extent can people show mCllIory for previous experiences even when
and asked peoplc to supply the remaining leiters. On this test, amnesic
they arc not aWJ.re of remembering them? What is the evidence for
patients wrote down more words from the study list than would be
sllch implicit memories, and how do they inAuence what we do and
expected if they were b '1H .. 'Ssing r.tndomly. Even more impressivei)" in
what we think in our day-to-day lives? What docs the existence of
some experimentS they wroCt" down as Illany words as did people who
implicit memory tell liS about the nature and organiz.1tion of mem
had no memory problems.2 How is it possible to explain such a curi
ory in mind and brain?
OliS pattern?
164
T h e H i d den World of I m p l i c i t M e m o r y
Sl'(/rdli ".� for .\lelU ory
olle reason �vhy �he three Warrington lnd Weiskramz suggested l to amnesIc patients: they lener cues might have been especially usefu vam memories that ordi help p:nicms avoid being confused by irrek: their recall of the correct narily spring to mind and interfere with orthy about the amnesIc answer. But something else waS notew r LO be aware �hat they \Vc�e patients' performance: they did llOt appea , they prOVIded them 11 recalling words from the study list when � d, they oft'en behaved as If response to the three-Iener [cst cucs. Instea showing menlory for the they were in a guessing b"all1c. They were ring" in the ordinary sense studied words, but they were not "remembe of the tcrm.
extraordinary about a Wciskrantz noticed something even more He started to study a .n�an different type of brain-d:lIll:lged paticnl. of damage to the Occipital who had lost much of his vision as a result s that arc necessary to per lobes, the structurcs in the rear of our brain n a light was Rashed in the ceive thc e.xterna! world around us. Whe damage, the patient typically part of visual space affected by his braill to " guess" the location of the claimed to see nothing. Bm when asked The paticnt seemed capable Rash, he performed extrcmely accurately! . . Weiskramz called this of some forlll of unconscious perception that it might bc relatcd in remarkable ability blilldsigllf, and suggested . . l . . ts. memory wlthom awareness III amnesIc patten to some w:w ' ns, which dovetailed with PIO I was excitcd bv ' these observatio a Milner and her colleagues neering st�ldies in the 1 960s by Urend t HM could h:':lr�l new showing that the profoundly amnesic patien moving target, hiS per a ing Illotor skills. Whe n H M practiced tr;ack intact memories-became forlllance--just like that of people with not awafC that he had ever increasingly accurate, HM, however, was
performed the task bcforc,' . ising findlllg. memory \Vhen fmt confronted with this surpr in it. The standard interpreta researchers did not show Illllch interest r skills bec;ausc motOr learn tion held that H M could learn new moto does not depend on the ing is a special kind of memory that ral lobe structures that were hippocampus and the other medial tempo researchers conceded that removed from HM's brain. Most memory of memory and pursued motor learning is different from other kinds \Veiskrantz's findings \"ieh the matter no funher. Yet \Varrington and nstration of blindsight in amnesic patients, wgether with thc demo ng in HM might �ave vision, suggested that preserved Illotor learni erintuitive observanons much broader implications. To me, these count n world of nonconscious intimated the existence of a subterranea
165
memory and perception, normally concealed from the conscious mind. I�hilosophers, physicians, and psychiatrists had already made spo . radiC observations about this intriguing hidden world. I was well aware that Freud and other psychoanalysts had theorized for decades about an unconsciOliS lIIind that is a repository of repressed wishes, . f.1I1taSleS, and fears. But, as far as I could tell, retention without aware ness in amnesic patients or perception without awareness in blindsight had nothing w do with repressed utges and desires. And there had been scant scientific progress in investigating or understanding the Freudian notion of the unconscious. Even before Freud, the British physician Robert Dunn reported in 1845 that a woman who h;ad been rescued from a near-drowning Illcidcnt seemed incapable of relllcmbering anything (probably because of oxygen loss to the brain). Dunn wrote with some alllazement how she learned to be a skilled dressl11:tker--even though she couldn't remember making any of the dresses! In 1 9 1 1 , the great French phiJosopher Henri Bergson distin guished conscious remembering of the past from le:trned habits that inRuence our beh:tvior unconsciollsly. Bergson argued with great e1o qllen�e that the past survives in two fundamentally different forms, consClo�s and unconscious. It was exciting for me to contemplate . uSlIlg sCientific techniques [Q study what Bergson and others had the orized about or observed in the clinic.� After returning to Toronto, J witnessed firsthand tht, peculiar kind of memory that others had described in amnesic patients. During the �un1Jncr of 1 980, Dr. P;lUl Wang, a clinical psychologist, invited lI1e to test a patient who had slistained a seriolls head injury in an accident. Theyatiem, whom I refer to as Mickey, remembered little or nothing of IllS recent experiences. I sat across a testing table from him and told him that I was going to try to teach him some interesting bits of trivia. . I :tsked him about obscure f1Cts that J had dredged up by rummaging through cncydopedia� and similar sources, sllch as "Where was the first game of baseball played?" (Hoboken) and "Who holds the world's record for shaking hands?" (Theodore Roosevelt). When Mickey did not know the correct answer-and he almost never did-I told it to
hi111. He was intrif:,Fued by these tidbits and enjoyed our trivia f:,'":lllle. A�tcr 1 lefi the testing room and returned twenty minutes later. Mickey maintained only a dim memory that I had tested him. He did not recollect that I had mentioned any items of trivia. Out when I asked him where the first game of baseball was played. he confidently answered "Hoboken," and when I inquired about the world's record
S e a rdli ".fl for M e m o r y
T h e H i d d e n World o f I m p l i c i t Me mory
for shaking hands, h e felt certain that i t was Theodore Roosevelt. He
the list. Conscious memory was, of course, much less accurate after a
generally said that he had no idea how he had acquired this knowl
week than after an hour, but there was just as much priming on the
166
167
edge-the answer just "seemed reasonable"-although SOlnetimes he
word fragment-completion test after a week as there was after an
proffered dldt he might haw heard about it from his sister.�
hour. The implication of this finding is fascinating: something other
. My encounter with Mickey dramatically conflflned what I had (11s
th:tn a conscious memory of seeing the word is responsible for prim
cussed with Professor Wei�krantz and read about in medical journals:
ing 011 the word fr:lgmem-completion tcst. Equally intriguing, pnlll
amnesic patients could indeed be influenced by recellt experiences
ing occurred even when people said they did not remember seeing a
that they fail to recollect consciollsly. At the same tillle. Tulving and I
word during the study phase; in fact, the priming effect was just as
contillued to mull over the Warrington and Wciskr.lIltz experiments.
strong for word5> that people did not remember seeing earlier as for
Why did amnesic patients do so well when given letter cues as hints
words they did remember seeing. The resules pushed us toward a
for recently swdied words? If these cues tapped into some sort of non
strong, seemingly un:lvoidable conclusion: priming occurs indepen
con�ciolls memory that is preserved in amnesic pati!.!nts, shouldn't it
dent of conscious memory,7
be possible to uncover something similar in peopl!.! without amnesia?
These findings hit us with the force of an avalanche. We behewd
We designed an !.!xperimenr to find out. Our reasoning was simple:
that \w had been able to get a handle on the peculiar kind of mem
if lener cues tap into a fOflll of memory that is sp ared in amnesic
ory that Warrington :lnd Weiskrantz had documCl1led in amnesic
patients, then we might be able to elicit sllch memory in healthy vol
patients with th!.! letter cueing task. This "other" kind of memory
lInteers by giving them letters from a previously studied word and
seemed to be lurking in the minds of healthy adults, and could be
asking them to try to guess the answer. Weiskrantz had observed that
tapped by giving the word fragmenr-completion test. We felt a bit like
amnesic patients treat the letter cue test as a gues.�ing game, If young
astronomers must feci when discovenng :l new star or an entire galaxy
adults could also be induced [Q treat the test as a guessing game, we
whose existence had been only suspected: a whole new world of pos
reasoned, then they might rely on the same kind of memory that War
sibilities is suddenly open for exploration. I also started to notice manifestations of priming in everyday life. It
rington and Weiskr:lIltz had observed in amnesics.
\Ve carried out our experiment in the summer of 1980. For you
is likely involved in instances of unintentional plagi:trism. Probably the
to get a feel fm our procedure, you should study each of the follow-
best-known case in recent dec:ldes involved the former I3e:ttle George
OC/OpIiS. aI!ocado,
mystery,
Harrison and his 1 970s hit "My Sweet Lord." Unfortunately for Har
slll'rm; and dimare, Now imagine that you go about your business for
rison, his melody nearly duplic:lted the tlille of a 1962 classic by The
an hour and then return to take a couple of tests. First I show YOll a
Chiffons, "He's So Fine," When a lawsuit was brought against him,
1I1g words carefully for five seconds: assassin,
series of words and ask whether you remember seeing any of them
Harrison conceded that he had heard "He's So Fine" prior to writing
on the earlier list: IwiliglH, assassill, dilloslHlr, and mystery. Presumably
"My Sweet Lord," but denied that he had ilHentionally borrowed
you had little difficulty here.
from the earlier song. Reasoning that the resemblance between the
ext I [ell you that I am going to show
you some words with missing letters. Your job is [Q fill in the blanks
two was simply too strong to be {he product of coincidence, the trial
as best you can: ch----nk. o-t--us, --og--y- - - , -I-Ill-te. You
judgc "held that Harrison's work did infringe through what the courtS
prob:tbly had a hard time coming up with a correct answer for twO
felt rnust have been unintcntional copying of what wa.� in Harrison's subconscious nlcmory." 8
of the word fragments (chipmllllk and bogeymall). But with the other two fragments, the correct answers probably jumped out at you. The
You Illay have enCOlintered instances of this kind of printing, too.
reason thcse fra.gments arc so ea�y to complete. of course, is that you
You propose an idea to a fellow employee or a friend, who seems
just sa\\ the words octopllS and dimate in our study list. This kind of
unimpressed by it or even rejectS it altogether. Weeks or months later,
memory is called prilllillg: seemg the words on the list seems to prime
that person excitedly relates your idea as if he had just come up with
your ability to come up with the correct solution when you try to
it. \Vhen you dra.w this inconvenient fact to his attention-with an . edge in your voice betraying exasperation-you may be f1ced with
complete a word fra.gment. We tested people either one hour or one week after they studied
either heated denial or a sheepish apology born of a sudden dose of
168
S e a r( h i fJ�1? for il'lemory
T h e H J d d e n Wo rl d of i m p l i c i t M e m o r y
explicit memory. A n incident from Sigmund Freud"s life clearly illus trates this. Freud had lnaintaim:d for years an intense and tUl11uhuous friendship with the Derlin physician Wilhelm Flie�. He frequently confided his latest ideas and insights to Fliess, and was emotionally dependent on his approval of them. When Freud announced to li(..'Ss a momentOuS new insight-that every person is fundamentally bIsex ual-he fully expected Hess to be amazed by the idea. Instead, Fliess responded by reminding Freud that he himself had made � xactly the same discovery two years earlier and told Freud alJ about It, and that Freud had rejected the idea. Freud eventually explicitly remembered the earlier incident, commenting that " [i]t is painful to h:lVe to surren der one's originality this way." Inspired by such observations, psychol ogists have recently been ablt, to demonstrate a kind of unintentional plagiarism in the bboratOry and tic it directly to prinung.9 R.esearch into priming exploded during the early 1 9�Os, as provocative new articles appeared in scientific joun� als. Priming occurred on ;1 variety of tests in which people were IIlstructed to identify a briefly flashed word or object, or guess an answer, r:lther than try explicitly to remember a word or an object from a list they had studied earlier. For example, Larry Jacoby and Mark Dallas found similar amounts of priming after deep encoding (focusing on a word's meanings and associations) and shallow encoding (focusing on rhe illdividual lcners in the word)--a remarkable result, since deep encod ing yields Illllch higher levels of explicit memory than shallow encod ing. Yet the priming efTect could be easily elinun:ned. If people heard the target words on an audiotape dunug the study task but did not see a printed version of them, little or no primmg was observed on a later visual test. Something about perceiving the actual word form was cru cial for priming to occur.IO Considered together with the results of Ollr word fragmelH completion experimcnt, these findinb"S indicated that the new and mysterious phenomenon of priming obeys differcnt rules than the kind of memory th:lt researrhcrs had been investigating: for years. I t bt.!came increasingly clear that part of the Inystery could b e traced to the instructions people are given when their memories are tt.!sted. For example, when :nnnesic paticnt" arc given word beginnings or other cues, and arc instructed to think back to the study list to try to remember target words, they perform quite poorly. But when given the same test cues with instructions to guess or to provide the first word that pops to mind, they do just as well as people without mem ory problems. Likewise. depth of encoding inRuences later retention
�
169
when normaJ volunteers try to remember tht, target items, yet has linJe effect when the)' respond with the first word that comes ro mind.ll Scientists love a good mystery, and many researchers tried to figure ou( what printing effectS might mean. Tulving and I had aln:ady staked Out a position: because priming seemed unrelated to conscious recol lection, we reasoned that it does not depend on the episodic memory system that allows us to recollect specific incidents &om the past.That system plays a key role in much of what I have discussed in the book so far: remembering what happened at last year's Thanksgiving dinner, remembering where you hit a tee shot during a round of golf, or remembering that you saw the word octopus in a study list. Amnesic patients have little or no episodic memory, but they often show nor mal priming. We concluded that the source of priming must lie out side the episodic system. But where? Semantic memory-the intricate network of concepts, associations, and f.1cts that constitutes our general knowledge of the world seemed a reasonable place LO look. When an anmt'sic patient such as Mickey learns that the first game of baseball was played in Hoboken but does not remember the episode in which he acquired that f.1ct, semantic memory may be responsible. Likewi<;e, in a priming experi ment, exposure to a word such as ex/olms might result in a jolt to semantic memory, a kind of power surge that excites or activates the semantic representation of octop"s, Perhaps amnesic patients benefit from such a jolt to semantic memory, even though their defective episodic memory prevents them from consciously recalling that they saw the word O(/OPIIS during a recent study episode. The idea i s rea sonable enough, but we could see thal it had problems. If priming depends on semantic memory, why doesl1't deep, semantic processing of a word during the study task lead to more priming than shallow, nonselll3ntic processing? Why does priming depend on actually see ing the word during the study task? And since printing can be quite long-lasting, and we arc constantly encollntering words in oLlr every day lives, shouldn't just aboLlt all entries i n semantic memory be chronically primed? We speculated that priming reRects "the opera tion of SOUle othcr, as yet linle understood. memory system." ll We had postulatcd the existence of a new memory system, even though we didn't yet know what it was. The idea that the ntind con tains more than a single memory system had been around for a while. Oergson had come to this conclusion in 1 9 1 1 when he distinguished conscious memory from habit, and other philmophers had made silll-
171
T h e H i d d e n Wo r l d o f I m p l i c i t M e m ory
170
the early nineteenth century, a lirde ilar distinctions. In fact, during ory e de Biran, had ar�ued that �ncm knowll French philosopher, Main rent systems (or Ideas, feclmgs, and can be subdivided into three diffe part psychologists were reillct�m to h:lbits. But many experimental and se memory system. It IS smlpl �r with the idea of one ail-purpo and a smgle memory system lInnl more parsimoniolls to assume ms. syste ory postulate multiple mem unless the evidence forces one to had fought a great battle about During the 19605 and 1970s, they called working 111el�lOry) de ends whether short-term memory (now -term memory. I earher n�ent�oncd on ;\ differcm system than long , yone was COllvl!lccd' Tulvmg lIlU� evidence that it does. but not ever , 111 episodic and semantic memory duced thl: distinction between -ten long �l resisted this division �f 1972 , and some psychologists Now we were proposlIlg the addI memory into twO further systems. ll1e. s to P table acce ? was simply un . tion of a [hmi sy�telll-and thIS . llndlffer gle, slIl n wltlu rs occu ved, . Priming, these researchers belie erent ways , f II1vestigated 111 dd be can that m syste ory mem entiated seemed ms syste different melllory Appealing to rhe operation of ll g. unparsilll onious and JUSt plain wron tions . To fuel the ftres, n w A lively debate surrounded these ques nts could learn perceptual skills evidence showed that amJl esic patie where they learned them. Neal without remembenng when and n� amnesic patients and healthy volu Cohen and Larry Squire studied has e yon Ever s. ons of conunon word . teers wbo read mirror-image versi but with pr.lctice people typICally first, difTiculty reading such images at patients showed a nortl.lal bell�fit read them faster and faster. AmnesIC consciously remeI1lbenn � whlch of practjce, yet they had problems , sllch skIll learn ' rchers suggested dut ho"d ,·e" I s tley I \\'or( od ,I � The resea . ory system that IS s red 111 an.1Ile ing depends 011 a "procedural" mem 'S· in ·'know1l1� bow to do thinb Sla. This system is selectively involved . oard, solve a JIgsaw puzzle, or read ride a bicycle, type words on a keyb ld the procedural memory �ystem words in nurror-image form. Cou procedural memory constitute . a also be involved in primjng? Or does to episodic memory, se nantlc fourth memory systcm, 111 addition ing and I l.ud alluded to, memo!)" and the memory system Tulv over llIulttplc ll1eJ11o�y �ystellls By the mid-1980s, the controversy icult to t:tlk about pnnllng and had become so intense that it was diff to olle side of the quarrel or the skill learning without COlllmitting allowed researchers t talk about other. The field needed terms that . of priming and learillng WIthout the exhilarating new phenomena to side with one or the ocher remembering, yet did not force lhem
�
�
�
�;
�
'
;
�
warring faction i n the memory systems dehate. I decided to f.1ce this problem squarely i n 1 984, when my colleague Peter Grafand
I were
writing up the results of some new priming experiments. We recog nized that new vocabulary was needed to talk about what we and oth ers had been observing in our experiments. We worked through several possibilities before settling on the con tr.tst that seemed best to capture the distinction wc wished to draw: impliril memory versus explicir memory.1J When amnesic patients showed priming or learned a skill, they were nnplicitly remembering sOllie aspect of a recent experience, even though they had no expljcit recollection of i t. When a college student completed the fragment o-t--us with oC/oprls, yet said that she did not remember seeing o(to
PIIS 011 the list, she was showing the implicit influence of an experi ence she did not e:>'lllicitiy remember. Soon
I began to see that implicit memory might play a more
promjl1cnr role in our everyday hves thall anyone had suspected. For example, social psychologist� who �ought to understand why people prefer sOllie things morc than others had shown (hat a brief glimpse of a drawing-so brief that i t was hardly possible to see it-ll:d par ticipants in ;tn experiml:nt later to say that they liked the flashed dr:lw ing more than one they had not sec.;n.Yct people could not expliCItly remember which
drawings
had been
presented. These
findings
smacked of sublil1lll1al perception, IUustrated by the possibly apoc ryphal story about a sinister 1 950s advertising ploy in which the words Ca((l-Cola and popcom were flashed on a movie screen so brieAy that nobody in the theater could see them. Supposedly, there would be a sudden m;td dash to the concession stand to purchase these products. Here, implicir memory for the unseen words appears to be reAected in an unexplained desire to drink Coke and eal popcorn .'h Hy lhe rnid-1 980s a number of well-controlled studies had shown that preferences and feclinb'S can be shaped by specific encounters and experiences that people do not remember explicitly. For instance, exposure to negative words that Wl:re flashed too quickly to regi�ter in conscious perception caused people hner to fcd hostility toward a fictional person. Some (orm of memory was responsible for their hos tility, but participants had 110 idea that they were "remembering" any negative informarjon. Likewise, studies of amnesic patients revealed inlplicit memory for emotional experiences they could not remem ber explicitly. For instance, the encephalitic patient Boswell, whose severe allmesia J mentioned in the previous chapter, took part in
;m
experiment in which one researchcr was designated a "good guy" (he
The
S e a r c ll ; lIg Jor M e m o r y
172
designated a "bad guy" (he gave UosweJl special treats). another was ed neutrally. Latet, Boswell denied rl!quests for treats) , and a third behav familiarity with, any of of had no explicit memory for, or any sense were each paired with pic . these people. Ycr when pictures of them was asked to choose wluch tlIres of unfamiliar people. and Boswell the " good guy" most often one of thl.: twO he likcd best, he selected and che "bad guy" least often.17 people who had been Thcre were also intriguing repons abom procedures. R..e�eived w sdo�n given general anesthesia during surgical d to anythmg that IS said holds that patients cannot perceive or atten g an opl.:ration. But in an or done when they are unconscious durin . surgeolls staged a mock cri experiment conducted during the 1960s ents to the effect that the sis during surgery that included dire statem t might not pull t �Ollgh. operation was in trouble and the patien sed to the mock CriSIS sub Some of the paril!llts who had been expo asked about it la er, s�g sequcntly became extremely agitated when it memory whlie lymg gesting that they formed some son of implic
�
�l
�
.
.
bl · " unconscious on tI1C opcratlng ta e . showed that anesthetized On a more positive note, bter studies they would make a qlIick paticms who were given suggestjolls that peratively than patients recovery spent less time in the hospiwl posto Yet none of the patients who were not given any stich suggestions My colleagues and I later explicitly remembered the sugg(.'Stions. of spoken words during demonstrated that patients who heard a list when tested during post surgery showed priming for those words no explicit memory for had op�r:\tive recovery. Not surprisingly, they .
.
the words. '"
of the memory dis Implicit merllory may also be related to some source of retrievcd the tortions I considered earlier. When we forgel incident actually occurred infornlation-who 5.1id what, whether an an inaccurate source and or was merely imagined-we may gellerate . Implicit mClllory, by defi hence become prone to f1lse recollections. information . Thus, we nition, does not involve recollection of source es in :lttempting to make may generate plausible but incorrect sourc or why we feel a certain sen�e of why a particular idea pops to mind elllotion.1JJ
a role in the perplexing For instance, implicit memory might play some occasion suddenly experience of deja vu. Most people have on g lived through an eWIll been possessed by :I feeling of already havin This unexplained feeling that is occurring ostensibly for the first time . nineteenth century, and of familia rity was first called deja 1111 in the late
it
�
H i d den World o f I m p l i c i t M e m o r y
173
�
ec� me (he su ject of spirited debate among psychologist� and psy chlatrtsts. Accordmg to one theory, deja vu reflects the influence of a
fragment of experience that is activ:]ted by the prl.:sem situation, but cannot recollected explicidy. For instanc(', if you are talking with
�c
an aSSOClatC at work and suddenly feel that you have had rhe same conversation before--but don't remember it-it might be because a phrase or an idea has triggered an implicit memory of something that . �"as said in a previous convcrsation. You are left with the task of try mg to make sense of the anomalous sensation.l' Implicit memory research has also provided a n-esh perspcctive Oil another important facet of memory: how infallts and yOllng children learn from experience. Developmental psychologists have shown that prelinguisric infants-even newborn babies-are capable of a sur prising amount of learning. Using :1 procedure in which newborns can control the sounds tbey hear by sucki ng 011 a nOll-nutritive nip ple. researchers have shown that a three-day-old infant will suck more frequently when hearing the sound of its mother's voice than when heari ng the sOllnd of an unfamiliar voice. This preference shows that an infant has retained in memory information aboU( the mother's voice. In another study, women repealedly read aloud a Dr. Scuss story during the final six weeks of pregnancy. Newborns showed through Slicking that they preferred to listen to their moth ers telling this story, rather than one they had never heard before. These infants encoded and retained something about their mothers' recit:]tion of the Dr. Seuss story that later influenced their sucking behavior..t2 1)0 such demonstrations show that an infant explicitly remembers encounters in the womb? No. Amnesic patjents with medial tempo �al lobe damage and patients undcrgoing surgical anesthesia can be
mfluenced by past experiences that rhe)' do not explicitly remember. and the same lIlay be true of many manifestation.. of early infant memory. Other research has shoWI1, however, that young il1£1I"]ts can rctain spec fic details of particular episodes. For instance, Carolyn Rovee
�
Colher and her coUeagues observed that babies as young as two to five months old can learn to move a colorful mobile that is attached to one
of their legs by a string. As soon as the infants kick, the mobile moves around and starrs to play music, which the babies enjoy greatly. When they are brought back to the lab a day or two later, even two-momh
?Ids will spontaneously kick a lot, indicating that they have retained III Illemory some information related to the mobile. Three-month-old
Se(Hcilillg fo r MeIllM),
T h e H i d d e n World of I m p l i c i t M e mory
infantS still show elevated kick levels after a week, and six-momh-olds
. by the psychologist Andrew Meltzoff show that nine-monch-old inf1nt.�
do so even after two weeks have passed.
can recall specific actions after a week's delay. For example. infants who
175
Rowe-Collier has also shown that infants do not kick [requendy
�1W an experimenter bang the top of a plastic box With his forehead
whell brought back to the lab a day later and shown a mobile that
often carried out the sallie action when they S;I.W the box a week bter.
physically differs from the one they learned to move. Even more
Infants who �1W the box, but not the action, hardly ever repeated that
amazing, when a cloth liner behind the mobile is decorated with
l riJy show th;lt the infants actu behavior. This behavior doesn't necCiS:
squares during an infant's first encounter, bur with circles one day
ally recollecr {hat the experimenter banged his head against the box, bm
later, si.x-l11omh-old infantS "merely gape" at rhe mobile. 13ut if the
they clearly know something about the episode. Other recent �tudies
liner is decorated with squares during the second encounter, the
with thirteen-month_old infants using a rdated type of imitation pro
babies kick fn.:qucndy.D
cedure have shown clear evidence for knowledge of specific event
These findings show that young infants can retain in memory
sequences after a one-week deby and Cvell after an eight-month delay.
details of an object and some information about the context i n which
For example. children who watched an e:\.l)eril11elltcr put together a
it was encountered. Are the infants "remembering" their past encoun
gong from several props later knew how to assemble it when giwn the
ters with the mobile when they kick spontaneously? Or are they
props. Out when adult anmesic patieTlts were given a similar task they
merely showl11g some form of implicit memory, perhaps a procedural
showed little memory, sll�estillg that the youngsters arc not merely
or mowr response? InfantS obviously cannot teU us what they remem
demonstrating prinung or procedural learning. This is the beginning of
ber, bue S0111e examples of infant memory seem more implicit than
a steady age-related increase i n cxplicit recall and recognition; eventu
explicit. In olle study, five-month-old infants wcre conditioned to
ally, children develop language skills and learn to impose narrative struc
turn their heads when a tone sounded to receive a squirt of milk. Even
. I n contrast. a growing number of studies have ture 011 their expcr ielln'S.
after thc infants were full and refused to drink Illore milk, they kept
shown that priming and related kinds of implicit memory show linle
turning their heads when they heard the wne! If the infants actually remembered what transpired when the tone sounded, why would
change during childhood. Three-ye
they continue to turn their heads when they were too full w drink?2'
dren remember much more than Ihe younger ones. Likewise, sixth
Over a decade ago, my colleague Morris Moscovitch and I pub lished a paper suggesting that the brain structures chat support implicit
graders recall more words from a list than first-graders do, but the tWO groups of children show nearly idt'mical levels ofpriming.b.
mcmory are in place before the systems needed for explicit memory.
In addition (0 these implications for memory development, it al:.o
And. indeed. we have already seen that the front:l! lobes. which play an important role in elaborative encoding, strategic retrieval, and
became clear that implicit 111emory provides irnportam clues concern
source memory, mature late in development. However. recent work . with one-montll-old inf·lIlt monkeys shows that lesions to Structures in the medial temporal lobe. including the hippocampus, disrupt memory.lS If the same applies to human infants, then even some rela
ing the nature of neurological deficits in variolls patient populations. Several rese:lrchcrs discovered that prosopag nosic patient.�, who have difliculties explicitly recognizing familiar faces (�ce chapter 3), nonethe less possess inlplicit knowledge oftheill. For example, Damel Tranel and . Amonio Dalllasio showed pictures of well-known and unknown f1ces
tively ear!y manift:stations of retention may depend 011 brain systems
to a prosopagnosic patient and recorded an index of physiological
involving the hippocampus, which arc linked with explicit remem
arousal, the skin conductance response. The patient showed a larger skill conductance response to f.1ntiliar than to unfamiliar faces, even though
bering in adults.The kinds of retention seen in Rovee-Collier's exper imcl1l�, for example, might signal the rudimentary beginninb'S of some
she did not consciously recogllize any of them! Sllb�eql1ent studies
primitive form of explicit memory.
using prinung techniques have also shown that prosopa!,'110sic patients
onetheless. it is only toward the end of the first year, around eight or nine months, that infants show strong S1gl1S of explicit recall. Then they begin to search (or and find hidden toys, even when they must \Volit
possess implicit knowledge about unrecognized faces.11 . As these f1scinating studies were beginning to appear, I was dra\\-'n
several seconds before look.ing for the object. More impressively, studies
toward another implication of implicit memory research for everyday life. Working with amnesic patiellts, I became acutely aware that
T h e H i d d e n World o f I m p l i c i t M t: lIlory
Sea rdljllg for N/rmtHY
176
memory loss wreaked havoc in their day-to-day lives. Most alllnesics could not hold down jobs or be trusted with elementary re�pomibil ities. The daily existence of an amnesic patient is impoverished and dull Yct studies of implicit memory indicated that tht--se people unde .
niably possessed some preserved learning abilities. Could rhey be put [0 work for tlw patients? Was there some way for amnesics to draw on
memory cap:lciries that. they wcre unaW;1re they possessed?
177
her explicif memory was poor, Barbara showed normal prulllng effects. Even more important, we already knew that Barbara could aC�lIire a surprising amount of new knowledge. Fellow psychologist . Ehz:lbeth Ghsky and I had set Ollt three years earlier to determine whether amnesic patients could acquire new knowledge and skills that would be helpful to them in their everyday lives. Previotls attempts at memory rehabilitation with amnesics had not been tt'rribly sliccessful,
2$
all failing to restore an amnesic patient's damaged explicit Illcmory. Glisky and I believed that a radicall)' different approach was needed.
We reasoned that if we could tap into amnesic patients' preserved
PU T T I N G P R I M I N G TO W O R K
implicit memory abilities, we could teach them knowledge and skills
The Story of B a r b a r a
to help them deal with specific problems in their day-to-day lives.
When rhe woman I call Oarbara turned twenty-six years old. in 1 980, her life seemed full and secure. She was happily married :md held 3n office job in a large company. Then, suddenly and unaccollntably, Bar bara became dreadfully ill: she had contracted encephalitis. As she recovered from the dangerous disease, it became evident that BarbarJ. W
forgout.:n large chunks of her personal p::.st and much of her general knowledge of facts. concepts, and the routine activities of everyday life. And she had litdt.: or no memory for the ongoing incidents of her life. Like the British artist David Jane (see chapter
5), Barbara was able
[Q rcle:lrn many of the f.1CtS and skills that the devastating virus had taken from her. She eventually was able to read and write again. But the disease left many permanent scar�. the most prominent of which was a profound amnesic syndrome. l3arb:lr
Here we
rerurncd
to
the
basic
insight from Warrinbrton
and
Weiskramz's early studies: when amnesic patients arc given letter Clles, they show normal priming for prcviously studied \vord�. l:3ased 011 this lIlsight. we developed a procedure we called the "method of vanish. IIlg cues." For exampIe. to teach an amnesic patient some basic vocabulary involved in II1teracting with a computer, we would show her a definition such as "a repeated portion of a program" on a computer monitor. If she does not know the answer. Ic.:tter cues start appearing one by one until she correctly states loop. The computer records how many letter hints the patiern requires. Later. that definition is pre sented with ont.: fewer letrer than the patient had required to cOllle lip with loop. En'ncuaUy, letter cues are withdrawn entirely and the patient generates the correct word on her own. We were encouraged by the results of our first snldy: amnesic patients learned computer definitions more rapidly when we lIsed the vanishing-cues procedure than when we simply repeated the words and definitions.19 And Barbara was one of our �. tar pupils: she picked up the computer vocabulary relatively quickly and retained it well. She was also a star pupil in another study. in which we used the van islling-cues procedure to teach her and other amnesic patients to cre ate and store their own programs, edit docurnel1ts, use directories, and so forth. Surprisingly. the amnesics showed essentially no forgetting when we retested them approximately a year after rraining--cvcn though several patients had no explicit recollection that they had ever worked on a computer before!.lI.I So when Barbara's company approached us, we knew she could learn complex ncw tasks in the laboratory and felt she could do the same in a work environment if a suitable task could be found. After visiting the company, we settled 011 a promising possibility: a job that required
Sear(h illg fo r M e m o r y
T h e H i d d e n World of I mp l i c i t M e m o r y
learning how [Q ellter data from company records into a computer file.
ders as a result of head injuries could learn the jobs we had taught Bar bara. Other researchers attempted to refine and improv e our vanishing cu�s procedure, and they reported new successes in teaching amnesic patients knowledge and skills that could be used in their daily lives.'l the fact that ailmcsic patiems like U;arbara rely heavily on 1l11phclt memory to learn complex tasks carries some costs. In all our tra nil g srudies, the knowledge that anmesic � patients acquired was �llllte IIlflexlble. When we made relatively small changes in the word IIlg of a cOmputer command that patiellts had already learned, they . ad great difficulty coming lip with the correct answer . For example, III our computer vocabubry study, p:ltients who learned to respond "loop" when given the defin.ition "a repeated porrion of a program" often could not come up with the answer when given the reworded definition "If you want a program to perform the same operation repeatedly, you PUt the instructions in a . . ." Changes of thi.� kind h;\d little effect on people without memory problems..l.I
178
To perform the job, Uarbara would have to learn a great deal of new information-the records contained various kinds of codes 311d sym bols, ;md some of the rules for entering them into the compucer wen.: complic:ucd-but we felt she could master it. We set up a mock version of the task in our laboratory, and proceeded to use the vanishing-cues procedure to train Uarbara. If we were slIccessful. the comp:llly agreed, Barbarol could try (0 perform the actual job in the work cnvirOlUl1cnt. When we bCbran training. we feared we had taken 011 tOO much. Barhan needed lots of lener hints to perform just about every part of rhe job, and she initially performed the task far too slowly to meet the job demands. A skilled performer was expected to enter d:H<1 :It a rate of about fifteen seconds per record. Barbara required nearly an hour! Nevertheless, each time she carried Out the task, she performed it more quickly :lI1d wit.h fewer hints. Eventually she required no hims and consistently cntered che data even faster than fifteen seconds per record.
ext came che acid test: Could Barbara perform the job ade
quately in the work environment? She passed with flying colors. Our m.ission had succeeded-but it
\\laS
nOt quite finished.
Performing this single task was sufficiem [Q employ Barbara for only a fcw hour� per week. To perform a full-time job, she would have to learn how to cnter data from many differcnt kinds of company records: invoices. purchase ordt..:rs, shipping documems, and the l.ike. Learning [Q etHer informacion from each one of these documents is a complic;lted task by itself, but if we wcre [Q train Oarbara for full-time
179
. B�n.
�
�
Amnesic p �tients were responding on the basis of a relative ly prim . . itive connection between the definition and the target word. Their
learning was driven ll1or{� by simply seeing the words in a sentellce th� n by any deep understanding of the underlying concep ts. The . prumng that allowed amnesic patients to learn seemed to be rooted more in perception than in comprehension. I started to wonder whether the perceptual quality of prirning could provide clues con cerning the nature of the memory system that Tulving and I had spec ulated about in the early days of implicit memory researc h.
employment, she had to learn to enter data from c1ewn differcnt doc uments! All told. there were over
250
different rules. symbols. and
codes that she had to master. As far as we knew, nobody had ever attempted to teach an amnesic patient anything on this order of mag
O BJ E C T S O F T H E M I N D
nitude. However, foUowing the same procedures that we used in the
Cht!ryl Warrick is an abstract painter who has always been fascinaced
earlier phases of our research. we obtained the sallle outcome. After six
by the fleeting shapes and objects that spontaneously pop into her
months of training, l3arbara \\laS able to perform this complicated task
mind. Images of circles, spheres, ovals. and other basic forms provide
Aawlessly in the work envirolllTlent. She had earned a fli ll-time job.J'
the raw materials for her elegam, o(ten mysteriollS paimings. W,1rrick
At (he conclusion of all this learning and practice, Barbara's explicit memory was no better. She still had great difficulry recollecting day
rre"lts the cal�vas as a metaphor for I llelllory itself, buiJding lip layers of : pall1t that Visually represent the layers of everyday experience that
to-day events. But by allowing her to draw on her preserved capacities
accuHllIl:lte in ollr minds. She then scratches, erases, and scrapes back
for prulling and skill learning. OLlr training procedure made a major
the byers of paim to reveal the hidden " past" of her painting, analo
difference in her life. And it had implica£ions for other amnesic
gous to the way in which we attempt to work back through layers of
patients. If Barbara could learn a relatively complicated job, there was
:)Ur �
no reason why Other patients couldn't do so also. And, indeed, follow
IIlgs arc umque to me," cOlllments Warrick, "but about human expe
up �rudies indicated that patients who had developed memory disor-
rience, the emotional spacc that you {ravel through to understand
person �1 pasts when seeking to understand ourselves. "My paint
180
Sl'lIrcll i llg for ,He m a r ),
yourself alld the painting. You have to underSl,lIld the past to under stand how we are now."'" In 1 9 9 1 , Cheryl noticed thac Ilew kinds of shapes kept intruding into her mind: knobby, fistlike structures attached to thill tubes. What w('re these peculiar forms. so different' from the circles and ovals that usually populated her paintings. and why did they keep imposing ch(.!ll'1seives on her? One day, while playing with her new baby, Cheryl spotted the intruding shapes right in front of her: baby rattles. Cheryl's life had been full of these rattles for months. She had been " remem bering" them in her intrusive images. but wasll'r aware that she was doing so. Warrick's painting "Visible Past" (figure 6.1) shows the intruding forms, at once unusual yet :llso vaguely r.1mil.iar. The title reRects Cheryl's insight that the images in the painting allow her unusual " memories" to become visible to all of us.)!; Writing about Cheryl Warrick's paintinb>S, one observer com mented: "Like memories or dreams, the images are hazy and illogical, but penetrating in their emotional force:'16 Part of their "hazy and illogical" quality stems from the fact that Warrick's painted images arc not explicit recollections of people and places.They are implicit mem ories of shapes and forms, perceptual fragments of experience th:lt materialize in awareness unattached to n:cognizable settings or stories. During the late 1 980s, I began to think a lot about percepfllaJ memories of shapes. forms, and objccts. Our work with :ul1nesic patients indicated that prinling is intimately related to perception. And Others had shown that when people are given a word fragment-('om plerion test, having seen a word during the study task produces a stronger priming effect than having heard the word. In f.1ct, some experiments indicated that priming is stronger when a word is smd ied and tested in the exact same typefonr or typecase than when these details of the word's visual appearance arc changed between study and test.)7 This implied to me that priming likely depends on brain sys tems that are especially involved in percepruaJ analysis. [ also began to set' links to some intriguing cases that had been reported a number of years earlier. Several neuropsychologists had described brain-damaged patients who could read r.1miliar words aloud reasonably well, but had litde or no idea what the words meant. One patient, known by the initials \VLP, could even say words with irreg�lar spellings, such as blood and (0I�l!", even though she could nm appreciate their meaning. To pronounce such words correctly, you must be able (0 retrie\'c a stored visual memory of the word, whICh in turn leads you to the correct pronunciation (to pronounce more
FIGURE 6 . 1
Cheryl Warrick, "Visible Past," 199t. 12 Gallery NAGA, Boston.
"
10".
Acrylic on canvas.
�aby mule: shapes kept popping into Warrick's mind after playing with her a ullawart! that she was remembering.
lI1fant daughter, but the rtist was
'82
Sea rcJ,jtlg for M e m o ry
regularly �peJled words correctly. you need only sound them out). By reading aloud a word such as
blood, WLP
was showillg that she could
retrieve a stored visual memory of the word's form and a link to the word's phonology. Gut her failure to understand its meaning showed that she could not retrieve a semantic memory of the word. The case of WLP and similar patients implied that visual information about words is slOred separately from sClllamic or conceptual information," At around the sallle time that ' was thinking about the implications of these intriguing patients for understanding priming, new studies using PET scanning techniques showed that different areas of the brain become active during visual and 'icmantic analyses of familiar words.
T h e H i d d e n World of I m p l i c i t M e m o r y
'8 3
suc h as a hair or a hOl lse produces priming whe � n people latcr tnPt to Ident ify fragmented pictures of chairs or hOlises . .\(I Fantiliar e � ts, however, all have nam es; I wanted to determine whether pnl1l1l1g occurs for novel forllls that cannot be cod e 'd casl'Iy wah a verbal I,ab.1 !..: . S0 I embarke d on a sen. es of experiment s with Lynn Cooper, a psycho)ogist vho has made pioneering con � ttibutions to . our undersrandlllg of oblcct perception . \we Tf IOlI r nd a way to dem . onstra te and expl�re I llph.c t mC lOry for novel visual shap �� � es. . . used un(mllhar objects like We " . those in fiVll · 0 · re 6 · 2 . S·ome are POSSIble' " 0b�ect . s-YOll could budd them out of woo d or c1ay-bul others
��� �
'
�
.
Merely seeing a familiar word activates :I specific part of the occipital lobes, the brain region that is essemial for visual perception. Thinking
FIG UR E 6 . 2
about the meaning of a word activ:ltes other areas in the temporal and frontal lobes. I'! Putting together the observations from patients like WLP with these PET results, we saw that a distinct brain system is responsible for storing visual information about a word. Could this be the memory system to which Tulving and I had alluded? Hecause experiments had already shown that seeing a word enhances visual priming, I fdt confident in theorizing that it depends on a per ceptually based memory system. This idea also fit well with the studies of Warrington and Weiskrantz, and of many others, showing that prim ing is spared in amnesic patients. Amnesics have suffered damage to the hippocampal and diencephalic brain regions that arc necessary for explicit memory, but not to occipital areas that are involved in visual encoding of words. If these occipital areas play :Hl important rolt.: in priming, the results from amnesic patients could be explained easily. This idea could even help to understand why patients like Oarbara learn new information in such a rigid and inflexible way. Barbara relied heavily on priming to acquire lIew knowledge. Perhaps she performed poorly when we changed the exact wording of questions because she was highly dependent on a perceptually based memory system. She might have le3rned the rules and commands as a literal sequencc of visual forllls. All tillS evidence seemed to fn together nicely, yet everything I have said so far about prinung and pcrception relies on studies that used verbal matcrials-familiar words. If priming is closely linked with per ception, then it should occur with nonverbal shapes and forms. The baby rattle shapcs that kept popping into Cheryl Warrick's mind, for example, probably reRect the influence of prirning. But I lleeded to figure out how to investigate this sort of process in the laboratory. Experiments had already shown that seeing pictures of famiitar objects
Sam�l of objecf$ used ill Scha �· cter and Cooper's experiments o n illlPlicit and expliCIt lllelllory for novel obie � cts . The draw.mg5 111 . the upper row show pos. . ',I. blc. objects th t could eXIst In three-dimensional forlll. The � drawillg" ,." ,h. ower row depIct II11P . 05SI'ble 0b' �eCls that contain s[rucUlr al viobtiolls that . . th�'m from would r. Pr. roIllbn actually existing in three-dimen sional form See text or unher explanation. .
.
184
Starcili ",!! for Memory
f M. C. Escher, they are impossible structures. Like the drawings o object brieRy on each Rashed could not exist in three dimensions. We to make a decision a computer screen and asked college swdcnts ons about possible about whether it was possible or impossible. Decisi minutes earlier. several objects were primed by exposure to the object ible objects. We Surprisingly, chere was no priming effect for imposs ic patients had found similar results in amnesic patients. Because amnes had seen, we they jects ob difficulty explicitly remembering which le objects reRects could be confident that the priming effect for possib implicit memory.�! d that prim� We WCfC excited by these resules, because they showe labels. Why wasn't ing occurs even for novel shapes with no verbal cannot create a there any priming for impossible objects? The brdin that priming ed unified image of an impossible object. We theoriz that stores informa depends on ;l perceptually based memory system the system docs not tion about the overall structure of objects. Perhaps e there is no store the overall structure of an impossible object becaus
consistent overall structure to store.'2 with the results The results of our object priming studies fit nicely that a percep on visual word priming: both lines of research showed basis to the tual system plays a key role in priming. I now had a firm
been groping orize about the memory system that Tulvil1g and I had co-authored I to characterize. In several articles. including a paper aliml systellJ, or with Tulving. I called this system the perceptllai reprcscm ay environ everyd Ollr in ; PitS. The PR.S allows us to identify object< PRS is The page. ment and to recognize f.'lllliliar words on a printed and objects, specialized to deal with the form and structure of words or what mean words what but it does not "know" anything about handled arc ts objectS arc lIsed for. Meaningful associations and concep PllS." by semantic memory, which cooperates closely with ation, so that cooper ss The twO systems nor!l1�l1y operate in seamle aware of what when wc recognize familiar words we arc immediately recall how they mean, and when wc see familiar objects we C;lI1 easily y can memor ic semant , to usc theJll. But in some cases of brain damage well. WLl� who be seriously disrupted while PitS functions relatively good example. could read words without understanding them. is a have difficulty but Other patientS can recognize everyday objects, for. or saying recalling their names, remembering what they are used patiem, J13, where you would be most likely to find them. One such ed with a present was shown a fork and called it a toothbrush. When ng bag, he said cherry, he called it an apple. And when shown a shoppi
T h e H i d d e n World o f I m p l i c i t M e m o ry
185
it was an umbrella. His ability to retrieve concepts and associations from visual inputs had been horribly disrupted, yet he could easily tell pictures of real everyday objectS from pictures of nonsense objccts.�· If my view is correct and priming depends on the PitS, then p;ltienrs sllch as WLP andJB should show intact priming effects. In the early '1 990s, I had ;l ch:lI1ce to test this idea. [ encountered a patient,JP. who had a seriOliS problem understanding spoken words. He could hear them and even repeat them accurately, but Ill: had difficulty com prehending what they meant. This made it difficult to converse with him, especially over the telephone. As it happened. 1 had just embarked on a new series of experiments concerning auditory priming, showing that hearing a word helps college students identifY the word several minutes later when it is played on a noise-filled audiotape (having seell the word earlier provides little or no benefit). The auditory priming effect, like the visual priming effects I describcd earlier, \vas nearly identical after deep encoding and shallow encoding, even though explicit memory for spoken words was much higher after deep than shallow encoding. Amnesic patientS, too, showed this auditory printing effect, despite the fact that they had almost no explicit memory for having heard thc words. Because auditory priming closely resembles visual priming, these resultS led us to suggest that priming of spoken words depends on an auditory PR.S--a cousin of the visual PRS we had already theorized about. If so, then JP should show auditory prim ing. evcn though he has little understanding of what words he is hear ing and identifying. This is exactly what we found.�5 PET scanning studies provided another \vay to test my ideas about priming and the PRS. PET studies of visual word priming, for exam ple. have revealcd evidence to back up my theory that printing is asso ciat("d with blood Row changes in the occipital lobes. In studies by colleagues and me, the hippocampus was not active during priming, but became very active when people consciously recollected \vords they had recently studied. Consistent with these findings, Hudies of patients with danl3gcd occipital lobes have shown impaired priming for words they have just seen,just as you would expect if this part of the brain plays an important role in visual priming.4<> PET scanning has also helped reveal the physiological basis for some of the differences we observed between possible and impossible objectS. We fOllnd that when people made decisions about brieRy Rashed pos sible objects, there was extensive activity in tWO adjacent regions at the interface of the temporal and occipital lobes known as the inferior tem poral b'Yrus and the fusiform gyrus. But there was little or no activity in
1 86
Sl'arclling for M e m o r y
these areas when people made decisions about impossible objects. Cooper and [ had theorized that priming of possible objects depends on inferior temporal regions. Our theory was based largely on studies with monkeys that showed that cells in the mfcnor temporal lobe respond selectively to the general shape of an object, as opposed to its size or isolated parts of the object.And other studies had shown that the fusiform gyrus is involved in perceiving and recognizing faces, which we tend to see as unified wholes. The new PET data provide strong eVI dence that these two areas are specifically involved in encoding the overall shape of an object, and suggest that they play a role in priming. The hippocampus was silent during priming, but became active when people explicitly remembered seeing possible objects.�7 These results, encouraging for the PRS theory, allow me to specu late about what miglll have been happening to l:hrbara when she learned so well on the vanishing cues task, and to Cheryl Warrick when the baby ratde shapes kept inexplicably popping to mind. I
T h e H i d d e n World
of
I m p l i c i t M e m ory
187
B E Y O N D P E R C E P TUAL P R I M I N G T h e M a n y M a n ifes t a t i o n s o f I m p l i c i t M e m o r y When J was poring over the stack of legal documents concerning Peter 13 onyhard's knowledge of MR heads, I realized that any testi _
mony J might offer about his case would have to go well beyond cit ing experullents on prirning of words and objects or theori�s about
the PRS. The exceedingly complicated knowledge he possesses is far more complex and meaningful than the primitive fragl11eIlt� of per ceptual expenencl.:s that have bel.:l1 studied in laboratory priming experiments. If all of implicit memory could be explained as percep tual printing, then it would be diflicult to invoke implicit memory as
a factor in Donyhard's case. The key issue here concerned the possible unconscious influence of complex conceptual knowledge. But there is indeed far more to implicit memory than perceptual priming of words and objects.
would hazard a guess that as Barbara required progressively fewer let
I have already mentioned that amnesic patient� can learn new per
ter hints to complete target words, changes were takillg place 111 the
ceptual and motor skills. Nelson Butters and his colleagues have
occipital regions of the PRS. And I would conjecture that when the
shown that skill learning depends on a different brJin system-proce
baby rattle shapes kept II1truding into Cheryl's mind, the inferior tem
dural memory-than priming docs. Butters's group studied patients
poral and fusiform regions of the PRS were strongly engaged. The
with Alzheimer's disease, who have damage to the medial temporal
hippocampus, however, was probably inactive in both cases, because
lobes and other regions of the cortex. They compared the Alzheimer's
neither Barbara nor Cheryl felt they were remembering their past
group to patients suffering from Huntington's disease, the devastating,
exper1ences.
genetically transmitted illness that destroys the bram's motor system .
These suggestions are highly simplistic, of course. No complex task
In Huntington's disease, damage is largely restricted to a subcortical
or mental activity involves only a single region of the brain. Multiple
collection of structures know1l as the basal ganglia, which are critical
brain areas lIlvolving distributed networks are active during the per
to executing learned movements. Butters and collaborators found that
formance ofjust about any task, and we are only :l.t the very begin
patients with Huntington's disease show 110rl11al priming on a word
ning of understanding what they do and how they communicate with
completion test, but have great difficulty acquiring new motor skills.
one another. The PllS plays a role in our ability to recognize words
Alzheimer's patients, in contrast, have no difficulty acqLl1ring motor
and objects. Priming reflects the f':tct that tim system changes in
skills but show ilnpaircd priming. These results demonstrated con
response to encounters with words and objects. Reading words on a
vincingly that priming and skill learning depend on separate memory
page, hearing words and voices, or seeing objects that populate the
systems in the brain.
world around us may sometimes produce subtle alterations in our
More recent work on procedural learning has shoWJl that in addi
brains, alterations that later influence the way we respond to the envi
tion to the basal ganglia, the cerebellulI1 (see figure 5 . 1 ) , a strucrure
ronment or that make it more likely for a particular idea or image to
long known to be involved in motor performance, is also crucial for
spring to mind, seemmgly out of nowhere. We are for the most part
motor skill learning. Patients with damage to the cerebellum have
entirely unaware that any of these changes arc taking place. Pri1lting,
grave difficulty learning tasks that require mastering sequences of
like other kinds of implicit memory, operates invisibly. It is a silem part
events, such as learning how to play the piano. Such patients also have
of our mental lives, but an important source of memory's fngile
difficulties planning out sequences of actions that are required to solve
power.
problel'l'ls. After reviewing the relevant evidence, Butters and co-author
S e a r c i l i llg JM Atfc tll o r y
T h e H I d d e n World o r I m p l i c i t M e m o r y
David Salmon concluded that the cerebellum plays a key role in car rymg OLlt the timing operations that allow liS to arrange motor move �nems in their proper sequence. The basal ganglia, in turn, are
case, The central question involved thc possible unconscious influ
188
responsible for refining the sequence and storing it as an organized motor program. Bec:lUsc the ba�al ganglia and cerebellum arc typically not damaged in amnesic patients, we should not be surprised to find
out that a severely 3mm:sic paticm was able to play r,'uniliar culles on the piano and even learn some new ones. Likewise, Mary Jo Nissen and her colleagues have shown that amnesic patients can learn novel
sequences implicitly on a task in which they respond as quickly as possible to asterisks that appear one after another in different 10catiollS on a screen. When the asterisks appear in a recurring sequence,
amnesic patients respond more quickly than when no pattern is pre sent-yet they show no expliCIt knowledge of the sequence. Recent evidence from PET scans has shown directly that the basal ganglia and
a part of the motor cortex play an important role in this kind of pro cedural memory. In a particularly striking experiment, people prac ticed making a sequence of finger movements outside the scanner, and
were scanned (using functional MR.I) at weekly Intervals. At first, when people performed the sequence there were isolated patches of increased blood Row in the motor cortex (see figure 2.4); but with
189
Skill and habit learning, however, were not the issue in Bonyhard's ences of scmantic knowledge on his job performance. Here, too, we have evidence of the operation of implicit memory. Consider the fol lowing sentence: "The haystack was important because the cloth ripped." Does it make any sense to you? Probably not. But I can pro vide a single word that should make this peculiar statement suddenly comprehensible: pari/chute. YOLI can now imagine a scene in which the unfortunate person whose parachute has ripped is saved by landing on a cushioning mound of hay. Likewise, the sentence "The note� were sour because the seams split" probably makes no seme until I give YOll the clue bagpipes. When my colleagues and I showed these sentences to amnesic patients, they, like you, could not figure out what the sen tences meant until we gave them the critical clue. Interestingly, when we showed them the sentences again minutes, hours, or days later, they easily came up with the clue word on their own. Clearly, the amnesic patients benefited from their earlier encounter with the sentence and the clue. Yet they frequently said that they had never encountered these sentences or clue words before, typically stating that the sen tences were just easy to figure out. This is not a perceptual priming effect that depends on the PRS: patients Illust understand how the
practice, they gradually expanded. One aspect of learning a new motor sequence, slIch as playing the piano, appears to Involve the
benefit. It is, instead, a conceptual priming effect that probably
increasing participation of neurons in the motor cortex.�� Procedural memory is also involved in the development of habits
depends on a modification of the semantic Illemory system. Other experiments with both amnesic patients and college students have
those well-practiced and largely unconscious bchavlOral routines we
shown that conceptual priming occurs, and they suggest that it
all carry out in everyday life. Pioneering studies by Mortimer Mishkin
depends on semantic memory, not on the PRS.50
critical word relates to the full sentence in order to show a memory
and colleagues have shown that monkeys with lesions to the medial
These experiments show that implicit memory operates in the
temporal lobes, who show poor memory for theIr recent experiences,
conceptual domain as well as the perceptual domain, and thus bring
can nonetheless form new habits at a normal rate. When given hun
us closer to seeing how implicit memory could be mAucntial in a real
dreds of practice trials, these amnesic monkeys can gradU:llly learn
world situation involving access to conceptual knowledge. Indeed, the
what to do in order to obtain a food reward, even though (hey have
cases of unconSCIOus plagiarism that I cited earlier probably illustrate
little memory for what happened on any particular mal. Human
the influence of conceptual priming. Ideas pop to mind unattached to
amnesic patients, too, can show analogolls forms of habit learning.
any setting or context, and we believe that we have corne up with
With extensive practice, amnesics can gradually learn to classify visual
them ourselves, even though they derive from a specific experience.
patterns into categories at the same rate as people withom explicit
TIllS is exactly the kind of conceptual priming that might have been
memory problems, and can even learn the rules of a made-up granl
operating in the case of Perer Bonyhard.
lnar at a normal rate.Yet amnesic patients, like the animals in Mishkin's
The occurrence of conceptual priming and other semantic forms
studies, have little ability to remember what happened on any partic
of implicit memory may have far-reaching implications for many
ular trial. Conversely, damage to the basal ganglia disrupts habit learn
aspects of our everyday lives. Recent research III social psychology, for
ing,just as it disrupts motOr skill learning.�9
example, has implicated implicit memory as a contributor to gender
Seaulljllg Jor iHl'/1I o r )'
T h e H i ddcn World o f I m p l i c i t M e m o r y
and racial biases that people are not aware they possess. We maintain
in a fight against the forces o frepression; they rcsult from special expe
190
191
stereotypes ahom groups of people, including women and minorities,
riences that relate to our deepest conflicts and desires. The impticit
that may be automatically and unconsciously activated when we
I"ll(.'mories I have been consi dering are f.1r more mundane. They arise
interact with, or arc asked about, members of the group. Even though
as a natural consequence of such everyday activities as perceiving,
we are unaware that we hold such stereotypes, once they are turned
understanding, and aering. The systems that perform these fUllerions
on they can exert a powerful influence on OUT judgments about group
often change, perhaps only shghtly, as they go about their business.
members. For instance, in studies by the social psychologist Patricia
Our brains are constantly adjusting and adapting to the world, and
Devine, white American studentS WCTC exposed to a list of words,
when these changes persist, they can affect our dlOughts,judgmenrs,
most of which suggest a stereoryped black American-we!f:1.re, bas
and behaviors in surprising ways that scienrists are just beginning to
ketball , ghetto, jazz, slavery, busing, Harlem, and so fonh. The words
wcre Hashed so quickly that they wcrc difficult to perceive and
understand. Yet because printing gener . illy refleers small changes in the PR..S or semantic memory. and acquiring skills and habits involves
remember consciously. Nonetheless, when these students later read
slow procedural learning that builds up over time, we require addi
about the all1bib'UOliS behaviors of an imaginary male (whose race was
tional machinery that allows rapid association and recall of the sights,
not specified) . they rated him as more hostile than students who had
been exposed to mostly neutral words. This biasing effect was JUSt as pronounced in students who expressed little racial preJudice un a
gher
questionnaire as in those who expressed h i
levels of prejudice.
sounds, places, and thoughts that come together in single episodes. As I have emphasized, networks of structures with1l1 the medial tempo
ral lobes appear to do J USt that.'l
Appreciating the pervasiveness of implicit influences on
our
Exposure to the racially loaded words may have automatically activated
thoughts, feelings. and behaviors provides an essential insigh t into the
black stereotypes that some students were not aware they possessed.�'
fragile powcr of human memory. If we are unaware that something is
Implicit influences on our judgments and behaviors may be espe
influencing our behavior, there is little wc can do to understand or
cially pernicious because they operate outside our awareness. Com
counteract it. The subtle, virtually undetectable nature of implicit
mercial advertising provides a good example. You may think that
memory is one reason it can have powerful effects on our mental lives.
because you pay little attention to commercials on television or in
Bue we must resist the temptation to attribute every strange thought,
newspapers, your judgments about products arc unaffected by them.
unusual feeling, or odd anion to the implicit effect of some experi
Out a recent experiment showed that people tend to prefer products
ence that we have consciously forgotten. Attempting to interpret feel
featured in ads they barely glanced at several minutes earher-cven
ings and behaviors as signs of implicit memory for a particular
when they have no expli cit memory for having seen the ad. Such
forgotten experience is potentially dangerous becanse there are n"l;lIlY
implicit effects make us vulnerable to what social psychologists call
possible determinants of what we think and feel.
"mental contamination": when our thoughts :lI1d judgments arc
These pitfalls notwithstanding, the invisible influence of implicit
biased by unwanted bur unconscious influences. None of LIS li ke to
memory is an important part of the StOry of memory's fragile power.
think that our purchasing decisions are swayed by advertising we
The past docs not always shape us so subtly and indirectly, however. I
barely notice, that our judgments arc affected by racial stereotypes, or
now turn to those times when memory's power is expressed with a
that our ideas are unintentionally plagiarized from somebody else. Yet
force so overwhelming
it is preCIsely because we are oblivious to the source of these influ
which our lives ;Ire built.
ences that we arc prone to mental contamination. Studies have shown that making people aware of a biasing influence can counteract some kinds of mental conramination, but it is difficult to become aware of implicit memories whose existence one does not SllSpcct:�l The nonconscious world of implicit memory revealed by cognitive neuroscience differs markedly from the Freudian unconscioliS. In
Freud's vision, unconsciOllS memories are dynamic entities embroiled
that it
can shake the very foundations on
Emotional Memories
IY3
utes earlier was reduced to a charcoal-seared rubble, her dog was killed, and all the possessions of a lifetimc, including valued family
SEVEN
heirlooms and photogr:lphs, wcre destroyed. Melinda's life and art changed immediately and radically as a result of the fire. She was fortunate to survive her three-swry fall with only a few broken bones, but found herself unable to evade :I persistent, throbbing memory of the incident. She left Chicago and moved to a new home in the California desert. I n place of her bold, exptessive canvases, highlighted by beautiful IlI:lUVCS and blues, she began paint
EMOTIONAL MEMORIES W h e n t h e Past Persists
ing darkly introspective works on lead, steel, and concrcte. Now she used only the colors of the fire: orangc, black, and okra. Her new an work became a vehicle for repetitively and exhaustively exploring her traumatic mcmory. The exploration has been almost entirely involun tary. Melinda describt,s how the memory silnply imposes itself on her as sht.: begins to paint: Sometimes I will be sitting thinking. I will be in a thoughtfu1 place,
I N 1 9 8 7 , M E L I NDA S T I C K N Ey-GIBSON was a promising young
and I will just be thinking and [he images will come, but I don't ask
artist whose colorful abstract paintinb"S had anracred attention in and
for them. It's not like I say, I alii going to work on this painting and
around Chicago, where she lived and worked. One warm June night
I need [0 get this feeling or I need to get this illlJ.ge. I am just think
Melinda was awakened by the smell of smoke. She lived in a converted
ing about the paiming, and this image. tillS evenl, will come. .
loft in all industrial sector of Chicago, close to inner-city neighbor
Then after J make the painting it will connect. I will reCOb'Tlizt' it as
hoods where fires were common. She saw smoke from her bedroom
pan of the mcmory. Like the way the black smoke looked. The
window, then emerged from the bedroom and saw ominous black plumes seeping up through cracks in the floor and through the hinges of the front door. She tried to call the fire department, bur the phone lines had been burned out. The thick smoke expanded rapidly, seem ing to double in volume every few seconds, until it encompassed the emire iving l space. Soon, Melinda found it nearly impossible to breathe. AU her possessions were in the apartment, as well as her beloved dog, but there was no lime to search for them. The third-story apart ment had no fire escape, so she first attempted to Ace down the stairs. Dut the blistering heat on the steps forced her to turn back. There was only one option: she would have to jump ontO a concrete landing dock three stories below. Walking out on a metal ledge, Melinda tried to Cut the distance between herself and the ground by hanging from the ledge by her fingers. She let go and wem crashing OntO the con crete. Shortly thereafter. the entire building exploded in a spectacular fireball. The loft where she had been sleeping peacefully a few min192
lights were still on, you know, the electricity was not off. $0 the light \vould be on and thcre would be this thick black smoke. I These reflections arc illustrated in her painting " Story I I " (figure 7 . 1 ) . Melinda surrounds a photograph of herself :lsleep ill bed, sug gestive of her last few moments prior to being :Iwakened by the con Aagration, with eerie black blotches and milky yellow-white blobs that capture her memory of the black smoke filtered by the apartment lights. The power of Melinda's memory for what she saw and felt that night is remarkable. EWIl when I spoke with her 111 1993.six years after the fire, Melinda poimed Ollt that her memories of those few awful minutes were every bit as intense and real as in tht' days and weeks fol lowing the fire; fortunately, they came to mind much less often. Only recently, Melinda ceRected, had she felt less controlled by the memory and " kind of complete" again. Happily, the new approach to her art that was brought about by the fire turned out to be aesthetically COln pelling, and in the years since she has achieved widespread recognition.
E m o t i o n a l M c m o r i es FIGURE 7 . 1
195
Melinda Stickney-Gibson's mcmories of black fumes and [thcrcd light illustrate how an emocion:ally traumatic mcideIH can bc vividly, intrusively, and repc:uedly recollected. Her experience represents only one of the ways the power of the past can be expressed. For now I will explore a type of vivid recollecrion that provides some hints about the sources of mcmory's power. Then I turn to far more pot('nt experi ences, where emorional traumas leave behind the kind of intense, seemingly indelible, marks that haunted Melinda Stickney-Gibson with a searing force that match cd the energy of the smoke and flames that changed her life forever.
FLASHBULB M E M O R I E S W h e r e W e r e You T h e n ? It was a school day like any other, and 1 sat in my lIslIal seal tow;lrd the rear of my sixth-grade classroom. I was not the world's most atten tive student in those days, often preferring to work out the batting averages of my favorite baseball players rather than closely follow the day's lesson. But 1 paid rapt attention when the school's principal unexpectedly emered the classroom and pulled our teacher aside. He brought with him the terrible news that President Kennedy had been Melinda Stickney-Gibson, "Story II," 1993. l1Yo x 12'l\". Oil, wax, gold leaf, and collage on paper. Litdejohn-Sternau Gallery, New York. This p.linting recalls the terrible fin' tklt woke the anist onc inatt'd hn lJ1emory for years.
t and dOIll
nigh
shot. I do not remember much of what happened just before or after the snmning announcement, but an illlage of the moment when I first learned the news ha.� remained fixed in my mind for over thiny years. For many of us, the memory of that November afternoon in 1 963 feds as though it has been frozen forever in photographic form, unaf fected by the ravages of time that erode and degradt, most other memories. In 1 977, the psychologists Roger Brown and James Kulick picked up on just this feature of people's recollections of the Kennedy assas
sination when they referred to thern as flashbulb memories. They sug gested that a novel and shocking event activates a special brain mechanism, which they referred to as NOli! Prim. Much like a calll
era's flashbulb, Drown and Kulick hypothesized, the Now Print mech anism preserves or "freezes" whatever happens at the moment when we Icarn of the shocking event. Brown and Kulick interviewed eighty adults in 1 976, forty white and forty black, about their recollections of the Kennedy assassination and other shocking public events, including the assassination of Martin
S e a rc hi ng Jor M e m o ry
196
Luther King,Jr., and l"tobert F. Kennedy. People were given credit for a Aashbulb memory when they answered yes to the question, ';00 yOll remember the circumstances in which you first heard . . . ?" and when they could provide details about where they learned the news, who told them, or how they or others felt at the time. All bur one of the
FIGURE 7 . 2
IIl IW 1 1 11 , I II 'IJN I I I IVII \ \/1 /I l l J..: lUll \/) IUII' I UOI/ J../ \(,.\ /l I l / \ 1.< 11/(\.5 1 1//\ ; ( IIU / I , I ( )J'OI 1111 1 I 0UI f) 'I \ I U \I 1 / 1 // \
interviewees possessed flashbulb memories of the JFK assassination, which Brown and Kulick comended reflects the unusual significance of this event for the entire population. In contrast, only about half of both
whites and
blacks had flashbulb memories
of Roberr F.
Kennedy's assassination, which was rather less cataclysmic than his brother's. Thirty of the forry blacks but only thirteen of the forry whites possessed Aashbulb memories of King's assassination. Drown and Kulick hypothesized that the "consequentiality" of an event determines whether the Now Print mechanism is triggered and the brain's flashbulb pOpS.2 The No\v Print account of flashbulbs is intuitively compelling, and it fits well with the subjective experiences of people who feel that their memories of the JFK assassination are among the most vivid of their lives. This hypothesis Inspired the photographer Anne Turyn to create an extended series of works that visually depict flashbulb expe riences for shocking news events of the twentieth century. For each work in her series, Turyn paired a newspaper headline of a jarring news event-the crash of the Hindenburg, the end of World War I I , and the moon landing are just a few examples-with a photograph of the physical context in which a person might have learned of the event. The photographs are characterized by a kind of hyperclariry, preserving precise nuances of light and shading a.� well as the exact arrangement of objects-the kinds of details that a Now Print mem ory mechanism might preserve, as in "5/10/1926 (Flashbulb Memo ries)," shown in figure 7.2.J Turyn's visual rendition of flashbulb memories that result from a Now Print mech:lIlism captures their salient features. llut is there good scientific evidence for the Now Print theory? Arc flashbulb memories ditTerent in kind from ordinary memories? Is the evem somehow etched indelibly in the mind, perhaps forever, in its pristine original form? llrown and Kulick did not query participams in their study about the JFK assassination until years after the event. To evaluate the accu r:lcy of :J. A:J.shbulb memory, we need some way to check the veracity of a person's recollection. Subseqllenl researchers have invcstigated melllones for flashbulb events-the attempted assassination of Ronald
Anne Turrn, "5/10/1926 (Flashbulb Memories)," 1986. 11
x
14".
Ektacolor print. Copyright © Anne Turyn. A headline procl:iiming that Admiral Byrd has flown to the back is pain.:d with
an
�
onh Pole and
image o a dimly lit desk in a study. One can imaglile
a person silting at the desk reldmg the headline or being told ahout rhe e\'ellt by sOIleone entering the study. The internal flashbulb pops, and the eXlct � scene IS recorded forever--or is it? For more modern incidents. Turyn fre . quently IIlcludes radio and television as part of the frozen memory.
S e a rlili ll,l! for M e m o ry
198
ltcabran in 1981, the explosion of the space shuttle Cluflll',,��er in 1986,
Emotional Memories
199
The Danish psychologist Steen Larsen was conducting a study of
rhe Gulf Waf in 199t-by obtaining recollections from people within
his own memories when he heard about the Palme assassination, and
a few days or weeks after the event. Assliming that these very recent
immcdiately entered into his computer a detailcd account of how he
l11emories are accurate, they can be compared with n;collt:ctions from
learned the news. When the computer queried Larsen about this
the s:tmc people obtained months or years later.
event several months later, as part of hiS ongoing study, he remem
Some A:lshbulb memories are ind(.'cd accurate and persistent. In a
bered correctly th:lt he had heard it on the radio while having
recent multinational study, the British psychologist Martin Conway
breakfast. He also noted that the sheer vividness of this mcmory
:lIld his colleagues examined what they believe constitutes a Aashbulb
contrasted with his impoverished recollections of how he learned
event for Uritish but not American adults: Margaret Thatcher's unex
about less ll11portant news events, which generally faded away
pected resignation as prime minister in 1 990. The researchers col
within a momh or so. But Larsen's flashbulb memory was not
lected memories from over three hundred Drirish and American
entirely accurate. When he checked his clear memory that his wife
college srudents within twO \veeks of the resignation, and then again
had been with him when he heard the news against his written
a year lacer. They found that British students showed extremely accu
record, Larsen discovered that he had heard the news alone. He also
rate retention of how they learned of the news, whereas Americall
discovered, much to his surprise, that his recollections of what he did
students showed a good deal more forgetting. ConsistelH with Con way's findings, Ulric Neisser and his colleagues have recently reported
immediately after learning tht: news were inaccurate. Larsen's erro neous flashbulb memory was subjectively compelling, however; he
rhat Californians who were affected by the 1989 earthquake in Loma
commented (hat he could still "see" the scene of his wife and him
Prieta (near San Francisco) showed highly accurate memories when
hearing the news together.)
tested several years later, far more accurate than a control group from
Other evidence, too, indicates that some filshbulb memories are far
Atlanta who had only hQard abollt the evellt on the new5. These
from photographic preservations of the original scene. In a study of
results support Brown and Kulick's idea that consequentiality-the
memory for the Ch"lIt'11gcr explosion by Ulric Neisser and Nicolc
personal sigmficance of a flashbulb event- plays a key role in the
Hatsch, college students were interviewed less than twenry-four hours
durability of memory for that event.
after tht: event and then again two and
a
halfyears later. Over tim long
Yet even some highly consequential flashbulb events are not wholly
interval, students showed substantial forgetting of the circumstances in
unaffected by the passage of tillle that wt:akens other memories. The
which they learned of the event, and the recollections of a number of
Swedish researcher Sven-Ake Christianson explored memories of his
them differed substantially from their earlier reports. Nevertheless,
country's equivalent oftheJFK assassination: the 1986 assassination of
many students expresscd high confidence that their false rt:collectiolls
Prime Minister Olof Pahne as he was walking home from a movie
were accurate. Indeed, Neisser and Harsch observed little relationship
theater. Christianson probed young aduhs' memories for the tumul
between the accuracy of a flashbulb mClllory and a persoll's subjenive
tuous event six weeks atter it happened and then abrain onc year later,
confidence that it was correct.l>
and (ound that the accuracy of their memories had declined after a year.� Even if flashbulb memories arc prone to f:lding and decaying over
Some have suggested that high confidence is the hallmark of a flashbulb memory. Charles Weaver, a psychologist, wanted to know whether people could form something like a flashbulb memory for all
time. they still might be better retained than memories for more or(li
everyday event. At the first meeting of his undergraduate memory
Ilary t:vcnts. I call remember relatively little abollt what happened in
bboratory, he instructed students that the next tillle they encountered
November 1963 other than the JFK assassination; even i( my JFK
their roommates (or a close friend if they lived alone), they should try
flashbulb memory has lost some information over the years, it is surely
to remember as much as possible about the event. He gavt: students a
richer and more reliable than memories of mundane events from that
questionnaire that probed various aspects of their memories for the
time period. (And Christianson found that people remembered the
personal encounter, and told them to fiU it out as soon as possible after
Palme assassin:ltion more accurately than they rel"nembered an unre
the key event occurred.
markable event from around the same time.)
Weavcr's timing turned out to be fortuitous. The first meeting of
200
Setlfcld/lg for Memory
his laboratory class was January 1 6 , 199t-che day President Bush announced the bombing of Iraq. Moving qUIckly, Weaver put together another questiOllilaire to assess memory for this flashbulb event, and administered it to his class when they next met, twO days later. He thcn asse�sed memory for bOlh (he personal event and the public event three months lacer, and again a year 1:ller. Weaver's results were clear: studenLS' memories were no more accurate for the iraq bombing than for the personal encounter, and there was evidence of forgening over time for both kinds of memories. Out the students were generally more confident abom their memories of the bombing chan abom their memories of the personal encounter. As in Ncisscr and Harsch's study of the
Chal/enger disaster, a person's subjective
confidence i n a flashbulb memory was not matched by irs objective accuracy.? Why should flashbulb C;!vents somctimes give rise to confidence in a Illistaken recollection? Part of the answer lies in the fact that people are pronc to forgetting or confusing the source of a memory when long periods of time have elapsed after an evem. Ncisscr and Harsch relate an example of a student who, when queried the day after the
Clwl/ellger disaster, said she had learned of it during her religion class when she heard some friends talking about it. After class, she went to her room and found out more about it ITom television. Three years later, this young woman insisted that she had first learned about it from TV: "When I fmt heard about the explosion I was sitting in my freshman dorm room with my roommate and we were w(Itching TV," she remembered clearly. "J[ came on a news flash and we were boch totally shocked."�The student was probably so certain because she was indeed remembering an actual event, although she didn't realize she
Emotional Memories
201
to the kinds of reconstructive errors that occur when we attempt to remember any distam episode. We may also hold unusually high confidence i n the accuracy of our flashbulb memories because we believe that they have been imprinted forever on our brains in some imlllmable form. Uut the evidence shows that they have not; some flashbulb memories decay and change over time. It is doubtful wht,ther such melllories are preserved by the Now Print mechanism that Brown and Kulick envisaged. Yet it is equally certain that flashbulb memories are, on balance, more durable and accurate than Illost memories of day-to-day events. One reason for their strength is that they are likely to be discussed and thought about frequently in rhe days, weeks, and eV('1l years following the event. Certainly this ;'rchearsal" was the case with JFK's death. The evidence also suggt'sts that rehearsal alone cannot explain why flashbulb events tend co he better remembered than more mundane events. The emotions elicited by ;l flashbulb evem also increase its memorability. For instance, i n Conway's study
of memory for
Thatcher's resignation. the degree of elllotional aTOus.1l (hat people experienced when hearing the news. as well as the amount of later rehearsal, contributed to the high levels of recollection that British srudents maintained even a year after the ewnt.IQ Both rehearsal and emotion arc relevant to understanding why certain memories stay with liS for much of our lives. I can remember what happened
Oil
November 22, 1963-but not on November 21 or 23-hecause of the emotional aoous:!l J felt at the exact mOlllcm of hearing the news
�
and be ause I have talked abOllt and strengthened the memory many . [lines smce.
was confusing tWO sources of her knowledge of the event. Neisser and Harsch note that such "time slice errors," as they call them, occur fre quently when people arc queried years after an event. The psycholo gist William Brewer has observed that these errors constitute a form of source amneSIa, and I agree.� Likewise, Larsen's iUusory memory of hearing ;lbout Palme's assas sination while listening to the radio with his wife probably seemed convincing because he had recollections of similar scenes from prior occasiom. This made it easy for Larsen to "insert" his wife into this particular memory.We have already seen tha( general knowledge and expectations can sometimes creep into memories for specific eventS during encoding, retrieval, or both-which in turn can produce sig nificant distortions. Recollections of flashbulb eventS are not immune
PERSONAL TRAUMA The Per s i s t e n c e of M e m o r y Flashbulb memories are fascinating phenolllen:l. \3ut when people
HI
a 1984 study were asked to produce their three Illost vivid memories, hardly any of the recollections involved events of national irnporrance: they tended to be highly personal events with great ('motional signif icance.1I Perhaps memories of episodes that induce emotional trauma are fundamentally different from ordinary memories. Might it be these memories are unusually accurate, depend on special brain mech anisms, and even involve something like the Now Print process? "An experience llIay be so exciting emotionally as almost to leave
202
E m o t i o nal M e m o r i e s
Searfitillg Jor M e m o r y
a scar on the cerebral tissue," observed the great Harvard psychologist and philosopher William James in 1 890. More recently. the
child psy
I
�84
203
tornado in TUrdl North Carolina, and combat expenence i n
VlCtnam and other wars-have yielded similar profiles.
The most
chiatrist Lenore Ten stated that after experiencing a traumatic cvem,
common posr-traumatic symptom is unbidden recollection of the
children retain " 'burned-in' visual impressions" that may last a life
trauma,
(1I11e.11 1 can readily think of several experiences that feel as though
they have left permanent scars in my brain. I remember all too well
�potty memory problems. In a few instances in which follow-up stud Ies have been done months or years after the trauma, available evi
eX:lCtly where I was and how I felt when I received a telephone call
dence suggests that the frequency of intrusive recollection!i tends to
from my mother informing me of the unexpected death of my f.1ther.
diminish but not disappear.I'
which Occurs in the context of emotional di�tllrbances and
On the positive side, I am grateful that I possess a "burned-in" mem
Some of the IllOSt poibrr1anr evidence for the persistence of emo
ory of the exact moments when my two daughters, Hannah and
tionally traumatic memories comes from the recollections of Holo
Emily, entered the world. One way to gain insight into the nature of memory for emOtion
caust surviv�rs . La\�'rence Langer has described and analyzed many . such memones III Ius eloquent and moving book Holocaust Testimol1ies:
ally arousing events is to probe the recollections of people who have
n'e Ruil1s of Memory. " I have children . . . 1 have my family," refiecred
experienced extreme or unusual traumas. In the great majority of such
one survivor, "but I can't take full satisfaction in the achievements of
individuals (as with Melinda Stickney-Gibson) , the most commonly
my children today because part of my present life
observed symptom is a repetitive, intrusive recollection of the trau
my memory of what happened then, and it casts a shadow over my
matic event. Consider. (or instance,
the memories of people who wit
life today." Another commented: "You SOrt of don't feel at home in
nessed the horrific collapse of two sky\valks at the Hyan Regency
tlus world any more, because this expericnc(.'---you call live with it it's
is my remembrance,
Hotel in Kansas City on July 1 7 , 1 9 8 1 . Nearly 2,000 diners, dancers,
like constant pain: you never forget, you never get rid of it, bm
and observers were
learn to
in the hotel lobby or on the skywalks when the
bridges connecting the second- and fourth-floor levels came crashing
�ou
live with it."IS
down-a thundering collapse that dumped SOTlle 65 tons of concrete
Similar themes are evident in the story ofJadzia Strykowska, a Pol . Ish woman who survived the Nazi concentration camp at Bergen
and steel into a lobby packed with unsuspecting victims. The disaster
Bdsen and later settled in the Chicago area. Jadzia relac('d her
produced 1 1 4 deaths and over
memories of the concentration camp to Jeffrey Wolin, a weD-known
200 injuries. The psychiatrist Charles Wilkinson probed the reactions of 102 of
photographer who has produced a series of works examining the rec
the victims, observers, and rescuers in the weeks following the tragic
ollections of Holocaust survivors. In "Jadzia Strykowska, b. 1 924,
event. Ne;lrly 90 percent of these people said they kept remembering
Tomaszow-Maz, Poland, 1993-94" (figure 7.3), Wolin juxtaposes his
the disaster repeatedly.
The intrusive recollections were potent
handwritten transcription of Jadzia's memories with an image of her
enough to disrupt the daily functioning of one in five of those who
holding precious f.·ullily photos that helped her to SUrvive the inhu
had witnessed the scene. Nearly half said they actively attempled to
manity of Bergen-Belsen.
avoid situations that were likely to elicit recall of the incidem. 13m try collapse were not terribly successful. The memories kept conting
The ine�capable power of traumatic memones is also exelllplified . III the \vartlllle recollections ofsoldiers who have experienced the ter rors of bank. Rl�,?el1emtiol1, Pat Barker's moving novel about hospital
back, bringing with them feelinb"S of sadness, alL'.:iety, depression, and
ized
even detachment. Nearly one in
a fictlonailzed account of efforts made by a real psychiatrist, William
as they might, these attempts to avoid remembering the catastrophic
three people reponed experiencing " memory difficulties" after the traumatic event, probably because they
�ritis� soldiers coping with the traumas of World W::ar I, provides
R..ivers, to help soldiers who wi!ih to hide
from their demons:
were so upset and distracted that they did not encode ongoing evel1{S normally. I)
These intense reactions and recollections are not unique. A number of other studies of real-life lrallinas-including the Loma Prieta
earthquake, the 1 976 Chowchilla school bus kidnapping, a devastating
The typical patient, arrlvmg at Craiglockhart, had usually been devoting considerable cncr!.')' to the task of forgetting whatevcr traumatic events had precipitated his neurosis. Even if the patient
rccobrrlizcd that the attempt was hopeless, he had lIsually been
E mo t i o n a l Me m o r i e s FIGURE 7 . 3
205
encouraged [0 persist in it by friends, relatives, even by his previolls medical advisors. The horrors he'd experienced, only partially repressed even by day, returned with redoubled rorcc to haunt rhe nights, giving rise to lhal most characteristic symptom of war neu rosis: the battle nightmare. " ll...ivcrs encouraged his patiems to spend parts of each day remem bering what had happened to them. Like many other survivors of horrif)'ing experiences, the soldiers under his cart' learned to live with memory's power by telling their stories, trying to fit these aberrant incidents with the rest of their lives, and waiting for the relief that only the passing of time can bring.
T R AU M A T I C M E M O R I E S How Accurate Are They?
Some researchers have adopted the view that memory for emotionally traumatic events is accurately preserved-perha.ps rorever-in great detail, and therefore differs fundamentally /Tom memory for nonemo tional events, which is subject to decay and distortion. 17There is a good Jeffrey Wolin, ''Jadzia Strykowska, b. 1 924, Tomaszow-Maz. Poland. 1993-94." 16
x
20". Toned Silver Print. Courtesy Catherine Edelman
Gallery, Chicago.
Jadzl:I Strykow
deal of merit to this view: memory for emotional trauma is frequently more accurate than memory for ordinary events. But even traumatic memories are sometimes subject to distottion. Consider, for example, Lenore Terr's studies of the children who had been kidnapped at gun poim on a school bus in Chowchilla, Calirornia, and then buried underground for some sixteen hours before escaping to safef)'. The children possessed the classic signs of traumatic memory-vivid and detailed recollections-but when Terr interviewed cwemy-three or the twenty-sLx children four to five years after the terrifYing episode, she noted the occurrence of rather striking errors and distortions in about half of them. Terr posed the key question: "One might ask: 'How can a
particular memory be precise, derailed, and at the same tillle wrong?' "11 She believes that the memory distorrions are largely attributable to perceptual errors that occur at the time of the event, caused by the Stress of the shocking episode. But " Ierr al�o observed that seven of eight children whose memories were accurate when they were ques tioned in an interview conducted shortly after the trauma-implying that initial perception of the event was adequate-exhibited distortions when tested four to five years later. For example, one mistakenly remembered a man who had pillows sHlffed in his pants and another
Sea r(/,illg fo r M e m o r y
Emotional M e m o ries
recalled a pair of girl kidnappers in addition ro the men who were
had worsened since the first interview tended to amplify the personal
actually there. These observations suggest that even "burned-in" trau
threat they had felt at the time of the shooting. Uut those whose poSt
206
matic memories are not immune ro change over time.
207
trlumatic stress SYIlIPlOlllS had declined since the first interview
Some l:vidence for distortion was also observed in a swdy of chil
tended to remember the shooting as less threatening during the sec
drell's mcmory for a sniper attack at :\11 elemenrary school in 1 984 that
ond imerview. People appeared to be remcmbering the event through
killed one child and a passerby, Based on imcrVlews conducted be
the filter of their bter emotional states. A related kind of emotional ftItering seems ro occur with combat "flashbacks" of war vererans, which are often so intense that vetcr:m$ feel as though they arc reliving an actuaJ t'xperience. Flashbacks some times comain elements of both real and feared or imagined evems. In
twecn six and sixteen weeks after the violent episode. the researchers noted chat children who were at school during ehe attack tended ro remember themselves as being in a situation of greater safery than they actually were. More remarkably, some children who were not present during the attack remembt'red that they were! One boy who had been away on vacation the day of [he attack recalled that he "had been on his way to the school, had seen someone lying on the ground, had heard thl: shots, and then turned back:'19 A variery of influl:nces could be al work here. The tendency of some to rt:call themselves as being safer than they were may represent a kind of emorionally driven retrospective bias: in attempting to reduce their anxiety about what had happened, some children may have reconstructed the cvelH in a way that fit more closely with their
his pioneering study of trauma and World War I veterans, John Mac Curdy observed that rhese overwhelming moments of " reliving"
prior experiences often involved veterans' "worst fears," rather than actual combat episodes. He referred to slich incidents as visiol1s in order to reflect the mixture of fantasy and rcality that they often con tain. This characterization is less bden with assumptions about the his
torical accuracy of tht'se experiences than is the commonly used term may be a more appropriate dt:scriptor.:!O
flashba(k and hence
The psychiatrist Fred Frankel notcs that the term
jlmlJba(k
did not
currem emotional needs than with the true details. Likewise, children
appear until the late I 960s, in reference to rhe experiences reported
who were nOl :1.[ the shooting may have felt a need to participate in
by LSD users. Sometime after the major effects of the drug had worn
the event. They probably discussed the episode frequently with their
off, lIsers reported flashbacks, in which they suddenly reexperienced
friends. Because children are oftt:n vulnerable to confusing the sources
aspects of their drug-induced imagery or hallucinations. Those most
of their knowledge when they are tested long after an event-and the
likely to report flashbacks were highly hypnotizable people who eas
participants i n this study were not interviewed until at leasl six weeks
ily cngaged in imaginative, f:mtasy-based activities. Frankel notes that
after the shooting-it is likely that some children mistakenly incor
flashbacks in such people are more akin to dreams than to real mem
flashback
por:ued bits and pieces ofincidems from other children's recollections
ories, The term
into their own memories. I would ber, for example, that the child who
pelling recollections of Vietnam war veteram. Echoing MacCurdy's
had been on vacation would not have falsely remembered being ncar
observations, Frlllkcl urges that we remain skeptical about the truth
the scene bad he been tested thc day after he returned home.
fulness of flashbacks unless they are accompanied by corroborating
Compelling bue inaccurate memories of traumatic events arc IlOt
was later applied to the involuntary, COIl1-
evidence. He describes a veteran plagued by a flashback in which he
restricted to children. In 1 988, a wOlnan entered a suburb:m Chicago
killed a villager who kept gcning up abrJin and again. This is a worst
school and carried out a daylong rt:igll of [error, killing a child and
fear vision, not a pbyback of something that happencd.z1
wounding five others. At five months and eighteen months after the
A clinical case that also appears to involve a worst-fear f.1ntasy was
tragedy, psychologists asked school personnel questions :lbOUl where
reported by the psychoanalyst Michael Good. He dt:scribes an adult
they had been during the shooting and how they had felt about it;
patient who was pbgllcd by a traumatic memory of having had her
most had been at the school, bur some had been miles away. Two of
clitoris removed when she was five years old. The patielH also
three who initially said they had been ill the building claimed l:lter to
described repetitive dreams involving this incidellt. When Good sug
have been close by outside; twO of six who initially said tht"y had been
gested that she visit a b'Ynecologist in order ro explore the matter fur
1lI0re th
ther, an examination reve:lled that she was anatomically normal-her
the second interview, people whose symptoms of post-traumatic stress
clitOris had never been removed. Good points Olil that the patient may
Searcili"g jo r M e m o r y
208
Emotional Memories
have indeed feared sllch an act as a child. The patient rcmembered that when she was between the ages of three and five, her mother, a highly religious woman, had made her wear a dcvice that madc it physically impossiblc for her to masturbate. As an adult, unfortunately, she may ha\'e been the victim of a kind of source all1llesia---;hc could no longer distinguish between an imagined and an actual eventY Even traumatic expcriences that extend over long periods of time are subject to a degree of distorted recall. The psychologists Willem Wage na:lr and JoP Groeneweg eX:lmined various recollections of inmates in Camp Erika, a Dutch prison that W,IS converted into a cOl1centldtion camp when it came under German rule during I 942-43.lJ Much of the maltreatment, torture, and even murder of camp inmates was perpetrated by Martinus Dc Rijke. a prisom:r who
\v:tS
and
intill1.idating othcr
inmates. When the camp \v:tS disbanded Dutch police imervicwed many ,
of the survivors. Fifteen of those survivors were then interviewed ag;.lin betwecn 1 984 and 1 988, when the case against De Rijke was reopened Oeading to his capture in t 987). Wagenaar and Groencwcg were able to check some of the memories obtained from survivors during the first and second interviews against obj ective records, and to assess the extent to which survivors' n.:collections agreed with one another.
imprisonment,
the camp survivors held
recollections that were gencrally acculdte. Most of them agreed about the torture methods employed in the camp, about the horrifiC treat ment ofJewish prisoners, and about the fact that
De rtij ke was a knpo.
Everybody recalled the general features of the camp ;lnd the gist of what went on. But when it came to specific events and facts, some forgetting
distortion occurred. For example, when interviewed
between
and 1948. nearly all survivors n:called their date of
and 1943
entry to the camp within one Illonth: forty years later, less than half of them did. In
some
cases, people remembered entering the camp
during the wrong season of the year. During the forty years between rhe two interviews, a
number
of survivors had forgonen specific
episodes in which they had been brutalized or had witnessed others being brutalized. A photo of De R..ijke between 1984 and
was
shown to survivors
1988, the same photo that had been shown on
national television. Among those who had not seen the show, 58 per cent claimed to recognize De Rij ke, whereas 80 percent of {hose who had seen the show
said
they recognized De
Rijke-raising the
possi
bility that exposure to the photo 011 television and not their wartime experiences was the source of recognition.
Studies of real-life traumas, then, indicate that memories of emo tionally traumatic events arc generally persistent aCClildre,
but
and
often impressively
also that they are sometimes subject to decay and distor
tion. When a person ha� actually experienced a trauma, the central core of the experiencc is almost alwJys well
remembered: if distortion does
occur, it is most likely to involve specific details.When a person has not endured a trauma bur believes to have, chances arc that he or she feared it. imagined it, or heard about it. The general principle ' developed in earlier chapters-that memories are nOt simply activated picrtltes the
mind
in
but complex constructions built from multiple contribu
tors-also applies to emotionally traumatic memories.
promoted by thc Genmns
to the role of kalJl), which IIlvolved terrorizing
Even forty years after their
209
EXPERIMENTING WITH EMOTION W h a t D o We R e m e m b e r from E m o t i o n a l Experiences? Recollections of real-life traumas provide important insights into memory and emotion. But to undersL"lnd more fully the basis of these rich and affecti ng experiences, we also need controlled studies. Dcspite the limitations of experimental research-it is obviously dif ficult to induce profound emotions in the laboratory-the benefits of enhanced control and precision mah' this approach to memory and emotion well worth pursuing. Some recent laboratory studies have begun ro tease apart differem f."lctors that render emotional events especially memorable. I n one, people looked :It some slides that were highly pleasant, such as pictures of attractive men and women, and other sljdes that wcre tcrribly unpleasanc, such as mutilated bodies. I n addition to these highly arous ing materials. participants in the experiment also saw neutral, low arousal slides, including pictures of household objects. People recalled Illany more high-arousal than low-arousal slides, but recalled pleasant and unpleasant slides equally well. This finding and silllilar ones sug gest that the accuracy of memory is often directly related to rhe emo tional arousal elicited by an experience. independent of whether it is positive or negative,J· Arousal may also influence what is remembered from an emotional experience by focusing rience. For
instance,
Ollr
attention on specific aspects or an expe
people who were exposed
to a traumatic
sequence of slides (depicting a bloody car accident) remembered more of the cclltldl, important themes from the sequence and fewer of the
210
(0 a did people who were exposed specific, peripheral detaiJs than c mati trau the in ome suggests that nontraulllatic sequence . This olltc emo was captured by the salient, condition, participants' :lttention de; consequcntly, less attention was tionaUy arousing parts of (he episo "left over" for the details.ll ent of a real-world phenomenon This laboratory finding is reminisc to a crime that involves the visi known as weapo/l Jocl/sing. Witnesses cally bank robbery at gunpoint, typI ble use of a weapon, such as a er rath weapon . I3ut they often have retain accurate memories of the inal's of the ewnl, including the crim poor memories of other aspects ure capt to ars ormation (the gun) appe face. The cmotionally salient inf into tbe scene are nOt well encoded attemion so that other aspects of le effect is most pronounced in peop memory. The weapon focusing is ing find This . n they see the weapon who report feeling anxious whe can ing that high levels of anxiety consistent with other research show al focus .:?6 lead to a narrowing of anention r ed by Vietnam veterans who suffe rienc expe es Some of the difficulti ing -driv disorders also reAect the attention .. from post-traumatic stn'SS chroni be may rans Traumatized vete effects of past emotional trauma. sig less harm thus prone to treating cally vigilant and hyperaroused, and threats. Their attention may be easily nals in the environment as serious i of past traumas, which can create captured by stimuli that remnd them in .xi ty and panic. This is clearly illustrated an overwhelming scnse of all.e by one Victllam veteran, which the a terrifying incident experienced ed to me: psychologist Richard McNally relat th ofJuly holiday years after hav He was driving his jeep on a Four dl children tossed firecrack ing returned from Vietnam, when scwr le. The sudden noise initiatt.'d a ers under the wheels of his vehic and acted as if he wcre once terrifying Aashback wherein he felt nd thc wheel, he slanUlled on agam being ambushed. Ducking behi the "enemy" and, moments later. the gas in a framic attempt to Aee rl'alized that he was in Colorado, crashed. Ahhou!;h on one level he vioral reaction triggered by Ihe not Vietnam, the emotional and beha exhibited years before during firecrackers was the same he had ambushes while in Vietnam.v remembering their war experi Some veterans become flX3ted on cult for thcm to remember much ences, to the point where it is diffi ally and his colleagues report that about other times in their lives. McN riconsumed by their Vietnam expe some traumatized veterans are so
211
Emotional Memories
Sl'tlf(hill,/r1 Jo , M e m o r y
ences that (hey continue to wcar war regalia-fatigues, combat m edals, POW bllttons-twenty_five 10 thirty year.� after having left . Vleln:trn . One veteran arrived in the l
�oming uF with specific memorir.:s ofpleasant events from any period
. m thelf hves. They are so emotion:llly tied to their Vie-rnam experi
ences that they attend to and care about little else. Emotions can bias attention and memory in similar ways with other . . kmds of p:ments. Mark Wilhams and his colleagues in Wales were the
� �
,:
fi t t
repo what are known as "overgenerdl" autobiographical mem . ones 111 their studIes of suicidaUy depressed patiems.29 These patients
fCmember the gener.11 emotional gist of past experir.:llces, but do not recollect as many specific dct3ils as nondepressed people do. The over
�
�
general memori s may csult from biased encoding. Patients' deprt"Ssed � noods focus their attentIon on the general negative themes in everyday . mCldenl� that fit with their previous f1('b>ative experienct"S. They tend to
� retrieve) everyday
encode (and therefo
episodes through a negative
filter that confers a kmd of repetitive and pervasive drabness on ;IU their
�
e periences . At the same time, thr.:y tend not to elaboratively encode the . . . dlSClllct1Ve particulars of individual e:-.:perienct"S . Consistent with this
idea, PET scanning studies have shown reduced activity in tile left
�
frontal l be of depresse�1 patients. We saw earlier that left fromal regions play an Important role In elaborative encoding. Even nondepressed people report chat sad moods tend to feed on
�
them c1ves: when YOll feci sad, it somchow seems all too e:lsy 10 think
�
neganve thoughts al d remember painfill expenences. Psychologist'S have llame for thIS common experience: lIIood-m/{l!ntcw rel,icl'al.
�
EXpeTllllents have shown that sad moods make it easier to remember
�
negati\e ex criences, like failure and rejection, whereas happy moods � make It easIer to remember pleasant e-xperiences, like success and acceptance.JO This means that when wc arc in a blue mood and haw
:I
�
:
rclat vely easy time recalling painful past experiences we may . ll1 wlttmgly perpctuate and intensify our sadness. This kind of a neg
!
� �
atlvc ce back cycle can have serious consequences for people who are cluucaUy depressed. Depressed patients, in COntrast to n011depressed people, more easily recall their negative cxperiences than
t�leir positive experiences-which can serve to maimain the depres_ �Ion. Pat�. ents who arc suffering from depression also acquire new lIlformanon more readily when it is negative than when it is positive.
212
Sc(/rc/ii"g Jo r M e m o ry
E m o tional Mcmories
pleasant words (such as smile) and When asked to study a series of depressed patients show unllsually unpleasant words (such as despa ir), t words, especially when they accurate memory for the unpleasan II to themselves. . ' think about these words in relation important c linic l il�1plica�lOns. Mood-congruent retrieval has other . n a de�rcsscd panents . ability to Mood-congruent biases might disto expcnences [h�t are .1Il1portant remember accurately early childhood , . . ence consIstent w1th thIS pOSSI.hl l in a therapeutic context. Some evid ined the childl ood re�oUewo�s ity was provided in a smdy th:H exam women regardmg varIouS quah of depressed and nondepresst'd :.duh depressed when they complete ties of [heir parents. Women who were experiences remembered their a quest.ionnaire concerning childhood rejecting than WOillen who had parents as being more unloving or that the depressed women were never been depressed. Could it be y? Possib.ly. �owever these women remembering their parents accuratel more rCJcctmg than women who remembered their parents as being were not depressed \ hen compl.et had been depressed in the past but essed mood whl lc con�pletlllg ing the questionnaire. Being in a depr e to the womel? s ne�uve n:cthe questionnaire seemed to contribut g similar occurs III patlent� wnh ollcctions of their parents. Somethin how 11l�ch pain hey experienced chronic pain: their recollection� of em paUl level�. . in past episodes depend on their curr . retrospective biases I conSid These findings arc reminiscelll of the people arc gene�l1y accurate ered earlier. But remembn ab.o that ines of their past hves. In facl. when reRecting on the broad olltl s difficult to obser�e wl cn peo mood-congruent biases arc sometime t qualities of the�r childhood, Ie are asked general questions abou istently when questions arc asked vhereas they are observed 1110re cons Effects of mood on memory may about specific episodes :md events. e\ent-spe.cirlc k1lowledge� and less be most pronounced at the level of � lOgrapillcai knowledge. pronounced at higher levels of <111tob
�
�
?
,
� .
�
�
�
213
monkeys. Even morc striking were bizarre aberrations of emotional behavior : the lesioned monkeys lost their fear of previously threaten ing objects that frightened normal monkeys; tried to eat unusual objects such as rocks and feces; and, uncharacteristically, attempted to copulate with mcmbers of other species. This constellation of abnor mal behaviors came to be known as the Kluver-Ducy syndrome, after the authors of the article. Some two decades later, a young neuropsy chologist, Lawrence Weiskrantz, showed convincingly that the specif icany emotional aberrations associated with temporal lobe removal were caused by damage to a single small structure hidden deep within the innermost regiom of the temporal lobe: the amygdala.lO The amygdala is a tiny almond-shaped formation located next to the hippocampus. (See figure
5.1.) The hippocampus, as we have seen, plays
a key role in our ability to remember the ongoing incidentS in our day to-day lives: when the hippocampus is damaged, people have difficulty remembering what has happened to them recently. The amygdala is a critical Structure in the brain network that reb"JiateS emolions including emotional aspects of memory. It has become increasingly apparent that the amygdala plays a vital role in the emotionally charged memories that wield such a potent influenGei\n our mental lives. I pointed out in chapter 5 that .Plonkeys (or rats) that have had only the amygdala removed are not generally amnesic. When given simple laboratory test.� that require them to remember where food was placed, or which toy object they were shown a few seconds earlier, annnals without an amygdala do just fine..J5 But these same animals can show the kinds of aberrant emotional behaviors that were observed by Kluver and Bucy, and they can also have problems with specifically emotional forms of memory. Fear learning is a good example. It is essemial for animals {Q learn to fear dangerous situations, and they are generally able to do so rapidly. In thc laboratory, for example, ratS that are given electrical shocks at the samc time they hear the innocuous sound of a tone soon begin to show signs of fear when they hear the tone. The animals Illay "freeze" when they hear
THE BRAIN'S ALMOND Amygda l a , E m o t i o n , a n d M e m o r y In 1937, a paper in the Ameriltlll jOl/mal of Physiology sUinmari� ed the results of behavioral experimentS with monkeys that had receIVed an
it-a sure sign that they are afraid of it. Or their hearts may begin ro race when the tone is played. another indication that they are in a fearful state. When the amygdala has been removed, however, animals do not learn to fear the sOllnd of the tone. even when given many electrical shocks at the same time that they hear it. As already noted, these animals are not generally or globally amnesic; rather, they have
operation to remove both telllporal lobes. The authors reported that . such monkeys suffer frolll a kind of " psychic blindness": they faIled to
a specific problem learning and remembering fear. A series of impor
recognize many familiar objectS that wcre ea5ily rccog n ized by normal
tant studies by Joseph LeDoux and his colleagues has shown that this
,
Searc/ring jor M e m o r y
214
E Ul o t i o n a l M e m o r i e s
nnpairmcnt can be produced by damaging a single structure within the amygdala, known as the lateral nucleus.lI> A recent study by Antonio Damasio and his colleagues has specifi cally linked the amygdala with cl11O(iol1al conditioning in people.
�
They examlncd several different patienlS; one had suffered dama e , restricted to the amygdala as a consequence of a rare hereditary diS order known as Urbach-Wiclhe disease; another had selective damage to the hippocampus after temporary loss of o:\.")'gen during a cardiac arrest; and in a third patient. both the hippocampus and amygdala wnC' damaged as a result of encephalitis. D:nnasio's tcam showed each of these pltienrs a
3
ries of diffcrem colored slides-red. green, bl�le,
215
fectly positioned to evaluate the significance of incoming informa tion, which is an essential function of emotion. Events of high signif icance
require
immediate
attention
and action; events
of low
significance can be safely ignored. A normally funcrioning amygdala helps a rat-or a person-determine the significance of an event, behave accordingly, and retain the emotional event. fu shown by the work of LeDoux and Oamasio, some kinds of emotionaJ conditioning arc retained independent of explicit memory for the conditioning episode. However, an activated amygdala can also drive the system to attend [Q and elaborate on emotionally significant event.'I, thereby pro moting accurate explicit memory for such events. The amygdala call
or yellow. The blue slide was sometimes accompanied by the startling
help to influence or modulate explicit memory for emmionally sig
sound of a loud horn. This jarring noise produces an easily detectable
nificant events.
pbysiological reaction, known as the skin-conductall e response, � which reflects a person's emotional arousal. All three patients showed large skin-conductance responses when they heard the blaring horn. After the blue slide had appeared several times with the sound, peo ple without brain damage showed skin-conductance responses to the . blue slide alone-emotional conditioning had taken place. The p:ment with selective hippocampal damage showed normal emotional condi tioning to the blue slide, yet remembered litde of what h:ld
� ccur�ed
during the conditioning episode. In striking contrast, the pancnt with
amygdala damage had no problem remembering what had happened during the conditioning episode, but failed to show any effects of con
�
ditioning. And the patient with damage to both the hi�poca1l1pu and amygd:lla neither recollected what had occurred dUring the episode nor showed any evidence of conditioning. These results show clearly that the efTeccs of emotional conditioning depend on the amygdala, and are processed separately from explicit knowledge about what h� p pened during the conditioning episode, which depends on the IlIp
This modulatory role of the amygdala is linked to its role in deter mining how various hormones affect memory. Studies of r.J.ts and mher animals have shown th:lt injecting a stress-related hormone such as epinephrine (which produces high arousal) immediately after an animal learns a task enhances subsequent memory for that task. This strongly implk"S that some of the beneficial effects of emotional arousal on memory are due ro the release of stress-related hormones by a highly emotional eXperie.,llce. The amygdala plays a key role in this process. When the amygdala is damaged, injecting stress-related hormones no longer enhances memory. The amygdala, then, helps to regulate release of the stress-related hormones that underlie the mem ory-enhancing effects of emotional arousal." Do th(."Se findings imply that the intrusive recollections of tr.J.lIma survivors are associated with stress-related hormones? Are Melinda Stickney-Gibson's persistent memories of the firc she barely escaped attributable to changes in brain chemistry that occurred in response to signals from the amygdala as she jUlllped from a third-story win
pocampus.37
dow? Recent evidence from brain-damaged patients and traumatized
well pbced to play an important role in elllmiollal memory because
whose amygdala had been virtually destroyed by Urbach-Wiethe dis
. As both Oa11la5io and Joseph LeDoux point out, the amygdala IS
it receives inputs from many other structures in the brain. The amyg dala has access to relatively primitive sensory inforn13tion from early perceptual processing stations, and it could use this information t? determine quickly whether a situation is thrcuening enough to merit a "flight or fight" response. The amygdala also has access to more refined and elaborated information [rom later processing stages, so that it can evaluue a current situation in light of previous experience and help to guide an appropriate behavior. In short, the amygdala is per-
people suggests an affirmative answer to these questions. One patiellt ease rCHH.:mbered emotionally neutral pictures norm:dly. But unlike people without amygdala damage, her memory was not enhanced by emotionally arousing picrurcs. Damasio's group has described another Urbach-Wiethe patient who was specifically unable to recall or rec ognize facial expressions of fear, even though she had no problem remembering the Identity of f:mliliar faces. Electrical stimulation of the amygdala in patients with temporal lobe epilepsy frequently pro duces an intense experience of fear, and can also lead to a general
,
Searching for Mell/ory
E m o t i o n al M e m o r i e s
"feeling o f remembering," even though pacienrs do nO( report any
hormones. After exposure to the slides and story, all participants were
216
217
specific remembered contents. In a recent PET study conducted by
asked to recall the story as best they could. The drug and placebo
the psychiatrists Scott Rauch and R.oger Pitman and their colleagues,
groups remembered the nonemorional story equally wcll. However,
war veterans and others with symptoms of post-traumatic stress disor
whereas the placebo group remembered the emotionally arousing
der remembered personal traumas while they were scanned. Com
story more accurately than the nemral one, there was no sllch arous.11
pared to a nontraumatic control condition, the right amygdala was
benefit for the drug group-they remembered about the same
one of several strllcttlre� that showed heightened activity during trau
amOlllU of emotional and nonemotiollaI information . This outcome
matic recall. Interestingly, there was increased activity in areas of visual
indi �ates that administration of a drug that inrerteres with the pro
cortex during traumatic recaU along with decreased activity in Broca's
duction of stress-related hormones eliminates the usual benefit of
area, a key region (or language production . These results and other
emotional arousal .Ol� memory performance. Cahill and McGaugh . found somethmg sll1ular when they studied a patient with amygdala
PET data are consistent with the idea that traumatic recollections are characterized by intense and absorbing visual imagery.J9 Swdies of Vietnam veterans who suffer &om intrusive recoUections
da111�ge. He remembered nonemotional aspects of a story normally but, 111 contrast co healthy volunteers. failed to show enhanced mem
and other symptoms of post-traumatic stress disorder have revealed
ory for emotional parts of the story.'l
abnormalities i n the levels of chemical messengers knowll as cate cholamines, whose release call be stimulated by stress-related hor
The release of stress-related hormones, signaled by the brain's emo . llonal computer, the amygd.. 1 1a, probably account� for some of the
mones in response to arousing e:-..-pericnct..-s . One study revealed a
extra �rdinary power and persistence that characterize llIany highly
specific association between intrusive symptoms, sllch as flashbacks,
emononal or traumatic experiences. Just like our more mundane
and the levels of two catecholamines (norepinephrine and dopamine)
memories, recollections of emotiomll traumas are constructions not
that were excreted in the urine samples of traumatized Vietnam vet
�
erans. Other studies have revealed that a drug named yohimbine,
lite� l rccordin�. The amygdala works cooperatively with Illany ther bram Structures III order to assemble ell1otional mcmorit,s. Bur unlike
which activates neurons that respond to stress-related hormones, can
our more routine rememberings, Melinda Stickncy-Gibson's memo
induce Aashbacks and panic attacks in combat veterans. These induced
ries of the terrible fire, the unyielding recollections of those who wit
memories often involve an intense reliving of a war experience that
nessed the collapse of the skywalks in Kansas City, the flashbacks of
has a here-and-now quality. One traumatized Vietnam veteran, for
traumatized war veterans-and maybe even my own recollections of
example. looked at a shadow made by a sink in the testing room and
�ovember 22, 1 963-all reflect [Q greater or lesser degrees the work
perceived it to be a shadow created by a tank turret. He was not just
lIlgs of the brains almond. In the next chapter, I examine a darker side
remembering a past encounter with a tank; he was living through it
of emotional trauma and memory by exploring the twilight world of
again as if it were happening in the present ..fO
psychogenic amnesia.
Stress-related hormones can also influence specifically emotional aspects of memory in nomfaumatized people. In an e":periment car ried out by Larry Cahill and colleagues in the laboratory of James McGaugh (whose work with rats has helped to establish and clarifY hormonal influences on memory), college students were shown a series of slides accompanied by a story line. Some participantS were exposed to a relatively uneventful, neutral Story. For others, the begin ning and end of the story were relatively uneventful, but in the mid dle there was an emotionally arousing section involving a victim of a bloody car accident. Prior to seeing the slides, half of the experimen tal volunteers were administered a placebo pill. The other half werc given a drug (propranolol) that blocks the usual effects of stress-related
I s l a n d s i n t h e Fog trauma and amnesia o
219
in our society, we llluSt examine carefu lly some
� the peculiar instances in
which a person's past seems to vanish
wahout a trace.
EIGHT
I became involved in such a case back in September 1 980. [he n graduate studcnt at , arn�ed from Or. Pa l Wang,
a
u
I \\';IS tht! Universiry of Toronto when a call the clinical psychologist who just months
earlier had arranged for me to test a fascinating head-iqjured patient
�VllO
gave lilt! a firsthand glimpse of implicit memory. Dr. Wang
IIlformcd me that a most remarkable nt!w patient had JUSt been admit
n who did n �t know his name, where he li ed, or just a l�Ythlllg else about IllS per ona l pasr. About all he could say
ted: a YO llng ma
v
.
I SLANDS I N THE FOG
about
s
about hllnseJf was that he had once been called by the nickname
Psychogenic Amnesia
LlII �lbeljack L Lumberjack, Wang cominued, had approached a : poiJcel�,\;a�l III dOWllt WIl Toronto nvo earlier complaining of e ruc atm g back pams. He was taken to the hospital, but wht!n he
x�
�
?
l
Dr.
days
arnv d the young man was Ilot able to identifY himself, nor was he THE
I N T R U S I VE
Gibson,
Jadzia
recollections lim plagued Melinda
Srickney
Strykowska, and numerous other people who IHIVe
experienced profound traumas underscore that emotionally over whelming events are frequently our best-remembered experiences. And the research I considered in the last chapter is beginning to uncover the reasons why this is so. But under special circumstances,
("llllna such a
is associated with f,1.r-reaching 3mnesias. Wh:1l accounts for
seemingly paradoxical
state of affairs? This question
has
assumed paramount imporlance during the past few )'cars becallse of the controve si
r es concerning recovered memories of childhood sex lIal abuse (which I exami e in th!.: next chapter). Heated debates have raged about whether or llot pcople can tem porarily forget terrible traumas. Students of memory, mostly clini cians, have reponed instanc(."S of trauma-related forgetting for more n
than a century. Unlike the material 1 have considered in previous chapters, tlll!se examples of role in
shaping the
traumatic amnesia have nOt played a major memory that have unfolded
ncw conceptions of
in recent years. When we entcr the world of trauma and amnesia, we encounter exotic cases of fugues and multiple personalities that pop ul:ue the
edges of memory research. We do
not yet understand such
cases very well. But some of the techniques and ideas I have consid ered are beginning to illuminate these strange manifestations ofmem ory's fragile power. Given the urgency surrounding questions of 218
carrymg any identifying information. A local newspaper printed his photo the next day
in an effort to locate f.1 mily members. Or. Wang
whether
I might be interested in testing LU1l1berjack's
wondered memory.
As a graduate student with interests memory,
ill both normal and abnormal I �ollnd such an invitation irresistible. Llimbeljack appeared
to be suffering fronl psychogellic, or functional, amnesia: a temporary loss of �l e ory th t is pncipitated by psychological Psy : chogellic amneslas m\'olvlllg loss of personal identiry have been
lm
.
a
a
.
trauma.
reported i � the psychiatric literature for at least a cemury, and they
are But in reality they are ae have estimated that x e i functional amne sias that cover large sectors of the personal past occur in less than I �
�
oft n deplCtt!d �n elevisioll and in movies. qUlle r r . PsyclmtrlSts e t ns
w
percent of psychiatric patientS. The incidence rate may be somewhat
higher during wartime, when combat-related stress can produce tem porary amnesic episodes in traumatized soldiers. One study of soldiers who were hospitalized duriJlg World War " , for exarnple. reported a 1
�
percent
incidence of various forms of psychogenic amnesia. Sol dIers who had been subject to heavy fire were more likely to present with amnesia than those who had no combat exposure.1 Motivated by pure fascination with the subject, I h d . t!ll o re lib ry stacks of musty, turn-of-the-cemury
a spent hours
�lulltmg �hrou�h r l .
ra
Journals III wl11ch PIerre Janet, Monon Prince, and other psychiatrists had described their impressions of patientS who responded to over whelming stress or unbearable disappointments by blotting
Out much
Sea r c h i ng Jo r
220
JHe m t H )'
of the past. Some wandered for days in what psychiatrim caU a Juglle
state, in which a person is totally unaware of having lost all knowledge of personal identifY. Pafiems in fugue states often focus (heir auention exclusively on achieving a specific goal, such as finding their way to a particular destination. In one case of a wartime fugue, an Australian soldier serving in Africa during World War II became traumatized when a Gnrnan fighter plane came swooping down :It him. He remelllbered trying to fire at an appro:lching dive bomber, chen he ;;blacked out." Thirty-rwo days later he "came to" in a Syrian hospi tal, hundreds of miles away. Mter the bombing incident, he had become totally focused on seeking refuge ncar a camp he had heard about in Syria. He wandered in a fugue for over a month, not know ing who he was or what he was fleeing, until he became aware of his memory loss in the hospitaJ.l Patients in fugue states arc generally oblivious to their disconnec tion from the past until a situation arises that requires them to iden tify themselves or to provide information about their background and experiences. Lumberjack was in just sllch a stat.e prior to entering the hospital. He had been wandering the streets of downtown Toronto for more than a day. It was only when hospital personnel asked him to identify himself that he realized, much to his surprise, that he could not. Back in
1 980, there was not a single controlled investigation of
memory retrieval during an amnesic episode of the sort that LUIll berjack was experiencing. Here was an opportunity to break new ground by carefully studying Lumberjack with scientific procedures. Dut I would have to move quickly, since psychogenic amnesias fre quently clear up within a few days, and Lumberjack had already been in the hospital for more than two days by the time I learned aboU[ him. When
I
met Lumberjack the next day in his hospital room, I
encountered a quiet young man with
strinb'Y blond hair who
appeared mildly embarrassed by his inability to recall his past. His IQ was in the normal range. He had some difficulty recalling stories and pictures that were presented to him, bU[ his memory for ongoing experiences did not seem to be seriously disrupted. Lumberjack could reCOb'llize faces of famous people and lise vocabulary normally, show ing intact scmamic memory. To find Out marc about his ability to recall episodic memories, I used the Crovitz technique described earlier: I read am to Lumber jack a series of cOlllmon words, such as tab/e, IIl1rt, and nlll, and asked
Islands i n the Fog
221
�
him to try to thin of a particular experience fTom a specific time and place that was tngg'ercd bv the J cue wo·d • . N orillaI young ad 1I Its . remc e memones rangmg from the immediate past to the early � years of chIldhood, but over 90 percent . of Lumberia 'J ck's memones came fIrom the two days since he had been admitted to the hospital. He could remember little else.
'
•
I noticed one intriguing feature of the few memories that Lum
belJ.��
k.
was able to recall from his pre-hospit al life: tbey were largely . restrl cted to a H. ille . perio d about a year earlier, when he work . ed for a . couner service. When I probed, Lumberjack prov . ided detailed recol lections of specific incidents that had occurred during his time there :md h remembered a great deal abou � t his fcllow employees and wha they dJd. l h d apparently managed to stumble upon a preserved island � of memory 111 a vast sea of amnesia. Thi� memory island turned Out to be a key feature of Lumberjack 's amflesl� . I contacted the courier service to confirm melll les and Iear (·d that employee s there had COme up with the �� � . name LUlllbclJack -and that this had been the only time in his life he had been called by that nicknam e. Why \ s able to remember this particular perio ,? d and n? ot lers� HIS t1 [ � at �he courier service, he said, was one of the hap ple t HI an orhenvlse dIfficult and sad life. It emerged later that Lum � befJack �ad been abandoned by his parcnt� as a young child and had . . �een raIsed almost smglehandedly by his gran dfather. Lumberjack's h�e a�peared to con ist of a series of disappointments, rejections, and � fadllrcs. At the COlmer SerVI. Ce, how ever, he was liked, accepted, and sllccessful.Th e olle happy period in his life seemed somehow inHllune from the a U1esia that lad hidden just about everything else. � , LlImbelJac s amnesIa cleared up the evening after tested him. . W lle watchmg the television rendition of the novel ShO;!IIII, Lum belJack began to recall during an elaborate funeral and cremation s�ene that he, to , had recently been at a funeral: his grandfather had � dIed a week carller. He then reme mbered his real name and, during the 'lext several hours, managed to recover and piece together the rest . of hiS past.
;
Lumberjacks
�u'.nbeljack n
�
�
�
�
? !
I
The eat l �fLlImbeljack's grandfather -lhe single most illlportant person III hIS IIfe-ha appar ntly trigg ered the amnesia. Lumbcljack � . eventually recalled gOIll to I l lS gran df uher 's funeral, and leaving it in � a state of shock and gnef. He recal led nothing else after that until twenty-four ho 'rs later, when he approached the policcman. Even � after the amnesIa cleared up, Lum berjack did not recollect anything
?
222
Sf'ar(hi"�'1 fo r Memory
that had transpired during the day o r so when he walked the streets
FIGURE 8 . 1
of Toronto in a fugue state-and it is unlikely that he ever will. In Illost cases of psychogenic anulesia, patients eventually recover their entire personal past with the exception of what happened during the fugue state. When I saw LumbeJjack again several weeks later, he said he had fclt "stupid" about being umble to remember his name and so much else about his past that clay. Now that I could compare Lumbetjack's performance in his normal state with his performance during the amnesic period. the results were clear-cul. His IQ and recognition of famous faces remained unchanged. but he was now able to recollect episodes and experiences from many pans of his life. He could barely comain his happiness as he showed me that he, like everybody else, could travel in tillle and tell the stOry of his life.
W H E N THE M I N D F O R G E T S I T S SELF B e y o n d L u m b e rj a c k Because there have been s o few controlled studies o f memory during episodes of psychogenic amnesia, it is difficult to say whether the COil stellation of feaUlres that characterized Lumberjack-loss of explicit memory for individual epIsodes and other personal information. a preserved island of autobiographical recall involving a specific lifetime period, and excellent retention of nonpersonal. semantic melllory-is typical of other patients. The neurologist Marc Kritchevsky and col leagues recently reported that ten patients with psychogenic ;lmnesias involving loss of personal identity performed just like LUlllbetjack on the Crovitz task, TCcalling many episodes since the onset of their amnesias and virtually none from before. But only half of these patients recognized famous faces normally; the other half, in contrast to Lurnbetjack, performed poorly on this test of semantic memory. All of them had problems recalling specific public events (for example, Who killed John Lennon?), a task that probably draws on both episodic and semantic memory. In contrast to Lumbetjack, some of the patients TCmained amnesic for weeks and months. These findinb� indicate that no single profile characterizes aU patients with psy chogenic amnesia and loss of personal identity.This should not be sur prising, because
such
amnesias
are
110
doubt
influenced
by
idiosyncratic fc:ltures of each patient's psychological history and pres ent conflicts.' (See figure
8 . 1 .)
Ma.rtha McCollough, .. Amnesia," t 992. 9 x 2 6
x
6 " . Mixed media
construction. Clark Gallery, Lincoln, Massachusetts. :�ychogenic. alllllesias oflcn senT the purpose of temporAry escape . from 3n nHokr:abl{' S1tuat�on, as highlighted in this I.'vocati" e wire-n1l'sh sculpture. \Ve . �:e part of the piece. wlllch cOl15ists of seven interconnected "pages " of wire. I he \vork centers around tht: printed phr�se: "The amnesi ac, recovering his m�1I1orr: changt!s his name and leaves home to start a ncw life," This is an elll�,'lnatic o�ering: in classical cases of fugue and functional amnesia. patit'nts . adopt new Identiti es and leave hOllle upon losing their memories. But the phras(' d�cs imply .that intoler:abk life t"Vt'1I1S caused amnesia in the first pbce. Be�ow thiS phr:ase IS 3 shadow figure. perhaps symbo lic of los1 identity. On the f.1CII1g page we see an �mpty grid overl:nd on the repe'ltl.'d \vord days, su g; . . . g�'stmg lost penods of tIIne. Other pages comain empty grids owrbid on the w�n:ls }'�ars �nd Il�,!rs; ladders leading to and from nowhere; and a sinking ship. WIth th i S plece. McCollou�h man�gcs 10 convey a sense of the bewildering . . of Illmd that char:actenzes panents Wilh psycho su.tt genic 3mllcsias.
224
SetHdlillg fo r Memory
Islands i n r h e Fog
These points are illustrated by onc o f the most bizarre cases of amnesia ever reported. I fIrSt learned about K. in April 1986. when I received a letter from one of his physicians. This flfty-three-ycar-old married man had been found sitting on his kitchen Roor, silent and dazed. He held in his hands a defeccive electrical element from a
220-
volt oven, but his body was neither scarred nor burtlcd. In all ambu lance on the way to the hospital, K. began to speak. He was confused and said that he had a terrible headache from being hit on the head with a baseban bat. It was later revealed that he had indeed been hit on the hC;ld with a bat-in a Little League game when he was four teen years old. K., however, believed he was still fourt:en years old and
had no memory for anything that had happened to hun after that age.
He failed to recognize his wife and children. He believed he was still living in his childhood town, felt shock and dismay when he learned . that his father had died, and was taken aback by how old Ius mother looked in photographs. He was equally surprised by the sight of his own face in the mirror and was amazed that he needed to shave every day. "It was as if," wrote his physician, "Rip Van Winkle had awak ened."; This extraordinary amnesia was unlike anything I had ever heard about before. A team of researchers at Johns Hopkins University who tested K.'s memory found that his anmesia was not confined to auto biogrJphical recoUections.6 He showed no men1ory for famous peo . ple or public events after 1945, 31though he eastly remembered tho�e hefore 1945. He was unfamiliar with, and amazed by, electromc
devices such as televisions and VCRs. Incredibly, K. had lost the abil ity to execute skills he had acquired after 1 945, induding such b�sic ones as driving and shaving. Yet he had no difficulty rell1:lllberlIlg . . ongoing, day-to-day events. Extensive neurological exanunatlon failed to reveal direct damage to the brain. It turned out, however. �hat K. . had been under severe job-related stress. He had been expenenclllg breathing difficulties and chest pains, and was on a disability leave for . these psychosomatic problems at thc time his �nmesla oc� urred. . Why did the amnesia affect the lifetime penod begmnlllg abruptly
225
experiences from one another. Although K. differs frolll Lumberjack in Illany respects, in both patients some lifetime periods wcre resistant to amnesia.
. The prospect of flking must be taken seriously in certain cases of
psychogenic amnesia; indeed, some w:mling signs often point toward a simulated amnesia. If a p3tienr has been charged with a criminal offense, is attempting to escape financial difficulties or some other lebral obligation, or stands to benefit in some material way from the amnesia, then there is certainly cause for suspicion.? In genuine cases, psychogenic amnesias may result from the com bined effects of brain damage and emotional trauma. A considerable proportion of patients have a history of prior head i njury or some other kind of brain abnormality. Lumberjack, for example, was involved in a car accident when he was four years old that damaged his right temporal lobe. This damage was serious enough that a brain scan administered during his hospital stay clearly revealed it. K. was hit over the head with a baseball bat at age fOllrteen. Several other cases of functional amnesia reported during the 1 98& also include a history of head injury or brain damage.� In fact, nearly all early psychiatric studies of psychogenic anmesias and fugtles published from the 1930s through the 1950s indicate that many patients had once suffered brain trauma or disease.' Knowing that does not tdl us much about why psychogenic amne sias present in the way they do. Psychogenic amnesias are rare, and ie is safe to assume that most people who once suffered brain (L1mage do nOt end up like Lumberjack or K. And we have already seen that memory is affected in specific \vays by damage to different regions of the brlin; the general notion of "brain damage" is too coarse to be helpful in illuminating psychogenic amnesias. But filrthcr on in the chapter, I will discuss how damage to specific parts of the bram could alter a person's response to psychological trauma occurring later in life to produce a highly unusual outcome: extensive amnesia.
in 1 945? K. experienced several salient life changes shortly after that year, including a f.ll11ily move, change of schools, death of a close
HOLES I N THE PAST
grandparent, and a 6re that destroyed his fan:Lly s un nsured house.
Limited Amnesia
�
�
Moreover, World War I I ended in August 1 94.:), signalmg the end of one lifetime period and the beginning of another. K.'s 3l�1I� esia pro vides further evidence that lifetime periods serve as orgamzmg struC turcs in memory, helping to separate different constellations of
Psychogenic amnesias arc not always as extensive as in the cases of Lumbeljack and K. Seress and trauma are sometimes associated with loss of memory for single evenrs or a slllall Ilumber of experiences a condition I call limited amnesia. Some cases of memory loss in COI11-
226
Sl'arrill' ug Jor Memory
bat involve temporary amnesia for a specific traumatic experience, Limited amllesias have also been reported in victims of brutal rapes and other violent crimes, who arc sometimes unable to recall the occurrence of the crime and the events leading lip to il.IO In
orth American and European societies, claims of limitcd amne
sia arc frequently seell in perpetrators of VIOlent crimes. One study revealed that 26 percent of men who had been convicted of murder or m:lIlslaughter stated that they could not remember committing the crime; in other studies, between 25 percent and 65 percent report some kind of amllesia. Because claims of amnesia could lead to a reduction in the severity of criminal charges, the prospect of faked amnesia in such cases looms large. Most experts agree that numcrous alleged alllnesias for violent crimes are feigned, but there is no b't'neral agreement about how to tell the genuine cases oflimitcd anmesia from the simulated ones.l1 In the studies just referred to, defendants who claimed amnesia had higher levels of alcohol intoxication during the crime than those who said they remembered their violent acts. Numerous studies have shown that excessive alcohol intake can impair explicit memory, sometimes producing a blackout in which people can rec:lll nothing that occurred during the period of intoxication.l! In many cases oflcgitimatl.: amnesia for violent crime, it Inay be intoxica tion, not emotional t.....lUma, that produces limited amnesia. These issut!s have also arisen in thc Illost infamolls case of a for gotten violent offense: Sirhan Sirhan's assassinatioll of Robert F. Kell nedy. Although Sirhan claimcd no memory for the Inurder, the dcfense psychi:nrist Bernard Diamond used hypnosis to re-create the frenzied emotional state in which he committed the crime. We have already seen that hypnosis is not a reliable means for recovering accu rate mcmories, but hypnotized people do occasionally recall actual experiences they might not otherwise remember. As his mood approximated his earlier agitated state, Sirhan apparcntly remembered
I s l a n d s i n the
Fog
227
:Vhel1. p�ople encode new information in a state of drug or alcohol
IIltoxlcatlon, they recall that information more accurat ely when they arc intoxicated again thall when they are sober. It rums Ollt that emotional states can produce a similar effect. When experimental volunteers learn new information in a sad mood, they somerimes relllelnbcr it more accurately when a sad mood prevails during attemp ted retrieval than when a happy mood prevails. Could such state-d ept'ndenr retrieval account for Sirhan's memory loss, and possibly other instanc es of amne sia for traumatic episodes? Possibly, but I al11 skeptical,lo More important, Sirhan's amnesia for the assassination is probably nOt attributable to trauma-induced forgetting. Moldea considers the possibility that Sirhan \vas intoxicatcd on the night of the murder. He ultimately rejects that idea and presents evidence that Sirhan has been faking memory loss for much or possibly all of the tinle since the shooting. When Moldea Interviewed Sirhan in September 1993, he h�ld firm to h�s story. "�I don't remt'mber being in the kitchen pantry,"
Sirhan stated.'" don't remember seeing Robert Kennedy. And I don't remember shooting him. All I remember i s being choked and getting Illy ass kicked." But Moldea concludes his book with a dramatic inci dent in which Michael McCown, a member of Sirhan's defense team, attempts to reconstruct the crime during a prison visit: Suddenly, in the midst of their conversation, Sirhan started to explain the moment when his eyes met Kennedy's just before he shot him. Shocked by what Sirhan had just admitted, McCown asked, "Then why, Sirhan, didn't you shoot him between the eyes?" With no hesitation and no apparent remorse, Sirhan replied,
_
.
"Uecause that son of a bitch turned his head at the last second. "
�
lhe assassination episode and reenacted parts of it. After the hypnosis.
as Sirhan merely engaging in empty bravado? Or docs this single . IIlcldent mean that he has always remembered hi� crime? We don't
when he rewrned to a more pbcid mood, however, Sirhan once :lgain
know for sure, but Moldca believes that Sirhan's amnesia fits a general
claimed amnesia. In the journalist D:m Moldea's recent reexamination
pattern of attempting to evade personal responsibility for the crime.
of the assassination, he quotes a 1972 declaration by Sirhan's lawyer,
This would be consistent with the emergence of memories when
Grant Cooper: ';Sirhan at all times stated he could not remember fir
Sirhan was hypnotized. Sirhan might have felt that remembering
ing the shots." After he received the death sentence. Moldea points
under hypnosis a!.lowed him to profess no consciolls knowledge of the
out, "all Sirhan could say to his beloved Inother, Mary Sirhan, was 'Mom, I'm sorry. I don't remelTlbcr anything." ' ll
crime, "I)erhaps, over the years, Sirhan has somehow managed to con vince himself that he does not remember the events of that terrible
The coming and going of mcmory in Sirhan's case appears to resem
night;' reflecu Moldea. "But I doubt it. , believe he relives that
ble the st:ne-dependent retrieval eflects I mentioned in chapter 2.
moment every day:'u
I s l ands i n the Fog
Sl'a Tfllillg fo, M e lll o , >,
228
229
Another case of forgotten-and-recovered memory for a violent
These cnve;1(S apply to memory for recent traumas. But traumatic
crime cannOt be easi l y explained in terms of faking. alcohol intoxica
cpi �odes from the more distant past arc sometimes subject to a kind of ' Illlllted amnesia: trauma-related fears and stresses that lay dormant for
tion, or state-depcndent retrieval. Marvin Bains, a fifty-year-old machinist who was upset with his wife for suspected infidelity, turned up on a neighbor's doorstep with the lower right side of his jaw blown away. Police were sUlllllloned CO the scene and discovered the man's
years are sometimes suddenly reactivated when people are exposed to . a new tr:allmattc stre�. To take just one example, fears acquired during early childhood, whJch had seemingly disappeared during adulthood,
wife in the kitchen of their home, dead from a shotb'1.l1l blast. Bains,
can reemerge unexpcctedly, with blazing force, in a stressful situation.
eventually charged with murder, claimed anmesia for the episode; he could provide no lIlformation about how his jaw had been damaged
Peopl � may have no memory for how they initially acquired the fear. reAectmg the normal amnesia that we all have for the first yeaTS oflife.
or how his wife had been killed. A member of his defense team who
In research studies, infant r.ItS who learned to fear
particular sound
was a psychiatrist hypnotized Dains and elicited an account of the
through a conditioning procedure seemingly "forgot" the fcar several
incident. According to Bains's recollection while hypnotized, he had
weeks later, no longer behaving fearfully when they heard it. But
intended CO shoot himself and had killed his wife by accident. After
when they were later subjected to stress--either by injection with
the hypnosis, Bains continued to claim no memory for the murder.
stress-related hormones or electric shock-they once again were par
But his account of the event under hypnosis suggested a possible solu
alyzed with fear by the sound.l�
�
tion to an unsolved puzzle in the case: the fate of a missing bullet that
AJthoug l normal processes of infantile or childhood amnesia may
nobody could explain. Following up on what Bains said under hyp nosis, the defense attorney and a prosecUfion expert returned to the
be �esp0l1Slble for this kind of memory loss, fear reactions acquired durmg adulthood can also fade with the passing of time and then
scene of the murder and searched above the kitchen ceiling, where
return under stress. Several cases have been described in the context
Bains had indicated the missing bullet had passed. They found a buck
of combat. One Israeli soldier who took part in rhe 1973 Yom Kip
led beam, apparently dam3ged by a bullet, in JUSt the right location.
pur war became traumatized when a grenade W'dS thrown into an
Based on this evidence, the charge of murder was dropped to
armored carrier and he was the only one to escape alive. With treat
manslaughter. After serving three years in prison, Bains was released.
ment, he eventually recovered from this post-traumatic stress disor
Shortly thereafter, he shot himself to de3th.16
der, and after the war he resumed military activity. In 1 982, when
The kind of profound anlllesia for an overwhelming emotional
Israel entered into a war with Lebanon, the soldier was called to
t'-duma that appears to have occurred in the case of Marvin Bains is
active duty. He performed well until he encountered a situation that
exceedingly rare. Most cases that involve amnesia for a single trau
was i n some respects similar to the original trauma: he was riding in
matic event can be attributed to such factors as intoxication, head
an anl'lorcd carrier that was hit by enemy fire. The soldier became
injury, or loss of consciousness during the trauma. Even in Bains's case,
virtually incapacitated by the same problems that had plagued him
we must remember that his jaw was severely damaged by a gun blast,
previollsly.'·
which might have caused temporary loss of consciousness or a con
This soldier might have been able to remember rhe initial trauma
cussion that contributed to his loss of memory. We do have some evi
all along but simply ceased to become upset by it as time passed. In a
dence
related case of a World War 11 veteran, dormant memories associated
of
limited
amnesia
for
an
overwhelming
emotional
trauma---cxamples from war veterans, criminal cases in which COI11-
with combat traumas suddenJy resurfaced over thirry years after the
plicating factors are frequently involved, and scattered case reportS of
conclusion of the war. Mr. A. was an American machine gunner who
traumatized people, many dating /Tom the turn of the century. But the
fought many battles in Germany, killing numerous enemy soldiers at
evidence is not strong enough to aUow firm conclusions about the
close range. In the Battle of the Bulge, he became disoriented and
role of emotional trauma (as opposed to intoxication. brain injury, or
confused after an artillery shell killed his assistant gunner and a
loss of consciousness) in amnesia for a specific event that would nor
sergeant. I n a later, even Illore disturbing episode, Mr.A. and some fel
mally be well remembered, a poim 1 win return to when 1 consider
low soldiers mistakenly shO! and killed several adolescent German
forgetting of sexual abuse in the next chapter.17
boys who had been playing in uniform.
I s l a n d s i n t h e Fog
Searching Jor Melllor),
230
After the war, Mr. A. adjusted well and showed no signs of pOSt traumatic stress disorder. He did, however, suffer various medical prob lellls
that
worsened
during
the
1 970s. Mr. A.
was
a
fiercely
independent man who found it distressing when. in 1976, he \vas forced by his health problems to retire and seek a medical disability. At around the same time that he \vas attempting to grapple with this new stre�s, he began lO suffer--for the first timL�repetitive, terrifY ing nightmart·s of the war. These unwelcome dreams made him tot'ally preoccupied with his memories of what had happened in Germany thrt:c decades earlier. The psychiatrists who described his case said that " [flrightcllillg memories of events that had, for the most part, been out of his awareness for over 30 years were remembered in exquisite detail and with affects that were morc intense than he had allow('d himself on the battlefteld."20 We have no way to assess the accuracy of the war memories that resllt'faccd during Mr. A.'s retirement. And it is difficult to determine whether Mr. A. was ever truly unable to recall these experiences prior to the onset of his nightmaf(.'S. For example, his psychiatrists note that :lfter his assistant gunncr and sergeant died during the Battle of rhe Bulge. Mr. A. had thought ahom writing to their families, which shows that he was not amnesic for the event. Indeed, in 1 964 he returned to the b:mleficld where they died. Nonerhc.lcss, for thirry years. Mr. A. was free of the intrusive, charged recollections of trauma th:lt :Ire so stJrkly evident in other survivors of traumatic experiences. This kind of forgetting is not quite the same thing as becoming amnesic for a violent crimc or other traumatic event that occurred only hours or days earlier. but it does show thal the full force of mem� ory's power may sometimes rcmain unexpressed for years.
Alfred Hitchcock made effectivc use of this compelling theme in stich films as
M(/mie and Spef/bOll/ld, which wcre probably inspired by the
reports of Sigmund Freud, Pierre janct, :lnd other turn-of-the-century psychiatrists who described clinical cascs in which childhood traumas not available to the conscious mind nevertheless influenced patients' ongoing experience :lnd behavior. A classic example was Tt:ported in 1907 by the Boston psychiatrist !sador Cori:lt. He tells the talc of a \voman who was fOllnd wander ing the countryside without :lny knowledge of her persollal past. After rdatives identified her, Coriat took her 011 a trip to the house in which she had lived :IS a child. She said rhe house \vas "str.mge and unfamiliar" [0 her but also pointed out with surprise that she h:ld recently dreamed of exactly that house--a possible indication of implicit memory. Coriat also reported that when he instructed the patient to relax and tcll him whatever c:lme to mind, she would occa sionally report isol:lted images and Aashes th:H depicted :Ispects of her past. But these disconnected fragments did not feel like personal memories. Tht! patient had no idea where they came from and referred to thcm as "wonderments."11 More recent case reports of psychoge.nic amnesia occasionally include similar kinds of observations, although the evidence relll:lins largely anecdotal. In one particularly striking example, a man \vas found in rhe desert after enduring a violent homosexual rape. He had no memory for the incident and had lost :lceess to much of IllS per sonal past. Nonetheless, after seeing an ambiguous drawing that peo ple often interpret as an attack, the patient becamc distressed and even attempted suicide--but he still had no explicit memory for what hap pened. l n another case of cxtensive amnesia, investigatOrs were unable to establish the identity of a patient who could not recollcct even a sliver of her personal past. Exasperated. they handed her
LEAKS FROM THE PAST I m p l i c i t M e m o r y for Tr a u m a t i c E v e n t s C:ln psychogemc amnesia patients, who have temporarily lost explicit Ill('mory for parts or all of their past, show any implicit mcmory for these missing pages of their life stories? Unfamiliar images that sud denly pop to mind, an aversion to a particular food. or an irrational fear or phobia-are these implicit memories of past events that are no longer remembered consciollsly? The specter of a hidden traumatic Illt!mory unconsciously influencing the emotions and behaviors of :In unsuspecting victim possesses undeni:lblc elements of high drama.
231
:I
telephone
and instructed her to dial the first number that came to mind. Hap pily, she. dialed her mother :lnd wa.� identified immediateiy!:02 Similar observations have been made in a few cases of limited amnesia for specific incidents. Again, turn-of-the-cenlury pioneers. most Ilotably Fretl(;h psychi:ltrist Pierre Janet, provided the most COI11pelling material. For Illllch of this century,janct's contributions were lost in rhe seemingly infinite sh:ldow cast by Freud's work over much of psychology and psychiatry, but his work on amnesia, traUIlI:I, and memory h:ls been increasingly reCO'11ized.lJ b In a case repon published in 1 904, for instance, janet told lhe story of Madame D., who was traumatized by the death of her mother. Even though she had cared
232
S e ll r c h i tlg for M e m o " ,
for her mother throughout her illness, Madame D. could not ex�lic itly remember the occurrence of, or the circumstances sur�ollndl�lg, her mother's demisc. Yet throughout the period of amnesia (which eventu:llly cleared up), Madame D. was h�unted bY isolatr.:� n�ent�� images related to the illness that she expcr1en�ed as " haUuclllatlOns. In these powerfill images, dr.:tails of her mothers appearance were pre scrved, yet the patient expressed no familiarity with any ofthem.Janet described other cases in which patients were plagued by o�erwhehn ing emotions that seemed to be caused ?y traumas they did not re� ollee[ explicitly. Based 011 such observatlol1s, Janet �ol1c1uded that III fUIle[ional amnesia, the patient'S "inability to cOllsclOusly and VOIU�l tarily evoke certain mr.:mories·' is accompanied �y "the automatlc, irresistible, and inopportune limpl.icitl reproductIon o� t�ese same memories."Joseph Breuer and Sigmund Freud reported slIm},ar obs�r vations and ideas, which led to their famous statement that hystencs suffer mainly from reminiscences." Translated into cOI�telllpora�y vocabulary, Breller and Freud observed that psychogeniC amneSla patients are plagued by implicit memones of events they cannot remember explicidy.�· . . sugg�snng Modern investigatOrs have also reported case studIes preserved implicit memory for specific events that arc IlOt consclous�y recollected. In a Swedish case, for instance, a woman who was amneSIC for a brutal rape chat occurred on a brick pathway rcported chat the words brick and patl! kept popping to mind, even though she had no idea why. This woman became extremely upset when takcn back to the scene of the rape, yet she did IlOt remember that the rape had occurred there.lS Some of these implicit effects of traumatic experiences might be related to the operation of the amygdala. As, we saw ill chapters 6 a�d 7, the amygdala plays a specific role in fear conditi�nin�, �nd amnesIc patients with hippocampal damage can be affected nl1phcltly by c.mo� . tionally arousing experiences that they do nOt remember expliCitly. . We don't yet know whether differences between the .111pp'0� ampl1s and the amygdala are implicated in the peculiar kinds of lI11ph.clt emo tional mcmory that have been observed in some psychogclll� amne sia patients. But the work of LeDoux, Darnasio, and others, dlsc�lsscd in the previous chaptr.:r, has begun to provide a biological baSIS for understanding why someone might experience el11otion� and affects . Though that result from incidents that are nOt recollected expliCitly. the clinical observations I considered earlier are largely 3necdoral, they remind us that implicit effects of past experiences may shape our
Islands
i n the
Fog
233
emotional reactions, preferellces, and dispositions-key clementS of what we call personality. Freud, of course, realized something similar when he postulated a dynamic unconscious and emphasized the important role of early experience. With the tools available to mod ern cognitive neuroscience, we can now explore the memory processes and systems that contribure to our likes and di�likcs and our habitual ways of responding to the world. While our sense of self and identity is highly dependent on explicit memory for past episodes and aurobiographical facts, our personalities may be more closely tied to i plicit memory processes. Leaks from the past in cases of psy m chogenic and organic amnesia could turn Out to be dues that can help us [Q think about the relationship between personality and memory.
H O W T H E PA S T I S L O S T D i S S O c i a t i o n , Repres s i o n , a n d I n h i b i t i o n Functional amnesias are often characterized as dissociative disorders. Dissociation, according to some psychologists and psychiatrists, causes the mind to become split into streams. Thoughts, feelings, and mem ories splinter into separate worlds of their own: memory systems and subsystems that ordinarily comlllunicate closely, passing information back and forth, lose touch with each other and go abom their busi ness separately. Dissociation does not erase a person's memories. Instead, stress or trauilla somehow severs the links among memory systems, so that large sectors of the past, or periods of ongoing expe rience, become detached fr01l1 a patients conscious awareness. Evi dence of implicit memory for forgotten experiences in functional amnesias could thus indicate " leakage" of information across dissocia tive barriers that are scrong enough to prevent explicit recall. The idea of dissociated memories dates to Pierre Janet, who believed that some people are generically unprepared [Q handle the overwhelming stress of emotional trauma. Instead, they automatically, and pathologicaUy, react to it by splitting off memories and feelings into a nonconscious stream th:lt parallels the comcious mind. Trauma, according to Janet, call dissolve the mental glue that ordinarily links together separate streams of ideas, emotions, and memories.v Modern proponents of the dissociation hypothesis, including the psychologists Ernest Hi lb":lrrl and John Kihlstrom, view dissociation as a natural consequence of the basic architecture of norma! cognition. For these and other proponents of dissociation, the idea lhat memory
23"
I slands i n r h e Fog
Scare/ling Jo r .He m o ry
tions. and ft.:dings. Our br:ains must constantly inhibit a good deal of
is composed of parallel, interacting systems provides potentially fertile
neural activity in order for us 10 function effectively. Recent experi
ground for the operation of dissociative processes. If our brains nor
�
mentS have shown tha the process offocllsing attention on one objeCl . . and Ignoring another mvolves inhibition of the brain's response to the
mally engage in extensive p:u"dllel processing, then there Jll ay be con ditions-including traumatic stress-that disHlpt the normal lines of
object that we ignore..lO il hibitory processes also oper..lte in memory. Recent PET scanning stud Ies have shown that whereas some brain regions increase their activity during explicit retrieval of episodic memories. other networks
communication among parallel processes.18
�
Dissociation, then, creates a kind of "horizontal" split in ment]1 life. Another way to think about functional amnesias centers on Sig
lllund Freud's idea of repression. Repression involves a "vertical" pushing down of affectively charged and unwanted mental coments. Repression is a defellSive process whose main function is to protect
the ego from threatening material. Like dissociation, repression does nOt erase a memory; it merely makes an experience difficult to recall consciously. Repressed memories, according to somc theorists, fester
in the unconscious and make their presence felt through peculiar images or inexplicable behaviors that relate to a forgotten trauma,
which we might now call implicit memories. Breuer and Freud con ceptualized psychogenic amnesia as a product of intense or extreme
repression, a view that has been widely accepted in psychoanalysis and other sectors of psychiatry. Some contcmporary psychiatrists, how ever, believe that repression operates on particular experiences, not on whole sectors of the personal past. For example, the psychiatrist David
Spiegel contends that repression is not a powerful enough mechanism to aCCOUTll for extensive fugues and functional amnesias. He arb"ues instead that dissociative processes must be invoked.lII The conceptS of repression and dissociation enjoy wide currency in some sectors of clinical psychology and psychiatry. Yet both ideas are difficult to test and neither of them provide terribly convincing expla nations of psychogenic amnesias. Bm there must be some internal mechanism that prevents or inhibits retrieval from taking place. Some thing in the brain shuts down recall processes that ordinarily allow a person to remcmber who she is and what she has done. For the mOSt part, memory researchers have paid little attemion to inhibitory processes, except for the enduring fascination of some with the con cept of repression. Yet [here is lllouming evidence that inhibitory mechanisms play a significant role in mCITlory. Inhibition is a fill1da mental process in the nervous system. Neurons communicate by send ing excitatory signals that increase each other's activity. They also scnd inhibitory signals that calise other neurons to decrease or "turn off" their activity. Without such inhibitory processes, our mental lives would be unbearably chaotic: we would be constantly overwhelmed by a dizzying array of external objects and internal thoughts. sensa-
235
?f St�llctures decrease their activity. reRecting the operation of , 111lllbnory processes. And just as some cognitive studies have shown that recollecting an experience makes it more likely chat we will be
•
able to remember that experience again at some later time, recent research indicates that the act of recalling one expt'rienct' may actu ally make it more difficult [0 remember other. nonrecalled experi
ences btec. Suppose, for example, that you study the following list of words, each one paired together with the category bbcl "fruit": apple,
pear, �fIlpe, pe'I�", slf1lwberry, ofill/ge, gfllpqrrtil, and I'll/III. Then I let you
practice recalhng a few of the words fTom the list. For example, I give you a cue such as " Fruit-Or " and ask you to write down the
appr�priate word from the list. The act of recalling ofllllge during the practice phase will make it even easier for you to remember oflltlge whel� 1 probe your memory on a later test. Surprisingly. hO\Vt;ver, . pracnclllg omll��e will make it harder for you later to remember other words from the category that YOli did not practice. Recalling some
words from the list causes others to become inhibited.l'
Along the same lines, if I instruct you to forget abOl][ a set of mate rials that YOll have recently studied, you lllay later have difficulry remembermg those materials when you desire to do so. Suppose that after YOll finished studying the fruit names, I cold you that you need not remember them; you should do your best to forget about them. If I later inform you that I would like you to try to remember the words after all. you will have problems recalling tht.:m in comparison to someone who was not told to forget them. Your recall of the tar geted items has been inhibited by the instructions to forget. The com ilion experience of nOt recalling something that feel� like it is on the tip of your tongue also involves inhibition. Research on tip-of-the tongue states has shown that recall of the sought-aftcr information is actively inhibited by retrieving other kinds of information about it. IZ
Nobody knows exactly how such inhibitory processes are rclatt.:d to the SPt.:ct3cular kinds of memory loss seen in some cases of psy . . chogel1lc amnesIa. In attempting to explain Lumbetjack's amnesia, my
236
Starcilillg fo r .\/t'/lJIlf)'
I s l a n d s in t h e F o g
237
co!leagucs and I suggested that in order to recall specific incidenr,�
I knew that arnnesias could presem ill unusual ways, and I was also
frolll our lives, we must first be able to remember higher-level auto
awarc that experlS consider amnesia to be a hallmark of ll1ultiplc
biographical knowledge, such as our names and general lifetime peri
personality disorder. Although at least one of the pcrsonalities usu
ods. Such knowledge might serve as an "access code" that provides
ally
entry into our episodic memories. We speculated that an inhibitory
personalities call remember only those evcnts that occur when tht.!y
process "turned off" SOllie of Lumberjack's high-level autobiographi
arc center stage, guiding the person's behavior and action. In a series
has some
mcmory
for
experiences
of the
others, most
cal knowledge (such as knowledge of his real name). With this access
of one hundred carefully studied patients, ninety-eight of them dis
code inhibited, he could not recall any of the particular experiences
played amnesia between personalities. Such patients often complain
that were a"sociated with it. Out he could recall experiences linked to
of "losing time": suddenly finding themselves in strange places or
the access codt, ;'Lumb<:rj:lck," which was not inhibitecl. ll These ideas,
unexpected situations without any memory of how they arrived
though suggestive, still beg the question of why a psychological , trauma would produce �uch extraordinary inhibition of memory III
there.}; The patient Dr. Nissen described seemed to fit this mold. Yet I had just finished writing a series of articles about simulated
the first pbce. t will return to this puzzle later, when I talk more about
amnesia, and immediately developed serious concerns that a patient
the brain and functional amnesia. But first let us enter into an even
with twenty-two personalities could well be faking the disorder. I was
more myster ious realm of psychogenic amnesia, one that has recently
also aware that diagnoses of multiple personalities had been rising
become a bloody battleground for competing views of memory, the
rapidly in recent years. Many critics believe that the condition is the
mind, and the practice of psychology ilSeif.
product of suggestible patienlS, misinformed diagnoses, and incompe tent therapy involving suggestive techniques such as hypnosis. Public curiosity rebrarding multiple personali ties had been around at least since the appearance of the popular book and film n,e "nm:e FllCCS of
MULTIPLE P E R S O N A L I T I E S
Elle in the late 1 950s. Hut mass interest skyrocketed with the spectac
Dissociation or Inven tion?
ular sliccess of the 1973 best-seller Sybil, which told the story of a
In the mid- 1 980s, a collaborator o f mine, the cognitive psychologist
child who had been severely abused by a sadistic mother and went on
1111ddle-aged
to develop .�ixteen separate personalities, or "alters." \� Some of the
woman who apparently harbored multiple pcrson:iliti("'S. 11I fact, Dr. Nis
alters were children; two were men. Before the appt'arance of this
"en sajd, she appeared to have twemy-two such personalities, ranging
book and television miniseries, patients tended to have two or three
from a five-year-old girl to an abrasive fony-flve-year-old male. One
different personalities of the same gender and age as the primary per
Mary Jo Ni�sen, came across a remarkable patient:
:J
personahty, thirty-nine-year-old Alice, was studying to be a counselor,
sonality, but cases diagnosed il1 the "post-Sybil" era rypically have
spent a good deal of time reading the Bible, and enjoyed painting reli
Illany more, including child alters and opposite gender personalities. I
gious subjects. Bonnie, aged thirty-si.". was imerested mostly in the the
worried that Dr. Nissen's patient might have been seen by a clinician
:ner. Charles, the fony-five-year-old, drank heavily, liked to watch
who was too eager to diagnose this exotic condition.
televised wrestling matches, and painted wild anjmals.Thirty-two-year
13m Dr. Nisscn could find no motive for thc patient to fake the dis
old Gloria was one ofseveral 1eft-handed personalities. She also painted,
order, nor any evidence that she was doing so. Oesides, the woman had
but more abstractly than the other personalities. Gloria adopted a dif
a relatively low IQ and did not seem capablc of the enormous men
ferem laSt nallle from the others so that she could obtain her own social
tal efrort that would be involved in keeping straight twenty-two
security number. Each of these and other personalities came forward to
feigned personalities. Dr.
deal with the external world at different moments in the patient's life.
nosis of multiple pt.!rsonality had been arrived at carefully and call
SOllie of the personalities knew about each other, but many had no
tiously. Hypnosis had not been lIsed to elicit personalities. The patient
issen felt confident that the clinical diag
memory for the others' experiences and were unaware that any other
had numerous gaps in her memory and often failed to remember
issen wanted to know whether t would be
where she had been or what she had done. And her histOry contained
interested in collaborating with her on a study of the patient's memory.
signs and symptoJlls of a disturbed idemity that dated back to child-
personalities existed. Dr.
S e a rr/l iug Jor M e m o r ),
I s b n ds in t h e Fog
hood. Beginning at around the age of five or six, the patient had djs
personalities, some totally amnesic for the others' experiences. For
238
pJayed ullpredicrabic burSlS of aggressive, violent behavior. Family members noted that she referred to herself by different names during these outbursts. Her attendance at school was irn:!:,'Ular and her behav ior erratic. These problems arc similar to those typically observed in children with dissociative disorders. They have severe behavior prob lems that arc noted by family members, teachers, and others; they are frequently in trouble; they receive a variety of psychiatric diagnoses from professionals; and they aTl' often referred to as pathological liars or pt'rsistcnt d:lydrearners. A person with a tfue dissociative disorder leaves behind a trail of serious pathology, a trail that was casy to fol low in Dr. Nissen's patient. .l6 Although multiple personalities had been known to psychology and psychi:ltry since the first repons of the condition appeared in the nineteenth Celltury,l7 the idea of separate personalities inhabiting a single body was-and still is--
(Q accept. But when looked at
from a slightly different pC'fSpeccivc, this strange disorder may be somewhat more comprehensible. All of us experience different moods and act
alit
many different roles in our everyday hves. As I noted ear
lier. experiments have shown chat memories established ill one mood state are often more readily recalled in that same mood state than in a different one. Perhaps in a case of multiple personality, different moods
239
instance. [he personality named B IV had no recollection of anything that happened to B I, yet occasionally experienced sudden "VIsions" that pictured incidents froln 13 I's life. "When seeing a vision," Prince wrote, "she did not recognize the pictorial experience as her own, even though it was of B 1'5 life; there wal; no sense of memory con nected with it."J9 If Prince's observations are gem:rally characteristic of dissociative patient.'i, then modern techniques should reveal hard t'vidence of implicit memory. We set up an experiment that included only pcr somlities who professed no explicit IlwmOTY for each other's experi ences. For instance, the patient's psychiatrist elicited a personality named Alice, who viewed a list of words from aile of my early prim ing experiments: O(tOPIIS, asslISsill, and so forth (see chapter 6). Later, the psychiatrist elicited the pcrsonality called Bonnie, who had no explicit memory for having seen any of the words. Nevertheless, Bon nie came up with more correct answers whell she was provided frag ments of words that Alice had seen than when she was provided fragments of words that Alice had not seen. We also observed evidence of printing on other testS that are thought to enf,>age the perceptual representation system (PitS) I comidered earlier. Interestingly, we observed bttle evidence of cross-personality
and roles come to be labeled with separate names. Somehow
implicit memory when tasks involved semantically richt:r materials,
nobody underst3nds exactly how-these
sllch as sentences and stories. Showing Alice the phrase "The haystack
clusters of experience
become dissociated from one ;lIlother. When one identity and an asso ciated set of memories is " turned on;' some or all of the others are "turned off:' Some multiple-personality patients may llse dissociation (Q a pathological extent, but the term nlllltiple persollality may nOt be the best way to describe thi� process. Indeed, the recognized standard bearer in clinical psychiatry and psychology (the fourth edition of T1le Ditlglwstic II//(I Swtistica/ .Mm/llill of Memlll Disorders, or DSM-I V) has recl'ntly changed the term /IIu/tilJle persollality disorder to di5Sociatil'l' idellfil)1 disorder.lij
Persuaded thal the patient Dr. Nissen described was neither a fake nor a product of shoddy diagnosis :lnd treaunem, I agreed to collabo rate on a memory study. We wamed to find out whether a personal ity with no explicit memory for another personality's experiences could show some implicit memory for them. There was already evi dence suggesting that cny,s-personality implicit memory might occur. In a classic case from the e:lrly twentieth cemury. Morton Prince described a patient referred [0 as Miss Beauchamp, who possessed four
was important because the cloth ripped" along with the clue word "parachute" didn't help Bonnie come up with the clue word later wht:n she saw the sentence. Yet, as we have seen, even severely amnesic patients show priming on this task. Why didn't this type of printing transfer from Alice to Bonnie? Alice might encode the scn tence aile way, but Bonnie might imerpret it differemly. When a memory contains a large dose of an individual personality's uniquc thoughts and associations, even implicit tests rnay not breach the amnesic barrier. It is impossible to know from this single case whether our results generalize to mher patiencs.OG I was therefore excited when an oppor tllnity arose in 1 987 10 study another patient with dissociated identi ties. Ie had a history of amnesic gaps, sometimes turning up in unfantiliar cities without allY idea how she had arrived there. She was brought to a hospital emergency room by local law enforcement in early 1 987 after walking across a crowded highway and attempting to injure herself. It was then learned that Ie's husband had contacted the
I s l a n d s i n t h e Fog
SI!C/f{ilillg for M e m o ry
police several times in the preceding month when she had ruso tried to i1uure herself. Her behavior, he said, had become increasingly bizarre. She regularly acced like distinctly differem people, her voice and temperament changing suddenly and dramatically, yct later had no recollection of the changes and denied that they occurred. Over the course of several weeks in the hospital, several distinct personalities emerged. All showed varying degrees of a\vareness of each other, but IC was totally amnesic for all of the ahers and actively resisted the idea that she harbored dissociated identities. Unlike with Dr. Nissen's patient, we could not elicit IC's alters dur ing a testing session. When these :i1tcrnate personalities emerged, lC's psychological condition usually deteriorated, so it was best to avoid situations that caused her to dissociate into another identity. This meant that we could not conduct studies on transfer of implicit mem ory across personalitics.13ut IC knew that she had memory problems and was curious about the mjssing pages of her personal past.We were, roo, because the professional litcrature contained 110 hard information on the autobiographical memories of patients with dissociated iden tities. So we began to explore lC's ability to recollect incidents from her past, using a variety of cueing techniques and prorocols for assess ing autobiographical memories. One particularly striking finding emerged: IC \vas unable to recollect a single incident from her life that occurred prior to the age of ten, and she recalled only a few scattered episodes from between the ages of ten and twelve. All of liS are subject to childhood amnesia: we remember nothing prior to the ages of two or three, and little prior to the ages of five or si.'\':. Out nobody in our study except IC had difficulty recollecting childhood experiences prior to age ten. We could not say conclusively why, but one possibility centers on evidence that IC had been sexu . her during adolescence.O\ ally abused by her f'H At the time we were studying IC, in bte 1987 and early 1988, Illany clinicians and researchers involved with multiple-personality patients believed that childhood sexual abuse is closely associated with the development of dissociated identities. Several papers had been pub lished linking dissociative disorders with reports of childhood sexual abuse, and we had no reason to doubt them. I n the ye:lrs since then, however, this issue has become considerably more contentious. With the emergence in lhe carly 1990s of the controversy over recovered memories of forgotten childhood sexual abuse, critics have claimed that memories of sexual abuse in patients with dissociated identities may be the product of the same Hawed therapy that helps to create the
241
�
]nult ple personalities in the first place. The early papers associating multiple personalities with childhood sexual abuse, the critics charge, arc based on patients' uncorroborated recolJections of abuse. If these Il�emories are recovered during therapy that uses suggestive tech mques, then it is possible that they are illusory. Cases have been described in which something along these lines appear:' to have occurred. In Mtlking J\I[O//sters, a scalding attack on therapists who aggressively pursue hidden memories of sexual abuse
�
the social psychologist Richard Ofshe and the writer Ethan Watte
describe the wrenching story of a woman they call Anne Stone. Anne �ntered therapy because she was having emotional difficulties adjust� IIlg to � er llew baby. When she addressed her husband one morning . like character, Anne's therapist became convinced that she as a child harbored multiple personalities, and proceeded to pursue :lI1d find them. Anne was later treated by specialists in dissociative disorders who be le�ed that patients with multiple personalities are nearly always vlcttms of sexual abuse. Anne initially denied any such abuse,
�
but as therapy progressed she recovered increasingly weird recollec tions of years of sexual abusl' at the hands of a satanic cult. She came to believe that she had been a high pricstess in the cult and had com nutted despicable act.�, including sacrificing children and eating her own aborted fetuses. The allegations became so outlandish that the cult eventually evolved into a conspiracy that included "AT&T, Hall mark Greeting Cards, the CIA, and FTD Aorists."l1 Even the Federal Bureau of Investigation \vas brought in to look into the charges. Per haps not surprisingly, the FBI failed to substantiate the incredible sto
�
ries. Ev , �rually, Anne abandoned her memories and her multiple persona mes and filed a lawsuit against the psychiatrist who treated l her.�l An October 1 995
�
Fromlille documentary presented two women who
were str kingly similar to Anne Stone, with a diagnosis of lIlultiple personality disorder leading to recovered memories of satanic cult abuse durin� therapy, ultimately followed by the patients' rejections of the per . and satanic cult memories after withdrawing from the thera sonalitJes peutic sening. I suspect that there arc many sllch patielll�, and believe that we should heed the critics' warnings that suggestive therapies can help to create both multiple personalities and illusory memories of sex ual abuse. If ill-conceived ideas about the widespread incidence of mul tiple personality arc leading some therapists ullwittingly to elicit disSOCIated identities during therapy, this is a tragedy for both the patients and the therapists.
2-42
I s l a n d s in [ h e F o g
Searc/ring Jtlr Memory
As a memory researcher, I would have grave concerns about study ing a patient whose persomlities emerged for the first tillle in ther apy, e<;pecially if suggestive techniques like hypnosis had been used. But it seell1� unlikely that all instances of dissociated idemieies cOllle about this way. In cases such :15 the twO I studied, dissociation was evi dent prior LO any therapy and hypnosis was not used to elicit p� rson alities. And recent research has provided external corroboration of sexual abuse in several patients with multiple persomlities." \Vhen dissociued identities do not arise in direct response to ques tiomble diagnosis and treatment, the character of the disorder may still be influenced by the contemporary social and cultural milieu. The extensive media exposure received by such cases as Sybil means that potential multiple-personality patients are likely to know about the disorder and perhaps have preconceptions about how it should look. The psychiatrist Harold Merskey has gone so far as to suggest that no c:lse of multiple personality has ever been reported "without any shap ing by or preparation by external factors such as physician� or the media."'l Social and cultural factors no doubt do play a role III shap ing the kinds of memory loss that are seen in patients with dissociated identities (or fugues and psychogenic amnesias). even when blatantly suggestive therapy has not occurred. The disorder may constitute a specific idiom of distress for some deeply troubled people who have
243
ing leads reside in a class of steroid hormones that are secreted by the adrenal glands and are knowll by the rather forbidding name of glu cocorticoicls. When we are aflccted by either a physical stressor, such as a brain injury, or a psychological stressor, such as :Ill emotional trauma, our brains initiate a cascade of responses that culminates with the release of glucocorticoids. They are an essential part of the body's response to stress: they help us mobilize energy where needed, increase cardiovas cular activiry, and dampen down processes that need to be inhibited during a physiological crisis. Yet as necessary as they are for
liS
to
respond effectively to Sfress, glucocorticoids also pose a danger. As argued convincingly by the neuroscientist Robert Sapolsky and his colleagues, excessive exposure to glucocorticoids can seriously dam age neurons. The region of the brain that appe:lrs most susceptible to harm from glucocorticoids is a f.1Tniliar one to memory researchers: the hippocampus. Endocrinologists and stress researchers are well acquainted with the hippocampus because it contains an unusually high concentr.Jtion of glucocorticoid receptors.n Sapolsky and colleagues have found that injecting glucocorticoicls in rats for several momhs produces a permanent loss of glucocorticoid receptors in the hippocampus as wel1 as significant damage to hip pocampal neurons; indeed, signs of degeneration arc evident after just
been suitably ptepared by the cultuml environment. But unless one
:I few weeks. Other experiments have revealed that exposing rat� to
wants to argue that all of these amnesias arc consciollsly faked-:lnd . neither Merskey nor other critics do-sol11e of these ca.�es may still
stimulates the brain to release glucocorticoids. creates many of the
provide important cluc-s concerning memory's fragile power.*
slistained stress (for eX:lmple, foot shock that callses anxiety) , which sallie destructive effects. These researchers havc also shown th:lt adlninistration of glucocor ticoids to prenatal rhesus monkeys produces neuron loss throughout
STRES SFUL EXPERIENCE A N D THE BRAIN C l u e s t o P s y c h o g e n i c A rn n e s i a s ? Science cannot yet provide convincing explanations of all the abcrr.l tions of memory I have considered in this chapter. Out something has gone terribly wrong with the process of remembering in Illany cases of fugue, psychogenic amnesia. and dissociated identiry. To better understand them, we need to figure out how and why some people respond to stress and trauma by "losing time" or forgetting chapters from their life stories. This is the fundamental question of trauma and memory, and so far no one has a definitive answer to it. BtH recent discoveries in neuro science do suggest intriguing speculations. Some of the most promis-
much of the hippocampus. Sapolsky has srudied primates in their African habitats and reports thar animals who occupy a low position in a social hierarchy are exposed throughout their lives to various strcssors-harassment, attacks, difficulry hiding from predators-that arc not encollntered by dominant anim:lls. These "stressed-our" mon keys show abnormally elevated levels of gll1cocorticoids. Sapolsky examined the brains of several subordinate monkeys who died as a result of prolonged social Stress, and found th:l[ they contained pro nounced hippocampal degeneration. (No such degeneration was observed in the brains of nonstressed control monkeys.) Another experiment revealed that hippocampal damage in stressed monkeys can emerge within a matter of weeks after the onset of social stress." Do these linkages among stress, glucocorticoids, and hippocampal
24-l
l s l :a nd s in ( h e Fog
S e a rc!lillg Jo r Memory
damage apply to human beings? I considered evidence in the last chap ter that prolonged stress results in elevation of glucocorticoids (cortisol) in some Vietnam veterans. Other experiments show that drugs that cause tcmporary elev:uions in glucocorticoid levels can produce explicit memory impairments in healthy volunleers. Longer tcrlll dfe<.:ts have also been observed. Patients treated with glucocor ticoids for at least one year had problems explicitly remembering a paragraph across a delay. l3ut they showed normal priming effects on an implicit memory test (word completion), suggesting an impair ment of brain regions specifically associated with explicit mt"mory perhaps including the hippocampal formation. R.emarkably, two recent studies that examined the b...in with magnetic resonance imag ing have found that the hippocampus is smaller in traumatized veter ans than in nontraumatized veterans. One possible interpretation of these f1l1dings is th:n high Icvds of glucocorticoid exposurc in the vet erans who found the war most stressful resulted in damage to the hip pocampus. l3ur it could also be th:at Velerans who entered the war with an unusually small hippocampal formation were for some reason more vulnerable to traunlalic stress than other veterans."" Traumatized Viemam veterans are not generally amnesic, yet they are susceptible to various abnormalities of memory that nlight reflect altered hippocampal functioning. I have already discussed the intru sive, uncontrollable "flashbacks" of combat experiences that can plague traumatized veterans, and have noted that some of these men have problems remembering specific epIsodes from parts of their past. They can also have a hard rime rccallillg a list of words presented to them in the laboratory. Studies of World War II concentration camp survivors and prisoners of war likewise show impaired explicit mem ory for recent experiences.!oO This collection of findings raises the possibiliry that prolonged stress, resulting in excess exposure to glucocorticoids, could damage lhe hippocampus and thereby contribute to memory-related abnor malities. The same line of n.:asoning may apply to people who have suffered extensive childhood abuse. Frank Putnam and his colleagues have reported that sexually abused girls and adolescents have difficulry regulating cortisol levels. A recent study used magnetic resonance imaging to cxamme the brains of women who had suffered severe sexual and physical abuse when they \"ere young. The volume of the left hippocampus in the abused women was sib'llificamly reduced compared to a control group. Abused women with large reductions in hippocampal volume tended to have more severe psychiatric problems
2-l5
than abused women with lesser reductions in hippocampal volume. Out none of these abused wOlllen showed any memory problems on a standard laboratory test of explicit memory for recently studied words, and all of them had always remembered their abuse. Yet a sep anne sample of women who reported an abuse history and showed . . normal explicit memory for recently studied materials nonetheless had problems, compared to a control group, comillg up with :autobi ographical episodes from childhood and adolescence in response to cue words (much like our patient IC). Consistent with the latter find i l� g, another s udy has revealed that depressed WOmen who report a history of cl llldhood sexual abuse, compared to depressed women who do not report such a history, have a more difficult tillle remem �ring specific aurobiographical memories in response to either pos ItIve cue words (such as s/l({esifll� or negative cue words (sorr ) Sl y. Co�t!d reduced hippocampal volume, perhaps brought about by excessIve exposure to glucocorticoids, contribute {Q memory prob lems in cases of dissociative identity disorders with a documented his tory of sexual abuse? Possibly, bur as of now there arc no direct links berwe�n reduced hippocampaJ volume and between-personality amneslas. Before any conclusions can be drawn, we need data from patients with dissociative disorders that directly and specifically link memory problems, reduced hippocampal volume. physical or sexual abuse, and glucocorticoid exposure. What about fugue and psychogenic amnesia patient�, like Lumber jack :md K.? These people became amnesic after a specific trauma or period of stress, but typically do not possess histories of lengthy abuse o� prolonged psychological stress that would be likely to damage the IlJPpocampus through excessive glucocorticoid exposure. Remember, �I�wever, that Illany functional amnesia patients have a history of head lIlJury ?r related brain insult that predates the onset of thei.r memory . loss. It IS pOSSIble that these insults directly damaged the hippocampus or other Structures impo rta nt to explicit memory. Interestingly neu ropsychologists have described a growing Iltllnber of brain-dal lagcd patients who, like psychogenic amnesia patients, have extensive retro grad� amne �ias that cover Illuch of their personal pasts, yet also have rdatlvely m ild problems recalling recent events. The right temporal Cortex (the general area where Lumberjack had sustained brain dam age as a child) is often damaged in such patients.Amonio Damasio has proposed that parts of the temporal cortex contain high-level knowl c ge, which he calls "binding codes," that allow us to piece together bits and pieces of episodic memories that are stored elsewhere in the
�
�
:
�
Searcllillg for Memory
246 cortex (see chapcl'rs
2
and 3). Oamasio's binding codes might b e (he
neural equivalent� of the access codes that my colleagues and I sug gested had been inhibited in LumbeJjack's case. If so, chell we can see how this early brain damage might have combined with a new stress to yield extensive a1l1nesia.� Yet even if a blow to the head docs not direcdy damage the hip pocampus or related structures, brain injuries are powerful elicitors of the body's own glucocorticoids. Sapolsky suggested that the brain's own protective respome to a brain injury, such as a head trauma, might result i n damage co the hippocampus because of its vulnerability to the tidal wave of glucocorticoids released in response to the damage. '" Could the unusual responses [Q trauma [hat culminate in fugue and psychogenic amnesia reAect, in part, the confused response of a once damaged hippocampus to a new and powerful stress? A new psycho logical trauma could suppress the hippoc'l1'npus through overexposure to glucocorticoids, and the effect might be magnified in people who have sustained prior hippocampal damage. However, damage to the hippocampus alone does not result in loss of personal identity and childhood memories, bm docs yield significant problems remember ing recent events. This is a very different profIle chan what we see in patients like Lumberjack.� It therefore seems unlikely that extensive psychogenjc amnesias arc attributable [Q ;I malfunctioning hippocam pus. The character of psychogenic amnesias is no doubl shaped by emotional and social forces thac are irrelevam [Q orb':tnic :unnesias, so it should not be surprising chat they differ i n important respects. Nonetheless, the frequent presence of prior brain trauma i n cases of functional amnesia, paired wich che data 011 glucocorticoids and che hippocampus, arc cantaliz.ing enough to factor imo our thinking abom elements that contribme to psychogenic :llllilesias. A similar kind of thinking may apply [Q people who arc plagued by the return of long-dormant childhood fears as a resuh of new stresses in their lives. I n a provocative paper, the neurosciemists WlJacobs and Lyl1l1 Nadel !Ioted that many fears develop in very early childhood but the hippocalllPus docs noc mature fully lIntil sornewh:lt later. A childhood fear might be stored as implicit memory in brain circuits outside the hippocampal system. As the hippocampal system develops, the fear may recede into the background. But when a ncw stress releases a bombardment of glucocorticoids that cemporarily suppresses the hippocampus, nonhippocamp:ll systems may become more actiV!..! . As a resuit, hidden iTllplicit memorics, such as long latent childhood fears, may suddenly resurface.S'!
I s l a n d s i n t h e Fog
247
As promising as these brain-based ideas are, psychogenic amnesias arc still puzzling to scientjsts. As we will see, our lirnitcd scientific knowledge about amnesia for emotionally
traumatic t.:vents has
important implications for the 1lI0st charged and divisive mental health crisis of our time.
The
\
NINE
T H E M E M O RY WA R S
S e e k i n g Tr u t h i n t h e L i n e o f F i r e
SUNDAY night, I was sifting through the electronic mail messages that had acculllulated on my compmer. , subscribe to all Internet discussion group 011 memory :lIld psychotherapy, and there was a large backJog of 1l1c.."Ssages to check. I dwelled over several � osts from an unfamiliar sender named Diana Halbrooks who described how, during psychotherapy that had begun ten years earlier, she came to believe that her mother had tried to kill heLThen she remembered that her father had sexually abused her as a child. As she delved deep�r into her past, listening to the "little girl" inside, as er thcrdplst . , advised, Diana grew to believe that she had been raised 111, and rttu , She ally abused by, a satanic cult that include SOllie of her famdy. , recalled horrendous acrs of torture and c1uld sacnfice and concluded that a baby sister who had lived only one day-supposedl� because of a rare and untreatable respiratory disorder-had been sacnficed by e cuh. Diana believed that she. toO, had participated in the ritual sacn� {ice of:l baby. . I had heard and read about similar stories, but I was partlcularly imrib'1.1ed by Diana's story because she no longer believed that any of these memories were true. She spoke eloquently abom how she had reunited with her family and turned her life around. What, I won� dered, could lead someone to abandon such vivid and strange mem� ories? When I answered Diana on the Internet, she �old me tI� al. try as she might, she could find no evidence that anyone III her family had LATE O N E
�
�
tI�
248
M e m o r y Wars
249
ever taken p:lrt in any satanic rituals. She obtained a hospital death certificate, signed by a physician, stating that her inf.lnt sister had died of a respiratory disorder. Yet her therapist said that this merely con� firmed that the doctor was part of the cult.' One day, when Diana arrived fifteen minutes late for a therapy appointment to discover her therapist had not waited for her-and would not return her repeated phone calls-she had a sudden crisis of confidence about her six years of therapy. She decided to give her family the benefit of the doubt and never wem back to the thcrJpist. Diana H:llbrooks's memories of sexual and ritual abuse at rhe hands of her parents were illusory, but there are stories about people who suddenly recover memories of long-past abuse that turn Out to be accurate. Ross Cheit, a college professor of public policy, entered ther apy because of a general uneasiness about his life. " I felt somehow adrift, as if some anchor in my life had been raised," ht, reflected. " I had doubts about my marriage, my job, everything." l Several months later he awoke from a dream with a strong feeling about a camp coun� selor named Bill Farmer whom Cheit had known as a youth in the 1960s. Within a few hours, that feeling turned into a recollection that Farmer had molested him al camp. With the help of a private detec tive. Cheit tracked down his assailant in a small town in Oregon nearly a ycar later. After thirty�two unsuccessful attempts to reach him by telephone, Cheit finally contacted him and taped their phone cOllver� sation. Farmer admitted that he had moleseed vartou.s boys and that he had lost jobs as a result of his problem. He remembered Cheit, bue did nOt recall abusing him at first. The illitial sexual experience had l10t been horribly traumatic-"I didn't dread it;' Cheil said; " I wasn't thinkillg, 'Oh my God, he's going to cOllie in again' "-and he had never thought about the abuse in (he iTllcrvening years. He recovered his memories of it decades later. The stories of Diana Halbrooks: and Ross Cheif arc pan of a social epidemic that has affected thous..lnds of American families during the 1990s. In the typical scenario. an adult, usually a young woman, recaUs during the course of psychotherapy long-forgotten Inemories of sex ual abuse at the hands of a parent or other close family member, or an authority figure such as a teacher or a priest. \Vhen confronted with the allegations, the :lccused typically deny them. Families often split at the scams as members align on different sides of [he dispute. I n many instances, the matter extends beyond the personal into the public domain of the COllrtroom. The psychological toll on those involved is massive and often irreversible.l
The
Searching JOT Memory
250
Memory \V3 r S
251
involved a murder in northern California. [ n 1990. George Franklin was
1 was soon inundated with phone calls and letters. SOIlIC of these communic:ltions were from accused parents of children who had
convicted of the 1 969 homicide of nine-year-old Susan Nason. The
recovered, i n therapy, memories of sexual abuse that, according to the
conviction (overturned on appeal) was based entirely on memori(."S of
shaken parents, had never occurred. Their calls and It.:ners g:lV(' me a
the murder that were recovered and reponed to authorities by
glimpse of die emotional devastation experienced by some people
Franklin's daughter Eileen. Eileen Franklin was eight years old when, according to her testimony, she witnessed her father rape and murder
caught in the maelstrom of recovered memories. Yet 1 had no \V3y of knowing what h:ld actually occurred in any of these f.1.l1lilies, nor did
her friend. She claimed to have repressed her memories of the awful
, have the clinical training or expt.:rtise to offer professional advice.
event umil 1 989, when a glimpse of her own daughter in a certain pose
The recovered memories controversy, though a complex affair that . touches on issues of incest, f 1.mily, social mores, and even religious
The first widely publicized case of a recovered traumatic memory
brought
Susan's death instantly [0 mind. Soon, celebrity cases involving
recovered melllories ofsexual abuse came to the fore, including ones by
beliefs, is fundamentally a debate about accuracy, distortion, and sug
a former Miss America and the comedian Roseanne. Oy \ 992 allega
gestibility in memory. This is why scientistS such as I feci profession
tions of abuse based on recovered memories were so pervasive among
ally obligated to try to uncover the truth about aspects of memory
ordinary American families that a group of accused parems joined with
that arc relevant to the raging dispmes. Searching for truth in this
concerned professionals to form the False Memory Syndrome Founda
charged atlIlosphere is not easy. When 1 participated in a December
tion, which establi�hed a professional advisory board thaI included some
1 994 memory symposium in Doston,
highly respected names in psychology and psychi:my. As of thiS writ
who picketed to protest the participation of Elizabeth Loftus, a vocal
I spoke to some incest survivors
ing, over 4,000 people :are either members of the Foundation or sub
critic of therapists who aggres....ively hunt for recovered memories. The
scribe to its newsletter. Approximately 17,000 people have contacted
protesters felt thaI those who questioned tbe validity of any recovered memory were in effect questioning, or at least undermining, the valid
the organization regarding repressed memory cascs.� As heightened tnedi:. attention began to foster a public perception
ity of their memories. Tbe angui�h of these people was palpable. 1 gave
thai false memory is a possible. even likely, explanation for ilIany
another talk the following week at an FMS Found:ltjon conference in
alleged recovered tn('mones of sexual abuse, some clinicians and ther
Baltimore, where I spoke with parentS who said they had been falsely
unjustified
accllsed of sexual abuse by their children. I listened to women who
backlash against genuine victims. They pointed to the lack of any sys
had recently disavowed the memories they recovered in therap)l.Their
tematic evidence for a false memory syndronw. Instead,
anguish, too, was deep and affecting.
apistS who treat abuse survivors wrote angrily :about
:1Il
they sug
gested, the bbt'l of" f:llse memory syndrome" may serve :as a politically
Having devoted a good deal of Illy career to the
study of amnesia,
convenient bur fundamentally inaccllr.lte way of denying a reality chat
I am naturally imrigued by the possibility that a person could exhibit
accused parties canner accept.'
amnesia for traumatic events over a period of lllallY years and subse
With the formation of the FMS Foundation and the opposing cries
quently recover them. 1 have studied instances of traumatic amnesia
�
of b:ICklash, a biuer debate erupted among professionals in the fields
such as the case of LUlllbeIjack,
of mental health, medicine, and bw.6 I found myself drawn into this
events can be associated with temporary forgetting and subsequent
arem after an :lrticlt.: by Daniel Goleman appeared in the New )'1)rk
memory recovery. I am convinced that child abuse is a major problem
Times on May 3 1 , 1 994.
in our soci ety I have no reason to question the memories of people
Tided "Miscoding Is Seen as the Root of False Memories," it high lighted a recent conference on memory distortion that 1 had helped
and I know that sOllie tralllllati
.
who have always remembered their abuse, or who have spontaneously recalled previously forgotten abuse on their OWIl.
organize and quoted me several times. The conference brought into
Yet I am deeply concerned by sOlne of the suggestive techniques
sharp focus the important role of source amnesia-forgetting how a . memory was acqui red-in gener.lting f,lse recollections, and Gole
that have been recommended to recover repressed me1l10ries. J am aware that people undergoing certain kinds of ther:!py h:.ve claimed
man built his excellent article around that theme. The article was
with great confidence
rcpnnted in newspapers arollnd the world.7
lives. and that some have recalled abuse 011 spaceships at thc hands of
to remember episodes that occurred in past
Scare/dng Jor Memory
T h e M e m o ry Wars
alien abductors,' I n short, 1 think I know enough about memory's
future. Indeed, I have already alluded to experiments in which partici
fragile power to appreciate that extreme views on either side of this
pants are instructed to forget about a subset ofinforillation that was pre
issue are likely co be wrong.
sented to them. Such "directed forgetting" instructions usually produce
_' 2 ,.
I believe that the depiction of the recovered memories debate as a
253
a modest decrease in volunteers' recollection of target information.
winner-rake-all battle between advocates of recovered memory and
It is hardly controversial, then, to state that people sometimes
proponents of ('lIse memory is overly simplistic and needlessly divi
attempt to avoid or suppress painful experiences. And since sexual
sive.� We need instead to distinguish among several intertwined ques
abuse, most would agree. is typically not discussed, victims may be
tions. each of which should be considered carefully on its own. One
robbed of oppoTtunitil'S to talk about and reAecr on their traumatic
question is whether sexual abuse can be forgotten. If some episodes of
experiences, which in turn could weaken their memories for those
abuse can be forgotten-I believe that they can-it is also important
cxperiences. This kind of explanation could well apply to a case like
to ask whether a special mechanism of repr(.'Ssion must be invoked (0
Ross Cheit's, where lhe initial experience was nOt highly traumatic but
explain the forgetting chat does occur. Here much depends 011 exactly
may have been distllTbing or confusing enough to make him avoid
what is meant by the term n'lm�ssio/1. A related but distinct question
thinking about it. It may also apply to a case shown in Ofra Bikel's doc
concerns whether forgotten episodes of abuse are ever recovered; I
umentary on the recovered memory controversy, "Divided Memories,"
believe that they are. This still le;lVes a separate question of whether
which aired in April 1995 on POS's FrollllillC series. ; J ane Sanders" was
people ever develop false recollections of tr.IUTllatic events that never
sexually abused by her father in a hOle! room when she was five years
occurred; I beljeve that they do. If recovered memories of actual abuse
old. He admitted his misconduct to Jane's mother, who reasoned that
and false memories of impiamed abuse both exist, it becomcs crucial
if she did not talk about the incident with Jane, it might fade from her
to consider whethcr there are reliable ways to distinguish between
memory-and it did. Jane first learned of the abuse as a young woman
them. To address this question, we must revisit the hidden world of
when her mother finally told her what had happened. Results of a
implicit memory, which has come to play a peculiar role in the mem
recent survey of rape experiences in adult women are consistent with
ory wars that have damaged so many people in our society.
these observations. Women who had been rJped rated their rape mem ories as less often thought about or talked about, and less clear and vivid, than women who recalled other bad experiences.1o
FORGETTING ABUSE H o w O ft e n D o e s I t H a p p e n a n d W h y ? Recall from chapter 7 that Melinda Stickney-Gibson, haunted for years by memories of the destructivc fire that nearly took her life, described trying hard to avoid thinking about the incident; somerimes she succeeded and sometimes she did not. And Jadzia Strykowska, who lived through terrifying years as a child in the Bergen-Oelsen concentration C3rnp, tried not to talk about the horrors of the Holo callst, :mcl11pting instcad to get on with her new life in America. Yet Jadzia never forgot her experiences and began speaking about them again afwr the neo-Nazis marched near her home during the 1 970s. Melinda and Jadzia both used a cob'nitive strategy that is probably familiar to everyone: when something painful happells to us, we try not to think about it. Rehearsal f.1cilitarcs recall of past experiences, so it makes sense that not rehearsing pail1ful experiences (or any experi ences) would lessen the likelihood of their springing to mind in the
Conscious suppression of childhood trauma also played a role in the s.1d and strange case offormer American University president Richard Berendzen, who came to the attention of psychiatrists in April
1991
when he was caught making obscene phone calls from his university office. In treatment, Berendzen revealed something he had never told anyone: his mother, who had a history of mental illness. had sexually abused him at ages eight and cleven. After pleading guilty to misde meanor charges, Uerendzen discussed his memories of the abuse with Ted Koppel on Niglulille. Reflecting on the various strategies he had used over the years to try to keep the abuse out of his mind, he said: "I pretended it had never happened. And that worked for a year or two. And then I decided I would just forget it. And [hat worked for a few months. Then I decided that I would work terribly hard. And if you're working very hard, you somehow don't remember it anymore." Berendzen's interview and his moving memoir about his abuse indi cate that he always maintained some sort of general knowledge about what had occurred; he conceded to Koppel that his suppressive strate-
•
Seare/lillg fo r Met/l O r y
254
T h e M e mory Wars
gies ultimately failed. As he relates in his book: "When I would think of the abuse and remember the confusion and pain, I would say to myself, 'That was then; this is now.' '' He managed to suppress details of the abuse, and the intense feelings associated with it, for significant pcriods of timc. But when he returned home upon the death of his father in the late
1 980s, Dcrendzen experienccd vivid memories of
what had happened there years earlier. Shortly thereafter, he began his campaign of sexually explicit phone caUs.11 Richard Berendzen's attempts to suppress his memories of sexual abuse wete only patdy successful; he never banished all knowledge of what had happened. His story is similar to that of Mr. A.. the war vet eran I described in chapter
8 who became overwhelmed by wartime
traumas some thirty years after they occurred, although he never for got having participated in the war. But in some caSL'S of recovered memories, people secm to have become tOtally amnesic for years, never suspecting they had been abused until going into therapy.ll If Diana Halbrooks's memories of satanic ritual abuse were real, then she must have repressed them completdy for long periods of time. Defore ther apy. Diana never had even an inkling that she had been abused by her parents or had participated in cule activities, much less murdered an infant. Could someone manage to forget about such ghastly activities merely by avoiding talking about them or mentally rehearsing them? There is no evidencc that intentional forgetting in laboratory experiments
produces
serious
amnesia.l}
Analogollsly,
Jadzia
Strykowska conunems that she and other Holocaust survivors did not talk about their e""periences for years, yet they never developed amne sia for them. It seems far more probable that intcntional avoidance of unpleasant memories reduces the likelihood that the suppressed expe riences spontaneously spring to mind with the kind of vigor that plagues so many survivors of psychological traumas. And, as stated ear lier, it might even make some individual episodes extremely difficult to retrieve. But this is a far cry from developing a [Otal amnesia for years of violent abuse. Remember also that when people are asked to assess retrospectively . the general qualities of their childhoods, they are usually f'lirly accu rate.14 If Diana Halbrooks had been raised in a vicious cult and lost aU memory of it for years, it would signal the presence of an extraordi nary distortion in her recollection of the general contours of child hood. lf hcr post-therapy memories were accurate, it follows that her pre-therapy childhood memories must have been entirely illusory. Because this degree of distortion is highly abnormal, a much more
formidable mechanislll than simple lack of rehearsal would be needed to produce it. This is where the concept of repression, a cornerstone of Freud's psychoanalytic edifice, comes in. The mechanism of repression has been portrayed as a protective device used by the brain to fend off the emotional ravages of experi ences that arc simply toO overwhelming to be borne by the conscious mind. According to some therapists, repre ssion is powerful enough to block out horrii)'ing mOllths and years of sexual abuse, rape, cven rit ualistic torture; some terrible events are thought CO be inaccessible to the consciolls mind virtually immediate ly after they occur.uYet, con sistent with Freud's early formulations, the repressed memories are 110( lost forever; they are thought to percolate in a remote corner of the unconscious, causing variOliS problems and symptoms, umil they are recovered through therapy or some other f.1Vorable circumstance. This kind of massive repression is. cvidemly, :l f.1r more potent means of suppressing ullplc:lsanr experiences than the intentional avoidance strategies that mOSt of us are familiar with in day-co-day life. It is perhaps ironic that freud's initial conc eption of repression was much closer to the mundane, everyday form of intentional suppres sion than to the massive repression mech anism that has been illvokt'd by some therapists. Freud's early writinb'S state specifically that repres sion involves intentional rejection of distre ssing thoughts and memo ries from consciOlls awareness. Bur the idea subtly changed over time. Freud began to usc the term re ression in a much more general sense, p co refer to a variety of defense mechanism s that operate outside a per SOIl'S awareness and aucomatically exclu de threatening material from consciousness. Freud thus created a good deal of confusion regarding the distinction between IIt/COI/SOOIiS defen ses and illte/ltiOlllJf repres sion.16 The strength of the scientific evidence for repression depends on exactly how the term is defined. Whe n defined narrowly as inten tional suppression of an expcrience, there is little reason to doubt that it exists. But when we talk about a repression mechanism that oper ates unconsciously and defensively to block Ollt traumatic experi ences, the picture becomes considerably murkier.
Some people may be more apt than other s to engage in a defensive form of rcptession. ln several studies, people who say th(.,), feel liule anx iety but nonetheless behave defensiv ely have been defined as "repres s�rs." T s type of person wiU insist that nothing is wrong even though l I lS face IS beet red or he strenuously resists advice oflcred by others. Repressors tend to remember fewer negat ive experiencL'S from their
�i
256
S e a r ( h i",� fo r M e m o r y
lives than non repressors. Defensive repression has also been reported in brain-damaged patientS. The psychologist V. S. Ramachandran has made some fascinating observations of selective forgetting in patientS with paralyzed limbs who are un;l\vare of their paralysis. Patiem OM, you Illay recall, was specifically unable to remember e:\:periences that were inconsistent with her delusional beliefs about her paralyzed arm.ll Even if somc form of defensive repression occurs, this still does not speak to the question of whether non-brain damaged people arc capable of the kind of repression that would block out overwhelming traumas. Evidence concerning memory for real-life traumas in chil dren and adultS indicates that these evems----such as the Chowchilla kidnappings, the sniper killing at an elementary school, or the collapse of skywalks at a Kansas City hotel-are generally well rcmembered. Some forgetting and distortion occur, but complete amnesia for these terrifYing episodes is virtually nonexistent. Many limited amnesias, in which people fail to remember a traumatic event such as committing a murder or being raped, arc due to alcohol intoxication, brain injury, loss of consciollsness, or even deliberate faking. There are only a few dramatic examples, like Marvin Dains's apparent amnesia for shooting his wife, in which forgetting is not easily attributable to these 6ctors. For these and other reasons, some therapists have argued that exten sive repression is observed only for repeated traumatic events. Lenore Terr contends that single traumatic experiences ("Type I " traulllas) arc generally well remembered, whereas repeated or multiple traumatic experiences ("Type I I " traumas) are repressed. The repeatedly abused child, for example, becomes more practiced at using repression in order to banish over.vhelming experiences from consciolls awareness. If the abuse is perpetrated by someone the child looks to for nour ishment and support, like a parent, it is easy to see how forgetting might aid the child's survival. Terr's ideas are provocative, but hundreds of studies have shown that repetition of information leads to improved memory, not loss of memory, for that information. To produce profound amnesia, the repression mechanism would have to be so effective as to sllcceed despite the normal tendency for repeated experiences to enhance memory. People who have lived through repeated traumas in war gen erally remember these terrifying experiences all too well. An individ ual experience or trauma may be set aside, especially when much tillle has passed, but with rare exceptions such as fugue states-which are generally of short duration-people do not forget an emire set of repeated traumas.
T h e M em o r y Wars
257
This point is well illustrated by the story of Erika Marquardt, an artist who grew up in Germany during World War II and remembers clearly the repeated traumatic experiences that shaped her childhood in ways she could not comprehend: The eady years of my life I �pent in bunkers, bombs f.l11ing, destruction, ruins. And strong political repression, first under the azis and then under the Communist regime-being scared of being overheard. You always felt submcrged into a world of fright: at the mercy of outside forces-not being in control of what you would like to do. I grew up in the company of women and kids, trying to sur vive. In a way I couldn't understand bccause I was too yOllng. But only felt how scared I always was. The sound of the sirens and you really have to run for your life to find shelter. And at night lhe . . . beautiful designs in the sky were of rhe areas to be bombed, and the fantastic Rash and detonation of houses being hit. The fright of uniforms and the sounds of boots marching at night. 1ft Marquardt's painting ';Miniaturc View from the Berlin Wall (#3)" (figure 9.1) captures some of this terror. Erika Marquardt and Illany other survivors of extended terror always remembered that these repeated traulIlas happened. This may also apply to traumas that arc associated with sexual abuse, as illus trated by the memories of people who said they were abused by Father James Porter, a MassachusettS priest. Porter ;Idmitted his guilt to one victim, Frank Fitzpatrick, :md there is 110 reason to doubt the testimony of the orht'rs who have since come for.vard. The great Ill;uority of these people always remembered their abuse. But approx� imately 20 percent of them said that they never thought about it until decades after it occurred, when the case achieved sudden prominence in the media. It is important that those who said they were repeatedly abused were less likely to forget thall those who said they were abused only oncc. 19 This finding is cX:lctly the opposite of what Terr's ideas about Type 11 traumas seem to predict. We can make sense of these ideas, however, by recasting them in light of thc distinction between general-event knowledge and event specific knowledge that I have discussed. Nobody doubtS that having repeated experiences of a similar type can make it difficult to remem ber the details of a specific e\'em, even though the repeated features of the general evelll are remembered well. For example, J spcnd a good
T h e M e m o r y \Vars FIGURE 9 . 1
259
deal of time on airplanes, and I have considerable difficulty recalling the details of many of the specific events that occurred during partic ular Rights. But I do not have amnesia for ever havillg Rown before; I can (eU you just about everything that ordinarily happens on a typical Right. I have excellent memory for the general event of flying in air planes and poor memory for mOst specific Hying episodes. Obviously, Hying on numerous airplane tnps is not traumatizing abuse, yet a person who experiences repeated sexu:.1 trauma could have considerable difficulty remembering the details of a particubr episode of abuse for lTIany of the same reasons that I cannot recall lhe particulars of an individual airline Hight: the specific evr.:!lts become blurred in memory and arc difficult {O separate from one another. If this is the kind of forgetting that characterizes Terr's Type I I trauma, then it seems entirely plausible that such forgetting would occur. I t need not have anything to do with repression, however. Nor would it lead to {Otal amnesia for all the relevant experiences-the abused per son would still recall the general evem of being abused. Bm blurring and merging of details from repeated episodes might help cxpbin why the memories of sexual-abuse survivors arc sometimes patchy and incomplete.XI
Erika Marquardt, "Miniature View from the Berlin Wall (#3)," 1991. tt
x
13W'. Oil/mixed media 011 canvas. Courtesy of the artist.
On the left are graphic renditions of tht· traumatic events that marked the
artist s early years: bombers. explosions, and bright lightS. On the ri ght arc a '
skull and slices of brain, perhaps indicating that the memories exist only in her head Uits and pieces of the Berlin Wall (whic h Marquardt chipped when it was destroyl�d in 1 989) are snick between the rememberer and her memori es . .
Remember also that in Lumberjack's case and in other examples of psychogenic amnesia, trauma is associated with a sevcre though tem porary memory loss. These cases demonstrate that emotionally devas tating events can be associated with substantial forgetting. But they diffe r from the kind of forgetting that seemed to have engulfed Diana Halbrooks, whose repeated traumas wcre supposedly blocked out ab'":lin and again. For Lumberjack, a single traumatic event produced amncsia, and virtually all his past experiences were subject to amne sia, not just a narrow band of tr:lulllatic events. LumbcJjack's amnesia lasted only a few days, and it disrupted his entire life. Repression is only one of several possible explanations for this kind of amnesia. Ultimately, the best Way to shed light on the possible operation of massive repression in cases of sexual abuse is to cx:nnine evidence concerning thc memory of sexual-abuse survivors. A few such studies have been reponed. all indicating that anywhere from 20 percent to nearly 60 percent of people who now rcmember their abuse say there was a period of time in the past when they did not recall it. But a major drawback is that many of the participantS in such studies arc people who recovered uncorroborated memories of abuse in therapy. Critics have pointed out some participants in these studies might have recovered illusory re-collections of abuse that never occurred. In a
260
SI,tl f c h i ".£ Jar jHem o ry
T h e M e mory Wars
more re<.:cnt study, trauma researchers Diana Elliott and John Driere sent a quesrionnaire survey (0 people selected at random from the general population; of the 505 who responded, only a small percent age were involved in any form of psychological treatment. JUSt over one in five reported they had been sexually abused. Among them, 20 percent indicated there was a period of time when they had no mem orv ' for the abuse. While less problematic than some earlier studies, without <.�orroborating evidence that the abuse occurred, it is difficult to make much sense of estimates offorgecting and anmesia.11 This problem was addrC5sed in an important study by Linda Meyer Williams. She intervicwed 129 women who were admitted (0 a hos pital emergency room in the mid-1970s because of abuse ranging
frolll inappropri:nc tOuching to sexual intercourse. The age of the women at the tillle ranged from ten months to twelve years. Seven teen years later, forty-nine of these women, or 38 percent of the salll pIe, failed to remember this particular hospital admission. Several critics h:lVe enumt':rated reasons why this figure might overestimate amnesia for the admission episode.!! Even if it does, the study shows convincingly that a significant proportion of women forgot about it. This is still a long way from repressing years' worth of abuse, however. The women might have forgotten the episode because they engaged in conscious suppression, or because it was one of many similar episodes that occurred at the time, or because they were too young to remember it. Indeed, among the women who did not remember the specific hospital admission that Williams inquired about, roughly t\\'o thirds did remember other sexual assaults. Another finding from WiUiams's study that is also important is that sixteen of the women ( 1 2 percem) reported no history of abuse. This finding comes closer to supporting claims ofmassive repression. How ever, some of (he women in Williams's study were infants or toddlers when tbe abuse occurred, and probably forgot the hospital admission for reasons having to do with normal infantile and childhood amne sia. Williams docs nOt provide the ages of the women who were among the 1 2 percent, but reports that those who h:ld endured repeated abuse tended to recall it :It least as often as tbose who wcrc abused only once, contrary to Ten's idea that extensive repression occurs in victims of repeated, Type I I traumas. Williams's findings show beyond doubt that some abuse survivors fail to recall single abusive incidents, and are consistent with the pos sibility that some may forget repeated incidents of abuse. Consistent with this latter observation, the psychologist Jonathan
Schooler
261
describes a thirty-year-old Illan called JR who had forgotten about several mcidents of abuse by a priest that occurred during the years of early adolescence. However, there is no evidence that JR massively repressed the abuse at the time that it occurred. All we know is that years later, he had forgotten about these painful incidems, perhaps because he did not think or talk about them until encountering reminders of what had happened.ZJ Williams has
recently reported new observations
concerning
women with documented abuse histories that speak to this issue. She asked those women who remembered the abusive incident that led to their hospital admission whether " there was ever a time when YOll did not remember that this had happened to you."�· Twclve ofseventy-five women ( 1 6 percent) responded affirmatively. Some of them provided information about how they came to forget the abuse. In mOSl cases, the women sa.id they began to forget years after the abusive incident. A woman called Kim, for instance, was molested at age seven . She said she forgot the abuse at age 1 2 and remembered it again at age 22. Tanya, sexually assaulted at age eight, said she forgot about the inci dent when she was 1 6 or 1 7 before remembering at age 24. Two other women, in contrast, said they forgot about the abuse immediately after it occllrred. " I blocked it out right away, the first time it happened;' commented one of them.2S The delayed onset of forgetting in Illost cases suggests that lack of rehears.11 or other relatively benign processes were responsible for it. But a more potent process of repression might have played a role in the tWO women who reported immediate forgetting. However, it is diffi cult to know exactly what mental processes occurred years earlier when someone says in retrospect that she blocked out the abuse right away: Was she truly unable to remember the incident immediately after it occurred? Was the "blocking out" an automatic, unconscious act of repression or a conscious attempt to avoid thinking about a distressing event? Some women in Williams's study misremembered when the actual abuse occurred, and it may have been difficult for them to recall exact details of when and how they forgot about it. For example, a woman called Joyce commented th.1t "I don'( know how old I was, I lIsed to think about it for the first two years, then I just blocked it out. I may not have completely forgot, I juSt didn't think about it.".!6 I have already pointed out that excessive exposure to stress-related hormones (glucocorticoids) can damage the hippocampus. I also cited evidence that some abused women have problems regulating stress-related hormones, may show some deficits in autobiographical
SeMc/lillg for .\lelll o r y
T h c M e m o r y WdrS
memory, and may even have a smaller left hippocampus than do
harbored multiple personalities. Family videotapes and photos showed
262
263
Ilonabused controls. All these findings fit with Williams's result�, inas
Ann, prior to therapy, as a vibrant young woman and a budding YOllng
much as they imply that some survivors of sexual abuse may have diffi
singer. But thc docullientary revealed serious problem'> in Ann's family
culty recalling some aspects of their abuse. As I pointed out in the last
life: her mother admitted that she had withdrawn from Ann emotion
chapter, however, abused wOlllen with reduced hippocampal volumes
ally during a separation from her husband when Ann was young. "It
alw:_ys remcmbered their abuse and f:1iled to exhibit IIlclllory deficits
was a traditional family," said the fum's narrator. " Every Christmas W:15
on laboratory teSts. And no direct cause-and-effect relationsh.ip between
celebrated. No birthday was ever forgonen and there wcn� always gifts.
sexual abuse and reduced hippocampal volume has been shown. Yet
Hut Ann remembers only anger and a yearning for her mother." Both
even ifreduced hippocampal volume is linked [Q some sort of memory
parentS seemed bewildered by thc accusations of sexual and ritualistic
problem in abused wOlllen, none of these findings proves or implies the
abuse, which included allCb"dtions that Ann's mothcr had attached elec
existence of a special repression mechanism that aUow·s people to blot
trodes to Ann s genitals and that her father had abused her with tools
out repeated, horrendous abuse immediately or soon after it happens
from a hardware store. Her father, on (he verge of tears as he described
(nor do they explain how memories could be recovered). Cases such as
" the enormity of the absurdity" of Ann's abuse memories, related how
the one reported by Schooler indicate that some people forget multiple
her medical records showed no effects or the viciolls ritual abuse that
inCidents of abuse, but the evidence is not strong enough to warrant any
she recalled, and her school records revealed pcrfect attendance despite
definitive claims abollt massive repression, as opposed to more benign
the torture that had supposedly becn inflicted on the young girl.
forms of conscious suppression and lack of rehearsaL Dissociation, rather than repression, might be responsible for exten
I f Ann had been dissociating th.roughout childhood to cope with nightmarish riUlal abuse-thus explaining her amnesia for the abuse
sive amnesia in abuse survivors. Dissociation refers to a f:1ilure to inte
prior to therapy-there should have bcen teUtale signs of a dissocia
grate different aspeCls of an experience, with the I"(.'sult that it is difficult
tive disorder, such as Spotty attendance at school, serious childhood
to explicitly remember the experience. I have discussed evidence
behavior problems, and the like. " I don't care if it's true," asserted Ann's
that people suffering from dissociative disorders, including multiple
therapist, Douglas Sawin. " What's important to me is that I hear the
personality patients, can forget large chunks of their pastS. Williams
child's truth, the patient's truth. That's what's important. What ;lctually
suggestS that the women in her study who reported forgetting inune
happencd is irrelevant to me." Asked abolLt the possibility that a
diately about their abuse may have dissociated the episode. It seems
client's report is a delusion, Sawin did not flinch:" Wc all livc in a delu
plausible to me that some survivors of sexual abuse Illight repeatedly
sion, just more or less delusionary." If these chilling beliefS are shared
dissociate during recurring incidcms of abuse, perhaps even creating
by other therapists, then it is hardly surprising that there are so few
imaginary identities to handle the abuse. However, recent evidence
well-corroborated cases of recovered memories and so little direct
suggestS that traumatized survivors of sexual abuse may have great dif
evidence for the operation of dissociation in ther.lpy patients who
ficulty forgetting about abuse-related information, at least when it is
remember previously forgotten abuse..!!!
presented to them in the laboratory. Moreover, if people become
In the Eileen Frank.lin case, the prosecLltion apparently wished to
skilled enough at dissociation to develop total amnesia for traumatic
avoid applying the terlll c/isscx:jalioll to Eileen, probably because it
experiences. it would imply the existence of a dissociative disorder-a
implied the existence of a severe dissociative disorder that could not
seriolls matter. If they have engaged in extensive dissociation, then
be dClllonstrated.1'l I suspect that dissociation may indeed occur in
p:ltients who recover previously forgonen memories involving years of
some cases of genuine forgetting of extensivc sexual abuse. 13m when
horrific abuse should also have a documented history of severe pathol
it does, there should be a long and well-marked trail of associated
ogy that indicates a long-standing dissociative disol"(ler.17
problems aud pathologies.
i ustrates the point was shown in A particularly affecting case that ll
My reading of the evidence concerning memory for sexual trauma
Ofra Bikers " Divided Memories." A young woman named Ann
pointS toward three conclusions. First, there is no question that some
described how she recovered in therapy memories of terrible 5.1tanic
survivors of childhood sexual abuse forget about single abusive inci
ritual abuse at the hands of her parents, and also discovered that she
dentS, and some evidence that they may forget multiple episodes of
T h e M e m o r y Wars
S c a rcidug fo r M e m o r y
abuse. This forgetting i s most likely anribmable to some combination of normal processes of memory decay and interference, conscious suppression and lack of rehearsal, and perhaps physiological changes caused by sexual abuse. Second, there is as yet little or no scientifically credible evidence thal people who have suffered years of violent or horrific abuse after the years of infancy and early childhood can immediately and indefinitely forget about the abuse. If convincing evidence of this kind does surface, I believe it will occur in the con text of a dissociative disorder. Third, the idea that forgening in abuse survivors is caused by a special repression mechanism-something more powerful than conscious suppression-is still without a scientific basis.
265
after mllch work and searching in psychoan:llysis. For more than fifty years there has been a large clinical literature on psychogenic amne
�
sias in.dica ng chat events that could nOt be recalled during the anmeslC episode are subsequently recovered. Decause therapists who �eek out forgotten memories of sexual trauma believe that accurate recovery can and docs occur, it seems only reasonable to expect that studies have provided solid evidence that recovered memories are generally accurate. Unfortunately, little . such eVIdence exists. This may be because acmai abuse often OCClirs in
�
se recy, making it difficult to find witnesses or other corroborating eVidence, and also because perpetrators typically deny abuse when it has occurred. In addition to the cases of Ross Cheit, Frank Fitzpatrick, and JR, all of whom recovered memories that were corroborated, another case
R E C OV E R E D M E M O R I E S H o w A c c u ra t e A r e They? Forgetting abom abuse need not necessarily mean that i t can be remembered abrain years or decades later. There are cOllntless banal episodes in our lives that we arc now unable to remember, and Illay never remember. Some lIlay come back to us when we encounter cues dnt trigger what we felt or thought during the experience, but some engrams may have faded away to the point where no clle can elicit them, perhaps because much time has passed and we have nOt thought or talked abom the incident since it happened. Probably the best-known recent example of a recovered traumatic memory is that of Eileen Franklin. Eileen's memory was compelling enough to convince a jury that her father was guilty of murder and [0 convince a psychiatrist as experienced as Lenore Terr that it is genuine. OUt there was no independent corroboration of Eileen's memory. As the attorney Harry MacLean describes clearly in his authoritative accoulH of the Franklin trial, there are reasons to doubt the veracity of Eileen Franklin's recollection of what happened on that tragic day. The recent reversal of George FrankJin's conviction may provide another opportunity to examine the credibility of Eileen's memory in the courrroom:JO Although the Franklin trial received enormous publicity because it was the first time :I recovered memory Iud ever been the ba�is for a criminal prosecution, the idea that a forgotten traumatic memory can be later recovered has a long history. Standard Freudian lore had it that repressed trauTllatic memories can subsequently be recalled, usually
�
wi h solid documentation has been reported by the clinical psychol . ogIst Michael Nash. He describes a forry-year-old man who entered therapy in part because he was bothered by an intrusive and unwanted memal image of himself at age tefl, surrounded by a group of threat ening young boys. The patient suspected that the image alluded to a sexual e:o.:perience and eventually proceeded to recover a traumatic sexual memory involving the boys. He then contacted a cousin whom, he believed, had been present during the episode. The cousin recalled the incident quite clearly and with considerable embarrass ment: he had never forgotten that the patient had been unwiUingly drawn into the group's sexual activities.ll Additional examples of corroborated cases are found among the twelve women in Linda Meyer Williams's recent study who had temporarily forgotten and later recovered memories of docu� mented abuse. Interestingly, none of the women that Williams describes recovered their memories in therapy or used special tech
�
niql es such as hypnOSIs to hunt for them. Most were spontaneously relllmded of the abuse by cues: Mary remembered when she encou ntered a man who looked like her perpetr:ltor and then started having nightmares; Kim began to remember when someone asked her whether she had been sexually abused; Tanya suddenly recalled her molestation as she watched a movie about childhood sexual abuse.ll Bue if recovered memories are somerimes accurate, we don't yet know how accurate they arc. The psychiatrist Bessel van der Kolk has speculated that memories of temporarily forgotten traumas might be exceptionally accurate. Ordinary experiences that we mull over and
266
Sl'flHh illg Jar M e m o r y
T h e M e m o r y Wars
267
discuss with others can be changed by the retelling; repressed memo
describe three patients who developed vivid, intrusive images of
ries oftraUI1l3 may remain frozen in their originaJ form:"Conccivably,
highJy disturbing incidents. One patient ;'saw herself as a child with
tr'Jumatic memories then could emerge, not in the distOrted form of
her father about to stab her, and then herself siuing in a pool of
ordinary recall but as affect states, som3tic sensations, or visual images
blood ."� In all three cases, the images were interpreted as flashbacks
(for example, nightmares or flashbacks) that arc timeless and ullmod
of repressed childhood trauma, and the patients were referred for
ified by further experiences." And, indeed, van deT Kolk and his col
appropriate psychotherapy. Something was amiss with these patients,
leagues report chat people who have experienced severe traumas
however. An three of them compulsively engaged in unusual rituals,
reexperience them as isolated pictures or bodily sensations accolllpa
sllch as cleaning or washing over and over again. These disturbed
nicd by intense feeling. whcn:as the same people recall personally sig
behaviors are characteristic of the psychiatric disturbance known as
nificant (bur nonrraum3tic) experiences in a more storylike narrative
obsessive-compulsive disorder. When the patients were given drugs
for1l1.)J
that arc ordinarily used to treat this debilitating condition, the intru
We have already seen lhal thc amygdala and stress-related hor
sive imagery disappeared completely. It turned our that the images
mones play a special role in emotional memories, so it makes sense
wae not flashbacks of actual events; they wen: symptoms of the
that mcmory for trauma does differ
patients' obsessive-compulsive disorder. This in turn suggests that the
111
important ways frolll ordinary
memory. But these differences between traumatic :md nontr:1ulIlatic
diagnosis of repressed childhood trauma was incorrect. Yet had i t not
recollections do not demonstrate or imply that traumatic memories
been for the dramatic effects of the drug, the patients would have been
that have been repressed and latcr recovered are also especially accu
engaged in a needless-and possibly disastrous-search for repressed
rate. The idea of an unchanging imprint of exactly wh:1t happened at
traumanc InemOTICs.
the time of a trauma brings us perilously close to the dubious notion
The current state of scientifIC evidence concerning the accuracy of
that memory (or at least traUlllalic memory) is likt" a camcorder, pre
recovered memories of childhood sexual abuse call be summarized
serving :111 aspects of an episode.oW We have seen that this idea is fun
easily: there are a few well-documented cases, but little scientifically
damentally misguided when applied to ordinary experiences, and I
credible information is available. The COllrts have recently started to
pointed out in chapter 7 that it does not work well for traumatic memories that people always remember. I t would be surprising, cven
ew Hampshire, grapple with this point. In May 1 995 . a judge in . f"lced with nvo cases in which recovered memories formed the basis
extraordinary. if it were to apply to traumatic experiences that arc
of sexual assault charges, brought in experts on both sides of the issue.
buried and then recovered years later. There is currently no scientifi
"The COlirt finds," wrote Judge William J. Groff in the opening sen
cally credible evidence to suppOrt the idea.
tence of his opinion, "that the testimony of the victims as to their
The flashbacks of war veterans and others suffering from post
memory of the assaults shall not be admitted at trial because the phe
traumatic Stress disorders are sometimes cited as t"vidence for the
nomenon of memory repression, and the process of therapy lIsed in
accuracy of recovered traumatic memories. But we saw in chapter 7
these cases to recover the memories. have not gained acceptance in
that flashback memories often involve a mixture of memory and
the field of psychology, and are 1101 scielltifically reliable." In a more
fanrasy. Flashbacks are heavily influenced by expectations, beliefs, and fears. The contents of :l flashback may say more about what a
recent New Hampshire case, Judge Linda Dalianas cited the same . expert testimony as Groff, but. ruled in f"lVor of allowing the alleged
person believes or fears about the past than about what actually hap
victim to testifY and allowing experts to testify cOllcerning the gen
pencd.
eral phenomenon of traumat.ic amnesia. Nonetheless, she also con
Flashbacks are especially relevant to recovered ITu.!nlories of sexual
cluded that "[tJhe Court will not allow expert evidence regarding
abuse because some trauma therapists say that memories of abuse
either the process or the plausibility of 'recovering' an allegedly
often return as isolated flashback images.lS A recem report by the psy
repressed memory, because the experts have not offered any data
chiatrists Joseph Lipinski and Harrison Pope dramatically illustrates
either supporting or refuting any theory of how or whether a 'lost'
that such flashbacks mllst be viewed with a great deal of caution. They
memory might be recovered.")?
268
T h e M e r ll o r y Wars
Sear{l!j"g Jor M e m ()ry
I L L U S O RY M E M O RI E S O F S E XU A L A B U S E What Is the Evidence?
269
ory of ritual abuse. But even though thousands of patients have "remembered" ritual acts, not a singk such case has ever been docu nlcnte..:d in the United States despite extensive investigative efforts by
We have already seen that some recovered memories are accurate.
state and fednal law enforcement. FI3I agent Ken L:I!Hlmg has inves
That still leaves a separate and crucial question: Is the..:rc any evidence
tigated over
that people can come to believe that they were sexually abused when
ing corroborating evidence for a single one. A recent report from the
300 cases of satanic cult abuse, for e..:xample, without find
they were..:n't.? In the sununer of 1 987. Diana Halbrooks's therapist sug
National Center for Child Abuse surveyed several thousand profes
gested terminating treatment. " I panicked, became very anxious and
sionals about satanic ritual abuse and failed to turn up conclusive evi
increasingly depressed," DIana remembered. "I felt it was due to think
dence for tillS kind of abuse or for the organized, intergenerational
ing about not seeing hlln regularly any longer, bur he informed me
cults that have been implicated in recovered-memory cases.l8
that it was not thac at all. that it was due to abandonment pain related
These failures to document cult abuse do not necessanly mean that
to my father." She became increasingly depressed. but despite her best
no satanic cult� exist or that no ritual ;lbuse has ever occurred. Events
effort'>, "I couldn't come up with anything that my father had done to . cause such pain." In a last effort to find out what her f'Hher had done,
such as the 1995 Oklahoma City bombing, the..: cult-rdated nerve gas
her therapist asked Diana to write down whatever came to Illllld
by the Wisconsin murderer Jeffrey Dahmer provide painful reminders
while she was in a hypnotic trance, telling her that "writing in a trance
that people arc capable of terrible deeds.J9The human capacity for evil
with my eyes dosed would aUow my unconscious co speak freely."
is not at i�sue, but the..: human ability to develop amnesia for repeated
Diana had become adept at ente..:ring hypnotic trance states in therapy.
acts ofbrutaliry IS very much in doubt. Until convincmg evidence
When she opened her eyes this rime, she was met with a shocking
forthcoming,
sight: " 1 had written that my father molested me."
ritualistic horrors perpetrated by cults arc based on illusory recollec
With a door to her unconscious seemingly opened, Diana contin
attack on a Tokyo subway, and the horrific acts of bur chery carried out
is 1 conclude that most, if not all, recovered memories of
tions. And since most recovered memories of satanic ritual abuse
ued this exercise. At the same time, she entered a weekly support
emerge only when therapy has begun, these cases lend support to the
group that her therapist had initiated, consisting of wome..:n who were
idea that false memories of brutal traumas can be created during ther
abio explonng recovered traumatic memories. The atmosphere of the
apy.
group was highly charged, as women discusse..:d and sometimes acted
Because Diana Halbrooks's ntual abuse memories seemed so out
OUt their memories and dreams of terrible events that had come back
landish, her doubts about the reality of these and her other recovered
to them in therapy. Diana recalls: "The memories that others were
recollections continued to grow. But these doubts met resistance from
sharmg in the group were getting more and more bIzarre: satanic rit
the people in her support group and her therapist." I continually ques
ual abuse, babies being sacrificed, group sex and horrible tortures." It
tioned the memorie..:s, doubted them," Diana acknowledges, "but
was not long before the same kinds of horrific incidents began show
when I questioned the therapist, he would yell at mc, tell me I wasn't
ing up in Diana's OWll trance writings. "In November of 1988, I wrote
giving my 'little girl within' the benefit of the doubt. Tell me that I
in a trance and 'recalled' the first memory of satanic ritual abuse.
was in denial.
Everything just seemed to go downhill from there." By
1 989 Diana
1 didn't know what to believe. But I trusted lum." Even
tually, most members of the support group recovered memories of ritual abuse..: and almost all, including Diana, were diagnosed as l11ulti
had renlelnbered ki!ling a baby. A surprisingly large number of recovered-memory cases involve satanic ritual abuse, including reports of child sacrifice, cannibalism, and various gory rituals. A survey of members of the American Psy
pic personalities. J)l:ma escaped this toxic therapy and has managed to reassemble the pieces of her life. She no longer believes
du[ her recovered memories
1 2 percent reported having
have any basis in realiry. In the world of recovered memones, people
treated ritual abuse cases. Memories of satanic ritual abuse nearly
like Diana arc called relWCfors. Retractors live Illost of their lives with
always emerge during therapy; clinicians who treat these patients
out any memories of abuse, procced to recover mcmories at some
acknowledge that it IS rare for them to emer therapy with any melll-
poine, and then later come to believe that those memories are inac-
chological Association n::waled that
The M e m ory
Se,u(/I i/l,{! fo r M e m o r y
270
Wan
271
CUraH!. A growing number of people are retracting their memories,
tory can be implanted in adults, but the evidence is certainly consis
but that does not necessarily mean that all their memories are illusory. . A person might retract a memory because of pressure from f'unily or
tent with that possibility.')
much to bear. Hut when the memories arc as improb:lble as those that
Hypnosis played a key role in Diana Halbrooks's story as well. She . 1ever remembered any sexual abuse by her f 1ther until her therapist � msrfllcted her to engagl.! in automatic writing dllring a hypnotic
Diana Halbrooks recovered, the most reasonable interpretation is that
trance. I know of no scientific evidence that writing down whatever
friends or because the pain associated with the memory is simply roo
comes to mind during a hypnotic t.rance promotes accurate recall of
the events do not have any basis in reality. Dian:1 shares features in common with other retracrors. A recem survey of twenty women who retracted their recovered memories of sexual abuse revealed some striking silllliariries among thcm ..oo
lIle
teen recovered their memories during therapy, and all of them report
forgott�n experiences. Trance writing was popular over a century ago, when It was used in seances as a tool for psychic communications.
�cattered anecdotal observations suggest that trance writing lIlay occa slOnalJy lead people to produce implicit memories of long forgotten
that their therapists inAuenccd the development of their memories.
events that seem strange and unfamiliar to them.13ur it is impossible to
Only one of the twemy did not participate in therapy. This woman
tell whether something th,lt pops to mind during trance writing is an
to Helll, the bible
accurate mcmory of a distant event or a reflr.:ction of current concr.:rns
of the recovery movement that has been roundly criticized for
and fears-just as there is no way to tell (without extnnal corrobora
admonishing people to believe that they were abused even when they (,1il ro remember it. Nearly all of the retractors-90 pcrcem
tion) whether memories recovered with the aid of hypnosis are true or . f1lse. With all the talk of satanic ritual abuse in her weekly suppOrt
repofted that some son of trance induC(ion was used in therapy to
group, i t is hardly surprising that a ritual abuse "memory'· eventually
recover IllCIllOTles. Hypnosis was the
popped to mind when Diana cng:tged in tranc(.' writing.«
recovered her memories after reading n,c
reported by
85
Gmmge
most common technique,
percent of the women. Trance writing, rcgression, and
Hypnosis stands Out as a common denominator among the s.1mple
suggestions of abuse were also widely reported. The majority of the
of retractors, but sharing memories
women (70 percent) said that group therapy inAuenced their recov
important tool used by therapists who believe that it is important to
ered mcmories. "The group progressed from eating disorders to child
hunt for repressed memories of sexual abuse.'1 Discussing traumatic
hood sexual abuse, to incest, co S R A Isatanic ritual abuse!," recounted
recollections with other abuse survivors would no doubt be reassuring
III
a support group is also an
one retr;ICtor. "Eight out of ten members developed SRA mcmories,
and helpful when those recollections are real; the experienccs of Diana
the tWO who didn't were cold they were in denial." Another wOlllan
and Other retractors teSlify to the power of a group in also helping to
commented that " [ilfyou don't have a memory yOll feel like you have
shape and maintain memories of experiences that never occurred.
to come lip with one to compete with everybody."" Obviously, there can be no unequivocal experimental data showing that :111 illusory memory of a sexual trauma can be implanted, but a
Social psychologists have for decades documcnted and discussed simi lar kinds of social inAuences, although there has been surprisingly lit tle work concerned specifically with social influence on memory.....
clever attempt to surmount this problem in a related area was reported
Guided imagery. or visualization, IS another mr.:thod recommended
by Nicholas Spanos, a hypnosis researcher. Spanos and his colleagues
by various practitionr.:rs to retrieve repressed 1ll1.!1lI0ries. Here, patients
conducted an experiment using a variant of the hypnotic age-regres
are encouraged to imagine abusive incidents til:\{ they seek to remem
sion tl.!chnique, in which people are given suggestions to ';regress" to
ber, attempting to create pictures in their minds of what Jlljght have
a very young age. His subjects were given suggestions to "regress" co
happened. When sexual trauma has actually occurred, guided imagery
a past life. Roughly half of them came to believe that they had indeed
can be a usdili therapeuric technique. Studies by the psychologist Edna
lived a past life. And when Spanos suggested to some that they had
Foa and her cOUeab'lll'"S have shown that the imaginary reliving of a rape
suffered abuse as children in their past lives, they developed more
produces a significant reduction in symptoms of post-fraUlnatic stress
';melllories" of the abuse than people who had not becll given such
disorder. But it is quite another matter to use !:,'llidcd imagery in an etTort
suggestions.u Because thi� experiment was couched in a "past lives" . contl.!Xl, it does not settle the issue of whether a f1lse sexual-abuse his-
to dredge up a supposedly repressed memory of an event that may or rnay not have taken place. I have already pointed out that freely irnagin-
272
Searcidtlg fo r Memory
ing an event, and then exploring i t and talking about it
T h e M e m o r y Wars as
if i t were real,
is a potentially powerful means of creating the kind of subjective feeling chat accompanies an authentic l'nemory. After enough visualization 3nd discllssion, patients Illay be unable to sort out whether the memory has come to "feel"like a genuine one because the event actually happened or merely because thL')' have been imagining it and talking about it.This idea receives suppon from studies by Ira Hyman and his colleagues that . have documented that using g1.lided imagery increases f'llse memories of childhood events (see chapter 4). Recent PET scanning studies con ducted by Stephen Kosslyn and his colleagues have shown that some of the same regions in the occipital lobes are involved in both visual imagery and perception. This Illay be one reason why incidents that people frequently imagine can come to feel like events that actually occurred: imagined events are generated by some of the same neural machinery that contributes to the perception of actual event�"1 Just as there is no good evidence dut techniques such as guided imagery and hypnosis can aid accurate retTieval of distam, forgotten, or repressed memories, there is no hard evidence that these techniques are specifically responsible for the creation of pscudomcmories in therapy. And it is of course possible that
III
cases where real abuse has
occurred and has been forgotten, such procedures might help some patients recover their memories. llut unless a ther:.Ipist can cite evi dence that a specific memory-retrieval technique enhances accur:ltc recall without promoting false recollections, it is inappropriate to con tinue to use unproven and potentially hazardous memory-retrieval t{�chniques. Nonetheless, a recent survey of 1 4 5 doctoral-level psy chotherapists in the United States indicates that close to one-third sometiJ'nes use hypnosis to help clients remelnber child sexual abuse, and about the s.,me percentage report using g1.lided imagery."'" I believe that three major conclusions are warranted concerning the likelihood of therapeutic implantation of false memoriL"s of sexual
tr.uuna. First, there is no conclusive scientific evidence from controlled
273
(;liluR."S to document 5.1tanic ritual abuse; recovery of lIlernori("S for seem ingly impossible events
(past lives
and alien abductions); growing num
bers of ther.tpy patiems who have retracted their memories; the constructive nature of memory for emotional events; and the risky mem ory-retrieval techniques advocated by some proponents of recovered 111('1ll0ry therapy.Yet we still lack solid data concerning the prevalance of therapy-mduced pseudomemorit."S. We simply don't yet know whether illusory memories of sex1.1al abuse are exceedingly rare, as some clinicians have claimed, or whether they are widespread, as critics of so-called recovered memory therapy have :llb"ucd. It seems unlikely, however, that they can all be written off to just a handful of w:l)'\v.mi therapisrs.1'I Viewed in a broader historical perspective, the idea that people can acquire convincing but inaccurate memories during therapy should not be all that surprising. The philosopher Ian Hacking points out that over a cenlUry ago, Pierre Janet routinely rr!,!aced traumatized patients by implanting false memories to replace accurate but painful recollections of horrible events. For instance. he hypnotized one patient who was overwhelmed by childhood memories of sleeping next to a girl with an acute skin disease called impetigo on her face, leaving it covered by pus tules and crUSlS. Janet replaced the traumatic memory with a pleasant but illusory image of a lovely face. Elizabeth Loftus described something similar in a 1982 paper. nearly a decade prior to the recovered-memo ries controversy. In an ironic twist, given later developments, she quoted nvo psychotherapists who implamed entire false histories in p!'!ople as a \vay ofmaking them feel bener. Working with people who had been fat all their lives, they successfully implanted f.'llse childhoods in which the patient� had grown up thin. The therapists noted that they "could very easily install mernories in YOll that related to real world experiences that never occurred:· "Made-up mell10riL"S can change you just as well as the arbitrary perceptions that you m:lde up at the time about 'real world events,' " they reflected. "That happens a lot in therapy."50
rt.'search t.hat f.,lse memories of sexual abme can be created-nor will such evidence ever ex ist, because of ethical coltSiderations. Second, there is likewise no defmiti...'l! scientific evidence showing that therapy per sc or specific sUg&1CSth'C techniques are alone responsible for the creation of inaccurate memories. Third, several separate strands, when considered together, support the conclusion that some therapists h:lve helped to crc :lle illusory recollections of sexual abuse: the experimentally documented malleability of memory in response to suggestive influences; evidence that hypnosis call produce compelling but inaccur.tte pseudomemories;
D I S T I N G U I S H I N G A C C U R AT E A N D I L L U S O RY R E C O L LE C T I O N S The Role o f Implicit Memory I f accurate recovered memories and illusory recollections of sexual trauma both exist, then an important question imnH.!diately arises: Are there any scientifically based critcri:l that allow us to distinguish mem ories of events that aCfUally occurred from false r!'!collections? The
S e a rchi"g Jor A1efll o r y
T h e M e m o ry Wars
answer, unfortunately, i s no. Laborarory studies have provided sugges tive clues about. differences between rnemories of actual events and imagined events, but there is no research that allows ciiniciall.s or sci entists to judge unequivocilly rhe historical truth of a traumanc mem . ory recovered in therapy Noncthdess. some therapists have offered lem� suggestions about how to distinguish an accurate recovered n .
published in various popular publications for incest survivors and that
from an illusory one.S1 One intriguing possibility involves ll11phclt
Illemory for a past experience, it is essential to demonstrate that a behavior or symptom is specifically related to that experience. With
memory for forgotten traumas.
general symptoms of the kind that are described in popular checklists,
274
,!
. Sigmund Freud and Josef 13reuer's classic studies of hystena described patiems who could not explicitly remember childhood sex ual abuse. but experienced disabling fears, nagging anxieties, intrusive
thoughts. or disturbing images that reflected implicit memory for {he trauma. However. these cases proved difficult to interpret because independent corroboration of the event was often lacking. As I noted
275
include such items as low self-esteem, sexual difficulry, eating disor ders, depression, fears of abandonment, and so forth. Here I agree with critics who maintain that such symptoms are so general that they could apply to many people.5o< To invoke implicit
it is diffICult to establish causal links in individual cases, allhough it i s o f course possible that they sometimes exist. The psychiatrist Harri son Pope and his colleagues found no evidence th:H childhood sexual abuse is a risk factor for the eating disorder known as bulimia, even though bulimia has been often cited as a telltale sign of forgonen abuse.J� We do not yet know whether particular kinds of behaviors
in chapter 4. Freud later abandoned his early belief in the reality of sllch traumatic experiences in favor of the idea that they are often fan
and symptoms are unconscious remnants of traumatic abuse.
tasy-based false recollections.u Breuer and Freud's early observations are germane to contempo
enter therapy with unexplained fears of or reactions to a particular sit
rary controversies because some have contended that true recovered memories-not false recollections-are nearly always preceded by behaviors :lI1d symptoms thlt reflect unconscious or implicit memory
�
for repressed trauma. Lenore Terr's research with traumatized child en shows that such implicit memory effens can occur. She studIed twenty children who had been subjected to various kinds of traumas prior to rhe age of fIVe; in almost all cases, the trauillas were corrobo rated by eyewitnesses, police reports, or other means. Terr found that nineteen of the twenty children-including several who could not relllember their traumas in words-showed the influence of the trauma in their play, fears, and other nonverbal behaviors. Terr nOtes that only one child-the single case of false memory in her sample- had no behavioral symptoms of trauma. This little girl had heard fam ily members talk about the traumatic event but had not actually
:
experienced it. IfTerr's observations apply to other situations, the�1 he
In some cases, however, more specific symptoms exist; patients may uation. smell, or object. "Attraction to, avoidance of. or distress around objects or situations unexplained by your own history arc \varning signs of repressed memories," writes the therapist Renee Frederick5011. ';Ouring
sexual abuse. your mind focuses on the events :md cir
cumstances surrounding the abuse. You may bury the memory, but you store the reaction to the objects or situations that remind you of the abuse."56 This is a plausible suggestion. In chapter
8
we cncounrered
instances of implicit memory for forgotten traumas in psychogenic amllesia patients, and I suggested a role for til(' amygdala l1! mediating persisting emotional aftereffects of experiences that arc not recollected consciously. Uut it is still a long leap to interpreting a patient's unex plained fears, attractions, or dislikes 3S implicit memories of sexual abuse. One problem is that even a specific symptom could have any number of causes. In a repressed memory case cited by Frederickson, a patient felt an unexplained rev ulsion toward forks. Subsequemly, she
presence or absence of implicit memory might indeed help dlslHl
recovered a memory of her aunt abusing her with a fork. Frederick
guish between true and false recovered memories o f sexual ablls .1l . . . But there arc problems in trying to apply this Idea to mdlVldual
son concluded that the abusive episode is rhe origin of the patients
cases 111 which memories of long-forgotten traumas are recovered in
for the abuse? Possibly. But suppose Ihat Ihe fork revulsion had noth
�
therapy. Some therapistS include a vast range of symptoms and behav iors as possible indications that a person who has no cxplicit memory of abuse has nevertheless been influenced by it. These symptoms pop ulate the notorious " checklists" for possible past abuse that have been
unexplained revulsion toward forks. Couldn't this be implicit melllory ing to do with sexual abuse, yet was one of [he factors that encour aged the patient or the therapist to explore the possibility that she had been abused. Or suppose that the therapist focused on the meaning of this revulsion because she assumed that it was a symptolll of abuse.
276
Sellrril i llg for JHclI/ () r y
T h e M e m o ry Wars
Then the symptolll could become a focal poim for constructing an
BEYOND C O NTROVERSY
illusory memory. Once therapist and patient become attached to the
As I write these words the recovere d memories controversy continues t� rage. Yet we stilJ have little good scientific cvidence that bears directly on the key issues that I have discussed. Few times in the his tory of psychology or psychiatry has the ratio of data to impassioned argument been so low. If we are to find the truth, I believe that we need to recast the tone of the recov ered-memories debate from its present black and white polarities to one that acknowledges more shades of gray.
idea that the symptom reflecrs forgotten abu�c, it should not be sur prising when a patient startS to produce images, thoughrs, and feelings that in some way relate to the- symptom. Nobody can say for sure whether slIch a process was operating in Frederickson's patient. but the psychiatrists Susan McElroy and Paul Keck have.: recently described a case in wl1lch it dearly played a role. Ms. B. sought therapy because of depn.:ssion and intrusive thoughts of harming her infant. She also told the therapist tim as a child she had experienced unwanted images of being raped, and wondered whether her disturbing ideas could be symplOllIs of unremembered sexual abuse: "The therapist responded to Ms. B. that these symptoms wcre 'clear evidence' that Ms. B. had in fact been sexually abused as a child, and instructed her ro draw pictures of anything that came to her mind:' After six months of trying, Ms. B. developed detailed recollec tions of sexual abuse involving her sister and brothcr-in-Iaw. However, Ms. B.'s condition did not improve, her sister angrily denied the abuse, and she could find no corroborating evidence that any abuse occurred. Ms. n. finally concluded that her memories were false and sought alternative lherapy. Eventually it was discovered that Ms. B.'s intrusive thoughts were attributable to an obsessive-compulsive disor der. As in similar cases I mentioned earlicr, they disappeared when crt.'ated with appropriate medication.\' It seems likely that in some cases of recovered memories, unusual fears, anracrions, and related symptoms Illay well turn out to be implicit nH.!Il'lories of prior abuse. In other cases, like Ms . B.'s, such symptoms may provide a basis for creating false recollections in response to suggcstive probing. rather than reflecting the influence of a traumatic memory that had been there prior to therolpy. Inferring implicit memory is a tricky business that calls for careful comparisons and "ysrcmatic reasoning. Behavio� and symptoms may have Illany possible causes, and it is diffiCllit to say whether one partic ular experience is the source of a specific behavior or symprom. In the laboratory, experimenters can control the events that give rise to implicit memories. In therapy settings where patients do not explicitly remember being abused, and where we do nor even know for cenain that the abusive event occurred, it is impossible to make comrolled comparisons. A therapist who engages in undisciplined interpretation of fears, altractions, and other symptoms as signs of implicit memory for forgotten abuse may be taking a stcp down a road to disaster.
277
For one, the notion of ''false memory" irself is too coarse to do jus . tJc� to the complex relati. ons between memory and reality. When a pa�lent remembers growing up in an abusive satanic cult that did not eXiSt, then we have a belief that defie s reality. Even if the ritual abuse . memory IS a meraphor for some other distressing experience, the . . . memory IS historically wrong in a way that most memories arc not. But what of a woman who was emo tionally brutalized by a neglect ful parent, or perh�ps exposed to sexua lly inappropriate language, . behaVIOr, or fondlIng, and then remembe rs incest when none occurred? he incest memory is iJIuso ry, and should be regarded as such, but It Illay capture something illlportalH about the past that should not be disl lissed. Historical truth can be respected while at d e � . . . sam� tllne domgJustlCe to a patient's narrative truth. We need to rec ognIZe that memories do nor exist in one of two states-either true or false-and that the important task is to examine how and in what ways memory corresponds to realit y.� Contrary to wl at some have said, there is a middle ground in the � re�0 ered-llle1l10T1eS debate; the prob � lem is to identify it. I believe that thiS IS Ol r best hope for resolving [he bittcr and divisive arguments � �hat COntllllIe to rage among patients, families, and professionals. Polit . Ical posturll1g and grand generalizations on both sides of this debate should come to an end. Risky thera peutic practices lleed to be stopped. Better techl1lques must be developed that allow us to distin . gUIsh et�veen accurate recovered memories and illusory memories that anse 1Il re ponse to suggestion . Achi eving � these objectives should . . help to IlIlnUll1ze the possibility that those who were not abused come to embrace the psychologically devastating belief that they were redu�e (and, one hopes, end) false accusations that shatter lives an, allllhes, and als maximize the credibility of the memories reported � . y genUll1e survivors of sexual abuse. Sadly, legiti mate concerns about pseudomemories have probably helpe d create doubts about the accu-
!
�
?
�
!
T h e M e m o r y Wa r s
FIGURE 9 . 2
279
rate recollections of some survivors of actual abuse, an outcome that should not be tolerated by therapists, researchers, or society. When Diana Halbrooks reflects on the peculiar memories that she now understands were illusory, she returns over and over again to a single theme: the importance of her family. Diana appreciatcs that there were problems in her early f.1l11ily life. She did not grow up in tht.: idyllic 1950s family that served as a model for many of the post-World War I I generation . l3ehind the vcneer of smiling faces in old photographs and home 1I10vies, there were real difficulties that Diana needed to confront as an adult. (See fi!:,"Ure 9.2.) Diana Halbrooks came to understand that she could acknowledge a painful reality without vilifying or abandoning her parents. "We are rebuilding," she reflects, "and trying to make up for lost time, making every moment count." Not all the victims of the memory wars will be able to unite with their ("milies again. This realization is sad as well as ironic. Our families serve as social repositories for autobiographical n:collections from many times in our lives; we revisit f:woritc episodes, stories, and momentous occasions during holidays and other family gatherings. Yet for some patients. recovering memories of distant trau mas-whether aCCllrate or illusory--serves to disconnect them from
Lorie Novak, "Fragments," Courtesy of the artist.
1987. 16�
x
22". Color photograph.
Novak is concerned with the nature of memories for family life. underscor
ing thl' discrepancy between our idealized versions of childhood and the more troublesome fecl ings that often lurk beneath the surface. In " Frag ments" a Polaroid snapshot of a classic 19505 family that includes the artist as a young girl creatl'S a nostalgic sense of a harmonious past. But the torn and fragmemed images in the foreground show Novak at all older age and imply that the innocent f.1m ily portrait masks a more complex and perhaps painful reality
.
one of their richest sources of personal history. The beginnings of our life stories are written in our families, and when we try to make sense of these stories near the ends of our lives, it is often to the family that we return.
S t o r i es o f E l d e r s
281
is especially concerned with reviewing, and attempting ro understand, a family tragedy that has colored h i s entire life: he killed his younger
TEN
brother in a hunting accident. The in cident was too painful for him ro face when he was younger. Like others who have lived through terri ble events, he tried his best for years to avoid the wrenching rnemory, mostly by working endless hOllrs o n his farm:"lf I kept at it, kept that ditchbank so clean you could eat Ollt of it, kept the weeds alit of the tobacco and corn, gOt rhe whole pbce looking better than it ever Iud, m:lybc everybody would forget some day that rd killed my own
STORIES O F ELDERS
brother. Maybe I"d forget, (00."2
He never did forget. Out it was only with the distallce in time pro vided by old age that Littlejohn could ponder what had happened. The novel charts his battle to comprehend the haunting memory, and ultimately to plaer.: it in the perspective of the fundamcntally decent
E I G H TY-TWO- Y E A R - O L D Littlejohn McCain, the central character in Howard Owen's novel
Lift/rjo/Hl,
is embroiled in a struggle with
memory. As he approaches the end of his life, this farmer from Nonh Carolina is often plagued by his diminishing ability ro remember his recent experiences. After forgetting frequently to turn off the burners on hi � stove, he becomes so flustered that he mounts a large sign on
the kitchen door with the words TURN OFF BURNERS embla
zoned on it. Sometimes Littlejohn forgets where he is or what he is doing, as in a jarring episode at the grocery store: " I had JUSt pm twO
�
cans of Camp �U's cream of chicken soup i n my cart and was looking for the self-mlllg Rour when I just blanked OU[. I couldn't quite remember what I was doing there. It had happened once or rwice before, but never this bad, or this public, at least. I looked around, and there ar the end of the aisle was the meat counter. It seemed like I rec
life that he has led. Littlejohn reminds himself of the broader context in which the awful evem occurred by turning to a symbol of the good things that happened ill his life: a crepe myrtle flower that his wife cul tivated when they first moved into their home. The house was later destroyed by fire. but even after selling olT theIr land, Littlejohn saved the largest crepe myrtle and used i t to help create a balanced recol lection of the past: "Th:n crepe myrtle comes out every summer all pink and be:lUtiful,just when everything else is dying, and it helps me to remember what a fine life we had, in spite of everything."} We see here a kind of age-related heightening of memory's fragile power: the elderly Littlejohn is increasingly plagued by memory's f.1ilures at the same time that he takes refuge in its cOlllpdlmg force. Pat Potter, an artist from Alabama who has spent a good deal of ti111e listening to the reminisccnee<; of elderly adults, evokes some of
ognized it, so I wem that way." After his grandson teases him about his
the qualities that arc so evidr.:nt in Littlejohn's recollections. In the
�enchant for forgetting, Littlejohn becomes flustered. "Son, ifyou ever Ive to be a� old as me," he explains to the youngster, "you'll be happy
ory that combined painting, sculpture. and texts in a widr.:-ranging
At the same time that he is tormented by the fragility of his mcm
viewed elderly adults about their e:lrly recollections of f:nnily mell\
�
If you can Just remember your own name."l
ory Linlejohn is also increasingly inspired. and sometimes consumed, � by Its pow�r. �e spends much of his time recouming the significant events of hIS hfe, many of which seem as real in old age as they did when
�e \�as yo.unger. Littl�joh'�
thinks a lot about what has hap
pened III I11S f.11l1lIy: the Stones I11S father told, the advice his mother gave, everything he learned from his uncles, aunts, and cousins. But he 280
mid-1980s, Poner mounted an ambitious artistic exploration ofmem llIuscum installation.4 As part of her memory projen, Potter imer bers and saliem episodcs from their lives. She :mempted 10 convey the quality of their reminiscences by ahering old phmographs that depict the recollened family member or the rcmembered episode, llsing var iOlls techniques or artistic transformation, illustrated by "Overlays of Memory II" (figure 1 0. 1 ) . We sometimes speak disdainfully o f older adults a s living i n rhe past, implying a present that is so impoverished that elders must take refuge in the comfort provided by their idealized memories. Adult
S t o r i es o f E l d ers
FIGURE 1 0 . 1
283
men and women often attribute episodes of forgetting to memory banks that arc losing brain cell<; by the minute. And lllany people worry that all of their memory capacities will inevitably decline and then disappear as they grow older. These are all myths about aging memory that I try to set to rest in this chapter. Research in psychol ogy and neuroscience indicates thac aging docs not produce an across the-board decline ill all memory functions; that memory systems do not necessarily lose significant 1ll1l1lbers of brain cells as we agc; and dut when older adulc.s focus on the past, there need not be any pathology involved. Memory is affected by aging, but the nafUre of the changes, and the reasons why they occur, are different from what many of us believe and fear.
A G I N G M E M ORY How F r a g i l e Is I t ? There are good reasons why people fear that aging inevitably brinb 'S a generalized decline in memory: decades of research leave little doubt that aging can impair mcmory. ln expcriments on aging memory, "old people" are usually healthy volunteers around seventy years of age. whereas "young people" ate generally college sfUdems. Numerous experiments examining
explicit
memory for recently
pre<;ellted
words, pictures, or stories have revealed dut older adults usually remember less than young people. And we are all aw-are of rhe perils of Alzheimer's disease. It is easy for an older person to worry that (1.il ing to recall someolle's name, or forgetting where the car keys wcre placed. is an carly sign of descent into anlllesia and dementia. The prospect of ending up like Frederick, unable to remember that YOll execuled a golf stroke a minute ago, is dreadful. Pat Potrer, "Overlays of Memory U," 1985. 10 x 7 " . Mixed tnedia, altered photograph image. Courtesy of the artist.
But many of us are not aware of rhe single lIlost imponam fact
about memory and aging: the performance of older adults varies
widely across different situatiom, ranging from perfectly normal to
The artist portrays octogenarian Addie Hutler's memory of her younger
significantly impaired. For instance. after studying a list of familiar
brother John as a boy.The multi ple fr.glllems ofJohn's image arc blurred and
words, the elderly h:1\'e problems remembering the words on their
innocent youth ill kn ickers and dress shin effectively comnmnic;nes that this
ber the same items accuraceIY-'Jlmos( as weU as college students do-
velled,just like Addie's melllo ry of him. At t he sanle time, the picmre of the
is an emotionally resonant memory for Addie. She rccoUectS affectionately
that John "was eight years younger and we would dress him lip like
3
doll."5
The image serves as a symbol of a distant childhood that cominues to echo
persistently in Addie's presell!. The faded qualities of Addie's fecoUectiOl1s do not diminish their power to call forth potent feelings.
own ("free recall"), without any hint's or Clles. But they call remem when they arc shown the words and asked to say which ones were on
the list: ("recognition"). When older people arc shown two separate
lists of sentences, they have a harder time than young people remem bering whether a sentence appeared on the first or the second list. Out
284
St:a rcll i,,� fo r Memory
S t o r i e s of E l d e rs
when some sentences appear o n the lcft side o f a screen and others
285
neurons. Normal memory loss and amnesia due to Alzheimer's disease
:lppear on the right, older adults remembl:r where the sentences
involve different kinds of changes in the brain. This means that the
appeared just as well as young people. And when asked to carry out . certain tasks at a designated time in the future, such as returmng a bor
next time YOll forgct where you put your car keys, you need not worry that you are headed toward Alzheimer's. Nor do you need to
rowed comb or arranging an appointment, they are more likely to for
become concerned the next time you fail to come up with the name
get to do it than young pcople arc. Asked to carry OtH. other tasks at a
of a friend that feels like it is on the tip of your tongue. But ifyou for
future timc, such :l5 pushing a bunoll whenever a certam word appears
get that you possess a car or you can't remember your own name, then
on a computer screen, however, older people remember to do it as
there is clearly cause for concern.
often as do college student�. If :Iging simply produced a gen� ral decline in memory. we would not expect to see elderly adults dOIll�
If normal aging results m less neuron loss from the cortex and hip pocampus than was previously suspected, why do older adults have
extremely well in some situations and poorly in others. Why does thiS
memory problems? The hippocampus docs show definite signs of
happen?<-
atrophy with aging, and abundant hippocampal atrophy is associated
. The aging brain provides some important clues. OveraJl br.ull mass
with low levels of explicit memory on laboratory tests. Also, aging
�teadily shrinks as we enter our sixtics and seventies, at roughly 5 per
produces marked loss of neurons in a few subcortical StruCfures,
cent to 1 0 percent per decade. Fluid-filled ventricles enlarge, and the
including one J mentioned in connection with amnesic syndromes,
br:lin's blood flow and uptake of oxygen both decrease significandy.1
the basal forebrain. The basal forebrain is important because it supplies
�
Many researchers have long believed that aging results in a widesp� ad loss of neurons in the cortex. the seat of our most advanced cognitive
the hippocampus with a chemical messenger called acetylcholine, which is known to be important for memory. fu we have seen, mem
funclions and the major site of memory storage. This belief is based
ories arc encoded by changes in the strengths of connections among
on studies of brains examined in autopsies in which fewer numbers of
neurons. Acetylcholine expedites these changes. When the basal fore
neurons wcre found in the cortex of old people than of young peo
brain is directly damaged, patients develop amnesia. Accordingly, a sig
ple. But Illost of these studies were conducted decades ago, when
niftcant loss of neurons in the basal forebrain probably contributes to
researchers had only a limited awareness of Alzheimer's disease and
age-related memory difficulties.IO
may have included both healthy and diseased brains in their �tudies. Newer studies that have excluded brains of people with sIgns of
older adults show intact memory in some situations and substantial
Alzheimcr's or other age-related brain diseases tell a different talc: loss
impairments in others. The frontal lobes appear to be hit hard during
Changes in the frontal lobes provide important insights into why
of neuronS in the cortex is either trivial or f;lf less than what the early
aging. Bram atrophy or shrinkage is most pronounced over frontal
studies had shown. Recent research with monkeys leads to the same
regions. as are reductions of blood flow and glucose utilization. These
conclusion.'
changcs in the brain are mirrored in behavior. Elderly adults often
In a compelling conflflll:ltion of rhis point, researchers carefully
perform especially poorly on COb'1litive tests that are failed by patients
examined several regions of the hippocampus that are known to pro
with damage to a part of the frontal lobe on the cortical sur(,ce
vas duce memory loss when damaged (including the CA 1 field that \ . disrupted ill the amnesic patient R.D, discussed earlier). Normal aglllg
known as the dorsolateral region. For example, when chese frontal patients are given a deck of cards that contains different colors, shapes,
was not associated with neuron loss in these regions, but there was
and other features, they have problems sorting the cards by category:
considerable loss of hippocampal neurons in the brains of parients
color, shape, and sO 011. So do older adults. Even whcn deficits that
who had shown signs of Alzheimer's disease when alive-.' This may be
Illay be attributable to impaired function in other brain regions are
why an Alzheimer's patient such as Frederick is unable to remember
carefully controlJed for, difficulties related to the frontal lobes emerge
golfshotS he hit minutes earlier: numerous neurons in the hippocam
as the most important factor in elderly adults' impaired cognitive per
f!
pus have been destroyed. However, an older adult who has di lCulty
formance on several different tests. I I Uecause some areas of the frontal
with unaided recall of a rccent experience, but relllember� It well when given hints or cues, still has an ample supply of hippocampal
lobe play a critical role in remembering, we have a potentially useful
_.1.-_
handle on the variations in explicit memory that are characteristic of
286
Sftl rr ll i llg
i(" M e m o r y
older adults. R:nher than resulting from a general decline in all aspects
S t o r i e s o f E l d ers
287
earlier. Remember that older adults have less difficulty with recogni
of brain function, many memory problems in older adults m:ly stem
tion than with recall. Under the demanding conditions of a recall test,
ITom specific impairmentS in the frontal lobes. If so, then older adult.s
whcn an older person has to search for and produce the correct
should have special problems with memory tasks that rely 011 frontal
answer, right anterior frontal regions may not quite be up to the job
regions. The weight of the scientific evidence is consistent with this
of getting the retrieval process started. Bur when the answer is pro
suggestion.
vided on a recognition test, and aU the older adult has to do is say . which of two f1ces appeared earlier, these frontal regions do con
Let's consider the contrasts I highlighted earlier between spared and impaired memory functions in older adults. Frontal regions are more
tribute. Interestingly, during the initial study of the faces, old people
important for recall than for recognition, which could account for the
showed reduced activity in the left inferior frontal lobe and several
fact tl1at older adults have more problems recalling words on thl!ir
other structures that are irnportanr for encoding. As we saw earlier, the
own than recognizing them when shown a list. Memory for tempo
left inferior frontal lobe plays a role in elaboratiw encoding. Older
ral order depends on frontal regions, which may explain wby elderly
adults apparently did nOt spontaneously elaborate on the faces when
3dults have problems remembering the order in which twO sentences
they encoded them into memory, whereas younger people did.l� How arc age-related fromal impairments manifest in the everyday
appear. The elderly have no problems remembering whether sen tences appeared on the left or right, probably because this kind of memory depends on brain regions outside the fromal lobes, which are not especially affected by aging. Older people do not remember to carry out future actions like arranging an appointment when they have to generate cues on their own, which probably maximizes demands on the fromal lobes. But when a cue word is presented, older people have no problems remembenng to carry out a prescribed action. probably because the frontal lobes were not heavily taxcd.ll Using PET scans, my colleagues and I have directly implicated spe cific :lrt!:lS within the ITontal lobes in age-related memory deficits. I earlkr discussed PET resulr.� showing that certain frontal regions become active when people work hard at trying to remember a recently studied word, thus demonstrating that parts of the frontal lobe arc involved in strategic or effonful retneval processes. We found that when young people wert' given cues and 11l3de extensive efforts
memory of older people? R.ccall that patients with frontal lobe dam age arc especially vulnerable to source amnesia: even when they can recall a newly learned f:lct, they have special problems recollecting
who told it to them. This may be because retrieving source informa tion requires the kind of effortful retrieval that depends on the frontal
lobes. In the
1 980 presidential campaign, Ronald Reagan repeatedly told a heartbreaking story of a World War I I bomber pilot who ordered his crew to bail Out after his plane had been seriously dam aged by an enemy hit. His young belly gunner was wounded so seri ously that he was unable {Q evacuate the bomber. Reagan could barely hold hack his tears as he uttered the pilot's heroic response: " ever
mind. We'll ride it down together." Tbe press soon realized that this story was an almost exact duplicate of a scene in the 1 94-t film A l-Villg tllld a Pmyer. Reagan had apparently retained the f.1CtS but forgotten their source.l�
to recall words they studied a few minutes earlier, areas in anterior sec
Evidence from several laboratory studies has linked this kind of
tions of the froneal lobes became extremely active. Out these areas,
source amnesia with frontal lobe dysfunction. For example, my col
particularly in the right anterior frontal lobe, showed few signs of activity when older adults carried out the same rcelll task. It seemed
leagues and I examined whether older adults could learn fictitious . " f1cts" such as "Bob Hope's father was a fireman." In the experiment,
as though elderly participants had difficulty starting up the retrieval
such information was given to old and young people by either a man
process-cng.lging in the mental work necessary to search for and
or a woman. We found that the elderly have milch more difficulty
dredge up episodic memories. Yet the hippocampus became :lctive
than the young recollecting whetht'r the man or the woman [Old
during recall in both older and younger adults, probably reflecting a
them the information-cven when they can recall the information
comlllonality in the way that older and younger people remember
itself correctly. Poor source memory in the d(!t:rly is related to their
words from the study list. U
performance on tests that are sensitive to deficiencies in the ITomal
In another PET study, bOth older and younger adults showed right frontal lobe activation during recognition of faces they had studied
lobes. Elderly people who perform poorly Oil these tests also tend to have special problems remembering source information."
S e (Htld ",�
288
Stories o f Elders
for Memory
�
the origina event or something they learned about when they were asked quesnollS about the event. If impaired source memory makes a person vulnerable to being misled by bogus information. then elderly adults should be especially susceptible to the misinformation etTcct
Source memory becomes importam in everyday life when we are given personal tidbits or "inside" tips on the condition that we keep thcm to ourselves. Think about what is involved in staying true to your vow. YOti mtiSt be able to remember later whether the tidbit is a secret
and they arc, Does this llIean that an elderly adult's testimony in court . le\\'ed with skeptici.sm? Not nccess.1.rily. There are large dlfT erences 111 evcls of explicit memory among older people. and
that you are not supposcd to divulge; that is, you must accurately
�
sl ould be
remcmber the source of your knowledge. If you retain the juicy tidbit but forget how you learned about it, you arc liable to inadvertently spill of gossip and told old and young people that some tidbits were secrets
�
this docs not indicate that :lIly particular elderly eyewitll{''Ss is less reli
that should not be disclosed, whereas others were common knowl
able chan a younger one. l'
edge. Older adults had more difficulty than younger adults remember
Recalling source information is an important component ofour sub
ing which tidbits were secrets and which were not. This finding does
jective experience of remembering paSt events. When we recollect who
not necessarily mean that you should never trust your grandmother
told us �n �echin �, or ocher details of an episode. our subjective experi ence W1U hkely IIlvolve "remembering." When we recall only an iso
with a secret, but you should probably handle Stich matters with care.l1 Decause forgetting the source of a memory opens the door to illu
lated fact, however. our subjective experience will likely involve "just
sory recollections, older adults are especially vulnerable to certain
knowing" that something is familiar. When asked to recollect recent
types of memory dis(Qrtions. Recall the £lIse fame illusion I consid
episodes, older adults report less " visual reexperiencing" of the episodes
ered earlier in the book. When people are exposed in the laboratory
than do younger adults.1Il And older adult� are also less likely than
to a made up, nonfamous !lame such as Sebastian Weisdorf, and later
younb"Cr people to say that th{.1' " remember" having encountered words
fai l consciously to recollect having been exposed to this name, they
or phrases they studied several minuc{.'S earlier; they tend to 5.1y [hat they
sometimes believe that Sebastian Weisdorf is the name of a famollS
"just know" chat the item appeared earlier. This age-rebted deficit in the
person. The only way to overcome the illusion is by recollecting the
subjective experience of remembering is not just a matter of old peo
prior exposure to that name in the laboratory. The elderly are espe
pic lacking confidence in their memories. The elderly arc just as confi
cially susceptible to the false fame effect. Decause they are less able
dent about their "remember" or " know" judbrtllelHS as young people
than young adults to recollect that they encountered the name in an
are; but they report fewer " remember" expericnces than the young. In
experimental list, but still fed that they know it, they are more likely
everyday life, this may mean due older adults' recollections of recent
than younger adults to claim that the name is famous. Similarly, after
e,,enrs will be rather sketchy and incomplete, even though they are ct'r : tam that an event has occurred. As with age-related source memory
taste, chocQlate, (andy, sligar, and other strong nonstudied word (sweet), older adults are somewhat less
studying such words as
problems. the frontal lobes play a role in an older person's recollective
likely than younger people to remember the words that were actually
experience. Elderly adults who make many " remember" judgments
presented but arc at least as likely to show false recognition of Slllce/,
tend to do better
perhaps because they are especially prone to mixing lip whether they
011
tests that are �ensitivc to frontal lobe impairment
than do those who make fewer "rcmcmber" judb'lllents.l1 All this evidence suggests that frontal lobe impairments lead to a ge related difficulties in recalling and pulling together the diverse elem nts that constitl te an everyday episode: what happened, when it happened. � and who saId what. Thl! result is that older adults' recollectiw experi ence of recent cvents is k'Ss vivid than younger adults' recoJ!ecti\'e e.x"Pe , nence, and they ;lre especiaJly vulnerable to illu�iolls of memory.
merely thought about sweet or aCfUally studied it (see chapler 4).1' These kinds of confusions could raise questions about the elderly
�
person's ability to serve as an effective eyewitness. Recall that the memory of eyewitnesses can be badly skewed when they are asked misleading questions. After seeing a videotaped evem, people who are asked a question about an episode that did not occur in the video sometimes incorporate this "misinformation" into their memory of rhe event. One reason why this occurs is that people forget the source of the misinformation; they cannot remember whether it was part of
�
many perform Just as well as, or better thall, young adulcs. While older adults on average have difficulty remembering source information,
your friend's secret. My colleagues and I made up various juicy tidbits
associates of a
289
-"-
Th esc frontally based problcrn.� al�o relate to the effects of aging on . working me.llory-the mental workspace we use to hold information
S e a r c h illg for JHelliMY
Stories of E lders
temporarily as we carry oU[ ordinary cogllltive casks like reasoning
gcsts that age-related working memory deficits could result from low
290
291
and comprehending. Try to read 3 couple of sentences in chis book
levels of dopamine receptors in frontal regions lh:n arc crucial for
while at the sallle time holding 011 to the digit sequence "5-9-
working memory. The idea is further buttressed by studies that have
4-2-8-6," To do both tasks at once, you will need to drJw on all the
revealed working mcmory deficit.s in two other conditions that are
working memory capacity you have available. When the working
both
associated with dopamine abnormalities: schizophrenia and
memory of older adults is taxed in ways similar to this, they perform
Parkinson's disease. Although the psychotic symptoms of schizo
much morc poorly than young people.
phreillc patients and the tremors of Parkinson's patients render these
TIllS is probably because the frontal lobes play a key role in the working memory system, and arc called 011 when we must actively
conditions very different from each other and from norma! aging, all
work to maint3in information across a delay. Patients who have suffered strokes or other kinds of direct damage to the frontal lobes have great
that resull m Illlpaired performance when working memory IS needcd
difficulty when theif working memories are taxed. In a PET scanning study carried out by the neuropsychologist Michael Petrides and 1m
three may be linked by dopamme abnormalities in the frontal lobes to hold information as other cognitive activities proceed.lJ In contrast to the problems they have when working memory is heavily taxed, older adults can remember nearly as many digits as
colleagues, heahhy volunteers held 111 working memory recently pre sented pictures of designs as they tried to POll1t to new pictures that
young people when they repeat the numbers inunediately and don't
had not been shown earlier-a task that is failed by patients with dam age to dorsobteral frontal regIons. Compared to a control condition,
ing the digit string alone involves primarily a sTllall part of the work
PET scans revealed activation in a specific part of the dorsolateral frontal region during the working memory task. Another PET scan
nO[ depend crucially on frOlltal regions.l'
ning study has shown th:lt a specific area in the lower pan of the right frontal lobe becomes active when healthy people hold i.n working memory the location of several dots, whereas a lower part of the left
have far-reachmg consequences. There is still some good news about
have to concentrate on anything else. This is probably because ret
frontal region becomes active when they use working 11lt:11lory to remember the exact shape of a geometric pattern.l2
encodings, age-related differenccs in recall memory largely disappear.
These linkages among the fronral lobes, working memory, and aging
As we age, wc may need to do extra work both dunng encoding and
have been strengthened in experiments with monkeys by the neurosci
during retrieval in order to rt:1l1cmber recent experiences as oftcn as
entist Patrici:l Coldman-Rakic. When the animals view a visual pattem
we Ol1ce did, bm if we make the effort we will be rewarded with
distinctively, and arc later given cues that help them regenerate their
that suddenly disappears, and maintain a memory of its location across
enhanced retention. We can still benefit from elaborative encoding
delays of several seconds, specific clusters of neurons in a part of the dor
when we grow old because semantic memory holds up well WHh age.
sol:lter:.11 frontal region called the principal sulcus remain active. When
Our abilities to call on our enormOllS networks of f:ICts and associa
the animals maintain a memory of the pattern itself, neurons just below
tions are generally wcll preserved. We also retain the capacity to use
rhe principal sulcus become active. These neurons seem to be "work
our semantic knowledge to make inferences and solve problems. For
ing" to allow the ,mirnal to remember the location or rhe pattt:rn. Gold
example, elderly chess players are just as capable as young ones of
man-Rakic and her colleagut:s have recently shown that the activity of
searching their knowledge base to choose and evaluate moves. Seman
some frontal lobe neurons involved in working rnemory is regulated by
tic memory is not totally impervious to aging-elderly adults com
a specific receptor for the neurotransmitter dopamine, one of the brain's
monly
major chemical messengers. Olher work from Goldman-Rakic's labo
objects-blit on balance i[ is less affected than episodic memory.l�
ratory indicates that working memory impalTlnents in older monkeys are linked to age-related losses of this dopamine receptor.
have
problems
retrieving
the
names
of people
and
Another piecc of good news is that the implicit form of memory known as priming generally holds up well as we age. This makes scnsc
Studies of elderly people have revealed that aging produces large
in light of everything J have just said, because the implicit memory
decreases in precisely lhe same type of dopamine receptor. This sug-
tests that researchers use to assess priming do not require people lO
292
Scarcil illg for Memo,>,
S t o r i e s of E l d e rs
remember source information or to engage in strategic retrieval; instead, people are encouraged [0 say the fIrst thing that pops into their
llIind�. Many experimems have examined how aging affects priming, using tests ranging from completion of fragmented words to making decisions about quickly flashed pictures of objects. The general out come is that older adults show either as much priming
a.�
young peo
ple or a little bil less,ZIoI In a recent PET scanning study, our research group invcstigated brain regions associated with printing in older adults. After studying a list of common words, slich as
table or gardeu,
elderly adults saw three-letter word beginnings, such as tab- and
gar-. and were asked to say the fIrst word that C;lIl1C to mind. With young people, priming on this stem-complerion test is associated with blood flow decreases in the occipital lobes, which I earlicr linked with the perceptual representation system (PRS) th:lt plays an important role in various priming effects. Our older participants showed the same amount of priming as our younger participants. and also showed asso� ciated blood Aow decreases in the occipital lobes (perhaps reAecting that thc PRS had to do less work to recognize cues that had already been primed). The PRS seems to hold up well with aging. v The news on procedural memory-the system that allows us to acquire various kinds of skills�is more mixed. Comr.lry to the cliche that we c:m't teach an old dog ncw tricks. some studies of procedural learning show that older adults can develop new skills with
� rani.c�.
They arc even capable of acquiring some complex new Ilnphclt knowledge. For example, Darlene Howard and her associates had old and young people carry out a task I mentioned earlier (chapter
6).in
which they push a button as quickly as they can whenever an asterlsk
�
appears in aile of several locatiolls on a computer screen. Unkn wn to the subjens, the asterisks sometimes appcar. aile after another, \11 a rccurring panern. When such a sequential pattern is present, both old and young peoplc respond more quickly to the asterisk prompts (han when no pattcrn is present. Yet older adults have more difficulty (han young people predicting where :1Tl asterisk will appear next; they have acquired implicit but not explkit knowledge of (he sequence.'" Other studies have shown, however, that older adults arc nOt as adept as young people at acquiring motor skilJs, learning how to read . upside-down words, or developing the cogllitivc skill involved 111 solv ing a puzz.le efficiently. Part of the problem may be that older adults . are generally slower than young peoplc, and so take longer to acqll1re new skIlls. Pan may also reside in the f.1.ct that some procedural Illem� ory tasks draw heavily on lhe frontal lobes. For instance, in a problem-
293
solving task known as the Tower of Hanoi puzzle, people are faced with learning how to move a set of rings from one of three pegs to another peg according to specific rules. With practice, people become progressively more efficient at moving the rings using the minimum possible number of steps. Some amnesic patients can learn a simple version of this task as well as age-matched controls. But older adults require more trials than young people to solve the puzzle in the min imum number of moves-probably because learning to solve the puz zle depends on some of the effonful, srrategic processes that are subserved by the frontal lobes. JUSt as older adult� have a hard time recalling all the different parts of an episode, they may also have prob lems assembling all the different components of a cognitive skill. The neuropsychologist Anhur Shimamura suggests that these difficulties arise because the frontal lobes serve to inhibit thoughts and associa tions that are irrelevant to carrying out the task at hand. We have already seen that too much inhibition may lead to amnesia (chapter 8), but too little inhibition is also a problem. Patients with fromal lobe damage, and perhaps some elderly adults, arc plagued by extrnneous thoughts and associations that distract them during demanding tasks like acqUiring a complex new skill or recalling multiple aspccts of a past cpisode."l9 Rccent research has idenrifled another, previously unsuspccted, manifestation of the 6ct that older people often have difficulty recalJ ing all the pieces of an episode: aging reduces the incidence of flash bulb memories. As pan of a study I considered earlier on flashbulb memories of Marb'3rct Thatcher's resignation, Martin Conway and collaborators asked elderly British adults how they learned about rhe news. When testcd severnl days after the resignation, the elderly had 110
problems describing where they were and providing other salient
details. When tested a year later, however, the recollections of only 42 percem of elderly participants Illel thc criterion for Aashbulb memo ries, whereas 90 percent of young people's recollcnions met the cri terion. The relative absence of flashbulb memories i n the elderly fits well with other evidence on age-related deficits in remembering sourcc information, because a flashbulb memory, by definition, includes details about its source. These results also suggest that 3S we age, we may be less likely to form and retain vivid memories of emotionally arousing events. Remarkably, next to nothing is known about encod ing and retrieval of emotional memories in elderly adults. Older adults, like younger people, do remember more from the emotionally
Se(lrcllillj! for j\1e m (/ry
S e o r i e s of E l ders
arollsing parts of a story than from the mundane parts. fiut this may
memory paintings became a powerful means of exploring her past
294
295
be due to the fact that the arousing parts of a story induce older adult..
experiences and understanding how they relate to her present life: " r
to cafry out effcctiw semantic elaborations, because studies have also
found that while I loved much of the abstract art r was really nlost
shown that the vividness of a memory
1ll
older people is not as closely
related to emotional arousal as it is in young people,JO
satisfied when I created something related to Illy past life and per sonal experiences and relationships. Art to me is a sort of therapy, a
These studies confirm my earlier suggestion that as we age, the
VIsual reminiscence." She adds that "[a]s olle ages, one becomes more
richness of OUf memories for what happened last week or last month
preoccupied with who one is than what one does. YOIl wish to recap
declines. We "remember" [ewer details of recent expenences and rely
ture those people, events and places that helped to define you as a
more on general feel11lgs of f.·l!lliliariry. This rnay be one reason why
unique person.".l2 She illustrates this process in her painting "Grand
older adults often prefer to focus on events from the distant past. Tr3cy
children # I " (figure 10.2).
Old Fril'llds,
which presents a pOignant portrait of life
Pittman is one of many elderly adults who have embraced art late
in a nursmg home for the aged, describes the day-to-day activities of
in life and used it as a tool to excavate and understand their memo
Kidder's book
a 111:111 in his nineties, Lou, who relates memories of his distant past to
ries. Indeed, the genre known as "memory pamting"-depicting in
his roommate,Joe, or to anyone dse who will listen. Yet Lou's mem
paint personal recollections of one's past-is dominated by older
ones of ongoing events and the tasks of daily life arc spotty. He does
adults who often lack formal artistic training, but who, like Pittman,
not recall the narlles and functions of his many medicines, and he typ
have a need to recapture their personal pasts. Bluma Punnell, a mem
ICally forgets e:lrlier occasions on which he had reminisced about a
ory painter in he.r nineties, commented: "Nine years ago, when I
particular incident, which lejds to numerous retelling. of the same
turned 83, I decided to become a paInter. Detailed scenes were pro
stories. It is perhjps fining that the fragility of his memory for recent
jecting themselves in my mind, windows of the past, waiting to be
events, which leads him to tell the same stories over and over, adds to
opened."ll Other elderly adults have created memory sculptures,
the power of his tales about the distant past: "Heard only twice, Lou's
quilts, and baskets in order to represent and recapture their reminis
memories could seem monotonOlls. I-Icard mallY times, they were like
cences.
Lou's memories contained
These artistic explorations exemplify the increasmg focus on the
such a density oflife that ill their presence death seemed impossible."}l
past that often accompanies agmg. Upon entering the later decades of
old friends. They were comforting. . .
life, many people feel compelled lO draw upon autobiographical mernories more often and intensely than they had in earher days. Yet REVIEWING A LIFE I n t e n s i fy i n g M e m o r y 's P o w e r R.osemary Pittrnan was born in 1 9 1 6 o n a f.'lflll i n rural Illinois. She received a degree in nursing and went on to hold high-level positiom 111 public health as well as a teaching position at the University of Washington III Seattle. Pittman occasionally dabbled in painting throughout her adult ljfc, but did not pursue it seriously until after her retirement in \ 98 1 . She then began to feel a pressing need to conjure up, make sense of, and reexperience her past. Pittman found that she could do so most effectively by painting her recollections of the distant episodes :Illd events that meant the most to her: childhood days on the farm, without electricity or running water; the one-room schoolhouse she attended; and cherished family moments from dif ferent times ill her life. She developed rapidly as an artist, and her
most Western societies have devalued reminiscing by the use of pejo rative phrases such as "living in the past" and by the characterization of rennnisccllce as an age-rcbted pathology. Professionals workmg with the elderly were traditionally taught to discourage reminiscence. "It was even said that 'rernembrance of things past' could cause or deepen depression among our residents," reflected Rose DobroC a social worker who worked with the institutionalized elderly during the 1 960s, ;;and God forgive us, we were to divert the old from their reminiscing through activities like bingo and :trts and crafts."l< Though this deeply held attitude nuy still be prevalent m our soci ety, resejrch conducted over the past sever:il decades has shown that it represents a misguided vicw of aging Inemory. The initial seeds of change were sown during the 19605, as gerontologists Increasingly began to recognize the potential value of reminiscence in old age. H. ..ather than denigrating the elderly adult's preoccupation with the
Stories of Elders FIGURE 1 0 . 2
297
past, researchers began to conceptualize it as part of a life review-a reminiscence-based process of coming to terms with one's life that can aid understanding and integration of the self, and perhaps enhance preparation for death. The potential usefulness of life review was sug gested by research findings Indicating that older adults who tend to reminisce are less likely to exhibit depression and mon: likely to show signs of mental health than those who do not. This optimistic result was nOl, however, universally obtained. Recent evidence indicates that the adaptive benefit of reminiscing depends on the exact type of rem iniscence in which an elder engages. For instance, reminiscences that either glorify the past or reflect persisting guilt over distant event.. are not associated with successful aging, whereas reminisccnces that foclts on previous plans and goals, or on reconciling pJst and present, are.J� Based on the swelling enthusiasm for the potential value of life review, and the findings that linked rermniscence with mental health
Rosemary Pittman, "Grandchildren #1," 1991. 1 2 board. MIA GalJery, Seattle.
x
23�". Acrylic on
In each of the eighteen squares, Pittman paints a memory of an episode involving one of her grandchildren when they were young: an encollnter with Santa Claus, a visit to the zoo. a walk in the s troller, and so forth. She has
in the elderly, a new wave of ;;reminiscence therapies" have emerged that attempt to enhance psychological functioning by promoting life review
III
older adults. Relatively few controlled studies have assessed
the effectiveness of such therapies, so it is important not to get swept away by an uncritical acceptance of the idea tilJt reminiscing is a kind
Illa.na.ged to gather LIp different moments in time that arc important to her
of mnemonic panacea for the elderly. But the widespread usage of
and to join th em together in space to create a tapestry of memory. The paint�
rcminiscem:e as a therapeutic tool constitutes a recognition of 11'lel11-
iog is both an expression of her need to revisit her past and an aid to review� ing it further.
ory's power in old age, and testifies to the fact that older adult.� are no longer encouraged to avoid or abandon their pasts. Which aspects of their personal past.� do elderly adult.. remember when they engage in life review? One way that researchers have addressed this question is by using the Crovitz autobiographical cue ing procedure I have described. Older adults are given familiar words
such as flag or
filii,
and then asked to provide a memory of a specific
event from anytime in their lives. As you may remember from chap ter
3, the typical finding with younger adults is that most memories
come from the recent past, and progressively fewer come frolll the more distant past. Older adults, too, remember fewer and fewer per sonal experiences from the more and more distant past, with one curi ous exception: the gradual decline in memories over time shows a temporary reversal arollnd late adolescence and early adulthood. The elderly recall more experiences from these years than from those immediately following, but then the curve! resumes its gradual decline into the years of childhood. The same sort of outcome occurs when older adults are given a dif ferent recall task. Try CO remember three experiences [rom your life
S e l f f ( h ; II.� for M e m o ry
S t o r i e s of E l d ers
(hat were so compcl.ling and so personally significant that you feel
with old army buddies yielded little above and beyond what he was
298
299
even today that you have a vivid and detailed memory of the eventS.
able to provide on his own-a sharp contrast to the.: common obser
When in your life did these three experiences occur? When elderly
vation that retrieval cues aid explicit memory. A subset of Howard's
adults were asked to perform this task, they provided more vivid
most salient wartime experiences had been extensively rehearsed and
memories from the years of adolescence and early adulthood than
elaborated almost from the moment of their occurrence, a process that
frolll any other tillle period.
continued over subsequent years and decades. Other experiences that
The enhanced memorability of experiences from late adolescence
were not talked about dropped out of the picturc .M .
and early adulthood is an exceprion to the rule that memories
I have already considered the idea that extensively rehearsed and
become gradually less accessible with the passage of time. Researchers
elaborated memories come to form the core of our life stories-nar
have given it a special !lame-the reminiscence bump-in order to
ratives of self that hdp us define and understand our identity and our
hjghlight that this blip in the forgetting curve feRects an increased
place in the world. The experie.:nces of late adolesct'llce and early
tendency to reminisce about experiences that occurred during a rcstriw.:d tilllt: sp:m.lI> Thc t:xistence of the bump appears to be wide
adulthood-going to high school or college, beginning a job or career, entering mto marriagc..'-Illay provide the core.: of the emcrg
spread among the elderly, as realized by Littlejohn McCain in Howard
ing adult life story that we carry around with us, largely unchanged,
Owen's novel: "It's funny how, looking back at it, tht:re's whole big
for the remainder of our adult lives. For Howard Hoffinan and others
chunks of my life that I don't remember too much about. Just work,
of his generation. the experiences of World War II 110 doubt played a
eat and sleep. And there's places where something se.:e.:med likt: it was
central role in their emerging adult identities and personal myths.
happening all the time. My fifteenth and sixteenth years was like tha(."l�
We can understand more fully the power that these highly accessi ble life stories may wield in the psychological landscape of the elderly
There is no single. agreed-upon explanation of why the reminis
by considermg them in relation to the problems that olde.:r people.:
cence bUlllp occurs. I believe, however, that its nature and existence
have remembering recent experiences. I have suggested that these dif
may provide clues concerning the power of the distant past in the lives
ficulties arise. at least in part. because older adults do not recall in uni
of many elderly adults. To understand what the reminiscence bump
son all of the sights, sounds, and meanings of ongoing episodes as
may be telling us abom memory and aging, we need to know more
effectively as they once did. Our the narratives of self that wcre estab
about what is fCmembered from the years of late adolescence and
lished in the distant past have been told and retold many times, mak
early adulthood. The oral historian Alice Hoffman and her husband,
ing it easy for the oldet adults to recall together all the components of
the experimental psychologist Howard Hoffman, have performed all
an episode. Recollecting a familiar life story probably docs not require
unusual collaborative study that provides a unique window on this
(he kinds of contributions /Tom fromal and medial temporal brain sys
issue. Howard, born in 1925, was drafted at age eighteen to serve as a
tems that are crucial to creating and accessing memories for recent
soldier in World War J I. Over thirty years after the war's conclusion,
experiences.
Alice began probing Howard's memories for his wartime experiences
This conception of memory's fragile power in old age may shed
in a serit:s of intt:rviews separated by intervals of se.:veral years. The
some light on a cognitive fu nction that older adults appear (Q perform
Hoffillans were able to recover a company log that recorded much of
more effectively than younger adult.�: telling stories. YOLI may remem
what actually happened during the period, as wdl as other oflicial
ber a f.1Vorite grandparent. aunt, or uncle whose stories of their per
docull1enL� and photographs that provided an external check on
sonal past WCfC so spdlbinding that you fdt as though yOli could sit
Howard's recollections.
and listen to them for hours. I can remember relishing the tales told
For the most part, tbe experiences Howard remembered wcre
by my grandfather Benjamin Fl:lI1zig. a Jewish immigram from Rus
recalled accurately and consistently. When asked about the same events
sia who landed in New York City during Ihe early years of the twen
on different occasions, separated by as much as four years, Howard
tieth century. He was a large, strapping man who loved nothing bener
remembered them in pretty much the same way. Attempts to cue
than captivating his grandchildren with stories of his travels as a young
Howard's memory via photographs, documcnts, and conversations
man, when he experienced adventures of all manner in far-off places
S e a rclri llg Jor i H e m o T ),
S r o r i e s of E l d e r s
thal he described in colorful detaii. We knew him a s Grandpa Ben, and
in American and other contemporary Western societies, where nega
300
some of his stories verged 011 the unbelievable. In one of them, he was kidnapped
from a train in Pennsylvania and forced to labor in a mOllntain camp lImil he managed to escape. In another, he worked as a cowboy on a ranch in Wyoming. But even when Grandpa Ben told much more mundane tales of selling hatS in " low:'ly" or going to bascbaU games in "Cincinattuh," his melll ories callle alive with a sparkling quality that was irresistible. The sto ries that my parentS told of theiT own pasts never quite reached the magical level that Grandpa Ikn seemed to achieve so effortlessly. Recent research has conflnned what anyone who had listened carefully
to my Grandpa Ben would have predined. When older and younger adults were asked to tell some personal stories from anytime in their pasts, raters who read the narratives judged (he elderly's sto ries to be of higher quality-more engaging and dramatic-chan those of the young. [ n another similar study, the elderly cold morc complexly organized stories than did the young. When old and young adults had to retell an unt:'l.Iniliar story chat they had just heard for the first time, however, elderly adults recalled less of the story, told it less cohesively, and made more errors in retelling it than did the young. As long as they C:1I1 tell the t:1miliar stories that they have told many times before, older adults seem to do a better job of it But when they are required
than younger adults.
to rell a new story, the quality of the
retelling is undermined by the sorts of explicit memory problems that I outlined earlier in the chapter.)\I
more prominent
in many tribal societies with richly developed oral are seen as manifestations of wisdom that command special respect .fO The history of Native North Americans provides a harsh contrast
traditions, where the stories and knowledge of the elderly .
between these nvo perspectives. Elders in Native American tribes werc traditionally viewed
with deference as sourc(:s of cultural mem ories that provide essential guidelines for Ilumerous aspects of tribal life. These imergenerational memories frequently take the form o[ creation stories that are passed down from generation to generation by tribal elders, containing vital lessons about the origin of the tribe, how co behave toward others. hunt, prepare food, relate to ammals, treat the enVironment, and so forth. One such creation story told by a Seneca elder is referred co as "the remembering." People who take to heart the lessons of the remembering prosper and lead happy lives, but those arrogant enough to ignore the stories of their elders arc ulti mately doomed to repeating the mistakes of the past. "The remem bering could not serve those
whose self-imponance had blocked the Knowing Systems of the Anc estors who had created the memories," according to the elderly storyteller. "For those still living in harmony, a new understanding had been added
to the memories." N. Scott Momaday, a Native American and one of the world's preeminent writers, reflected on his own encounters with a storytelling tribal cider: "It did not seem possible that so mallY years-a century of ycars----could be so compacted and disrilled. An old whimsy, a delight in language and in remembrance, shone in her one good eye. She con being."'!
B r i d g i n g Generational Time
Tragically, the imposition of Western culture and religion that
The srorytelling abilities of elderly adults have important social and cultural implications. [n many societies, the primary function of elderly adults is to P:ISS on significant personal and cultural lore to younger members of the group-to tell stories about their own expe riences and about the tr.lditiollS and momentous events of the society. l3ecallse many of tile :nuobiogr:,phical memories of the elderly and
from the remote past, older
adults can draw freely on these highly elaborated and structured melllories. They can use their storytelling abilities to the fullt,st, unim peded by difficulties
tive stereotypes of aging are unfortunately all too cOlllmon. I t is far
jured lip the past, imagining perfectly the long continuity of her
A G I N G S T O RY T E L L E R S
the collective memories of society derive
301
that arise when they attempt to remember recent events. This storytelling function of old people is not fully appreciated
destroyed so much of Native life
had a devastating effect on the
respect accorded, and role played by, traditional modt:s of remember ing that centered on the stories
of elders. "With this replacing oflong
held tribal reJjgious values," COlllments a prOininent Native scholar, "the Indians lost the basis of their old ways of life 3nd,just as impor tandy, their old ways of remembering. . . . Protestant and Mormon missionaries still appear to be working overtime to eradicate native tribal religions, by seeking to subven the long-honored wisdom of medicine-makers and elders of tribes."·l The Canadian
artist Carl Beam, a member of the Ojibwa tribe, has
created powerful artworks that explore the loss of memory and
Search i"g fo r Memory
302
FIGURE 1 0 . 3
decline of the storytelling elder in Native life. DC:Ull has struggled for years to integrate his Native heritage with his experiences as a member of modern Western society, as refleered in " Remembering is sometimes quite difficuh to do. . ." (figure Days" (figure
10.3) and " School 10.4).·) Beam seeks to redress cultural amnesia by
reminding Nativ('s and nOll-
atives alike that it is centrally impor
tant to integrate personal and collcctive pasts with the concerns of the present. The decline of the aging storyteller in Native life led to a break in the chain of iJltergencrational memory that Iud disastrous consequences for many. Th('sc considerations highlight that a crucial task for elderly adults is to imegratt" the past with the present. In the arena of social and cultural memory. the experi{'ncc and knowledge of the elder can serve as a guide to the future for sllcceeding gener ations; in the arena of personal lnemory, the elderly adult's life review provides an opportun ity to reflect on the past in the context of the present. This integrative role is nowhere illustrated more poignantly than by the struggles of aging survivors ofche Holocaust. As they approach the conclusion of their lives, many elderly survivors have not successfully i ntegrated the traumas of the Holocaust into a more encompassing life story. The psyr.:hotherapist Yael Danidi has wrinen eloquently abollt the "conspiracy of silence" that made it difficult for survivors to imc grate their Holocaust experiences with the rest of their lives. Unable to mourn their losses and to fed that others understood their experi ences, the survivors' ll1emories of the Holocaust remained cut off from other knowledge and recollections." The process of life review that is important for llIany elders thus
-
becomes utterly urgent for aging Holocaust surviVors. Placmg these experiences in proper perspective is essential, Danieli reflects, if sur vivors are to understand that their feelings of helplessness do not mean that they are helpless people. or that their memories of evil events do nor necessarily mean that the world is cvil. lntegrating trau matic experiences into a broader lif!.! story is also necessary to ensure that the intcrgenerational chain of lnemory is not broken .4S As the
realization bas dawned that only limited time remains for
the last generation of eyewitnesses to the Holocaust, :lttempts to pre serve their legacies through mcmorials and videotapes have become more widespread. Danieli highlights that a central preoccupation of aging survivors focuses on the intergenerational extension ofremell1bering: "For the survivor, essenlial components of the aging person s '
preoccupation with 'Who loves Ille?' 'Who cares if I live' . . . are the
Carl Beanl, "Remembering is sometimes quite difiicult to do
.
.
.
"
•
1992. 14 x 10". Mixed media on plcxiglass. Courtesy of the artist. l3e:ull pri 1tS (he (itle of (he piece below a degraded photographic image of an � . ;ulIcdduvlan tribal ritual-thc kind of intergencrational memory [h:l.t is now
bardy knowll to llI:1.ny younger Ojibwa. A prtstine image of a feather servt.'s as a reminder of the tribal memories that an' lost to the prt"Scm gcner:ttion.
S t o r i e s of E l d e r s FIGURE 1 0 . 4
305
devast;ning questions 'Who will remember me?' 'Will rhe memory of my people and of rhe Holocaust perish?' ,,«, The need to pn:st'rve memories across intergenerational time, though accentuated in aging Holocaust survivors, is a fundamental human imperative. Remember Proust and Magnani: their unrelenting obscssions with the past emerged in part from a deep desire to impart
•
their recollections of Combray and !lomito to a brger network of rememberers who could keep these mcmories alive in the future. As the psychologist Merlin Donald has argued persuasively, a crucial step in the evolution of modern culture involves its increasing reliance on "e:-aernal symbolic slorage" for conserving and transmitting memo ries across gencrations.'7 Beginning with the development of the ear liest writing systems, and progressing more rapidly with the invention of the priming press, modern societies have relied increasingly on print and electronic media to preserve memory. It is no coincidence that the mnemonic systems I discllssed in chapter 2-once essential strands in the f.lbric of society-largely disappeared after printed stor age media became available on a widespread basis. As reliance on external storage devices has increased, the transmis sion of socially significant knowledge and events has relied less and less on the autobiograpillcal recollections of elders. This may have contributed to what has been termed a ;'crisi5 of memory."-<3 Begin ning in the nineteenth century and exacerbated dramatically by the reccnt asccndance of electronic media, the crisis of memory involves a progressive sense of disconnection from the past and tradition:�1 forms of remembering. Society'S most important memories now reside in the electronic archives of the mass media, lIOt in the heads of individual remcmberers and storytellers. With such immense amount's of information electronically coded and readily available, the memory-preserving role of elders Wilh stories to tell and knowledge •
Carl Beam, "School Days," 1991. 60
x
Courtesy of the artist.
•
42". Mixed media on paper.
to impart has been diminished considerably. It need not be that way, however.lnrensified efforts to seek and video tape lhe oral histOries of Holocaust survivors bring the personal recol k'ctions of the elderly into direct contact with comemporary external Stol":lge technology. The autobiographical stories of these elders can per
faded photograph of N;!.tive chil
haps achieve, through electronic recording, the kind of immortality once
dren in front of a school that resembk-s one he attended, relates a bitter relll
conferred by more traditional means of ol":ll transmission. And preserv ing testimonies from thousands of remernberers can help to ensure that
Be;!'Ill's own handwriting, scrawled above.':
;!.
iniscence of when his te.':achers commanded him to worship a new God and forget the s tOries of past generations passed on by his elders. Instead, he \vas encouraged to become a young patriot and to embrace modern technology
and \varfare, as alluded to by the imagcs of tanks and trains at the bottom of the piece.
forgetting and distortion-which can infiltrate any individual remelll berer's story-arc counteracted by the overwhelming truths that emerge fi-om core elements that are shared by numerous remembcrers.
306
S e a r(liillg fo r klemory
Elderly adults are also inrim3cciy involved with anmher form of external memory storage: f.unily photographs. Photos serve as cues to autobiographical recollecrions for just about evcryone---an insight not lost on film and camer:1 merchants, who run a virtuai mcmory indus try Um older people tend [Q value family photos as their single most cherished possession, whereas younger people rank them as less imponanr. Older people typically say that they cherish photos pri marily because of their memory-cueing functions: photos allow the elderly to make contact with, and even relive, parts of their personal pasts. My colleagues and I havc recently carried out experimcms in which we have found that looking at photos enhances recollective experience in elderly adults.·" Phocographs of events and people from rhe past make it easier for older adults co assume their time-honored role as storytellers. It is perhaps fitting that the external mcdia in which we pass on our personal memories-including f.1mily photos, portraits, and other heirlooms-are in some ways duracterized by the fragile power that J have focllsed on as such an essential feature of human memories. These physical traces of the past Illay fade, decay, and even change over time, but they nonetheless exude a compelling emotional aura. Ben Freeman has managed to convey this realization with uncommon elo quence and force. Once an abstract paimer, Freeman found himself increasingly drawn to the old photos and f:1mily heirlooms that he collected during excursions [Q amique shops and Rea markets. He . became f1scinated by what he calls "the chemistry between time and our attempts to resist its passage by immortalizing events or moments in enshrilll'ments of objects, images, and conc/;.'pts." Though faded and tarnished, the images and objects he encountered spoke with undeni able force about the people whose liV('s they were once part of and now conunemorate. For Freeman, these ex"ternalized memories are " a crying out to the furure to say that we did exist and that we were important." I-Ie describes them in a way that also fits the traces of the past that exist inside our heads. " As these enshrinements become veiled by time," Freeman observes, "they lose their clarity, definition and meaning but retain a visceral presence which carries the energy and culture of the moment ill which they were created."» Captivated by the physical traces of our lives that we leave behind in treasured objects, Freeman abandoned his abstract canvases and started to COlISlruct large-scale paintings that incorporate old photos, family heirlooms, and yellowing maps. They arc visually stunning and emotionally resonant works that speak to many of the themes I have
FIGURE 1 0 . 5
.
Ben Freeman, "Commitment," 1992 . 66
x
72". Mixed media. Darbara
Krakow Gallery, Boston. The centerpiece of this work is a nineteellth-ccmury family photograph shown both in its ull:ld r ed form and also blown up, palmed oVt"r, and vciled ? Fragmt:l1tS of rhe fal1l11 s past surro und these two images: small photo � s of unknown people. pOSSibly rdatiw a s; piclUre of the f:1mily residence; a bleached lIlap . of Bmtoll, where they liwd; a page torn from a farmer's allll�nac; and a stam cd postcard with a barely decipherable message written � on It. Thes aged objects managc to convey a feeling for the richness of � a past whose particulars rt'main hiddcn from us.
:l
�
308
Scaull illg JOT M e m o , ),
plified by his haunting pamting considered in tlus book, as exem "Comminnent" (figure 1 0.3). lpt to presenl(' (he past, the frag Like the objects in which we ancll a general sense of who we arc ile power of memory provicil:s us with gh it hides many of the specific and where we have been, even thou be profoundly moved by expe il1cidcl1t� chac helped shape us.We may ly, or by illusory memories of riences that we remember inaccurate . Our thoughts and actions are events we only feared or imagined incidents that we do not recollect sometimes influenced implicitly by des in our lives have vanished at all. And many of the specific episo ce. however, our memory sys from our memories forever. On balan rving the general contours of telliS do a remarkably good job of prese many of the important things that our pasts and of recording correctly have evolved as a species other have happened to us. We could not brain's attempt to 1lIake sense of wise. Memory is a central part of the s abollt it. These tales are aU we experience, and to tell coherent storie nt determinants of how we view have of our pasts, and so they are pote s are built from many differ ourselves and what we do. Yet our storie lly happened, thoughts abom ent ingredients: snippets of what actua fs that guide us as we :ltternpt to wh:lC might have happened, and belie fragile but powerful products of remember. Our memories arc the aboU( the present, and lI11agme what we recall from [he past, believe
NOTES
I N T RO D U C T I O N M e m o r y ' s F r a g i l e Power 1 . Quotes :m:- from Mirqu�z (1970), pp. 50, 53. (1989), p. 2.
2. Bellow
3. For n"Oluti�n:l.rY pcrs�cllves on memory. �u
Don"ld (1991). Ro:l.Iu (1976) and perspective need not 1Il1pl): t1lJt · · �u(;h as � ,d abl·'l1les . , analy�' of ,-'" memory mu�t be perfect or o)ltim:;ll. EvolulIon:;lrv . . , \ ., � )by �' CosnudC"S. 1995) and language (Plt1ker & Bloom, 1992). adm'0wl·. lIlOn rr c dge : . . . ImperfeCllOIIS III these p�.esses, �,et at t ,Ie �me 11mI.' elllph�sl1.e the extr.lordinarv �comph�hmcn� of the cognitil'e �dapt�tiOiIli that allow U5 to sec and communicate: ' he psychologl�ts Jefferson SII li:,'er :;Ind Peter S:;Ilovey ....'('re astQn;sh..d when they o!x...n....d thIS n:marhbl)' polClll mfluence ofthe P:lSt on presellt emOl1OIlS through the agency of menory. "How could [ll'e:;l1J oft a given memory Ita\'(' the affecm.... pov.Tr � to md�cc phyYological ll'Spouscs of such magnitude th:;lt subJccts could Ix- mm.....d to Sherry and Schaefer (1987). Adopting an c\"olution:;lry
"bout the future. ..
_
tean, giggles. or trelllblmg f..a r , .
gr.lll1ed, we
5. Stadler
were
5tunned by
(1 ?90), p. 144.
. ?"' they :lSk. " F:;Ir from t"king [he phenomenon for
11:' S<e Singer �nd Salovey (1993) . p. 14.
6. The original SJ.t I ....lent of tile and (198::»� .
IIllphdt/explidt memory distinction W:l.S nude by Gr.lf Schaner St",:,eral other di�nncnons Ul the Jiter.ttUTt' are simiur to the l1nphclt/exphcit distinenoll - . . '-.lth mdudmg the contI":lS' I>etwcen d<"<"u r .... and nondedar.anve memory (Squire 1992, . ....hn & l� ork . 1 m) . 199,') and dlll:ct and mdm.""Ct testS of memory (ItJeru.rr!son_ KIa, I . . Much ofthe contemponry mlerest 111 muluple memory S)'Sll'UIli derive� from the . . d Stmcllo ll between eplSOdie and sc:nulltie memory adv:;Inced by Tul\'mg (19T') l \� \ U :lS from other sellllllaJ dJSl1l1coons put fOTW;lrd durmg the 1970s (Hir;h 197: o Kccfe & NadeL 1978). For1n 0\....1V1ev.' ofll'SCarrh 011 memory systelllli, sec the col� lect ofchapten edltccl by Sehaete,. �nd Tulving (1994). . en dl�USSlllg mull1pl.. forms of memory. It IS e:rsy tQ become confused by the dlfferenttCTIlB thaI an: used by VUIOUS ��rcher1. In thiS book. I usc the terms ImpIifli _
�
309
Notes
Notes
310
<e manner. !O refer 10 dIfferent W;I),S in which mallory :l.IId txplicll mallcry In :;p, dcscripth such retrieved lmd cxpr�d. In COntrast, I use thc dTccu> of pnor experience un � rlQ/Hm lYI rtp",sn l*",J l"'rre , memory ml pfoccl/u , memory memory, l('molll;( i terms as rpsMir S)'$lcrns that an: involved Ltl Ittl!, :lIld l4..,rkitW memory 10 refer 10 underlymg buill olh. Imphcit relru:\':I.1. explicit retricv.r.l. or b my u, willch [ h3\1: developed JOintly with 7. My collecuon of mcmory-n:bted artwor New the at g o atal c ion exhIbit for a show and \Vir.., Susan McGlynn, for med the blsis ry." ..d "Fr:lglle Power: Exp\or.l.!lons of Memo h lun Art!> Center III October 1993. ellti t "The Mcnlccd A-SSlssm"' e's Magrm for fxcept book. thiS ill ced All urworks reprodu i dISCUssed dcvdopmcm of thi!; collection s (figure 2.2), are part of our colh:cuon. The . tL\'l: c pe s er p �l c by White (1993) from a sociologi
311
13. The experiment concerlllng the effects of brrcfiy Rashed words IS described by RaJa r:t i reponed l � (1 993) and the study on dlvtded all('nllOIl and JJl(,lIIory for facC$ s m, Gardiner. and Rosser (in P""!IS). Previous siudics by G�rdlller and collraglTcs by PJrk showed Ihat dlVldmg attention when experrlllenol particIpants srudy � ItS! of words n-duco the hkcllhood of 1.1Ier "remembermg" th,..1 rhe words were pn:selll('d, but
has
lnti(' effee! 011 "kIlO\ving"thal the words were pn:semed. Cammer has also $hown that eXlell)lVe anal)'Sls of words
d uring dl(' study ph�sc of an
experrlllelll cnh.lnc("S mbsc
qUt'lII "remember"' reipon5es but d0t':5 not incll'asc "know" responses. GardJller�
experrmenTS are sUIlUlurrud m Gardiner and jaVOl ( 1 993).
0" Ihe basis of numerous findin� showing [hal ('xpcnmrlll,,1 IIumpuJauons affeci
"rcmcmbe�" and "know" rt':ipOTl5t'S {htTerently. Gardmer and colleagues h;l\"e Jrb'tled
differences belween Ihe two forms of rccollect,,·(, experi"lIce. In COtl(in press) h:H rt'cemly come"ded that diff"ll'llcCS bctwCCII remClIl bermS and kll�'mg an' largely qummJtive. WIth "I"Cmember" simply mdicanng a slronger sensc of 6miliJTlty than "know." DOIu!dwn T:liscs wme imp orlam poiltls, bUI for qu�htJtlve
1r:tS�, OOIl)ldsoll
CHAPTER 1 P o i n t e d at T i m c " On RClll c m b e r i n g : " A Tele s c o p e Boston Guden. mcluding Will McOonoush'5 1 . The tioSl"" GI
2. Ddlow (1989). p. 53. i -depth analysis ofpsy 127, who providf'$ an n 3. The quote 15 from Tuh'ing (1983). p. the gre)t Hnvard psy ago. entury c a O\'er ry. memo ic episod chologiCal l"l""ICarch on [:>oint: "Memory Similar a e d ma Jamt:"S (1 890) chologist and philosopher William in Illy p;m. In dated be must [I pa51. the m acl f � of n'quires more than Illere dating its occurrence" (p. 650). Jlrnes cc:d e x�nen y l c t dll'l, I Ihll ink h t mUSI olher words, [ "warmth and intimacy" Ihat IdentifY them :H added that personal recollection!! ha\,<: a
a "properry" of Ihe self. logical and philosoplucal perspectives on -I. For a U5Cful historical discussion of ps)'cho
(in pn"'SS). subJecu\'e expcrlences of ,..,membcrmg, \.Ce Brewer
lIlierview on AUb'"l.lst 7, 1992. The quoled " I I Arum/ I I ViSIOns: I '}<)2" at the OeCor m�lerial is from the exlubltioll olalog for . s husett c s
5. Wallers dt�r('d her thoughts with me in
an
and Swanson ( 1 993). [t IS not entirely clelr 8. The experIment IS rqlOrted i n Robinson ces eT perspective. but not vke veru. influen why swtlching from the fidd to the Obsctv ) dIS 81-1ij2 1 PI" 99.}, 1 ( n SWlll50 �nd son subJecti\'l' t'lIlolional experr('nce, but Robm i ities. cuss several pOSSIbl
" and "knowing"' W�, imroduced 10 Ihe 1)5)' 9. The distiuCllon between "Telllembermg This dimncttOIl IS quite Sllmbr 10 thme 985). 1 ( g n chological literallire by Tulvi
made by Mandler (19&) , jacob)' �nd Dallas between Il'coUoxlion and fam..ili�riry IS dC"SCTlbed m Brewer ( 198R). More (1981) , and others. The "beeper" experiment evidence from J mote (ighd)' con ed provid 994) \ ( Y CoJt\v:l recently, Dewhursl Jnd illfoT that contirn15 the import.lllce of vt�uJI trolled senl'S ofbboratory ('xperiments . ection nlll10n m the experience of recoll point, see Kossiyn (199-1). 10. For a thorough documentation of thIs ed that Ihe more oflel1 college students I I . Johnson. Raye, Wang, alld Taylor (1979) show Iner claimed to remember ha\'lng S{'Cn they often re o m imagined seemg l picture, the nmTUcung people 10 ullagme chtldhood II. Hy1llan and Pelllbnd (111 press) found thll that 'o','Ould gener:tte a fals< memory of 3n event
eVents mcre:Hed the hkelihood th.1I they (in pA'SS) report dlllt imagLJ1ing an e\"nl never happened (see chapter -I). Garry et a1. ed expenence happened 10 them. n"\C"rr� coUege SItldents' confidence that Ihe ImagIn
12. The ankle ., by Block (1995).
II IS not delr that hIS an)IYS1S accounts for all obsef"'<:d ditTerences ix:t\\"en remember
and kllow responses. 14.
�hls experiI,Hem IS. tepom'd by Tuh'lIIg (1985). l'eople Illay be more hkely 10 repon . rellH!mb<"r cxpeTLenr,el when they reCJIl on their own (free ro:-call) than
ill response
to 1�1I1lS (cued t"f"eaU) h<"c�uS(' a cUt'd ""C)1l t.,.;t is m,,", likd), Ihan a free reall WSI 10
ehclI weak or fr.aglllo:-nt:lry
tun'S
that suppon " know" bUI 1I0t "remember'" experi_
ences.
IS. I'or s�LLdiCS of partial T\'call and the fedlng ofkilowing. s('(' UroWI1 ami M:ICNeil ( 1 966) :;111" SdJ.lr,ler and Wuding (1 985).
16. Early e\"ldence for Ihe etTeets ofcue falluitant)' on fedmg ofknowing W:H rcport('d
III
[ found that wh('n pt'ople f;lile{1 10 Il'eall a target word III !"O:-SPOIIS(, to ... prt'viQu ly :iS5ocimed <':lIe. they expressed � slronger feeling of knowing about the unrCGllled targct wl...n Ihe cue word scelll('d th e final expenlllent ofmy 1981 Ph.D. th('Sis res.earch.
�
luglll)' f...nultar Ihan when the cue seemed unfallubar. I never felt Ihal Ihe !"dults of
10 lIter it puhlicalion. htU �lLlxeqllem work. describ.,d in Me{c�[fe. Schw;lrtl. and Joaquim ( [ 993), Iteder �nd
that tinal Ph.D. th('Sts eXpeTltllent were {I ulle convlllClllg ('nough RUler (1992), and tlrt' collt'ctlon of readmgs
III
Metcalft' and Shimotmura (1 994), ha�
shown eI('arly that cue fotTl1llrnlry affects fcelmg of knowmg.
In
th(' experll1l(,llts of
Metcalf.:- and her colleab'ucs. p('ople were given cue words and Ihey tried 10 recall pre
vi ously associated target words. Se\'('T;l! nunutcs before tlus rt'e�ll k'St. tI,,:y wert' shown
half of the cue words whde perfoTllllng wh,..t was presented to them as otll Inodental
�
lIlrelated ruk. The key fmdlog was Ihal cue words Ihat had been expo-ed during th � mCldentl1 tJ.k produced �Ironger feding-of-knowlllg ('xpertell ces about uureealled
targetS thau did cut' words thaI had not been exposed durmg Ih(' inClden !.l1 usk. Yet the ILnrccalled urget mformatlon
"crt'
familiar thJn when they
was
w('re
not m fact any mOR" accessible "hen tll('
Clles
IIIlfJmiliar
17. S<>e jacoby, Kelley. and Dy\V'�n (1 <)89) for tire Id.:'", thJt rem�lIIber1llg lIwolve5 3l1nbu
�
ons.
�or related id.:-J'l. \.Ce Johnson, J l.uhtmudl. and Lindsay (1 993) and Ross (1989).
18, I roUSt s colleCllon of 1I00rds My
""Jdmg and 01.11
IS
oot kn�'11 in English
:H
Rfmflllm-iln« c1 Thill}!!
quotC$ all' based on D.J. Enngln'5 retellt rt'\'lston of l'Jrher
HUI,
tuns_
ialLOIiS by C. K. SCOtt MOllcTlef and then Terence Kllmlrtln. [n the EnTlghl tT:lnsl.1nOI1
(ProUSt. 1992), {he 5eri('S IS IIIled III &11((1, ojLou 'lime. [9. ThiS quote Jnd the foll(mlllg ones are from the IIIOSI recently ",vised tral15buon of SIIIIIIII � lilly (proUSt. 19')2. I'P. 6()...63).
20, ThIS POIIII IS lI11d(' doquently III Shatruck's (19R.}) superb analYSIS of the role pla}'('d by memory and t lllle
111
ProUSt's work.
2 1 . Th(' leiter 15 quoled in Ibid., p. 46.
Notes
312 22. Ibid.. pp. 46-47. n. Mab'11�ni's story IS told doquently
N o tes
. SacIts (1995), who � �. the: neu�logisl Ohver
kind t"nough to put me In touch wnh Magn�m .
24. Pearce (198M),p.
IS.
25. &lcks (1995). pp. 175-177.
26. Ibid.. p. 166.
27. SU!OllIl SchwOlrlzeilberg informed Ille III AuguSI ,995 th:.!1 pleled hili amblllou$ kilchen renov,1.Ilon.
b" I\I ;& ' I i had nearly lI ....
COI11-
28. Sacks (1995), p. 186. . and a/J ' ed ill the ble nineteenth cen29, The It"rms lr'n"!Ilmdr IIImWJIiI h'll�mrdr Ilnl'II'l"U'I were COUI . \lIry by the Frellch ph�kian Ch;lrlcs Aum. who described IlIel1l0ry loss m ;I WI:Il-knOWII c:& ofmuluple pcr!iOn:ililY. Se-e Hackmg (1995) for a re\Taling trealmenl o !AD m.
30o GR's osc IS d�ribed
111 dt"tail by Lucchdh, MUggia. ;lnd SplIlnler (199 :) . QuolCS 're 0 rom f p. 170 of thetr ;&rtldt'. ln :mother case- Ih;11 Ih ey d escribed, a lIlan lo'll much 0, h15 . o 0 ' jury alld tI pt"nonal past Oller f SUSI;lllng ll a ht'.ld in H �Il suddenly TCCo\Tred It ;& mom,I . . 'r hl f"('mmdtd bIn whel1 a miSI.lke: thaI he made dunng ) lenuts nutCh �f a Sll1Ilb , , s '0 . 1 ' " _I I llb sIIl nty 0, thelt Illlstake that he: had made ycan urleT •uce Ie I ct .... . a o noted the
�
�
c;ases 10 a c;&se of I1ll'mory reco\'ery aft"r .'motional trauma thlt Illy col1e gues �Ild I . reported some yelTS ab'O (Schacter et aI., 19M2). I Idl this story 1Jl chapter 8. Kapur (II . pms) sugges[S that psychologic;&1 facton plJycd a role in the atnn<::SIJ and recO\'Cry 0 . Gil.. and the other p;!tielll described by LuccheU I el aI. . i made forcefully by Sm�r and � memory Oil lf se of 31 . The dependellco: of the sense r.lph. The Rl'llmnMrtd Stlf (1993) : " Ahhough memory IS per SalO\"ey in their monog . ukUl" �lIapshots ofeach and e\'ery txpcrience Ih;!! we �ncounter, there al... ''' . ....tu;!lly ,.., � , , emerges a con:: of shdes to wh le ' h we return repeatedly. Thts dog-eart."d bunc I 0
�
es conlt�S to form the celllral conc�rns ?f our per� slightly obscured or distorted imag . mllality. . . . Although Ihese memories may COlluin but ;! kCrllel of their ortgltl31 Ir\llh
.
ms. false- recollecllons. d�'SCrJpIlOll$ provIded by othtn. . and multtple c:\'enlS blended into secnungly singular oc ur!:llces hese ehanctenStlcs
and be filled with etubelilshme
e
.�
III no .......y dinlJllIsh theIr power in org:lIllZlng WhO "T a� (pp. l_-:-13). . 32. Estes (1980) provides an ilIunlln�li ng discussion ofSl11ubntles and differences berv.«n human ;&nd computer memories.
.
.
�
'
ff e� nt per33. See Dennell (1991). pp. 21(}-214. �nd Penlme (1989). pp. 4� 7, for di . blogr.lphy of1urmg. e:
�
35' Denllell (I99I).p.431. l osopher John St'�rIt. wh0 cbU1l$ }6o Pl'fhaps the best knowll skepric of strong AI is phi 0 0 rui thu ;& computer s ;!bl y to m:l1npu )Ie �ym 1>0, n l ,.ng out rule-based :dgomhms S by Of. , (i t' cakulJuon procedulTS) nt'ed not Imply that tht compUler Ulldentamb the
sy11l� �I�' or �i III ;&ny sense consdously aware of them. In a rc�elll crmque of Dennett s i n,t N(W\�,rk Rellieul rf &oks (1991) book publIshed n
C"
�IOI15-
hc m�tery of CO'
. " ), Searle cOJ1lcllds that Dennctt dentes tht ness' Part II . NO\CI11 ,,· ,,.'· ::1 , pp. "...-v ber 16 , I ' o
h
, realiy � of t e human subjecti\·e e:
(I"
.
58), Dennett "keeps the vocOlbubry of C?llSClousness whllt
'0. 1etler \0 h denying Its t'xistenct'... In Ol sUlJM'quell! I e Nrlll }Wk RtIII(W (Dt'ct"mber 2 1 . 1995, p. 83) that lakes e:
�
COllSClollsness call •. I)C: 6ound
.... 0, • .• ... - -.. ific
;
�
tillle at whICh 11\(ormallon enten COIISCIOUS-
313
Iless ("FIrSt person pluul: PhIlosophical problem s ofconsciousness with chnical irnph cation.�:· New Tr:lUJIlalOlogy Conference, C\c)rw;l ter Beach. Florida January 1996). . Other philorophers such as Colm McGum al).,'ll c that it is difficult to imagine how or why mert."ly e(jlupplng a robol wllh ;lppropr iate softw:ore would or could produce consciou'i expenenct'. And the Oxford mathem alical ph�lclst Roger Penrose h:as con tended that the h�l1l1l�rk of computer 1I11elllge nec-fol1owmg rules and executing algorithms--doo not depend on or evcn mvolve COilSCIOUS aW;olTenc::M in ellher hutll,lll$ or computers. He suggests funhtr that human consciouSIlCS$ IS Imulvcd m "forming ne\\' judgments'· in sirua{ions in which old rules do not apply: "The judgt. ml'lIIjMIII;IIg that [ am cbinung � i til!.' h�lhnafk of comciousnes.s is iltlj\ome thing that i the AI people would have no conccpt how 10 prognlll 011 a com 'ut('r" (JlenlUse. 1'J�'J. l p. 412). Se� also McGinn (19<JO) and Searle (1 983). 37. It IS interesting to note that Carnegie-Mell on computer engmeer Hans Mor:wt'C. � noted proponelll of Slrong AI. concedcs that nonve:r bal. �ubjecli"e reaction� �re rele \'am to a Turmg tCSt and �cknowledges that they pl"Ob
C percepluai models of the \\urld cOJlIa.ining mylh_ iC;l1 aliusiOl15 �ud PlCturt."S and emotions. There IS much uOllverb�1 machinery in our heJds . A TC.l!ly in�lghtful Turingjudge would he probing for thl'"Sl: tlllllgo;. asking 'I-low do you fed about this: or 'Hell" i� a situatio n. how does i t strike:: youi' And I beli�\'c there is no more comp;&ct wa.y of encodmg that machinery than something analogous to the actu:d structures we: havt In our bnllls·· (ciled in Crevier. 1993. p.272) . 38. Edelman (1992). p. 238. In �Qrlf$' EnD••Anton io DanUSlo (1994) goes 0111.' StCp f\lr ther and linb conscious c:
CHAPTER 2 B u i l di n g M e m o r i e s : E n c o d i n g and R e t r ieving Ihe P r e s e n t a n d the P a s t I . Roediger (1980) reVIews .�plml ll1cta hon of mt'mory, :lIId ul11cbucr (1975) descnbes p the "�rbage call" allaIOb'Y' Korial Jnd Golcbmith (in p�) contrast Ihe storehome metaphor of memory to an al[em�tivc met.lph or Ihal emphaSI1.C5 how well remem bered "Vents ( corrnpond to the origin;&1 t'xperiences. 2. NI.'J5.Ser (1967), p. 285 . 3. Cecl. DeSimOll t'. ;<d Johnwn (1992) dcscnbt' the cue ofUubblcs I� and report l series of experiments concermltS hiS memory abtlmes. The Importance of thc "magic nunt bt'r" k'\'en WlIS descrlbt'd by MIllet (1956). 4. Research conctrmng ....urking memory has been pioneered by Uadddey (1986) and col leagues. Baddt'I")' fr,\ctionates workmg memory IIlto sc\'Cral IIJbsystellu: a central e:
d
7. This fm mg w:os fint reponed by Cr:uk and TulVlng (1975). Other e.uly experiments documenting the Imporlance ofdaborJt1ve encodin g included those by Stcm and Ur,m.s ford (197'J), which Tn..:aled Ihat cven suhtk dlff.·ren l'e5 III the eXaCt kllld of ebbor:otlon that pc:oplc: perform call luvt: a major ImplCt on .su�qu ent l1leI1lOry pt"rfOflllJIlCt.
N O les
314
N o tes
8. Sec G;urlillC'r and ),1\'01 (1 993) for dabonu\"(' cm::oding and expenencC"S of rememb.:r ing and knowing.
9. Sec Nickersoll and Adams (1 979). 10. This rend!tlon of the nory of SUlIollides i� based on Yatd (1966). who provides � defin.itiv� history of the': origins of IlIIlC"IIIQllles. 1 1 . Thc slOry of mllcmonia and the Middle': Ages il; beautifully !Old by Carruthers (1990). Scholarly dL�usslotU of ViSUal Lmagery mnemomcs and memory Llllpf'Q\"('ment Clll be found ll i UC"llelu 1 981 ) and Hown (1 972 . A popubr treUIllCnt of how to use mnemonics to enh�ncC" memory function hOlS been provided by Lonyne and Lucas ( 1974), among many others. Herrl11;lIIn. Raybetk and GUll11al1 ( 1993) foem �pt"cifi cally on improving memory performance in students. 12. For the backbsh aglinst mnemomcs.sce J. Spt·ncc (1 984), PI'· 4 and 12. i ussions of imagery, mmd. and br�LII. SCe': Kosslyn (1981. 1994). 13. For wide-r�lIgLllg d� ded by another CarnC"gie-Me]1on runner, DD. .. matched and eJ[c.. 1.1Icr were ts \4. SF's fea who w:as ablc to achLe':\"(, correct rec.&ll of 100 digits by using ebbontiYc encodmg � on his knowledj,,'<' of running times. For studies of SF a�d nntegu:s thaI wen: b,," DD. �ee Chase ami Ericsson (19R I). A mrding case of exceptional memory that d!f fers from SF and DD i nvolves a young man known as 1(�j�n, who wa� able to rcme11l t,cr Ihe fll),t j 1 . 8 I I digits of pi! As de>erilx'd in � thorough ana!y�is by Thompson, Cow,m. �lId Frieman (1993). l-tajarl apparendy did not usc any conscious dJboT:lt;\lC: stnte':glcs. I- lis exceptional nll.-mory, howe\"C"(. was speCIfic to numbers.Thompson et al. provide a useful dl�uuion of olha mnemonisn. ' . 15. For studies of memory in chess. bndge. and other areas. St'e the collection of papers In EriCMOn and Snmh ( 199 1). . 16. For smdle5 of memory in aclOrs. see Noice and NOLce (1 996): quot.: LS from p. 2. " According to K. Anders Ericsson (1')<)2). a leadi ng inv�tig;tlor in this arel, Th� sup�' their n r o conselluellce .'cl dm � be 10 s ppear a c)(pertS of e c an m r rfo pe rior memory mal meanmgful encodmg of il1form�tioJl in Ihelr domalll" (p. 169). For blOgT:lphlcal studies of Ihe acquLsitlon of experllS . see I)I00m (1 985) . 17. For a deuilc
(
)
,
�
?
C
in the world.
20. In a PET study.the volunteer is eltiu:r 1Iljccted with or mhales a r.ldlo.1ctlvc l!iOtop.: Ihat taken up imo Ihe brain. The ISOtOpe il; unscable :l.Ild conS<'{lueutiy emits pIlSnrons (hence the lerlll p
is
the exact poml of conislon. K'I.nuna nys are emitted al a 18()...dc�e ;mgle to the poml of collision. These g:.Jmma rays aCU\'ate detectors in Ihe �anner that bur allow n:scaKhcn to reconSlnLct the e)(�ct poml of collision. RegIons that are more �ti\'e': dur ing a task hl\lC: grealer blood flow than regions Ihat arc IC"S-� aCI1\'c. \\'Illch brings a gn:�ler amoulLt ofIhe mdLoaaive isotope and ht'nce a pe"ter number ofpositron/dedron col hSIOll$. Th.. delectors in Ihe PET !-Clnner regmer Ihu cnhanct'<1 acti\'ity. and these nw " PET counts" are ultinutdy 1r.l.Ilsformed 1I1tO inugn t1Ut depict "hot spots" in bnin :H"Cas Ih)1 are cspeC1.1.\ly aCO\'aIW by a wk. Measurement of regIOnal cerebnl blood flow il; jusl one approach to PET scan of mllg; anOlher �pproach ill\'olvn the measurement of glucose upt:l.ke. T e n:l.lILre PET IcchllLques IS dLscus,ed in all accessible m�nner by I'osller and R:nchle (1 994) . PET in\"Olvcs tXpOSlIl!l; people to � $tnall amount of nd iauon but the doses an: so
�l
,
minuscule thll Ihe procedure po$d no nsb for volunteers. 21. For more mform"uon 011 Jerry Coker's hfe and art. St'e HarTIS ( 1995) , which COntlLIIS a bnef �y of mmc on the role of memor y in Coker's ""Ork.
315
22. The study IS descnbed b y Kapur e t :1.1. ( 1 994). Each usk bned about " minute. which IS the amount oflimc: that il takC5 to complete l slIlgJe PET ""n. For Iht, eboonlivc t�sk. Ihe volul1leers de Ided whether fJIlIIliar wOTCb shown during Ihe One-IllL llllte
C
scan refer 10 a liYlng or a nonlivi ng thing. To carry OUt Ihis encodmg t:lsk, it is nec_ essary to con51der the me"ning and aSSOCl:.tI1\·e properties of each word. For the nonelabontive task, the \"Olunteers dcclded whether or nOt each word shown dur ing a St'pante onC-lInllUte scan conums al) a. No ("labor:mve processmg I� requre i d 10 matc tim deciSIOn. Follow-up 1C"Sli ng revealed Ihal. as cxpccted, people remembered more \\"Ords e':lIcountered during the cl:.abontive tl.lk than durmg Ihe lIondaboratl\'e task. 23. Kapur et a1.'s {I 994) results wnh PET !.C:uLlli ng haw lx'en contlrmed by Demb et a!. (1995) with functional MRl. Demb et al. found that daboratl\"e processing is :t.SSOClated wnh blood flow increases IIl lhe l.:ft mfenor frontal cortex. r-or a dLscu:mon offunc_ tional MR.J procedun:s. see Posner and I-taichle (1 994) . Positron ellllSlS on tomography slUdiC5 showing aCh\'al1on of the lefl inferior frontal cortex in assocl�tion with sc:man l1C encoding we� initi�lly reported by I'.:tersen et al. ( 1989). For encoding ddicm and frontal d:..m"ge. sce Ihe reVle\\!l by Schacter ( 1987b) and by Stuss. Eskt"i. and Foster (1994).& Dam�sio ( I 994) reminds U§. b.:t:�use the fmllt'll lobe5 include many different subregions, spe�king in geneul ternu about " fronul d.lInagc" LS of limited v.tlue. 24. For studiC"S conc.:rning distinctiveness. ellborntIVI: encodinS. 3ml event-related potcn tials, see Fabialll and i.)Qnchin (1995). 25. Positron emission tomogl1lphy wta showi,lg luppoo.mpal contributions to encoding nO\"('1 pictures are reported by Tulving el aI. (I <)94h). Our experiment \\�th impossible shapC"S is reported 11\ Schacter. RC"iman. ct al. (1995). Although J n'fer he� and else where to acllV2tion or bl()(ld Row increase.; in the hippocampus. it must be kept in IIlmd Ihat 1imll�tions in the spatial re!iOlution of the PET techniqllC5 we �nd oth�'rs ha\"e used make it difficult to dLstlllguish between activation in the luppocampm proper and actlv.ttlQIl LII the adjacent parnluppvc"mpal gyrus. Some "hippocampal"' acth'allons f.ill din:i:tly on the hippocampus. others on the par.lhLppocampal gyrus. When I refer to activati on of the hi ppocampus. I am includmg both the hippocampus and panhippocampal gyrus. 26. r-or an O\'\.""tvlew of Semon's Ihcory of memory, sec Sch:lctcr. ElCh. and TulVing ( 1978); for a broader IrUI111em that deh'es into Semon's life and ideas III the COlltext of Ihe hislOry and sociology of :;cit·nce. �ee Sehacler ( 1 982). For EILgli'h InnsbtiOlls of his work on LlIl'lIlory. s�'e Semon (1921. J'J23). 27. W,m 1 905), p. 130. 28. See Hebb (1949) for the origuw sta{ m 1Ll of what has come to be known as "Heb b.an leJ.ming:· For a modern treatmelll, sec McNauglnon and Nadel 1 989) . and for a revi w ( of reeent CVJdence, St'e Mel"'lenich and S:amcsllLllla (1993). 29. The classic reference on Ihe encoding Spt""ClfiClty pr inciple IS Tul\'mg and Thompson (1 973); see also Tulving ( 1983). :m. As an example. Ou'lder an expenlllem by Ihrcby et al. ( 1974).Th!:)' required people to think about scntcncd stich as the followUlg: "The man lifted Ihe piano." It is likdy Ihat )"Ou Imagine someone slruggling hard 10 budge the wC"lghcy instrument, and perhaps ""Onder whether Ill' can SUCCC"S'lfully hit II alone.The experimenters shov.'t:d other pe0ple a shgluly different scntence: "Thr Ill�n tuned the plano:' Here )"QU prob.:abJy inug lIle !iOlllcone pluckUlg Ihe Stnngs or teMIng the kC")"board; you nuy C"\!en menully" hear" the sound of � note. 111e sentence contcxtS mduced you 10 ..ncad\' the taT"J:,>eI: ""Ord, pi"'l<J, differently II! Ihe t\\"O examples. Afl�r time has passed. the exp�ril1lcmen prubt:d memory for fhe critic word (pia..,,) by providing bri('f phnscs as retrieval cues. The cue "'something heavy" may remind you of a man strugglllg l to 1n0\'C" the pl..;I.no, bill it probably wtll not make }"OU thmk of all}"One pluckmg Ihe !trings. In conlnSt. the cue "somelhml/: with a lIice
(
(' C
(
(
�l
Notes
316
Notes
sound" will probably remmd )VII of someone pluckmg me strmgs. but "'IU not c\TIke a nllln auempring to mO\� the mSlrulJlI."m. This is t){:letly whal happened III B�rd.ay et a1.'s study. ··Something hnv{' elicited
or 3 \";Iriety o fother f3ctors. Rele''alll evidence and dISCUSSIon can be found ill Uuck ner lind Tuh'ing (1995). I)uekm'r Ct al. (1995). Gushy et al. ( 1993). SCh ..ct....r. Alpert. ....t
al. (1 996). and Ullgerielder ( 1995). 42. To dl5entlnglc reme"al effort from the �uhj....cti\"c I'"xpeflence of recollec tion, we \Iscd II depth-of-processing manipulation. Participants uw a it§t of ,,"Ords. They engJged in d....ep, dab()r�ti�... proccssmg of some words and Jhallow processing of othen.After the de....p ....neoding task. thl! mbJects dId not ha..... to work vcry hard to Tt""calJ th.... tlrget
good re<;;r.1\ of Pla",1 only when people stud
m:m lift.:-d the plano": cOlwer.ely, "something wnh ... lIlet sound" elicited good 1'&,,11 ofI'ia"o only when p<:oplc studied "The Illall Wiled the plano." ied 'The:
3 1 . Andcoou 32. For an
(,'1
al. ( 1 976).
('"cellent Tn'WI\'
of research
1111
Male-dependent relTLCVlI. see
Eich ( 1 989). Eich
highlights an imporemt quahfier about Slate_dependent retrieval: if the cxpf.'rimemer provides p;r.nicip�nti wilh hum th.u help to trigger explicit menlory, II no longer mat , f ten whether the drug state is II,,: �me or different at smdy and t�1. For rumple, I
words, lind they remembered most of them well. Afler the shallow encoding task. the subjects had to work qUIte hard to try to Tt""tricve the Items and remembered only a few of them. W(' performed br:oio scans as rhe subjects �tt""1I1pled TCm"V<1I; there were sepllr.lte scan'l for \\"Ords that had been studied in the deep ellcodlOg ask and for words thn h..d been !tudied in th.. shllllow encoduIg tl�k.The hlppocarnpu� was mOSt lIcti\"�
experimental \uiumcen who are mtoxicatcd Sludy a list dut colltams the words JWlJlh, apple, bonum", ligo, h(}fJt, and IIJl1flkty, II sute-dependem dfeCl will be o�rved when they
ne
bter asked to
when people were n'C1!llllg words from the deep task (which they remembered wdl without much effort), whereas the frontal lobc,s were most acu,·c wh....n p""o p1c were rt'calling words from the �haJ1ow !
remember all of the words on their owll---they wlll reclill more
words when the), are lI1toXlc�ted than when they
lire
sober. But when the expen
menter provides n-tnev.al cues s\lch as "ffUi�"lIlld ··..nilllllls"·!O aid R"("olh:Cllon.lI n:u: i no longer o�ef\'('d; memory pertorm31lCe IS lIbout the 5:lme III s
dependcnt dfect
I ntoxicated and saba conditiollS. Thus, rcinducing a prior Stlte of mind hl'"lps recol when specific. effec
lection in the absence of other cues, hilt il bl'"c01l1cs superfluous
Icction aft"" related to hip poc..mpal acti.....tiun. Jnd til)' res<·�rch gmup IS actively trying to answer it. COll5istellt with our results. Nyberg. Macintosh. Houle, et al. ( 1 996) have
UVl' Clle$ are avaibbk 33. ThIS exp erimem w,,� reported b), Fisher lind Cuik ( 1977); � similar one was reported
recently reported PET d:ua showing
3 Slmng po�iti"e correbtion bc,tween hipPOCllIlI pal aClt.'it), and successful retnev;)1 within illdh.jdu�1 subjects.
by Morri�. Br:lIl'lford. and Fr:ank� (1977).
these striking findings
H. For the distinctiOIl between lIssociati\1: and .\.Ir.llcglC TCtrie'-:U. see Moscovllch ( 1994). "4. The I'"xpcriments on [one of '"Olce lind bcial l:."I(presslOn were conduCted \\.jth Kevin Ochsner. a gnduate !tudem In my laboratory. lind Kari Ed'\";Irds, 1I psychologm lit 13"""'n Uni\-enity. Loftus lind P.llmer (1974) ha\... reported d;n
thlll p1("lUrn of diverse real-life scenCl t....lld !O elicit highly distinctive ellborati\'e
45. See Tulvi ng ( 1983) for a forceful !ClItemell! of the Idea that what we call a memory IS
34. The experiments showing IUj;h le\'('ls of retention after exposure to numerous words
by M:intyl:i (1 986). Studies by
Shepard ( 1967) and Stlndmg (I 973) h�\'C shown that. when people an- shown hundn-ds or ewn thou5:lnds of dlstlllC!1Ve PIC are reported tuTes
of real K"l'"nt'!i. they can correctly recogmle Ihl'"
testl'd soon after .seemg the pICtures. One IS
vast lIIaJonty of them whl'"n
\\'3y to think lIbout
memory distortion. has tIIrncd out 10 be prcsclem;" llIelllory ds i tortions. rememb..rer;· 'rcmemberinl!' things that did not occur, could be attributed to the « )11sfructi�-e role of rctrie\'"�l informadon" (p. 181).
encodmgs. These encodi!l� can be remSfllted easily at the time of tdt. becall>l'" the
a joim PrOOuCt of cues and engrams. Tulving app li....d this idea to
retrieval cue (the piclUTe itself) providei a highly spcclfic match to the
off....ring a COlllllle,lt that I beli...., ...
t-ncoding. Whl'n peopl" are tested �t longer delays. howe\'er. they rcmemher many fewer PlC
tIIrcs or words.
35. For II rcview of e\'idellce from people :lnd anim�ls on retrieval of SCCIIlUIgly forg()lten
ml'"1ll0ries in resp onse
36.
317
10
46. The
cues lind rellllllden. !>Ce C..paldi and Nellth (I 'J'J5).
cb'lSic
volume on connectionism and parallel distributcd proccs.mg, edited by
McCldbnd and R.umelh..rt ( 1986), provides all excellent O\'('rview of connectionist
N�lr� (";\>e s i describc,d in detad b)' Vargha-Khadc1ll. l5:laC$. and Mishkm (1994). QUOtes an- from pp. 692-693 ofthllt article.The Inmor was III the pl!l�lIl region ofthe third ventricle.Allhough II ,,·... s treated �lIcct:SSfully. MR.J scan! aner trelltmcnt fC\,-ealed
approllcht'!i
to
memory. More n-eent de\-elopments and olher perspectives can be
found III Edelmlln ( 1992), Grossberg and Stone (1986), and McClclland ( 1995).
abnornulities in struCIUre5 thought 10 be: 1I11portlnt for memory. lIlcludmg the left hippocamplli formation. parts of the dlenceph.al.on. lInd thc fornix."hich connects th�
CHAPTER J
hip pocamp us and dicllccphalo,l.
Of T i m e a n d A u t o b i o g r a p h y
37. C..nmuu and Hilhs (1 9'.1 1).
38. For a read ble discus,ion of pOSSIble cellular baSCi of memor)' retrieV<1l, !lee Johnson
a
( 1 991). For psydlological �nd cOlllputational ( 1 995) and Metcalfe (I 'J'J3). 39. !-or a detailed ebOOrJllon of this Idea. sec
I . The quot.... i� from Dav,,1 Bonetu's n'Vlew of MIldred Howard's exhIbition at the PJul .... Anglim Gallery. San Fr�I IClSCO, Arr l\!eu'S, November 19<) I, p. 15". Mr dis(:Us�ioll of
dleories of �Iri<:val, see McClelland
HO\V<1rd's family background is based on p ersonal eom"CT);Itions wilh Ihe artist and on
.
Danusio (1989) and DamaSlo and DlImJ.Slo
two exhibllion caulOS'\.: Mildred HO\V<1rd. 1991
( 19')4).
40.
Ai/,,/me Knu AU\lrd £-.:liibiliol1, S.:III
Fr:ancisco Art hutitute. and Mddn-d HO\\";Ird. TAP: Im-rJligalioll of Mtmory, Tntar
Tulvmg et a1. ( 199411) summulZt' evidence concermng TIght/left frontll asymmetries
Galler),. New York. 1992.
during rt'trie\..aJ..
Ebbinghllus's cbnic monograph. see EbbmghalU tlle jo",,"d if £-.:pnimnua/ l'sydlo/t"IJ!)' dcvoted a spcci.al. issue 10 the TOOth lInni\"Crs;I.f)' of Ebbmghllls's publication featllf111g a ICrlgthr rctrospecti\,(, by Siamecu (1985) lind sewnl commentaries. The form of Ihe forgettmg cu....-e can be accur:alely descnbed by a math....nut iol expressIon knOwn ;t!i a power fimctlon. which simply means that the rate offOT),,'t:uing is slowed down by the passage oftilllc.Wixt....d
2. For an English tnnsbllon of
4\. In the SqUIre et 1I1. ( 1992) Mudy that showed hlppoo.mpal aellV<1uon dUTlng TCIrICVoII. people remembeT1:d recently p�nted ...."Ords when gl\...11 thn'e-Iettcr word Ixgl� lIin�. Since that lillie, sollie expenml'"ntli ha� re\-ealed cvldence for htppocampaillcu
(1885/1964).111 1985.
\'auon during rt"trie\"ll. bllt othen hllve not. Thu m;ry be beclll!le the lIctlV<1t!on ofthe hIppocampus depends on the speCIfic manner in wluch people recollect a pa�t cvent
_-1-_
Oles
N o [( ! s
318
�nd Ebbcsoll (1991) pl'OVldc: compelhng CVIdt'llct: 011 forgemnl!: :.1� � power function of nnll'.
3. Cro\'lIZ �nd Schiffin;r.n (1974): s« :.Ilso Rubin (1982). In both of lh� �tudK'1. th(" shape of the: curve was clClr.lonhn)niy well described b)' :.I power fimctlon. For tht" work of G�lton th:.!t CrovLl:1; rcdtsc::ovcrcd and ll]l.xhficd. Sl'e Gallon ( I R79). Gaiton tinted lind noted 1m own as<;()Cbtion< to word cues. Unlike CroVIt�, he dId not specif ically require the Tt"lrievai of 1I particular epi.sode_ GaltOll'S paper w:n publuhed SIX rl"�rs �fi)r<, Ebbinghaus's hook, which is g enerally rr-garded 3� dll,' first txpenmcmal m\�sng:;lUoll of 1llt"lllory. nut Gahon did not uu· ex�mnclltll cotllrob. wh......as Ebbmghllus did. 4. The study 011 recall of accldcTlts LS by C:/.ih and Moss (1972) and IS CI{ed In Lofi:m (1982). The quote is flum Cuh and Moss (1972). p. 5, as CIted by Loftus (1982). p. 127. ...Ithough Mlme aCCident \'Icurns rrob;,r.bly forgot to report the aCCident becauSt' of head IIlJunes. th.s cannot explalll the dl1lmatic dmp--<)f1'of «,call m people mtervlewed rune to twdve months after the aCCident compared 10 Ihose interviewed less than three mOllths afler Ihe accident. 5. The 1I11erfcrence theory of forgetting ha, a long and d'S11n,,'ui,hed hIstory III the experimental study of memory. See. for ex�mple. Post111�n �lld Underwood (1973). 6. TIl<" idl'a that all expeTien(es are Itored permane ntly ill memory is reviewed uitically by Loftus and Loftus (1980). In chapler 10. I consider an 3ppa�nt exception to the rule ofgraded fOl"b>etting ai a funcuon oftime. known as the rrlllilli$ttllrt blimp. Another excepti...) is found in the work ofUahnd. (1979. 1984). which indicates that Mlllle t'xtremeiy well learned inforn�tion r:nters a " J)("rn�nore" III whIch 11 no longer exhIbItS detecublt' fotgt·ning. 7. lJ,:nf,dd"s expenments a� �portt-d III I�nfidd and Perot (1963) and are reviewed carefilily by Loflus 3nd Loftus (1980) and Squrie (1 987).The qllot� fmm the pments are from Penfield and Perot (19(,)). pp. 653 and 650, respecllvcly. 8. Penfield (1969). p. 165. 9. See Squire (19B7) for simibr criticisUls. 10. QUOICS u("' from Ih'Kaud. Brunet-!Jourgin, Chall\·d. and Halgren (1994), PI' 7 8-79. · 1 1 . NeurobiologKal evidl'nce for the los, of synapti c cOI1t1cctlVity IS providcd oy Bailey and Chen (1989). 12. Linlon (1986),p.63. 13. For runt'S. �e Borges (1%2); th.:- quolr: is from p. 112. Tht' story of Shl'TCshevskii is told by Luria (1968). 14. For forgetting as an adlpt1\'e response to the SlrU(ture of the envlronmem. sec Ander son and Schooler (1991). 15. Excellelll l"l""Vlews and dlSCU5Siolls of hypermnem are provIded by ErddYI (1984, n i press) and Payne (1987). I-lypernmt'Sla seems 10 occur moT(' fudll), for PlCtlll"C5 than fOf words: P�)"ne (1987) conSIders v.mous pOSSible "xpbnauons. For hi,lorical Jnaly ses of Ih" comolidarion idea, ,eC" l>aliter. Nadel . and SchaetCT (1991) and SqUIre (1987). 16. For reviews of alllllCSla followlIlg head injury. <;ee Levin, Hcnton. and GroSJman ( 1 982). Russell and Nathan (1946). alld Schacter and Crovil7. (1977). For '"the dmg,"' see Yarnell and Lynch (1973). 17. Abel et :l!. (1995). p. 302. Abel 1'1 al. provide ;1ll excellent o\-crVlew of Ihe (ellubr aspects of research on short- and long-term memory in ...pi)"Sla. mICe, and other orgJrllsms. Su also Kandel, Schw;lT!z. and Jessell (1995) and Rose (1992). Nt,\\, stud It'S by Kandel's gronp (Bart'l(;h r:t al.. 1995) have shown Ihat ApiYSIJ can cotlWlldate J long-term memory evt:n 3ft"r only a single burst of scimuiJllon. ThIS happens whl·n cellular processes that normally suppress the I1Ipld forn�llon of long-term llIemOflCS are pTe\"C'nted from doing so. 18. The !Jw IS smed and exr:lllphfied in Ribot (1882). For an l1lforl1lauve d,SCUSSIon of
319
R..!bot"s Ideas. !iee Roth (1989). and for his role m the early dC\'elopmellI ofa $Cientific apprwch to memory. see I-iackmg (1995). 19. For the de\er: KolrC (1995), Kris ( \ 956). Sch�llk ( 1 990). and Singer and SaI0\·t1' (1993).
Notes
Notes
320
36. Pri<:e (1992). 37. For revIew of s[udies on retrospect!w.' estim�tes of childhood and family life. see
lIrewin, Andrev.'S. and Codib ( 1 993). They ,ondude tim concerllJ about du.· unrelia bility of retrosp«tl\·... rq>Orcs concerning the genenl char;lcter of childhood experi ences are needl�ly eugger.ned.
38. IJan:iJy ( 1986), p. 97.
39. QUOtes from habcl AlIl'nde �re from an imervkw in the 3mml GICIbe by Cynthia D<x:krdl. "The Spirits of Inbel Allende:' May 24, 1995. p. 80. Quote from Paubi; leI ter IS III Allende (1995). p. 322.
CHAPTER 4 Renecdons i n I . Ureznilz
321
l"l""Cogmnon, and �memher/know Judgments. Other slIlubr false recogmtJol! phe nomena ha� been reporled by olher ill\ ug:uon, al; revlc...."Cd 111 Schacter (1995a). 1 1 . My colbhorJtors on lhc PET .tudy �re Dan Ihndy, Tun Curnll, K�thleen McDer� molt. Ene RCllllan, l lenry L. Roediger, and Lang Shen Yu nl!. For Ihe sludy ofamnesic panenl.'i. see Schacter.Verfaeili('. and Pr�dere (in pms). The Idea thn fal� recognition cal! be based 011 reo.lIing Ih(' giS! ofa paS! cxpenene(' has been devcloped mOSI exten . "l V� �' by tht· CoglllU\'e r" ychologlsts Chlri('s Br.nnerd and V�lcrit Reyna III lhelr UK' ful uuy tnce th('ory, whIch holds that accur�le recoll('c llons dep('nd on a "verba tim or spcclfic rr:presenl.llion of what occllrl"('d dutlng an episode. whereas dis[orted . I"('collecllons depend on a gl�1 n:pn.'SentJtiol!. Accordmg 10 fuzzy [rJce [heory. a gm . n:prcs(,lllJIIOIl c�n gin" me 10 "vague IInpresslom of similolrity" (Dnin<'rd. R..e),na, & Unn 1 995, p. 360) between a presem e\'enl and a PUt on(' that lIIay l"('1;ull III false n:c ��;lIJtlOI\. False re<:oglllllon of slrong assocutes such ;IS JlI�r, howe\"er. produces VIVid recoll",cll �ns. 1101 \�Jb'"Ue lIIlpressions ofsImilarity. Schacter el al. (in press) �Ugg..'S1 a modified versIon of Ihe fu1.];), trace idea 10 account for false recoglliuon 111 amnesic and nonamnesic indh'iduak 12. For a discmllioll of c�llnectlOIllSI]J and memory distortion, see M<:CleUand (1995). 13. The story ofArnold 1J [old by Geary ( 1 994), who provides :lll informalive analysIS of tht> Illtul"(' and functlons of llI('mory ill .,Ie"emh-century Europ<'. 14. All C.lriy bbontory demOIlSfl
'CS
� f
�
•
a
Curved Mirror: Memory Distordon
(1 993). p. 179.
2. For a sUlllllury ofIhe W01lus case and a lengthy explOr;luon of Dellljanjuk. see Wige nlar (1988): 'luOles arc- from pp. 17-18. Dellijalljuki; acquitt01l by Ihe Isr;ldi Supreme
Nrw \�rk TimfS, "Kin llringing Demjlnjuk Horne 10 Face Troubles," by Stephell l.:!.balon {$(-plember 2 1, 1993. p. 17A). The article :Uso poillts i p ropt""r and that e\"en out that "The Ju�uce Departmcnt has said Ihal It dId nothing m i umgr:.nion plpen to if Mr. Dcnuanjuk was nOl 1\,lIl, he was an SS gu;ud, lied on his n the United St- pnaldy critial an:l.I)"ls ()f Ihc recollection� presented to him m Ihenpy and the hyp nmic techniques u§<'d to dicit them. Mas.roll (1984) comends that It was a career-sav ing mO\'(: altribul�bk w a f;lilure of courlge in Ih(' f�ce of criticism, J vicwp{)int she 3nd Watters (1994) clallil that Freud bulhed his echoed by Herman (1992). Of Court was reporh.'d by the
clients IIlIO grner.lling f.llse memones. 4. D. P. Spence (1984) provides an excell('nl an�l)'Sis of these p{)int<;. For an Engluh trans btion of Frelld'� paper on S("rccn m...nmries, see Freud (1899). 5. I t � curious thaI Uardetti; (1932) bndmark experiments havc never been I"('p llcued; see Gauld and StephellJon (1967) . 6. See Buckhout (1974) and aboWag<:naar (1988) for Ih(' Carbone mlSldentificallon and photognphs of all lhree men. Wagennr (1988). pp. 132-133, point_ out hO\v some thing sunil3t nuy ha\"e occurred III the DenUal�uk use. 7. Schooler and Eng5der-Schooler (1990) dellloll$tr;lted thaI encoding vcrbal I.�hels impairs face and c{)lor I"\'"cognitiou. Melcher and Schooler (in press) found the SJme with wine \.J.sting. Interestingly. recognizing the bSTe of wine W;lS not impaIred in e�rt WIII(, tasters, who had eXlern!n: experience tr.Ulsbung uste 11110 w{)nls. These effects may he beller con<:eptualized as "recodmg" e/TI'<:U Ihan "encoding" dfccts. be,au;;e III expernnent<; demonstrJting Ihe dlstortmg mRu('nces of vcrhOlI bbeb. peo ple gen(,rJte the labels !tOllle time aftn }u\'ing encoded a nonverbal sti nmlus.
8. For Ihe b.l!K:b:ill experiment, see Arkes and Freedman (1984). For simlbr kinds of demonSlral1ons. see Ur;llIsford �nd Frank! (1971) and Sulin and Dool.lllg (1974). 9. Psychologists often refer to thl'S{"" kinds of inferences ;IS schema�based inferences. A i used 10 iutl"fPI"('I and ana s(hl'ma ref('rs to an ol"jpnized unit ofp:m ('xperiences Ihat s by SIr F�deTlc l3udelt psychology 10 introduced "';IS term the situation: lyze a current (1932) III hIS cbsslc monograph Of) Tt:l11cll1bermg. See Alba and Hasher (1983) for a review of research and theory concerning schelllata and m('mory. ""';IS reported by Deese (1 959). who cxamined only rn:all Intrusions. Newer and 1lI0re compeUing VCrslOns of Ihese elCperunellU are
10. Tbe oTlgm:ol "s""'l:el"' delllollstntion
rr:porled by Roedlg<:r .lnd McOermotl (1995). who pl"Ollldl' dau on reo.lI, )"�/no
.
�
�
':' ··
·
N o (es
Notes
322
th� Evidence Thlt $t':l!cd HIS F;lIe:' Mdlo POints OUt that SpazI3no w;u hardly ;I. choirbo),---he WlIS a conVIcted npist-but alw dcuils v:anous kmds ofpoten u�lIy exom:r.lUng c\,tdcnce Ihal were withheld from the JUry in addition 10 the mfor l of m:ttioll about hypnosis. A (ollow-up article pubhshed after Chiles gr.uilcd the s:"y "XCCUlian on June 15. however, reve�lcd thu the governor's b\vy.:r still belu,'lIcs Ih�{ SplZi;mo is guilty CSpniano Gudly. Chiles' Lawyer Dccides after Revlewmg Case," by Michael Griffin and Bcd} Taylor. Orlatld{) &lIIi"e/ UUllt: 17. 1995, p. A ! J). Tho:- next day, however. another arrick polllled OUI Ihal Dm,io is now wavering :,IooUl Ius hyp nouc;tlly LIlduced testimony ("Eway-Wriung uwyer R.ejoins Kilkr's C...K-:' by Beth Taylor. Orlauda &/" ..,,(/ UUIlC 18, 1995. p. U Ill. By the: mile he W:llS i ntervie:wed on the June: 30 edinon ofAI3C, "World News Tonight:' DlhslO had re(:antcd hIS testimony completely, stating uneqUIvocally that "AI this point, I belil'\'e WIth aU my hean Ihal I n�r went to the dump with Jot Spallano." As ofiate f:ill 1995. Spniano, f:llte remalll.'i QUe51101l§
undecIded. i cmMons ofhypno�ls and Ihe cbims that have been m;&de about it. see: For uS<."ful ds Pettinati (1988). in n haple c the 19. A good example of how hypno<'is liters � person's willmgn("SS to call lIlental evcnCl " memories" is provided by Dyw;w �n d Bowers (1983). They 5howl.""d I.""xperim"utal vohllH('ers line drawings of common oOJecls �nd hler Lested their memory of th<."" duwmgs. Ailer testing. half the subjecCl wen: hypnolize:d and half were not, and another Ill<.""mory tesl was gi\,"n. Dywan and Bov.·ers found Ihal Ihe hypnoti1.t""d sub jC"<:b recO\,"recl more pre\'lou�ly unn'called pictuTt'"!l than dId the nonhypuOIized sub J""clS. but they also product'd even gre;&ter numbers of '"falS<." melllofles'" of plctum that had ne\"er tx:en pfCSt'nted. Dyw,l\l (1995) :lind Kbtzky and Enlelyt (1985) pTO\'lde helpful dLscussions of tim ISSUC:. For studies on confidence and hypnOSIS. see: Ornt' et al. (1984. 1988). Lynn and Nash (1994), and Sheehan (1988). Orne et aJ. (1988), pp. 27-28, also summarile e"idenn' concernmg m i ab�ry and hypn�is. 20. J..:r,urence and Perry (1983) repOT! the "noises at 111ght' study: the quole is fmm p. 524. l_yl1l 1 and Nash ( 1 'J'J4), Brown ( 1 995). and Kihlstrom (in prcn b) summarizc the: brge expl.""rimental lileralllrt."" on hypnotically induccd ps<'udo",emories. 21. The Frolil/ilic show aired on April 4. 1995. Bakcr ( 1992) offers a critique of hypnoti cally mduced "mcllloru:'�" ofpul li\"cs and alien abductions: Spanos ('I al. (1991) pro \llde rd"'·:1.111 experimentll eVIdence. Mack (1994) pmvidt'S lhe pcr�pectJ\"e of a ··tru<."" behevcr" m the reality of ahen abductions. but the cases he dt""'ICribn of :lIbduction !llemonn reme:mtx:red VIa hypn�is are qmte consi$tent wllh the Idea that hypnOSIS h"lped to create. rather than rt""C(1\'er. these biurn- mClltll expcnenct'S. 22. Loflus (1993). p. 532; «'t' also I.ofiw and Ketcham (1994). In foIlO\\'-up smdla. lof tuS and I'lckn-1I (1995) n:p-oT! Ihat approxnnaleiy 25 percent of participants generated false memones of childhood eWIlIS. 23. Sec H}'mall, Husband, and IlLlhngs (1995) for lhe b;asic false memory dC1110llStrAlion. I-IY111�11 and P<.""ntbncl (in p�) for the cffects of imagming episodes. and Hyman and BLllIng! ( 1 <)<)5) for indiVIdual differences in false memories. In Ih., lattcr stud)·. thc len d.mcy 10 �nerate f.11se memOries was corrdat"d significantly (+.36) widL scores on Ihl' Creati\'C Imaginalion Scale (WLl�on & Barber. 1978). which 1l1eaSl1res vividnen of menol llllager y :lind respomi\lCncss to suggestion. F:iIse memory crealion was also cor rebted SIgnificantly (+,48) wllh SCOTt'"!l on thc Dissocuu\," Expem.""nce Scale (Bern stem &. PUtman, 1986). whIch meUllm reported tendenClI'$ toward bpses m attentton :lind mcttlory. 24. For e:xpcrtme:nn (:onccrnmg repetttion, rehe:aml. and confIdence. see Ilcgg, Anas. and Farinacci (1992), Poole and Whne (1995), and RoedIger. Wheeler, �nd flajar.un (1993). For the n:lalionshlp between eyewitn("SS ide:mificatiOIl :lind confidence:. see Lgby, and Castillo ( 1991), :lind .. Both\\"eU. Deffenbacher. and Bngham ( 1987), K:1o;sin. H ·
323
WeUs (1993). In a recelll rt""view and tneu-analrsis on confidence/:lIccllracy rebllons. Sporer et at. (1995) poml 01ll 1hat confidence and accuracy tend 10 shO\v little or no correlation 111 51udies that include both witnesses who m�k� poslli"e Ldentifications of sllSpecCl and those who ar� unable 10 choose a sus]l«"t from a luu:up. HO\',",","r. whcn considering only the subset of witnesses who make pO)I\1\"C Idenufi(:al1ons. Ihey obsen"Cd a moder.L1e posi\1\"c correlation betw<."e " n confidence �nd �ccLiracy. 25. The final quote IS from Ncisscr (1982), p. 159. 1'lu' maL.'ria! fmLLI the Seplemhcr 15. 1973. meeting is from the I le�rill� hefore the Sde<:t COlllnUllt'C 011 Pn."SldClllial Call1p�ign Ac tiviucs of Ih<."" Unil<.""d Sralcs s...n�H." (N1I1ety-third Cong., I st se�., 1973. p. 957) and s i reprint<.""d 111 Nemer (1982). p. 147. For mnlLes ex�mining til(" reli�hility :lind accnT;;LCy of q't'wlUless tesl1lllony. see Wells (1993). 26. For discussion ofmemory-rd�ted issua III thc HW-Thonu� C" .& � .. sce Pezdek and Prull (1993). Eltlabcth Loftu� d I scussed ISSUes reblC"d to confidence and rehe.1ml III the 0. J. Simpson ase In the [...os Angdts Till.n (Augmt 25, 1995, p. 89). '"The Wholc Truth and Nothing hut Ihe Truth? '" 27. Thompson's uS(" is descnbed by R�'ad t't :iI. (1990) ;as �n tUunrJuon of'"unconscious tr.l1Isference:· which occurs when a wltn<.""SS confu�es an innocent bysunder wilh Ihe actual criminal; ser also Ross 1'1 al. (1994). Thompsoll ( 19R8) h imself provides an informed theoretical analysis o( related memory distortions. 28. For Ihe early Loftus e...perimCllts on c}....witness . mggcstibility. sc.' l.oftm, Miller. and Burns (1 978); for llIore recent studLcs. see l.ofms, Fridman, and lhshir]J (1995) _ 29. McCloskey and Zaragou (1985) pmvide compelling evidence that origlllal m<.""morics are not o\'CT"\vriuen in the l.oftus parad igm. Lindsay (1990) (:ollducted the: �tudy where people "'ere told lhat Ihe POst·C'o'C1ll narrati,," w:as f.llsc. Other CYldence unpticating source memory f�L1l1res 111 eyewitness �uggest:ibiltty s i reported br Belli et aL (1994). Lin;Sues, S("e l.oftus. Flenberg, and Tanur (1985). 35. Gene was one of several patLen� who exhibilrd JOun::e amnCSLl in the experimen!5 reporled by S(;hacter. H�rbluk, and Mcuchbn (1984). The tcrlll SVIHl"C amllN.a w�s coin....d by E\'lIlls and Thorn (1 966) 111 their studics of hypnosts. 36. For source amnesia 111 patientS wllh 1c.'lons restTlctcd to Ihe frontal lobes. see };l1lowsky, Shimamur.L. and Squire ( 1989); for impaired temporJ! memory in frontal patients, see Milner. Corsi. and l.eonard (1991). 37. Moscovitch (1995), p. 228. As MoscovlIch .:Ind mhe" e.nphaslze. confabubtlon IS nOI obscn'ed 111 all patJen� wllh from:aJ lobe WIll.lb'C. whICh follows from Ihe fact that Ihe frontal lobes an: composed of numerous subregions Ihat perform d.fferent functions (Dallt;l510, 1994: Shmu111ura. 1995). EXtenli,\'C (:onfabubuOIl to:"'lds to be seen only whe:n IC'lions penetrate to lhe 1I1ner (ventromedLal) rcgLOIlJ of the frontal lobn and damag<: the nearby oosal forrbrain. Perhaps rt'LalCd to confabubuon, :.r. rec;ent PET study of schizophrenic patlellts (SLlbcrsweLg (""( al.. 1995) re\"(�alcd a relalt\le absence of frolllal lotx: aCllVlty when patients experienced hal1ucmauom, whLch may reflect :.r.
N o tes
324 diminished \lb,li!)' Imcrcslil1�Y.
10
mOl1l10r
tht' $Oun:c:
the hlppoc.lmp
Notes
(internal or t'xtl'"rn�l) of �
w;,u
!Ilent.ll
event.
olle of SC\"Cru Str�CIU� that bec.ln�r:
o:tTellldy active durmg hallucUl.luons. In \'ICW of P�T Wt.l. hllkmg the IllPPOC;J.111P:l.� cxphclt relrH.'\";\\ (Nyberg e\ al.. 19'h; $emu",r, R(,�l1l:l.n. c:t :11. . 1995. . I 19%), Iht" combU1.lIIion of hlppoc:.l.mp:.tl :l.C"\"�t1on and fmnlll Seh.lct.-r, AIpcrl, c, a.. formation and
dCJct!\';Il!OI1 III K,I" ophremc P.ltJCllts 1ll1-l.1 1'>" h;/o\'I: contributed to their nusl'}k'II1g a pUt ('xpencnet:' for :I. prt'Sc:nt 011C'.
(1993). 39. T.llb.nd (1965). 40' Thu VICW h:l$ been ;ldlf;lllcC'd by Moscovltch (199:» . 41 , A fidl report of our cxpo:rullcms is conl;.oincd in Sch:lc\cr. Curr.lI ('I :1.1. (m pJ\'ss). , 38. Dall:.! B;J.rb:l.
•
Although lilY lIucr�t III I·r.mk
was
I ated III · stmlll
� slUdlC:S show�n h""J PET �annm, . ,
•
••1lt r. lrullt:!.I lob<.- activ'ation illS n � . dutlllg c:l:phclt r<::tne\'al. the location of FlOlnk s 1�lon t actlv31ed in PET Stud·IC:S ('nown as are, 10) . IS po!ile�lor to the regl011 that 15 )'ric�H)' Accon,IIIg,y, It .I'. dI/Tlcllh 10 say how Ihe fal�e rt""cogllltion phellOl11en� we have . _ . ,T Stud'IC:S 0f '_ ' . ', f �" " II . 10 ' rall" ,I"" ' F obst.·rved III , fight fromal lobe acuv:luo!lS 111 I . heal thy \'ol,lIItccrs. Abo. We C';\1\1101 determine on the ba�ls of th�s slIIgle (as,' whe:II....r . is uniquely associaH:"d with righ t from,,1 d:unagt. pat I10IOI!IC�I (,h . '! ree""'1Il110n ""' 0 . 0 cas<' a reported f p�tIiOIog!<;� ..1 6.15e Tecogrec<'utly hav� IBdeed, P.lrkin (""[ al. in press . . , 111t\01l �',ter d;nllJ'" 0 Ihc IcCt fronl:ll iobe. For all eXI�nded diSCUSSion oflheor�tlc;al . ! ' pn""Ss) . ., llltlon �f{er br�in d.llllag<'. se<· Norman and Schacter (III aspects 0 f'aI\t'" reCO' ( 1'�5) , Gllzar ""- ( 199'or an ') and M�tcalfe .. Funnel1. and Ganamga , • • w .. Sec 1'1IeIps :l1I( :n . F _ '·nll"oduction [0 splil-buill panents. see Gaz:lalliga ( 1 98:) . For re\'l<'W and ,ilscussion. �ce I3rllt, :md CCCl (199::0) alld Nathan and Snedek..r
.
42. 43.
( I 995).
44. In M�y ,�" ....,,:0. a s"."
'Olin of appellis m'("rwrned the COnvinlOll$ of Robcrt Kelly. Jr., ' . e\"t . sc:-.""CnI w.:eks for I hel11. I-IO\ � :r. alld 0fKat'lryn J)�",TI Wilson and ordered new ttlJls I� Slipreme Courl stopped th ' ruI'Illg and provlded Wle p� . 1�ler the NortI' Carolll1�
"
, aliOther e:hance 10 make: th.:it C�'iC th.lI the conVlCtlOllS sh011Id Stalld and eCUlors WIII •• �, � .un,." � � not warnmed. The story is �lInUllarll:ed .In the Chllrl(Jill': VI Illt new tTll� I, .. ...Uy CUI':. l'ros«lItor-s G...t Chance f
23. 1995. p. C4). . . " <"- �Iso Bruck :;r.nd Ceci (1995) for a decl.lled d . l�uss,on 4:1. Cetl :md Uruek (1 99:I') ,p. I ?. x:'" Estc:s Thol1lson (May
_
46.
oftll<' Michaels
For a IIlOrullgI, Bruck
•
and diSC"lIssion of chlidrell·s cycwltnc:s� t.::'illlllony. 5("'" Ceo and
( 1 993. 1995).
(1 995). p. 103. . � I th�nk Mlehc11e 49. The Sam $1011': sludy i5 rf"poTlcd by leichlman Jnd CCCl (199::0). . I Sle\'t! Cc:CI for pTOVldull; 111\" wilh the quOle from the thr<::e-)'ear-old LclCIIIt1l:til an{ . SirI. In addltlon 10 their finding Ih.1t nml...admg suggesUOl lS produced inaccuntc rec. . '" children III advance of his VISIt that Sam SlOm' Ihey aIso r;.:'port�'d ,haI lellin" olkctlom . . d b I ,'d, , ' ' children 111on: likdy to falsely n"membt:r things that s'1m ha 1101 II " wa , ' � l( Ie O\\ ., . IIlTrOrmJ tl.OII and .� who \wre exposed 10 both advance llCgaUV( actua'"y ( OIle. CI" I,I�n . ''''' - ''01'< nilsIeadIII!; .SU "",'" .., v.en: the most hkel)' of all to gener.ne Ill1suken r<::coII('mh neg.ltl\"c advance mforl1Unon and nusIea{ SlIgges1Il1s.:"ern . .. Id I dy when ch I ren wen: genII)' : st : u m nonS. T' "' of false r«:Ills dropped sub Ie perce1lt:J"" . neng!ed.' �boul their nleIllonc:s by an Intervte�w ) Kc Cha . r Wh0 :\.;11·d. '.v,Oil dIdn ·I rcalI" . hnn do anytI ]llIg 10 IhC booklteddy bear dId you?'- Under Ihese (:ondmOIlS only abeIII 20 l}CtCel11 of Ih�- and (our-ycJt-olm \\ ho receiVed both IIlIslcadmg suggc:s I� memoriCS. AIIhougII [hl� Ihelr , a 110m and nep" ' � ,d�'allCe mfonnatlon stuck bv .
47.
For a
("".IS('".
�'1CW
48. The
rcv;ew of these expt'tlmems, see CeCl
quolc i� frolll Ceci ( 1995).
,
_
•
3' - ,"
finding 5uglS gt:li that ollly � minOrity of children were 10tlUy CO!lvlTlced thai Sam Sion.. had done anythmg [0 a book and teddy b<ar, the fact Ihat .so many children wert"" wil.hng 10 ·'back otf'·thdr meTT\OrH.""S III respollle 10 an iTJ!t""rviewcr funhc r undencon::'l th" power Ih�1 adult figures Wield wllh )"urlg childrcll and how malka bk their meTlJ or)' rt""porlS can be. 50. Bruck el al. (1995).
Sec fivuYt and Schwarll1IUellcr (1995 ). Goodman (I al. (1994) and Sa)'wIIZ and Moan-Hardi.. ( 1994) also ptO\'1 de eVidence for accunte rn(mory of e�r)'cby e\'CIIl'i 111 young children. for a tc\'Iew and di!iCIISIS OIl of oth...r smdlC: S on memory di51Oriion ill children.se... HnIck and Ced (1995) and CCCl (1 995). 52. Schacler, Kag.m. ami Lelcluman (1<),)5). 53. For th... Ingr,1l1l uory. sec Wng ht"s ( 1993) Nt'" \o,.I.'tT artiek and surn...q u"nt book (Wright. 1(94): 5C1: also OlShe and Wall,'N (I9'H) . 54. Olio and Cornell (1995) providc a critiqu e ofOlShe's oh50erv:HiOlls aud �nt ..ruill alter nalive lTllerpr"taliolU of Ius e:l:pcrn nellt wilh InglOllll. InglOllll's plighl wa� proba bly also rebted 10 id".)!iyncnlie fealures of his past and p(rsonality. He admin"d that he was a din�nt. sometim<'"S negl..ctf ul. (ather. Ingram W:1S abo likely m ore prone 10 sug g..stin" in uences than most peop le. 51.
A
CHAPTER 5 Va n i s h i n g Tr a c e s : A m n e s ia a n d the Brain I.
Thc Iwo rounm of golf were originally repon
ed
111
SchaClcf (1 983).
r'Or a biography ofHM. s...e Hil ts (1995). 3. S..e Scm'i1le and M ilner (1957 ) for an early descriplion of HM. Corkin (1984) pm \,des a comprehen s ", ... teV\ew of Ihe case. 4. See Hirsh (1974) and O'Keefo:- and
2.
Nadel (1978). case RB, see Zob-Mu'lY'n. SqUIJ\'. and AmalOl l (1986). For th... rt""c...nt C25t'S SlllU br to !tll. seo:- Zob-M0'lY'n (in prc::u
5. For
).
6. For Ihe neurology of herpes simple x enccphahtlS. K'e DamaslO and Vall H�n (1985 ).
7. The case ofSS s i thoroughly presented by Cermak and O·Connor (1983). Damasio.
Tranel. and Damasio (1989) summ anzo:- th� case ofBO$well. DavidJane sent 10 ITT". �Iong �vilh a 1<'lIer describmg his situ�liol\.IIl Jal1ua ry 1994. 9. Se... Jones-Gotman (1986) a"d Smith 3nd Miln(r ( 198 1) . 10. For a review of David Jane's Mill paintings, sec Hall (1993). I I r'Or a T('Vlew of deficits ��5ocb l..d with enc(phlhm, see I·�rkin and Leng (1 993). 12. Mi�hkin (1978. 1982) . 13. Hippocampal LTP W.i5 discovered by I3li�s �Ild LQlllO (1973) . Numerous experiments have sinc<, shown thaI hlpp·OClllllpJJ tTl' possess(S a number of prop"ni es that ll1�h" il well suiled 10 SeT\-e as � cellular b:l5ls for memory. For recenl diseuS$ions ofll'!' Jnd mentory. see miss and CoUmgridg e ( 1 993) and Mar(n :.tnd l3audry (1995). 14. For Ihe original (ognitiVl: IlUp theory of hippocampal functIOn, see O·Kee fe and Nadel (1 978). For recelll diSCUSS ions of Ihe hippocampus and spatial memory. !ICC Nadel (1994). Cohen, and Eiell\'lIbaum (1 993), and Cave �nd SqUire (1991 ). Evidence concerning the contributIon oflhe hlppocalllpus 10 fccognillon m<'mo ry m monkeys s i provided by Zob-Morgan. Squire, and R.:llIlu S (1 9<::14) . 15 Sec MurlOlY, Gaff"an. and Mishkin (1993) , SqUln! and Zola-Morgan (1991) . and Zob Morgan et al. (1989). 8.
Thi$ quol<' IS from ;1.11 unpublished into:-rvl{""w thu
16. UllIlcrs and C...rmak (1980).
N otes
326
Notes
17. The examples of confused Korsakoff patlellts arc from Talland ( 1 965). pp. 46-48.
eral dl"5Cription ofSS. Another well-studied encephalitic patient. known by the initials
18. The convenation with th... KOlYkoffpatiem s i reported in Gardner (1975).p. 183.
19. rvlRI data are reported in Jernigan et al. (1991). and postmortem data are discusSC'd by Mair. Warrin!;1on. and Weiskrantz (1979) and Vi(;!Or. Adams. and Collins (1989). See also Parkin and
20. This Clrelllt
LS
L...ng (1993).
ofi...n referred !O as tht' Hlpt"Z Om.i!. Mayes (1988) �nd Zol.a-Morgan and
Squire (1993) provide J good ,UI1UI1.1ry of pernnent observ.nions. Although the idea of a single medial telllp0r.\I.-diencephalic network is arnacove in irs simplicity. it has been bcticvil...d by n i consistent and failed at1elllp� to confirm
to
327
RFR, also recalls "s...nlantic·· memories of his personal past. y."t cannot provide detailed recollections of particular illCidents. R.FR retaincd knowledge of words thaI had <:tltered the bnb'llag<: during time periods for which he has no episodic memor;';'s. For
tnstanc<:, RFR could provide adequate definitions of such term!; as AIDS and TIMrd,·
U'S'" despite his in;,bi!iry to recollect puticular <:pisodes fmm (h<: 1980s. When pre
. scmed with famous llnd IIonfarTlous nallles and f1Ces from the past, RFR had no dif ficulty telling apart Ihc famous �nd the nonfamous_ Although he had wm� probkm
a simple prediction thaI fol
naming pictures offamous people from th<: past, when RFR was gIven a few hints. he
low s from it: dl!llage to the fornix. which connecTS the l1l<:dial temporal �nd diencephalic l J"l.""gioll'l. should pnxJuce amnesia. Early clinical reports failXl to provide C
26. Conway (1992) 01f<:1"'l a �imilar Jnalysis. Gene and SS had
dence that danJah'l.· to the omi.>; f causel memory loss. More recent observJtioll,. however.
indicate th�T p:trients with danJab�
to
onb'Oil1g <:xperiences (Galhn. Gaffan,
Ihe fornix do have difficulrics TCI11embl.""ring their
& Hodb"-'S. )991). Dm such patient� awar to exhibiT
rdarin:ly mi l d memory probl<:n1s, not �,<:re and global allUJesia.
frequently e,me up with th(' corJ"l.""ct albwer. Se." Warrington and McC,rthy ( 1 988).
tion areas that store memories. When damage is restricted to the Ill."dial temporal
lobes. more limited forms of retn:>gT
A M.Lnher twist in til<: lleuroanatomy of amnesia may help explain the aPPllfCntl)'
28. Quotes are from Hodges el 31. (1992), p. 1797. who provid<: J thorough �nalysis of
mild amne!;ia a5sociated with fornix damage-. In the early 19805. Mortimer Mishkin
semantic dementias. Hodg...s et al. note that these patients may represent a subtype of
( 1 982) emphasil<:u thJl two differel1l circuits conneCt Ihe medial temporal lob ... Jnd
Alzheimer's dementia.
di...ncephalon. One circuir indud� tl,... hippocampus and the manl!lliliJry bodie!.
29. For cat<:gory-spccifl(. impairments. s...e Damasio ( 1 990), Hillis and Caramazza (1991).
which are connect('d by the fornix: the other inc1ud.·s the alllygd,lla and a critical part
and Warrington and Shalli<;e (1984). Then: �rl' J "driety of theoJ"l.""tical interpretations
of th<: thalamus (the dorsomedial nucleus). but doc> not inn,lve the fornix. Profound
of hnw and why catl"gory-spe<;ific impairments come about. For di$Cus�ion of alt<:r
allllll"Sl:l. may require damage to both circuit\.
native viewpoints. se." Damasio
21. Por the neuropathology of Alzheimer's disease. see Price �nd Sisodia (1992) and Van 110esen and DamJsio (1987); for genelic comributions to Al2heimer neuropJthology. SC'e Pollen (1993). Hassel11l0 (1994) provides �n imcJ"I.""sting th<:or<:tical analY5is in
(lo/JO). Farah
and I-lodges (1995)_ 30. PET data concerning idemification of tools
Jnd McClelland (1991). and Patterson
vs.
objects arc reported by Martin et al.
(199(,); Decety et al. (1994) report PET data concerning imagined movements. Mu
whidl depiction of acetylcholine. a neurotransminer that is deficient in Al2heimer
tin et al. (1<)<)5) found th�1 the left middle temporal gyrus s i acti\':[(ed when p<:ople
pJtients. leads to " runaway" modification of synaplic connections, which in turn (re
genCr;ltc action word�. For a revi<:w ofbr.lin art'"as implIcated in differem kinds of cat
Jte<' pathological plaqucs and tangles.
22. For rccem ��dellc<:
Oil
semJntic learning in amnesic patients :md reviews of earlier
"gorY-Ipecifc impairm...nts. Set" Gaillotti N "I. (199.')). i 3 1 . The conversational quotes arc ffom Gardner (1975). PI'. 1 8 1 �182_
$cudi...s. see Hamann llnd Squir<: (1995) andVerfaellit'. 11..ei55. Jnd Roth (1995). In stud
32. For expenmCll1al observations concerning awarene!s in Korsakolf pal1eJL!�. see Shima
w words and facTS. albeit at a slower than amnesic patient!; to learn large numbel"'l of n...
33. For amnesia :l.fter :l.nterior communicating artery aneurysm!; and basal forebrain dam
ies th.lt 1 describe in cbapter 6. my colleagut"S and 1 devised techniques thu :l.llow normal
rJu.'
(Glisky, Sch,lcter.
& Tulving. 1986a.b).
For studies of remember and know r<:sponses in amnesia. st'e Knowlton and Squire ( 1995). While aU researchel"'l agree that amnesIC patil·llts ha"e difficulty recalling con
textual deoils of episodes. there has been debate about whether aIllIl",s.ic paTientS also lose the ability to recogni2e recent e''<:llts on the basis of simple familiarity. Comislcllt
with Knowlton and Squire's results. Haist, ShifllJmura. and Squire (1992) prQ\�dc evi i amnesic patientS with i paired n dence that reC:lll and recognition are similarly m
medial temporal lobe d , ltllage. Some amnesic padcn�� do seem to be less uLlpair...d on recogmuon teStS than on recall testS (Hirst et al.. 1988). but e,-en these patients �re sen
ot"ly impaired on both typt"S of tests. Other ,mdies suggest that compared to people with im3C1 melllories, :mlTlt'sic patientS hase their recognitIOn decision.'; more 011 whatever fu!ings of familiarity th<:y do possess alld less on recollection of context (Verfaellie
& Treadwell. 1993). 011 balance. howe"er, th<: <:vidcnc� support!; the con
c\U!;ion that fedillb>S of familiarity are impair<:d in amnesic patients.
23. Tu!vmg et al. (1988) provide a defJ.il"d cas... study. Although
we
did not itaV<' MR.l
datl av,n1able at th... time. Gene has Slnce had an MRI scan that revealed damage to the lefl hippocampus.
tllUT:l (1994)_ ag<:. see DamJ_Iio Ct a!. (1989) and P.ukin .md Leng (1993). Hanley ct al. ( 1994) pro vide evidence of spared recognition relative to recall.
34. The prediction study was c�rried out with EliLlbeth Glisky and Susan McGlynn and s i n"pon�d
m
Schaeter (1991).
35. The encephalitic pJtient is describ<:d by Rus<: and Symomls (1960). p. 195, and the diencephalic patient by Kaushall. ZCtill, and Squire (1981). p. 385. For HM's aware ness. s...... Hilts (1995). p. 140. Corkin (1984) also describes a\\'af<'ne,� in patient HM. For reviews of research on awarenes� of memory and other cogrutivc deft(;]ls. se<: McGlynn and Schacter (1 989) and Prigatano :l.nd Schacter (1991). 36. For ob�ervations concerning transient global amnesia. see Evans ( 1966). l lodgl'<; and Warlo'" (1990). and Kritch...,'Sky, Sqmre. and ZoulOunil (1988). 37. For reviews, see McGlynn Jnd Schacter ( 1989) and Schactcr (1991). 38. MeJ"l.""a el al. (1977). 39_ For patient BM, see ltamachandran (1995). The quote is from PI" 3_i-36_ 40. See Prigatano (1991), Schaerer ( 1 991), Jnd StuS5 (1991) for discmsion5 ofal-'.'areuess of deficLI and rehabilitation_
41. See McGowin (1993) for Ihe story of Diana's il1n�s.The qUOte IS from p . 8 .
24. SeeTulvmg (1993) for J discussion of Gene's personality. and Hayman.Macdonald,and
42. Glenn Collins's reflections appe�red in the l ... 'e w �"'rk Ti",..s, Nov<:mber 10. 199--1,
25_ For tlosweJl. see Dalllasio et aJ. (1989). C...rmak and O'Connor (1983) provide
43. For thl' relation betwe<:n confabulation. frontal lobe function. and una"'-
Tulving (1 993) for IllS Sl·mantic I...arning
" Enduring a Disease that Steals the Soul:'
:l.
gen-
328
N o tes
ales
All.heimu·s dls.t'ase. see Dalb 13�rb� �t al. (in pra§). For � g�ner.ll revIew �nd dlscu� slon of awareness �nd Alzheimer's patients, see McGlynn and Kasl.ni.lk (1991). CHAPTER 6 T h e H i d d e n World of I m p l i c i t M e m o r y
Richarmon-Kb\'ehn and Bjork ( 1 988). pp. 476-477, offered the 0pulion that research on implicit memory COI1StitlltM a "revolution in the WAy that we tJ\e�sure and inter pret the mRuence of PaJ;1 evellts 011 current experi�nee and bdlavior:' 2. Sec Warrinb'ton and W�bkl':lml (1 968, 1974). 3. For th.... link bet\\'een :l.mnesia and blmdsight. see Weiskr:Ultz (1978); for � thorough Ircallllent of blindsight, S{"e Welskr:r.n!z (1986). Sehaetu (1992) provides a revlcv.' of implicit knowledge in a wide VOIrielY of lIeuropsychologlCaI syndromes. 4. For mOlor sklll lcarning and HM. sec Corkin (1968) and MIlnt'r. Corlon. and Teuber (1968). For mor(" reeem evidence 'howmg IIItacl learning and retention of motor skills in arnm-sla. sec Tl':lnd el :..t. (1994). For :I. hislOric:l.I TCVI<'W of early observations of implicit memory. sec Schaner (1 9R7a). 5. For a sumnury of Freudian and other carly ideas about the unconscious. st"e Ellen berger (1970). For attempt! to tCSt these Ideas experimentlll)·. see Sht'vrin (198R. 1992). For the amncsic drCS$maker. Ke Dunn ( 1845).and for mcmory \"t"rsm h:l.bil, see Bergson (19] I), 6. I laler developed Ihe procedul"l."t used with Mickey into the \OUl"l"e alllncsu par:r.digm dc-scribed in chapter 4 (SeluCler. HnbIuk.l5ot McLachlan. 1984). 7. The experiment U I"l"poned by Tulving. Sch:l.ctcr. and Stark (11)82). Our finding Ih31 priming is unrdllCd to whelher or not a re�,,' remembers having seen :I. word reAa:ts � sl,;!le of aff:l.irs known by thc technical tcrm mJ(li�slj{ imJepcndetl{f. The analy sis of slocha'tic independcnce subsequently became a COlltlQVl·rsl:'u issue. For di;;c;us Slon, see Hapll:!11 :l.ud Tulvillg (1989). 8. Dannay (1 980). p. 681, quoted in HrowlI :l.nd Murphy (1989). p. 441. 9. For the Freud qUOIe, see Taylor (1965). p. 1 1 13. Brown and Murphy (1989) ;l.IId Marsh and L:l.ndau (19(5) provide an expt'Tllllemal lnalog of Ummentlonal plagIarism, which is sometime! referred to as oypl<1tlUltsi(l. See Baker (1992). 10. The experimellt! are described by jacoby and D�llas (1981). Later Itudies showed th.ll pTllllmg IS :l.lso reduced when people see a word during the study phase and an: l.,ter gl\'en an auditory Icst in which they Iry to identifY the word when it si m.uked III I.
(1995). Sevcral TeSClrC'hers have attempted 10 UlllfY the single system and muluple sys tems apprQadH�S, lI\cludmg maxton (1 995). Gabridi ( 1995). Roedlb-er (1990), and Sch:l.cter {I 990). For gCllerJI discm�ion of memory systems. sce SchaCler and Tulving (1994). 14. Cohen :l.nd SqUIre (198O).1'ht' task of readmg mirror-;!1\·t'rt('d scrIpt ....-as devdop<"d sevcr:.U )'e:l.n t'arher by Kolers (1975). 15. See Graf and Sch:l.cter (1985) for the uuual dlSltncuon betl.I'een explicit and implicit memory, ;md see Schadcr (I 987a) for a hl�tOrtcal revit'W ofimplicit memory. For more up-to-date reviews of Implicit memory. K<" Roediger and Mcl)erlllol( (1993) and SchJCler, Chill and Ochsner ( 1 993). 16. The finding �m biasin� ofpreferellC<.'S W� first rcpoTtcd by Kurm-Wilson and ZaJollc (1980). Despm.' thc Coke-and-popcorn Story. there is litd., c\'idene<' that subliminal mcuages :l.ffcc! real-world belu\'ior (Merikle, 1988).Although laboratory studies hal'e shm\'n that infornulioll nOI registered by COIiSClOUS perception un inRuellce perfor nUlice on subsequelll usb, the effects are gener:r.lIy short-bsting and do not support the usefulne� of COnlrlleTCIally aVOllbble sublim;n.,1 tapC:'!. Curiously, howevcr, p<"ople express comlderable concerti Ihat their behavior will Ix IIIRu�llced by subhmmal mes S.1gCS (Wilson & BrfuficJnt pTl1\l illS effects wilh 011t' anesthetic agellt. lsoflur:l1lc (Kthhtrolll ('t aJ.. ]990), but not with another aneslhel\C. sufcntAl1il (Cork, Kilhllrom . (I.' Schacter. 1992). The positi.,.e filldlllgs WIth anest/lesia suggest th:!1 implicit 1lI(,1Uory IllIght also bl" obser\'f;� for information presemed during ordmary sleep. Findings conccrnmg "slc('p . . hJ\"C gene.. le:l.rmng lIy be(,11 neg':m that III�poc:llnpal lesions disrul)t rt:CogrllttOri memory III mfam monkcY". 26. l'or a reView of findmgs on recall of hidden objects in infancy. see I )lanl0nd ( 1990). Me1noff (I995) provides � helpfUl d,scu5Slon of his fmdinb" 011 delJyed nnitltion of actions by mne-month_old IIlf�nlS. Ndson (1993) offt'r� 3 useful concephlahzation of
�
�
noi!.f' .�eJackson and Morton (1984).
11. For difft'rent t'ff«ts of deplh of encoomg effect! with dIfferent test inSfTUctlons, see Graf and M:l.ndIcr (1984). Gr:r.f. Squire. and Mandler (1984) showed thlt amnesic patients' performance on Ihe 5lem completion lest depends critically on usk instruc tions; 'lee also Cermak et al. (1 985) and xh�Cler, Bowl'n. and Booker (19R9).The gen el':ll pallen} in these experiments si that �5king normal subjects to think b�ck to the study lisl lI11provM rC(;III. but has little or no cffect on the performanct' of alllilesic patients. who tend to rely on primmg no matter whal they are instructed to do. 12. Tulving t't al. (1982), p. 341 . 13. For Mame dt' 131r:m's ideas, see Maine de UIl':ln (1929) lnd sumlll:l.rtes \II Schacter (1987a) �nd Sch�cter :l.nd TuIvmg (1 994). For short-term venus long-term memory. see Ihdde\ey (19M6). For the epi.\Odlc/s.t'mlllt1C dtSIUlClion. see Tulving (1972, 1 983). SillgJe-systell\ �lternativt"> to the IIlllluplc 1llt'1lI0ry SystCIIIS hypothesis gellel':llly foeus Oil the kinds of t'l!Codillg and retricval processcs c�rrted out by people III dif ferent 1Ilt'lIlory tlsks. RepraenLulw \'lews:l.rc discmsed by j�coby (1983). Masson :l.ud M:&eLeod (1992). Roediger, Weldon. Ind Ch:l.lhs (1989), and lutdiff :l.nd McKooII
329
"""--
-
ores
Notes
the dc\'dopllI<:nt of 113rrarive forms of amoblOgrapluc.11 memory. Nallo and KOlll:ltsu (1 993) reVH:W recent reseJrch on dcvdoprn"nt of implicit and exphclt memory. Patricia flaw:r and her colleagues haw provided impm_iv(' evidence for delayed imitation ofcvem sequ<:nc� in thirteen-month-old infants. revl<'wed by Bauer (1996). . Data showmg memory fai l ure by .1mn�ic p.1tienu on aduh versIons of such tasks are provided by McDonough ("{ oU. (1995), '"Iu." faci that ;1l11nesu; paTIents perform poorly does 110t. ofcou�. 11�('SS;Irily Imply th;1I mf.mts explicitly recall th", c\'ent K'qucnces, bm II is consm..m with h t is JXK�ibihty. Assesis ng the IIllphcnh-xplicil naturr of Tl"ITicval In very young childreTl IS dIfficult \)c,C3U� of their limned abilities 10 COIll municate. rm...n:sungly, Myers, Pcrri�. Jnd Speak..r (1994) t.m!)ln Il."n- and fourlcen month-old infallls how 10 OperJle a lOy pUppel and examined their behavior toward the toy on �everal OCC;!s101lS 1Il0nth� �ud years I�tcr. when lanb'1.1ab<e skills had impro\'ed. Compared with youngs to:o without prior o:xposure to the lOY, Ihese dul dren showed 1ll0� ime"",1 n i the pUppel and had all easier time lIIaking it work. Y�{ Myers 1."1 at obsO:Twd almost no t:'\';dence of verbal fCcall of P;J.St episodes involving the toy. and conduded thn rt'tennOIl was almosl exclusively based on Implicit memory. As Bauer (1996) nOl.:1., these findmgs han, lI11port:.llu implications for understJndmg the infamik amncsla we all have for the first two to three )'nrs oflik because they indi cate that �ome aspcCI:! of events can be retained for 10llg periods of time. Howe\'er, th<'Se evenl rcprescntJtiom nuy nc\'er Ix-come convened jlllO the nar!':lli.,.� form nec essary for bter recall (for observanons lnd diSCUSSIOn of infanlile amnesia. �c Melt zoff. 1995; I'Lilemer 6. White. 1989; and Usher & NeiS5("r. 1993). 27. Sce T!':lnel and Damaslo (1985) and also Bauer (1984) for skill conducullce studies of prosopai,'llosics; s«; Young (1992) for prumng stlldia. 28. for revicws of �arch on memory rehabilitation aftcr b!':llll d�rllage. �ee Gli�ky �nd Schamr (198%) and Wilson (1987). 29. Gli�ky, Schlctcr, �nd Tulving (1986b). Wc suggested that the vanishmg cue� rechnique aid� �"OCabubry learning bec�U5(' It enables alllllCSIO to llIakt' use of priming. but other flcton an' also rele"',lI1l. For example, Hayman et al. (1993) ha\'C found that the pro foundly amnesIc patlelll I c1l1l Gent' can l"arn a great deal of new semantic mforma0011 wht'll hc s i prevented from makmg erron that interfere with subsequenl learmng (sce Wilson ct aI., 199-1 for a sinular approaeh).A1lhough the \';llllShing cues procedure does not prevrl1l Incorreel gu�, it does ensure that palients e.,."'"lUall)' provide � correel answcr on every trial. HamlJlIl �nd 5'lui", (\995) have found that �em�ntic learning in amnesic patients benefits greatl)· from t!':lining conditions that eliminate n i terference produced by P",VIOUS error<;, although amnesic palLcnts still e:dubit Impaired semantIC leammg compared to control subjects. 30. For Ih., computer leamlllg stumes. sct' Ghsk}'_ Schacfer. andTulving (1986a) and CILsky and Schacm (1988). 31. For the Job tr,lIllLng studies, see Cbsk)' and Schacter (1987, 1 989a). Much to our aston ishment. these studIes \\�re reponed as imllt-pag" news in the 11�1I StrutjlJlmllli on October 5, 1 9')3. in an article by David Stipp with Ihe hNdlin" "Amnesa i StudIes Show That l3!':lin Can 11e Taught at Sulxonscious L,,\�I." 32. One parucubrly proulLsmg extension of the \';lnishing cues proccdurt' is the errorless learning teduuqne developM by Wilson. Baddeley, E'':.J.ns, and Shiel (199-1). 33. We ref�rrcd to this kind of rigldlly as "hypcrspc:clfie learnlllg" (Clisk)' "I al.. 198�). For follow-up rCS<"arrh, s«; BLllters. Ghsky. and Schacter (1993). fur analogous phe nomena In 10m wllh hippocampal lesions, �e Eich"nbaum (199-1). Hamann and SqUlTe (1995), by COl1lr.lSI. observed only a nonsl!;lllficam trend for hyper
patients in Hamann and Squirt"5 stlldy mily have relIed more on residual exphcll mem ory, which is UOt particularly mflexible. 34. Joanne Sih�r. "Show Focuscs on the DIVersIty of Black Art" (llImml Hemld, February 5, 1993). 35. T"l"phone ill1en'iew with Cheryl Wnrlck. October 25. 1991. .36. Nancy Stapen."lmab'CS IIolll the UnconSCIOU�" (&sr,,,, C/�, October 25. 1991). 37. Some sludlCS ha\'c shown th�t visual word pruning is decreaj.t'd whcn dctat.1s such as typefont or t)'peca� �re ch�nged betv.�en slIIdy and test. but olhen haw failed to observe such ('!TeclS. �b1Wlck. Kosslyn. �nd SquIrt' (1992) dlscu.!$ some of these slLLd_ Ie'S and provide eVIdence that type-case speCific priming is a.m>cilted wilh Ihe right . cerebral hemisphere. Srini\';.Ls (1993) T('port� that priming offaJUlliar pIctures can be affected by changes in physical details. and Church alld Sducler (1'J'J4) ha.,.c shown that auditory pmnmg can aim Ix- highly �pcclfic, affected by e\ocn small changes in the fundamental frequenc)' of a speaker's 'OOlce. For re\'iew and discu\Sion. s«; Curr:lIl, Sclucter. and 13t"'ioscnoff (in pn::ss) and Tenpenny (1995). 38. For WLP, �e Sch\\':.J.rtz. Sa!Tr:m. aud MarLlI (1980). 39. See. for example, Demonet CI al. (1992) and Peterson et al. (1990). 40. For dlSCU.!$101l ofstudIes on priming of6miliar pictures. M'e Srinivas ( 1 993). 4 1 . Our initial \\'ork 011 {,bjeel decision primmg is rcport'",d in Schacter. Cooper. and Debney (1 990). foor studIes with amnesIC pal1cnl5. sec Schaefer. Cooper. and Treadwell (1 'J'J3). Olher srudlC$ ha\oc TC\ocaled that amnesic patients can show inl.lct priming for '';lrious kinds of nO\·d perceptual illformanon, including geometric patterns. nonscn� ....,orris. and unfamilur flces. For � TCcem n:vlt'w of Ihest" studes and Iheir theofCtic�1 I Llnpllcatioll5. se., Ke�ne el �L (1995). 42. Schactcr CI al. ( 1 ?90) �lso showed that, when peopl� aT" t'1I(:uur.lged 10 come up with th., nam., of an object frum Ihe real world that fLls each shape. expliCIt mO:lllor}, for thc objects is enhanc.-d. but the priming etTeCl diSr�1 bi�s to call pr�vlously studied obJecu "possible." For �iblt' obJccl!§. thls bils prodllc� pril1llllg. For 1Il1 posslble obJeclS.they a.!$�rl. the bIas IS coun le!':leled by explICit m�mory fOT th.. unusual ft'�ture\ thaI makt' Ihe'e objects im�5i ble, \\';Ih the ll.'Sult that no priming LS obscn'Cd. IbtditT and McKoon have ptO\'lded some ""'Idence that IS comment with these Ideas. In 3 lengthy connde!':luon of theIr position Ihal attempts to cbnty the i5sucs. we ha\� pointed out rhJt theIr hypodicsis does nm fit with all aV'Jilable data and h�ve SllggC'Sled an alternative account of theIr results (Sducter &. Cooper. 1995). In our fim article on posslble/LtnposSlblc obJeCl pTll11ing (Schactcr el al.. 199() , we poulted out thaI failur., 10 oilsen'e priming of impoo;sibl" objecu could be attributable to differenccs in Sl�e. complexity, or otlter f.-alures of possible and Llllp<WIibk objects we had not controlled. We also nmed that prmung of Impossible obJecl3 mighl be obser.ocd If such fealUres could be equaled. (;ar!':lsco and Seamon (m pTCSl;) recently reponed thai the impossible objects We' used are perceived as mono complex than the possible objects. When they equated pc�el\led complt:xIIY. tltey found prmung ofbmh possible and impO�Slble objects. ThIS findmg suggests Ihal people can form some sort of structural rcpr.,st:ntauon of simp!" irnp;:w;ible objec s l. 43. For the PRS theory, see $chatter ( 1990) and Tulvmg and SchaCler (1990). 44. ThLS paUent 11 descnbed at lenb'lh by Rlddoch and Humphreys (1 987).
330
331
S,hactl."r, M cGlynn . Milberg.. and Church !iludf'llts,!iC'C' Church and Schacu:r (1994). :,md for auditory priming ill amnesic palif'llcs. sec Schaclt:r. Church. and Treadwell (1 994).
45. For auditory prnnmg 111 patH,'1It JP.
!)(';("
(\993). I'or audllOry pnmmg in college
46. Th{" first smdy to eX.llllin.. priming ",ilh PET Kann;ng w:as rrporl"d by Squill:' el a!. (1992). They found ,hat prmullg was �'5OClated with blood flow dl"creascs III l"Xlr.1ltri�le occIpital corl("ll", but also found �clw.uion o(the hippoc:uupus durmg pnmmg.
ThIS btter findmg probably n:flects the (
ullIlII:r.tt:'d" prlllung
LII
Squire et al.'� (>xperulll'm, :as Iht" authors thctuS/:h1:S acknowl
,
,
,
,
..
Schacler, Church, & HollOn, 19(5).
5 1 . See Devine (1989). For a review and dISCUSSiOn of nnphcLl memory in sodal conlexts,
nill orn.en� blood flow rlecrr�S<'S in eXll1lslr;au:
52. Su Perfect and Askew (1994) for the eXp<'TllIlenl on ad\'erli�ing and impicil mcm
inaled COlII.lminalion from t"xplicil memory ;lIld also ehmmated the hLppoc:�rnp.11 WI,"
ficial grammars in eoll...g... �Iudellls. For a review of Ihis work SC(" R.dx:r (1993) . 50. For Our ambiguous sentenccs exp"nmcnl, sec McAndrew� G1isky, and S<:hac(er (1987). For other \\urk on conceplual pnmmg, see Blaxlon (1989), GT"lf, ShmialllllT"l, and Squire (1 985) and Hamann (1 990). S ome research indiC:1I1!S Ihal. whe" primmg n i voh� acquiring n"w �malllic associations amnesiC pauenlS do 1101 show 111I;lCI per formance (Sch:ac tcr & GrJf. 1986: ShunamuT"l &. Squire, 1989). The same appears 10 hi: lrue WIth some OIher kinds of nO\·c1 aSSOCI:lllons (KinoshiWl & \v.I.)bnd 1993;
1996). WI' dUlI
1.. edged. In nUT PET $C:Ulnmg slUd)' of priming (Schacter. Alpert et ... aCIL'�uon dunng pnnung. Yet
sec Greenwald and thnajl (1995). l
ory and SanY:l.1 (1992) for a discllS1ioll or the reblion betwet'll IIUphCLl memory
occiplul region� durmg prlmmg. Furlher e\"ldence ImJong OCClpLWlI c orlex wuh vLsu�1
research
word priming IS reportt'd by GabrlelL et �l. (1995), who found Llnp�m:d VISual word priLlllng i n
a
patit'nt with damage
The observ)uon that prnmng
333
N o tes
Notes
332
co
the occipital cortt'x.
W;lS
a<:<:ompanied
by
blood flow dWfiJSts suggests
th�t LdcntlficULOn of primed �Ii!lluli requi� less Ill<::tabolic aClivity and pOSSIbly fewer lleurons tlL;1tl identification of nonprimed stimuli. Thu idea LS supp(')f!ed b)' cxperi nwms wi th LlIonkrys show ing that as stimuli ""corn" inc�asingl)' f.1mi1i�r. the n:sponses of 50111(' neun U1 .. ' m th<' mfcnor wmp0r,l.1 cortcx gl1lduall)' decrease (for a review of these studLes, sec DeSImone, Miller Chehzzi. & Lueschow. I'J(5). However, prim i ng may not �lw·Jy� :Lnd exdusivel)' invoke blood flow decreaK's SchaCler,Alpert, et at (19%) nOled some priming n:Jaled inc�aK'S outside Ihe eJ
.
and consumer ps)"ChoIOb'Y. Wilson and ll�kke (1'J94) introduce the Idea of
menial conWlmination and review a luge bod)' ofrelevant c"ldence.
53. For dIscussion of the fUIiCliolis of ditferem forms of 1ll"lIIory. ami fOf the comraSI """"""" rapid am! �low learning systems, sec Sherry and Schaner (1987). Squire (1992), and McCklbnd ct al. (1995).
C H APTER 7 Emotional Memories: When t h e Past P e r s i s t s
-
,
.
'
-
d«rrases in �lation to :luinul sludi" :lnd � n i reunon (0 blood flow mcre.aes :lnd deerelK'S III skill leJrning experiments. 47 For PET sc�nnmg and object dc:cision, 5« SchaClcr.. Relln:lJI. CI :.J. (1995).. Thc Ldns leadmg up to Ihe PET sm dy :Ire docnbed IllOSI fillly In C.oopcr el :II. (1992). For du
I . Inlen�ew wilh Melinda Stick ney Gi bson December 17. 1993. 2. All ofBmwn :llld Kulick's ( 1977) subjects "'t'r(' seven re3rs or older al thc lime ofthc Kennedy �sm�IJOIi. Wmogr�d and KIlJmb't'r (1'J1:I3) report Iha[ nearly everyQne born in 1956 rcuim an �IIl:ltion flashbulb. "�Ih gT"ldual1y decreasing numbers of flashbulbs reporled by people bom in Ihe subscqu"m six years. Although Brown and Kulick's report IS gcneT"llly regarded as thc firsl inv"tig:.tion of flashbulb memOTlCS, ColegTO\,"(, (1 899) reported a simu i r in'·estigation of memoT)· -
for Ihe ;JM;l!Sinanon of Abraham Lmcoln, wilh roughly s.imibr I't'§uhs. For
..
cussion of Ihe role of inferior le1f1por:d :lnd fusiform regions n i objeci and flct r«og I\luon, 5« fOb.ul and faT"lh (1990) and Danusio (1989). 48. The dl«o(lJllons bcf\\"C('Il pnming :md skill learning an:' reported by HUllers, Hemdd.
Salmon (1990). hnpalred sequence learning and p];lIullng in cerebcH�r p:l.tlents IS n."poned by Gnfinan ('1 al. (1994) :lnd Pncual-Leone eI al. (1993); �e Salmon and llUl I<'rs (1995) for reVLew. 1'�T"\'t'd pl:lllO playmg and Il."anulIg III amlWSla "'Crt'" reporl<'d by Starr and 1'11IIh['5 (1970). For further dLscuSSlon of (he cerebellum :lnd 1carmng see Thompson :Lnd Krupa (1994). Ni'\5Cn and Bul1"mer (1 987) �porl imact sequence learn ill); II! all1n("$IC patJ<'nts. �I ld Il..auch, Sa\"�I,"t'. CI .a\. (in press) provide PET datl. K�rni el �1. ( 1995) report Ihe filllctional MJl..I stud), offinger setjuencd. 4'J. For habil learning in monkeys, see Mishk in, MalanlU(. and UJchevalier (1 984). For impaired habit learning with basal ganglia damage, !K'e McDonald and While ( 1 993) and Ihe review by Salmon and UUllers (1995). For caleb-ory learnmg III amlLeSI:I.. sce Knowlton �nd SqULTC (1 993) and Knowlton, SqULre, and Gluck (1994). Kolodll)' (1994) reporb !lUl amne�ic p;lIients can show normal c3legor)' I...arning when the t.15k Ltl\lolVC$ calcgont.mg dot paltems. Kolodny also reports m i paired cat...gory leaming in amnCSLC patients on a more complex wk imulving cbssificanon of pamungs by dlf kmos of categoTical knowledg.... For preseT\'t'd learning of anificial gr�lIllllars
III
..amU5, and Squue (1992). KnO'\ lion el at. baseO tht'ir �lI1neslC pal1ellls, St'e Knowllon , R \\urk on Ihe cbsslc 511ldiCS or Reber and ;lS.SOCIales showmg IInphClI learnmg of artl-
geneT"l1
3. TIle ('mire fluhbulb memory SC'flt'S IS reproduced m Turyn (1986).
4 For the multin:lrion�1 study, see Conw:!y et :1.1.. (1994): the Lom� ['Tleta sludy is ..
dc:scribed
by Nes i ser el al.. (in pll:M); and
Ihe Olaf P,d,u" sludy � i reported
by
Chris
tianson (1989). 5. Larsen
(1992) plUVLdcs a deullcd analySIS of hiS memory for Ihe Pahne assassm�non
compared 10 olher news events :lnd finds that mundane news events art'" forgotl""
quickly. In ContldSI 10 flashbulbs, ft'W people c:ln rememhl:r eJ<:l.ctiy how Ihey lcarned
,
WIlli
:I.
review of fLashbulb memorics, .see Co nway (1995).
and
fert'LlI 3rtins. ThiS suggt'S1S that exphei l memory lIIay be necCSSlry for :.t.CqlllTlIIg ce(
.
abolLl Ihl' nl'WS thaI the b'Owrnmelll fin:llly passed its 1llU51 re'CIII budb"t'l or how Ihey recent
learned about who won Ihe mOSI
mayoral race In their lown.
6. NeisK'r and Harsch (1992).
7. Weaver (1993). 8. Neu�er and Harsch (1'J'J2). p. 9. 9. Brewer (1 992). 10 The evid"n,e cOllc"rning contributions of reheJTS:II and affect 10 flashbulb memories is not enlirely dear-cut. For example l'llIemo:r (1984) has reponed litde eITecl of�hears.al on memories of Ihe Reag:1Il :lSS:1SLS n:Llion a!templ. and Neisscr and l larseh (\ 992) failed ..
,
1 1. . 12. 13. 14.
10 find dfeclS of r:l.led affCCIi\'"(' :lTOusal on I't'temion of tht' Ch,d/rogt!" disasler. Rubin and KOl.LII (1984). Th" quotc::5 a� lium j:l.mc::5 (18<JO), p 670. and Terr (1988), p. 1 03. ..
Wilkmson (1983). For Ihe Loma Prieu earlh(IUakt', K'e Cardena and
Spiegd (1993); for Chowchilb, set'
N otes
334
T.:-rr (1981); for III( North Carolin� tornado. see MadJ.k.15\r.J and O'Brien (1987). Kr)�I;al, SouthWICk, and Charney (1995) summarize numerous studl(�S of comb�1 WI c:r.IIU.
15. QUOIC5
nc
from langeI' (1991). 1'1'. 34-35. 11 from Barker ( 1 991), PI'· 25-26. Dr.Wilham Rwc:rs was an actual psychl;l.!rISi who lre,lIed protcsring Hnnsh }>O("I Siegfried Saswon. U;l.Tker's novd 15 a fictlon"l accoum of Rivers's treaum:m of S:ruoon and other soldiers. R i,'C'ns :.lelUal climul nscs and views arc describt-d lucidly In RJ\'Uli ( 19 18). 17. See. for example, \"lIn del' Kolk (199�). 18. Tt'fT (1994). p. 28. 19. I'rnoos :l.l1d Nader (1989). p. 238. 20. For tht 1988 school shooting 5CC Schwam, Kowalski. and McNally (1993). For (01111m tbshbach, ..c.... MacCurd)' (1918) and ;11>0 Pendergr.lsl (1995). 2 1 . Fr.ankd ( 1 994) . p. 329. Set' :1]St> Spkgel (1995). 22. Good (199"). For other eXllmpl<"S ofmisremembered traumas. see CCCI ( 1?95). 23. W�gelll;lr Jnd Groenewcg (19K!:!). N. lIT"Jdky el at. ( 1 9(2). For sinllbr rcsult!;. >ee Br�dlcy ln d l3:odddey (1m). Brewer (1988). �nd Ouna �nd Kanunl)o ( 1 967). 25. Chrislianson alld Loftus (1987). 26. For WC�pOll focus. see l.ofUl�. loftus. and Me5So ( 1 987): >ee Kr:.lmer. BuckhoUl. and EUl)ellLO ( 1 9'X1) for individual diff<'rencCli rebted 10 anxiely and mrmwiug of altt'JI tion: for anXIety �nd memory, see Eyscnck and Mogg (19')2). For a revlcw of sludi� on how emotIon affects memory for central and peripheral information. sec Heuer and Reisberg (1992). 27. Pcnonal comlllumc,uion. Richard J. McNally, May 1995. 28. For memory III rt'l!aha-wnnng \·eter.m�, see McNaUy el al. (1995). See Krynal 1.'1 al. (1995) :md \CJn dC'r Kolk (1994) for re\'lew� of mldics ill\ulving memory III Vietnam vctcrans wllh �-lrJumauc Stms duorrkrs.Turner (in press) di'iClISSd the exVC'nencn of md1\"ldual ,·eter.lIIs and JOCielys reaction5 to the war. 29. For a rt'\'It'W of Tl'�Jrch on o\'ergcneru memories, see Williams (1992). lIaxter �I �l. ( 1989) ftrs! reported rc-duced len front1.l aetlvlI)' m depressed p�li"l1ts. and Ihe fmdmg Juj smcl' lK-cn rephc;1(( ' d by olhers. .m. For dISCUSSIon of moad-<:Ol1gruenl relrie,,:!.I. see B ower (1992). 31. Sec Cbrk �nd Teasdale (1982) for mood-<:ongruem retTll'\-;l1 in depr�d pane111s and Mmch and Nugent (1995) for a Te\'lCW of memory bl;lSl.'S III deprC'SSlon, �11)net)'. and rebted cl11llc�1 condlUons. 32. For depressed panenrs, see l�wl1lrohn �nd Rosenbaum (1')87): for pam plllems, :ocC Elch. Rl'e\·I'S,J�"gl'r. and Graff-Radford (1985). 33. Sec lIrewm.Andrcws. �nd Gotlib ( 1 993) for a re,'lew of rdevant llteratmc. 34. Kluver and !lucy ( 1 937);Wcukralltl, (1956). 35. Mishkin ( 1 97t'1); Zob.-Morgan et 31. (1991). 36. For clCcclkm Sl1 mm�rie� of the role of various pam of th,; �mygdala in fear l:Ondl Ilonmg, Ke LeDoux (1992, 1994). 37. See Bechm el at. (1,)95). 38. For a thorough revIew of atlllllal research l:oncermng strns-rebted hormones, the amyt;d�b, lml melllory, se.. McGaugh ( 1 995). 39. MarkowltSlh el al. (1994) report sdecti\'e emotional memory lou in one of thdr p�t1enb. �nd Gloor (1992) summanzes hiS own �nd others' r�arch on dectTlcai SI1l11u\;;l.1I011 of the �mygdala. Adolph! l't al. dc-scnbcti Imp31Tt'd fear recogmllon 111 �n Urmch-Wiethe pauenl With blbteral lnl)'gdab Ibmage (199", 1995).Adolph5 ct aI. (1995) report lhlt uOlbt enl amygwla cbmage doe! nOI produce nnpalred fear recogrlllloll. lnteTCSungly, Larl)' 16. Rh'':-rs's obsr-rv.lI1on
Notes
335
Squire has found that an amnesic p:ltiem wllh extenSl\'e amy gdala cl1l11agc: has no problems rtCogllil:ing felr (persoll,,1 COmlllUnlClnon, October 19(5). B..em>e the patient described by Adolph! et al. had amygrllb danuge SIIICC blTth. and Squlre' s pauen! only sustained It 111 adulthood. the fear rt'cogmuon fadure III Adolph!; et al:s patient may be altribuuble to an early fadun' 10 learn emonon.. 1 expre-ssions. For till' PET §c�nning srudy. s« Rauch. \'lI1I der Kolk. el Oil. (m press).This srndy must be mler p�ted cauuously. bea.u� It ucked a control group. In a related Slud) by Shin et aI. (1995), the rg i ht amygdala \\-;li �C1l\';llrd �Ild Broca's �rca de;tCU\-;lted whell Vlellum combat v('terarn widl posl-tr,lIInullc Stress dlsord{"r fOTlned mental muges of Tt'cemly �cn l:omb�t pictures. But nelthl't of these ctreclS WlIS obsen'ed in h..allhy comb�t \·cterans. 40. Thc dfeclll of )'ohunbme on memory �nd perception III Vietnam ,"Clerans arc described by �t1.l el �1. (1995). For eVldl"IICl" on catecho!anllncs. see Yehuda et OIL (1992) and Brown (1994). Krystal l't aJ. (1995). and \o;In der Knlk (1994) pfO\'ide reviews of �ychoblOlogical aspect! of post-tral1nallC l StTdS di'
CHAPTER 8 I s l a n d s i n t h e Fog: Psychogenic Amnesia I . "lumberjack" IS nUl the patient'l Jcrna! I11c kname. A full Tepnrl of lhe case is provld",d III Schactcr.\Vang, Tuh'lng, and Fr,'edI11Jll ( 1 982). 2. Abeles and Schildcr (1 91;) estimale lhat less lhan 1 pereent of �ychlatT1C palients exhibit fimuional anUlesl�: Klrschlll'r (1 973) offerl an esnm�te of bc!ween 1 perl:em and 2 percent. for Ihe 1 4 pc-reent e:s11111ale of alllllt'Si� during wart illle. see Saq,'\'1lt and Slater (1941). Thu esnmale includ..d bolh "xlcl1si\'t' alllnl'Sla for the entirt' personal past. and 1110rt' limited amnCSI!1S for particular en·nlS. 3. This case is dC'KTlbed by Fisher (1 945). For Te'!'leW$ of fugtJn and re];lIed flmcriona.l relTUl)rade amnc:sias, see Klhlsuolll and Schacter (1995) and Sehaclet and Klhlstrom (1 989).
Kritch�'5ky. ZOUZOUtllS, and SquIre (Ill pms). 5. Thi s leIter \\-;lS sent to me by Dr. Roberl Kaye' on April 29. 1986. 6. The case 15 reported byTrtad\\�y el al. (1992).As ofthe Nfly I9'XIs. K. had nOI rt'cov ered hi5 memoril:!i (Michael McCloskey. p",no!ul commurucltlOn, Decelllber 1995). Thry abo dc-scnbe another patlcnt who 1� III �'"Cral rt'spects sUluiJr 10 K. 7. The lIritilih p�ychlatT1st Ch�r1es Symonds adOI'll:!! Ih" Cl':ITeme \.jew Ihal 311 cues of fugue and e-xlellsi\'e function�1 amnc:si� lre conscloudy slmulalCd. He cbmled tlllt J simpll' �peech had allo\\"Cd hun to "l:Ure" the approxunarc\)' half-dozen pallenlS on wholll he had tried II. "I know fmm elCperlence Ihal ),our prt"tendcd 10'iS of memory IS the re:sult of some intolerable c111otion�1 �illmtion." Symomh informed his amneSIC patients. "If }�>lI will lell lIIe lhl' whok �tOry. J Jlroml)l' 3brolutdy to Tl"�peCI rOUT con lid<'nce, will giw you aU til'" help I C.ln and wdl ""Y 10 your donor and relati"es th.lt I h3ve cured you by hypnOl1srn:'This q uote COI11C'!i fmm an addr� SYlllonds g:l\'e to the National Hospital in London on February 27, 1970. The elllirr address IS Tl"pro duced in Merskey (1979). pp. 258-265; the slIllubuon quote is on pp. 26+-265. Pendt'rgr.c:1 (1995. p. 122) also Clte:s Symonds's 51111u\a110n speech. For a case in which genume amnesu turned n i to �imubtion.
336
N otes
could not remember still felt that they mighl recall the {"vent jfther were g!vcn cu('s ,md hints. Simulators. by contTaSt, maintain"d that cues and hints would not help th..m to remember. The general ide:.t that simulawn; tend to overplay their role, hf.ha\'ing " more amn�ic th�n amnesics," is central to other tccJmiqul'S for delcCling faked amlleSla. 8. Recent use'! offunctional �mnCiia with a hisfory of brain injury indude Akht;lr, Lind sey. �nd Kahn (1981), Daniel and Cruvitz (1986), GudJonsmn and Taylor (1985), and GlldjnllSlion aud Mackdth (19!1J). 9. For n:vicw of ("ady nudies mentioning brain injury ill fugue and functional amnesia, sec Sehaer..r and Kihlstrom (19i19). 10. For amnesia after rap... see Christian.soll and Nilsson ( 1989). For rcvkw� of imited l 3mllcsias. sa Kihhtrom and Sehaet"r {1995), Schacter and Kihlstrom (1989), and Spi,,!;d (1995), II The 26 percent mcidence ofamne�iJ is provided byTaylor and Kopt"hmUl (1 984).The other stu"i� are consid..rt"d in an article of mine that surveys what is known �bout amnesia �Ild (Time (Schaner, 1 986)_ See also Ht"rman (1995). 12. I'or alcoholic blackout, set" Lisman ( 1974). 13. Quotes are from Moldea (199.') , Pl'. 124-125. Fur a flothand aCCOUlJ{ of Sirhan's �mnt"Sia :tnd reenactment of the crime under hypnosis, see Diamond (1969). 14. Bower (1981) proVIdes an early discussion ofmood Stlte-dependt"llt retrie'OII. In the years -dependent Il."trieval has uften pmved -Ah... sinct" the puhlication of Bowt"r� paper, mood sr an dusive pht"nomenon, with a "now-you-see-it-now-you-dun't" quality. Mood Stilt<.---ependt"llt --d n.,tr;eva�higher levels of nxall wht"n moods Illatch :l.f encoding and rctrit",-a.l-is generally not as robusl as mood-congnlenT rerriev;.!, which I discussed in chapter 7. In mood--
Notes
337
18. See Jacob<; and Nadel (1985) for a discussion ofrecovercd childhood fcars and a rev;ew of relevam animal research. 19. Solomon et al. (1987).Tht" rcse;lrch study in willch this patient wu mdllded revealed lhat "ight ofthirty-fiw ISIsponded in a similar manner to two independ�nt l'n'nu. 20. Van Dyke, Zilbt"rg, and McKinnon ( 1 985), 1'. 1072. 2 1 . Corial (1907). Tht" cause of amnesia '11<1$ ne"er concluslVdy determllled In this cast". 22. The homosexual r:tpe- case is dcsnibo:d by Kaszniak et al. (PhiS), and Ihe telephont: dialing case IS reported by L}"()n (1985). Ot.her clinical examples ofimplicit n,,:mory an- rcviewed hy Schaerer Jnd Kihlstrom (1989) and Kihlstrom and Schacter (199';). 23. For discussiollS ofJanel, see Ellenberger ( 1970). Hacking (1995), Perry and LaUTl'nce (1984), and van der Kolk :lnd '':In der Harl (1989). 24.Janet (1904). Tht" Janet quote is from ElIenbt"I),.'t:r (1970). p. 371. For Breuer and Freud's cases. st"e Freud Jnd Brt"uer (1 966). 25. Christianson and Nilsson (1989); for other cases, see Schaeter and K,hlstrom ( 1989) and Tobias, Kihlstrum. Jnd SchactC"T ( 1992). 26. For n-view and discu.s.<;ion of implicit emotional memory in alllll<.'Sic puielm. s�t" 'Ibbias t"t al. (1992). 27. For a lenb'lhy t"XpositiOIl ofJallet'S ideas, st"(.' Janet (1 907), 28. Mortun Princt" ( 19\0) also viewed di.s.<;ocialion ;IS a natural co"'e1luellCe of the archi tenure of cOl,'Illtion, J� oppost'd to the �Trictly pathological process Cllvisaged by Janet (1907). For modern perspectiws on dissociatiun tht"ory that bt"Jr on multiple person ality p�tiems, sce Bowers (1991), Fn-yd (1 994), Hilgard (1977), Kihlstrorrl (1 984). :md Spit'gel (1991, 19')4, 1995). 29. See Spit"gd (1995) for a thoughtfill discussion of the relation between dissociation and repre�siot1 with rt"gard to p>ychOt,"CllL" amnt"sia. 30. For a rt:(;eJ1l revit"w of inhibition, �tten\1on, and the br:lin. st"e UesinlolH' �"d Duncan ( 1995), 3 1 . For PET studies and inhibition, sec GrA�by et at (1993) and Nybl'rg, McJntruh, C�bt"la, e-I a1. (1996). In thest" studies, there \\':IS eVldcnce for 111hlh1l10fl dUTlng retrieval when a bT:lin region showed dt"ereaS("d blood flow during explicit rdri"\',II
Notes
338
Notes
personalltlcs. and Aum found thaI he could xlut\'t' the !.line cffut Ihrou�
�ypnoslS.
Shortly :iller the puhhc:mon ofAum's �. there \\� a delug .. ofTeportS of !oIlIwr C;;I5C:S
ITl France aml lhen America. For dct.1ilcd hlS!on� ofdu: mllclCCmh-cclltury d.,yeJop menl ofmuluple pcnon�1itics. sec J-1;ac\:ing (1'J95) and Kenny
(1986).
38. �e Uowcr (1')81). Kltilitrom (1984). Pumalll (1993). l. : I1d SpIegel (1991) for VlITUnts on the id..as tl!scUMed 111 thlS pll.ngnph.
39. I'rmce (1910). p. 265. See :,150 Cori�1
(191&)
and Janel ( 1 907) for slI1uiar
�bscrvauons.
40. For our study, �e Nissen CI al. (1988). AU of th.. names of the personalmes dOIl)'Iill.
ne
pseu-
.
"1. EVldcnce of the abuse was provided both by Ie's lister
and h...r mother. Ie, .!lUlla,11" ,I"d ' nOl admil lO tht· abuse', but later conced�d thaI It had occurred. II is not c ear W 1<'( leT Ie IIIlt1ally f�l1cd to relllember the �buse or simply did not wish to �cknow1cdgt: th�t
II h�d OCOlrrcd.
42. Ofshe �nd Wmc-rs (1994), p. 2)9.
43. Of!hc lnd W)I1c-rs'S version of what h�ppened il1 Anile Stone's casc IS disputed by l)�. Bennett Urlun. the mam psychiJtrm involved in her .... t umem. In D,1'1' is quoted
�s
11
June 22. 199::.,
a Ch1C1b'"O m�g;t:(lI1e, Bnun's at1orn� Oebr;, . �yll1g that Of,he �nd Watters's account of the C;lSe U " Just a\.lsurd.
�rtlde by M�tt Keen;1.l1
til
Nrw City,
�
44. The rrorll/illf documentary &arrJri",![j", Smmr wa� bro:l,ka�t Oil Octobe� 24, 995. S.ee . Coons (1994) for corroboT
45. Mcrskey ( 1992). p. 337.
.
� �� .
46. For thoughtful dlscll.�ions on the rule of social and C\lltuml (actors In shJ P I chanCier ofmultiple personality p�C1ent:S,5ee Hlcking (1995). Kenny (1986). an
t C
u�
hern (1994).
47, My dlS(;U\SIOn of g1ucocorticolds IS based brgely on S3polsky's (1992) excellent u'eatmenl oflbe subject.
48. The experiments on primat" art' R:vtewed by Sapolsky
(1992).
310-31 1 .
PI'· 269-270 amI
49. Experiments show1I1g memory lrIlpalntu:nl as a !"("Suh o finjections thai cauK' tempo
r.try elevation of glucocorticOid levels arc reported by Wolkowllz CI al. 51990) �l1d N.-wcom.-r CI aI. (1994). In th.- \�lolkoWllZ et al. Study. memory ImpalH1l.-m was
rrflecled by
IIICRa�d .-rron of comlnruion during TCnll
of l word list. In the New
com"T .-1 31. study, II1lpalrnlcnl W"lS rdl«t.-d by lllCreascd l'rron of omi�iOl1 during , expo reeaU of slOrie-s. Keen�n et �1. ( 1 9')5) report long-term effecl!; ofglucocorticoid
surt' on expbclt bUI 1101 llnpliCiI Illemory.
The e\'ldence on reduced hlppoa.mpal \'olume
rt'porled by llremn.-r et "ll.
U1
tr.tu111aciz"d \'eler.ms has been
(1993) �nd Gurvllz ct 31. (m pn-ss) , i n Gurvitz et aL'S 5 3111-
1'''''-''
pie. � strung posL1lVC corrclation (+ .72) W"lS observed between degree of comb"-I .
sure and hlppoca111p�1 \,0IU111"', f�\'onng the Idea that tr.mlllltic combal exposure may
Stress
aSSOCIated wllh
ha\'e mdeed playrd 11 rule 111 the reduced hippocampal volumcs
\11 combat vctcr.tns (Roger Pittman, person�1 Com111U11lCall0n. Nowmber
1995).
50. Urcmner et al. (1993) reporl tlut \'etcrans with post-Ir.tLLlll"llic suess disorder remem
bered fewer neutT
51, For stUdies on cormol l'eb'1J.b.llon III abused glrk. St'e D", Dellis, Lefter, et ai,
� 99�); De: Bel
lts. ChroLnOS, et aI. (1994).The ullagmg Wldy IS IqlOrted by Stem et aI. (199::.),:.md the arll des Oil aUloolographinl memory impairment
m
,",'OlIIen With Jbme h�ones are by Park
and Balon (1995). and by Kuyken and 13rewin (1995), who st\ldied depressed W0111en.
\\ IIh so-called focal TCuogr.tde amneslas, s�" Hodgc:s (1995). For ideas about bmdmg codes and the I",mponl lobcs. sce Oa11111s1O
52 For a reVIew of bram-dJrnagcd pallents
( 1989). Hunkm et al. (1995) apply D�lllJ�io's Ide�s
amne�la.
339 to
a casc of focal retrograde
53. Sapohky (1992), p. 334. Sapol!ky also points OUI that. perhaps ironically. p",opie who hav" �usta.111",d lenom bnm i1uurics arc often trrJted widl steroids Ihat IIlCn:'aK' glu cocortICOid le"ds and h"nce may fimh"'r endmger the hippocampus. 54. Some amnesic p�{Jellls wllh medial lemporal d;lln�ge do han! fairly cXlen$ive rctro gr.tde :Ll1111c<;ias that cxtend back mure than a decade. And in llt.- syndrome uf tr:an siem global �mneSla. which has becn hnked (Q rc:duc",d blood £low 111 the hip pocampus and rebt",d litrUCtUrcs n i the: medial t"'mporal lobe, some pallenls have been described who cann01 remember personal cvents d�tms back to cluldhood, "v",n though they recognize (:1111011$ public fib'lLrt:1 from the di$t�m p�st; s"'c Evans. Wilsoll, Wra.lght. and Hodge-s (1993), See al50 I I(>dg('5 :U1d Wlrlow ( 1990) �11<1 Kmche\'sky ",t al. (1988). HO,",'evcr, whc:n Kritch,,\'Sky el al. (111 press) directly com par.-d tr.tnsient global amlle<;ia pati"nts wilh p�)'chogel11(, amnesia palil·nu. they found slrikingly d,tl�rcnl results: P"lti�nts with tr;amicnt globJI amll�sils rccall...d remotc e)(periel1c� more eaSily than reecnt OIlCS whereas pau",ms , with vsycllOs"nic amnesias sho\\'ed precisely the oppoSlte plltern. Also. the: psychogen ic amneSia patients had 110 anterograde memory problenl.'i. whereas the 1r.l1lsient global amne sia I'�ticnl!; did.
55. &eJacobs and Nadel (1985).
CHAPTER 9 The Memor y Wars; S e e k i n g Truth in t h e Line of Fire I . Personal communication from Dian:l Halbrooks. April 24, 1 995. All 'luotCS attribU1\·d to 01311a i-lalbll)O\(s in Ih", chapler aT!; I"-k,,,n from thiS 11'1I"'r. wllLch Dlan� wrote to lIle n i �POIlSC to my rrquCSI for informanon about her story for this book, A brief descriprion of Diana's ca� �ppeal\""d in the D,lll.u '\/I'rtHlt(' ,"1'14'1, "Memories Almoot Split Tlus Fanuly," by St""'''' Ulow (May 2 1 . 1995). 2, Ch"'lt is ql101l'd in PelldergnSl ( 1995), p. 102. My diS(;uMion ofCh",u's calc dr.tws both from Pendergnst. who Internewed Ch",it, and from I",nb't y h anlCles on M�)' 7 and Mar 9, 1�95. in the Pr(}llidm(t j(}unJ,,/.Jjllllrrm, "Be�rli1g Witn"ss: A Mali'S ReCOI'.-ry of HIS Scxual Abu!.... as a CIllJd." by Mike StJllton, Thl'se articles descnbe n i detail Ch",it's scn("h for Farmer, hiS one-hour phone ....ol1\·ersation With him, and
his �1I"'mpts to sue Farmer and the camp th�1 f'lI1ployed hUll. Onl' cunous feature of tIm conyersanon is th�t Farmer qUIckly 3dr11115 to molesting othl'r boyt. but says he remembers Ch"i! only after cOl1Sldenble prodding. Farmer has ciJi1l1cd that he only admil1",d 3buSI1lg Chcn and others 10 get him offthe phone. Yet Ch",u ;1150 dis cov"red that Farml'r had prc:viously been forc",d to leave positions beuusc he \\';IS suspect",d of molesling dllldrl'n, mcludlng one lllCldelll in wlllch he was forced 10 l",ave town as � resull of bcmg accused of rnol"sting a Judge's son. It sec:ms highly Improbable th�t Ch",it would ha,,{' just h�ppen ....d 10 rccO\'Cr a 1111'1llmy about a 111311 who 1Idmmed molc:!t.ing childrrn and had Imt JObs becau,,,, of his problem. had Cheit nOl bl'en allUs",d hmlsdf. 3. For detail",d prCSCnl"JUOll of individual ca<" of r«O"ercd memortcs and tltl';r df"cts on famille<;. see Goldslem and Farmer (1 992. 1993), Loftus and Kc:tch;l.I11 (1994), 06.he and Walters (1994), lnd Pcndl'rgrast (11)1)5). 4. Olffermg �ccounts ofdlf' Fr�nk l ll1 ca� exist. ror Ih", defense perspecll\'e. sec Lofius �nd Ketcham (1994). and for the prmeelltioll perspective, sec Ten (1994). MacLean (1993) provides a deuucd and comprehensm: Journalistic aCC0\111I_ The
Nru, \;',1r li,"" (April
S. 1995) reported thai Fr.mklm's conVICtion
was O\'er·
NOH-s
340 tUTIlC'd
III
Notes
part beC3U� the JUry was pll"\·..m.-d from learntng that lIe:niy n,<,ry cor
robonll'd deuil of ElieclI Llpsk...r Fr,lIlldm� memory
ne\\'lpa}X'"T ;l.CCOUllts shortly
TroTT
(1994)
was
publicly ;l.\';ubblc: from
after the: crmll:.
tdls Ih" Story of formcr Miss Amcncll. Marilyn V�1l Dcrbur Atler. For
ROSI';l.unc llan. sec Loftus and Ketcham (1 994), p.
79. The
numbers CQllcermng the
False Memory Syndrome Founcbnon were providC'd by director Pamcb. Frcyd (per sonal communi.;:alion,
Decemher 1995). She Slales
thaI overall. about 3O,()(X} people
h3VC' asked FMSF for infonnauon. [n addition 10 17,000 that �p�;l.r 10 i'1\'ol"" repressed memory rrcovcry by an adull, about
1.500 arc
9,OOO ;lre inqUIries from
professlOllals.
from �oplc qUc:'Stionmg thelT own recovt'rcd memories, :md 300 are from
who !un" reIDelI'd their I11rrnories. The remainder arc from uulividual. who s;ay thl')' ha''(' been f�lsel)' accust'd of abuse on � bHis other than recovery of wprnst'd people
lIIeIllOr}'. �rndents, and genenl mtcre:n mqumC1.
5. For discu!Sion oftllc bKkbsh. kC" Uass and Davis Ham:y
(1994). pp. 477-5.34, HC"nlian and
(199.3), :md Olio (1994).
6. For general ",views of the debate. se�' Lmdsay and Read (1 994) and Loftus (199.3).
Some sellse of the passions aroused by this debate can bc glC"�ned from (he fJct that a
\'anery ofjournals h;l\'C reccnlly deVOted ellure i!Sues to it: tlpp/jrd C":!!,,iril/t P$yr/IO/
12. 1.3.
15.
techniques)
many Ie-tie" concerning the review and was gratified Ihat vcop!c responded positively
LrgoJl")' ill DispUle (Crews. 1995). ThC" volume comaim crilillUl'S of recovered memory dler�py by Fredend: Crews that had be:ell pubis l hed Pw.'lously III 'nlt Nnll ) "b,k Rtlfltlil oj Books, tOgether with responsC"S from critics of Crews's wmings. 10. The study of nvc memories § i reporled by Tromp el iI. (1 995). I should note that no
unple�m m....mories Ihal .... omen . pnyndcd. If Ihe- t:l.pe memOrlCS well: older. this
in a blurry or fugJ1l....nted �nbram. Freyd (1 994) empha§I7.C� that Illkll1g �bout pasl experiences with Olhen is cnncal for creaung lin accC"Ssihle and SOCially "$hareablc" engram. H owcvcr. the soci;11 p�yehologlst Dan Wegner has reported a ,erie-s of exp('r iment! Ihal show Ihal $OnH:tulles peopl " have greal d,fficulry Irymg nOI to Ihink 300UI specified items. For example, expenment:.ti "olunlee" who are told not to think about :t. "white beu" end up thinkmg about 1\ more than those who are not i,mructcd 10 stop thankmg about thc word (for a review ohhcse experlmelllS. see WegJler. 1 992). Koutsu:a.1 and Schaaer
(Ill press) provide- a length)' diSCUSSion of Imennon:.ti forgetling
and VQlunury thoughl suppression an r.:lauon 10 forgetting of sexu�l abuJe. For an m�lghtful ficllon:.ti dl.""piclion of how :I person goes about Irylllg 10 dehbenleiy forge, pamful e\·ents. Jee Van Arsdale ( 1 995). II. Bere-nd�"n's
Niglllliflt mterVlew aU'ed 011 May 2.3. 1991. The
qnote from hiS autobio
gnpillcal recounting of the abuse and Its consequcnces is in Berendzen and Palmer
of specific
to be distinguished from the originabimplimc 1I01i0n of repression as the
For recent dC\'t:lopmems concerning the coucept of repression thaI attempt to relate ;( to comemporary mcmory research. S('C Jones ( 1993). 17. Fo, studies of n"prCSSOI) and memory for negative e...perienct'S. sec OJ\'IS (1990) and Myers and Urewin (1994). Ibmaehandran (1995) dcsc nbt'$ pallent HM. Holmes (1990) sur....eyed Ihe ro::scareh literature and concluded thaI no e\'1dence for d"frnsin:
mfornunon ....� :t.v-nuble about the re\auv.... ages of the r:tp<' memOrll>$ and the- other
could be why Ihl')' "..,re less elear and '·IVld. Nonctheless. Ihe: cbu are conSlstem wilh Ihe Idea thaI fJ.iling (0 think about or ulk about a lraumatlc l'xvcnence might resul!
discusslOlU of thIS kmd of repression. see Herman (1992). Frederickson
forcing om or keeping OUI ofwme specific mental con lem !Tom consciousness? It s i thl5 problem that Freud sought to resoh'(' n i his monograph, lI,hiblllO,tS, Symptoms, fllld Anxiety (1926). where he proposed Ihat the lerm drjnuf' (A&tI'f'h,j n'place the by Ihen "l'rgrown construct of repression. and Ihar the orignal i Il'rm be reserved for the earl\" Simple meaning, namd),. mOliv;ucd alllCSLa ll or forgetting. ......Ithough the suggestion � Impleml.":med by sollle later psycho:t.Jlaly.lts . Freud himself did 110t pursuc II wnh �ny coll,istency" (pp. 219-220).
al. (1995).
I pu;kl'd �
For rel<:\�nt
speaking of d"fensc proccsses ill genera!."' HI."" goes on 10 depict Freud's dill.""llIma dearly: "HO\\" was Wpr('$SIOIl in this general sense (sub!;uming a t11ulti phclIY
8. For nuten:.ti concerning " memOrlCS" of past h\'es and alien abductions. see BakC"r (1 992) . Spanm el iI. (1991). and Mack (1994). 9. I IIIJ.dC" this pomt in a !cngthy review of SC"I"'r:.U books concermng recuvered memo rll'S that was published III the April 1995 !lf1Ilific X Ammcall (Schacter. 1995b). I n:u'i\"ed
1995. a volumc appeared entitlcd nIt ,\t.>mcry IiiI/!: FrtJ/J:S
alldJohn
Freud "st�tes that 'repn"ssion is the found.uion stont' on which the whole structure of p,ychoanalysis rests. Ihe most e-s�l'mial part of it' . . . we are to understmd .. Ihat Ir" is
7. A eoUewon ofpap...." pres.::med at th" conf"rence can be found 10 Schactc:r. Coyle. el
popubr title. beuus<: ill fall
Pendergrast (1Y95). andY�pko ( 1994). For reviews ofrelevant cxperlments on directed forgetting, S«' Bjork (1989)
(1992). and Terr (1994); for crillquc:s. � Crews ( 1 995). Loftus lnd Ketcham (1994). 06he and Wallen (1 994) . Pope and Hudson (1995). and Pendergrast ( 1 995). 16. These poillL� an: made forcefully by Erddyi (1 985) . p. 218. who points out that when
1994). COlisdouS/lru 0111/ Cll,I;lIiti"" (S....pt....mbt:r/Deccmbcr 1994). lutrma. ,jollal}<mmal of C/j,,;wl alld E:qltrilUfllMI HypllOSu (OclOber 1994 and Apnl 1995), and Ptyrlu"atri( Au"a/.! (Decemb....r 1995). among others.
ory W��:' which providcd thc baSIS for the title of this chapler. ....pp�rentl)'
(199.3). p. 67. There I! one pawge at the begmnmg ofthe book whC"re Berend>!en can be read as suggesting thaI his forgettlllg 1Il\"OI\'�d something more pov,;crful than eon KIOUS $upprasion. Recounnng the first lime his mother had sexuall)' molested h1l11. lkrl:ndzl.""ll s:ud thaI " Once It W;lS O\'('r. it w .. � erased" (p. Xl). Th15 cOllld be: taken 10 mun Ihal he was lilerally unable 10 remcmber Ihe C\"Cnt ItlUne(hately �fter il occurn'd. But 11 seen iS lIIore likely Ihat it n'fl'TS to hIS famlly's Jbility 10 act as If nothm g had h�p_ . pelled. which Ikwndzen goes OJl to des.cribl."". For examples of such cascs. see Loftus �nd KetehaJU (1994), OIShI." and Wdtl"e" (1994).
SOli ( 1 994) . H. Brewin et iI. (1993) revIew studies showing that people arc generaUy accurate lil n"C ollectmg the general co ntours of cllIJdhood (see chapter .3).
'':I,')' (August
to m)' attempl 10 alter Ihe st�ndard porlrayal of Ihe debatc. 1 titled tlu' 1"l'\'lew "M"m
341
18.
repressions e:
Erika M:t.rqu�rdt. artist's Slatemenl. 1 992.
19. The mformati on about Ihe study of the Father Porte, VIctims was pn".
by per
sonal conUllUniOlions from Dr. Stu3rt Gras.sian. Dccembe:r 1994 and October
1995.
20. Sec. for example, Harvey and 1·lerman ( 1 994) for cxamples of �ketchy p3rllal amneSlas III lC"xu�1 abuse survivors. and UriCf(' (1995). For earlier studies. see !:Iriere and Conte (1993). Her man and Schatzuw ( 1987), and loftus. Polonsky. Jnd Fulhlo\"<' (1994). These StudlCS
21. See Elliott
abu havc v.lriOIlS Olher problem) (for det�il('d critiques. sec Pope and Hudson [19951; KJhlsu"01ll [in pTeS$J; Linds;ay and l"tead 11994J, Of she and Watters [1994J. and Pc:nder gust 11995]). To t:t.ke Just one example. Herman and SchatzO\,' (1987) wponed that fourlet'll of ftfty-three chellts (26 percent) who parliCl paled III a group therapy pro gram for mccst survivors reponed "5eVC""re" memory IIllpalrmem for the abuJe prior 10 memory recovery. OUt on avrragc:. the- abuse began when Ihese patients well: undcr fI,.., yean old. I ha\'(' already pOlllled om that fot II1mt of "'. C"�rliest recollecuOlll begin around ages 1\\"0 to thT«". and not Illuch 1$ rememberc:d UlIIII a few yealll laler (chap ter 8). The " K"\'t'rt" memory impaIrment III fourte-en group therapy particIpants could
otes
N O les
be altribut:lble to normal forgelting of early childhood tXjX"rienc� a, opposed to mas S""t." repression. Fmilly. all rc:trosp«II\'C studies shaft' anOlher mt."thodologlCal problem: It IS nm dear how accul"oltdy people em respond to slIch question! as " \Vas there t\1!'r a time when )'011 had no memory of this en'm?" (Elhol1 & Bnere, 191)5. p. (35). I)lf ferem peopk may !rLlcrpret such qllcmons differently. :Iud i t m�)' be difiicuh III retro- . spt."(;1 for people to recolle.:t with any preci�ion prior Stalt."S of forb�mllg. 22. Respondenu 111 imervit."ws concermng sexual abul'l' sometimes withhold mfornlation mitially (for reasons other Ihan amncsla) thn they bier dinllgc in follow-up darlfica lion 1Illl'rVlews. and Williams did not report any danficatlon intcrvlt."ws. Moreover. If these I"l"Spondt."llts had becn abused more thall onn". they nllght h�ve confilsed Ihis panicubr incident with anothn abuse episode. Indeed, two-thmls of Ihe \\,omell induded 111 tht." 38 percent fib'l.m:· remembered other episodes of abuse. For rurthl'r diS CUSSion, see th(' critiques clled m thl' previOils nOle. 23. Schooler ( 1 9 94) reports Ihal Ihe abusl''"' ulCldents JR had rorgotten about apparently occurred ov..r a period ofyears. When he eventually reCO\'�n'd the menlories after sec mg a 1110\ Ie thJt dealt with �exual abuse. the priesl admitted the 1110Ics(;,Jtion. HermJIl and I-br ... e y (199�) ha,'C �Iso rt.'poned forgetling of extended Jbusc m the form o f ;J compo'llte CiL� compose(1 ofSC"\"l'"r:.U different pJrienu' �lOnes. refentd 10 as " Emily B:' In The Williams (199�) study, Wilh.1ml does providc the ag.,.; of the women who failed to recall the index hospical admission. On the one h.and, the�e ",,'Omen were al thc nme of Ihe mdex admission on ;J\"l'"l"olgc yuunger than women who recalled the admission (...'-en yars old vs. milt' Y";Jrs old), Implymg that normJI fOI);CT{ing of chlld� hood inCldl'11Is plays a rolt' in what Wllhams observ..d. On the mhcr h�lId, roughly half were sewn or older whell they were brought to till' hospllC' WC-TC: expenenced by the wum..n in Wi!lia/lls'$ $3111pk (q;. . about on�-thJT{1 of cases invol,-ed intercOlllW. whcTC:iS allmh�r onc-thnrl 111volvcd toUCh111g and fondling).W.. do nOt know whether all of the women I1Ic1uded 111 the 12 pereent who reported no abuse had 5uffcred I'xtemiw and 'IC"ere abust· (which. If forgol1ell, would imply the existence or m;J$li,'C repression). or whetht."r 50Ille or aU of these women endured milder forms of abuse thJ{ mlghl be subject to " ordlnary" forgening. Moreover, Wi1!iams ( 1994) found a marg111ally 51gnificam !Tend for more fon:dul abuse 10 be better remembered than Ies.� f,.rceful �busc--the oppo)lIe of whal Illighl bt- expected If a repression mechanislll well' openung co block 0\11 Ihe mOM unbear able abuse Curiously. although Table 2 m Wilh�ms (1994, p. I 172) �h()\\'"5 thIS trend, the text ofWdhams's paper .uys Ihat "There is a tendency for Ihe wOlllen who w�re subjected 10 more force 10 nOI recall th.. �buse" (p. I 172).This error w:u Ipol1cd by a psychology gr.Jdu;}t� �Iudent at Tempk UIII,·eDlty. Evan HMTlngton . who discusses il III Ih.. r-ehruary 1995 edmon of th� E\fS FoII/ld,l/rlm Nm>$/mn. Harrington clunetenzcs th� 1Il1St.1k� :I.'§ all undetected typo ill Ih.. m�nuscnpt"
repressed memOf} c.w::'i. Wakefield and Underwab't'f (I9IH), p. 87. report"d the results of a $un"t')' senl to accused parcnU who belong 10 the FMS I-uundmon. They found Imle ('\-Idenc.. for a hIstory of psrchopatholOf.:)' 111 Ihe accusers. Thu SlUd) is linnte.d by th� f.lct Ih3t 11 rdies on the n'lrospecuv( (1tllnares ofthc �ccus..c!. Howt."\'Cr. as tht;' authors poi11l (JUI, thf.." results �n: c01l5istell! wllh dat.1 reported by Spano) t;'t al. (1')')3), \\ ho found no evidence of scnoIU psychopathology 1/1 p\'. J l11ultUlnllion doll.lr I..w SUit I� filed aga11lst the alleged p<rpelntors. 29. r..hcLCJn (1993), pp. 391-395. dlscu� the reb(Jon bel"e<:n repressIon and di§socll lion 111 the Fr:mklm c:l.'§e wnh respect to the testimony or Dr. lJavl(l SpLCgel. who strongly IllJlllt.llI1cd a dm JJleli on b..lw....n the IWO. 30. Maclean's (\993) hook providt'S Ih<: most deuiJed accountin g :.o.w.ibble of Eileen
342
24 Wllhams (1995), p. 655. ,-,.
Ibid.. p. M3.
26. Ibid. 27. McNally et al. (1995) describe a direct..d forgetting expenment 111 which S\ln1'\'Ors of
sexual abuse suff..ring from post-tr:nlln�IIC StfCSil dnordet. when comput-d to abu'e surviw,rs wHhout POH-traumatic nrcss dl50rder,showed enh:ulced ll1t'lllOry for ;Jbuse� rt"btf.."d words (e.g.. mccst) and w..re less able than controls to fo��t abom abusc related ....,Ords when mnructed 10 do so. These findlllgs arc in rome �peCIS sundar to memory biases obsen'Cd III dcprt.'S!lon and other emotional di50rders (sec: chapter 7); it s i undear how Ihey reble to memory for an actuJI epi
Fnuklin's ",<,mory.
343
(199�) for th� '}OllIIg IIIJn. Likewi..., in Ih... "t:II-known cue of forllle-r M,ss Am...ricJ M3nlrn Van Dt:rbur Aller. who recoverccl m<:nlOrLes of 51'xual abuse by hn . fllher, confirm:.o.lion W3§ provided by J sister who had JI,,�,y� rem..mbered her UWIl :.o.bu:se. Van Derbur Atler wcm pubhc wnh her recO\'"red mt'morH."1 111 1991. but she had lIullally recovcred them some Ihre.. decadt."S earh..r OIl 19c twenty-four. during a COn\'CTS3110n with an old fTiend. She Slated Ihat the ahu!-C by her ratht'r went on from agt fiv.. until she Icrl for COllt;'f,'I: and !lUI sht;' had rorgottttl about It complt-Id)'. According to Tnr (199-1) . VJn Derbur Atl<:r "�plil" into a day child and a 1l1ght ch,ld. �"d forgot ahom rhe abus.: ,irlLl�!ly as �n as 11 occurred Allhough thIS ma)' �m 10 he eVldenc� for ma��in: repressIOn or dISSOCIatiOn, Pcndergnsl (1995) points OUI th;;lt it i� difficult 10 Sliy much about the n�lt1rc of fOl),"etling procCSSC'l thai took pbce 'IOl1Ie tluny to (ony yean pnor 10 Van D..rhur Ader's 1991 a1l110Uncement. [n another docum�nl..d case ofwhal �ppC;JD to be a reco\-ered memory. Sujnbl'rg ( I\1'93) d=ribed a twcln'-ynr-old boy who cnt�red ps)choan�lpis bcc�usc of severe obsessh'C-<:ompulslve sYlllptOm5. DUring the period Ihat he "";IS III analYSIS, the bo)' "".IS riding wllh IllS mother and "he �sked If she h�d ever tried 10 Slr.lngl.. him. Stu tI...d that he remembered, mother admitted tillt �. he had. Nf.."ith<:r could recaU how old lie "";IS at tilt" mne. 50 they drove home to comb through picture albU1lls.They w.:re able 10 d.u� IhlS 10 hiS SC\'Cnth birtluby" (p. 716). SUJnherg utats this :as recO\-cry ora n'pmsed memory and links LI 10 subsequent changt."S in th.. patient's symptoms. It is unde.1r. howcvcr. wheth�r alld 10 what ext<:nt the boy had b�en unJble to recall Ih� mddem prior to mel1l1omng 11 10 IllS mother. 32. St;'t;' WIIl,aIllS (1995). In addition 10 Mary. Kun. and Tanp. W1!1unlS descnbes in some det:ill n,'O other IlIIii"idual cases, Jaekie w;u apparently told :.b<)ut the abuse by her mOlher al agl' seventeen. Faith appe�n to lu"," alw:..)"S rt"lIlemhered �t least one mCI dent of abus<:, exccpt for ill1ervals of forgetti ng thai occur when she IS happy. TIIl'� women recollected an exp..rience they had not thought ahom for reJrs in rnponst· to 1 cut'S that cliCl1ed 50tIle :l.'§PCCU of what Ihe)' hJd encoded about the "xperL� l etrie, ... encc--Just as m eXJmplt."S of nontraulIIJlic memory 1 con$ldercd earhcr III the book. 33. rh.. quote IS (rom v;m der Kolk (199�), p. 261, Data conccrmng character� i tics of tr;lU mallC and lIontraul1latic mcmorles are reported by vall der Kolk Jnd Fmt."f (1 995) . They 1I00e thaI. ahhough 11 is "possible" that lr.lmnahC memOrLt'S are "n'ilecl1ons of selll'lllon C:XjX"nenced at the llIomem of the InUllu," It IS also possible thai " lIlcrcJifil aCII\1ty of the amygdab al th.. momf.."1lt or recall nuy be respollsible for Ihe subjecuv<' asslgTlllient of accuracy and pt;'rsonaI 1Ignlficance." Hennan (1992. 1(95) also provides thoughtful dlscuuions of the rebnon belv.-e.en tranmanc ami nomr:mmanc memOries.
31.
Sec Nash
Notes
344
OICS
34. For example. Fredenckron (1992). p. 88. SI
. records evcT)·thmg that happens '·using at luSt one of Ihese: mt""lllory processes. Fred
erickson allow5 for some lllfidclicy in memory records, noUng that the Slress ofan abu
si\'C experience Illay cau$(: :tltered perceptiOnS. with the result that ··SorllC aspc� of
1Il1�g..:ry may be eX:I�er.lled. even though each image rcpn:!K"nts an accurAle shce of the abusc·· (p. 90). 35. Ste, for example. Fredenckson (1992), Hernun (1992), and Ten (1994).
36. Liplllksi and Pope (1994). p. 245.
37. Groff's decmon s i rendcred in The Sllte of New l"blllpshLTt� Hillsborough County SupCrlor Coun, SI.lrc:
New
Sralr of
�
ofNt"UI Hamp,iurr I'.jM/ H""gt'ifoflI 94-S-045 through 94-S 7; . I'. j.?/m .Hom/MII 93_5_1734 through 93--5-:-1936 D:tlwZlLs S
Hampsl!irr
: Non-mbcr 1995 ruling is rendered IJ1 The SUle of New Hampsh i re Hillsborough Superior Court Southern DiSlrict, S/alC of l\'(1.l' H�mpshirr I'. lJ;:vid 11'illrm 93-5-21 11. 2112.
38. Sel"" 06he and Wallers (1994). pp. 178-1l'1l. for a description ofunnins·s findin� and
�
Young (1992) ior 3 Iher.opi t·§ penJK"ctl\"e on rlnlll abuse.The �urvey OflU Il""fican Psy � chological Assoca i tion membet> i.. part of the largl""r rc:p-ort from the Na1l01l�1 Center
for Child Abusc. sUlllm�Tlzed by Goodman l""t at (1 994). For an informati\"e allai),!i5 of the mual abuse: pht""lIonlenon . sec Naliun and Snc:dc:kcr (1995).
39. japanest' sources report tlul
over 300 people ha\"e vanished since joi rung the euII tlut . has been Implic:ued m the nerve g:u attack ami that they ha\� r cO\"ered .1 � ing machi"... thaI nlay luve b een uscd to disposl"" of the rem�ms of the VICtims. �he
SlOry is
reported
�n�_gnnd_
in th� /1.:'$rO" GlolH, 'japan Cull May Havt"" Ground Up 300
Brnhc:s,
Medll Report ' (May 25. 1995). ·
40. N elson and Simpson (1 994).
41. Ibid., p.
126. For other compelhng 5tonC5 of retractors. sec Goldstein and F.1rmer
(I'J9J) and Puley ( 1994) . 42. Spanos et al. (1991). 4.3. II lurvey of o\'rr 800 psyeholhcnplst5 by the dinil""i.1n Michael Yapko suggeSts th.al
nUllly are IIOt familiar with. or put lillie
. stock in. weU-colllrol1l""d nudl(� of hypnosIS.
Yapko asked respondents to indic:ue whelhcr they agrec or dl�� wlIh a Vomety of
queslions about h)'Pnosls and other npects ofther.opy. Forty-5e\'en percenl ofthe ther .
apiSts agreed either dlghd)' or stTOngly wllh Ihe sUlelllt·nt ··Psychot he�pl51S can have . greater fmh m the del;)lls of a tr.IUIIIltic e\'rnt when obtJ1Iled hypnouo. lly than oth erwlsc" ; 31
pereent
agret""d wllh Ihc st3tement ··Whl""n someone has a ml""l1Iory o f a
IT;l.UIll;o in hypnoSIS. 1\ obJecth'rly must have occurred·'; 54 percent agreed With the
S{";owmem ··Hypnosis c�n be: uscd
to
reco...er memones of al""lual �'{.""nts as f.1r back as
birth'·; and 28 pc:rc....m agreed with the SlJtelllenl ··HypnoslS can be used 10 reco\-er Jccur.lte memories of past liv.:s:· No SCientific evidence exisls to support any
stJtcments. I t is somew hat reaMurmg Ihat I«l percellt ofthc
fI.""'lpondents
of thest'
inYapko's SUT
\"C}' agn:t""d with Ihe statement "It s i posSible to suggC1t false mt""lIlori..-s to someone
who Ihen IIlcorpontC5 them as true l11....mories."· But it also uuplles that one-fifth of
his sample believes th.1t It
IS
not possIble 10 su�1 faisc memoriC$. Ste Yapko
(1994.
write about known trJUm3S thaI Ihey o:.-.:plidtly remember, :IS Pt""lInebaker has dOIll"". and having pe0l'lt· h unt for repn:ul""d melllories Ih;1I mighl or 1II1ghl not have occurred hy " ntlllg down whatever pops 10 miud. as was do ne In I)Iana Halbrooks} thcr.tpy. The c:ue of Neil discu� in chaptl""r 2-the )·oung 1>0). who could remem ber hiS recent experiences by Wntlllg but not ulklllg--suggests different retriev.lol palhways for wrlllen and spoken materials. BUI Neil's ("a5l"" s.ays nothing �bout Ihe p-Olt'mial accuracy of forgotten cxpericnces retrievcd Ihrough tr:r.ncc writing. 45. Sec. for example. UafoS and Davis (1988. 1(94). Frederickson (1992). and Hnm:1II (1992).
3 collection of papers dealmg with social influen ces 011 memory, sce the volume edited by Middleton .1nd Ed,,"�nh ( 1 990) . 47. For therapeutic c:rreCls of illl3smal rehving of actull tr.tuma. � Foa el al. (t 99 I). For imagining uIITl""lIIernbered abusc. see Frederickson (1 992) . pp. 108--1 12. Hym an el al. (in press) report effects of mugery on fJIsc: memory creallOT!. For a summaT)' of work
46. r'Or
KoW)'n
on imagery. perception. and the br.oin. sel"" (1994). 48. The survey ofpsychother.tplsts IS reported by Poolc el .:U. (1995). r'Or a dl""t:ed :lli analy ,is and di§cu",on of ml""lllory teChlllqllM used in psyehot!ll""r.op'..-s concerned wllh d"ldhood sexual ahllse.see Unds:ty and ReJd (1996).
49. For sOJrply contrd'ling e:nim�tcs of the prevalence of illusory lIIt""lIlories of sexual abuse:. see Whitfield (1995). who c1ainu on the basis of clinical experience that false memones of s.exual abuse hardly e'·er OCCUT, and PCndl""rgrasL (1995). who reasollS that the phenomenon h.1s reached c:pidcmk proportluns. 50. The quote; are from a book t""ntltled Ffl'I5!f jill" '''I/I(t'$ by ther.tpi�rs [bndler and Grinder (1979), p. %. They arc reproduced in Hacking (1995).
(1987a) reviews early anecdotal e\'ldt'ncl"" concerning implicit memory and trance or aUlomatic writing. Swdle$ by Penneb:tker and colleagues have shown that wnung
about tr.oumatic experiences cm Yield ther.tpeuuc benefits (for revlcw. sce Harber &
Pennebaker. 1(92). HO\\'C\'Cr. thn.c: benefits were observed III C
quesllon tltat the tr.tUllll occurred. There
I� a
huge d,/Terence between luvmg people
LofLLl$
(1982). p. 149. For janet, <ee
5 1 . For experirnentll research on distincllons between memone; of real a"d innginl""d t'\ocnts. see johnson el .11. (1988) and Schooler. Gerhard. and Loftus (1986). For d,nt cal suggesuons concerning ways to dutinguish true and faisc reCO\OCll'd ml""IlO l Tles, see Pcrson and KJar (1994) and Terr (1994).
52. For contrasting perspecth·o:s on this point. Sl""C Masson ( 1 9l'14),
Schiml""k (1987).
Erddyi
(1 985), and
53. SeeTerr (1988) on tr.tunUl. and pby. 54. For mellin' critiques ofsymptolll checklun, see Lmds..ly and Rc�d (1994), Loftus and Ketchanl (1994), Of she and W�lters ( 1 994) , Pendergrasl (1995), and Yapko (1994).
55. Sel"" Pope and I ludson (1992) and Pope el al. (1 994) . 56. Frederickson (1992.p.41). 57. $ce McElroy alld Keck (1995): quote IS from p. 732.
3 useful pllllosophJ(;.1I diSCUSSion of §ubtletlc:s Il'garding Ihe rebuon between memory and rc�hly, sce Hacking (1995), esJK"cially chaps. 17 and 18. I sho uld empha size thaI I ;om Iwr asscning thaI all n'covered memones of cht.1dhood sexual abuse nec
58. For
ess;orily conum a kernel of trulh. m the sc� that such memoTies musl c apture SOll1e thing that was tcrnbly wrong in a p�non·s early family hfe. In agre cmenl
wilh Neissers (1994) analysis oflhis issul"". It se...."u there are many pOSSIble sources of all Illusory memory of sexual abuse; a problematic urly family life s i only Olle of th....11I.
1995) for delJils of the survey. 44. For an excellent lUSIOHcal review of 1r.IIICC writing. sec Kouf!iual (l992). Schaeter
345
C H A I� T E R 1 0 S t o r i e s of E l d e r s 1 0,vcn (I992), pp. 1 5 , 5 1 . 2. Ibid. . p. 97.
J. Ibid .. p. 160.
N o tes
Notes
346
4. The .,xhibiti oll G1tJ.log for O\oerbys of Memory COlllall)! an es5;lY b y memory rese�rdu:r Ende! Tu]vmg. Much of tht IflsulJauon IS b�d 011 Tulvmg'$ lde� about forms of lllt"ffiOry.
5. Pal Vonel'. persona! COl1l1nUIlICauon, M�rch 29, 1993. 6. For recent n:\';"w� of explicit recall and recognition deficItS LII (."ldcrly adults. s« enik Cll], (IY95) �Jld Light (1991). For the r..call versus recognition COntrast, see Cr�d( and McDowd (19R7) . I'Jrkin. WJha. �nd Hunkin (1995) reponed preserved memory for l..ftlright location compared to unpaired memory for tl'mponl order, although they i et aI.. IIOt<: other l'"\·idt,no: of 1l11paired 'palia! memory in older adults ($1'''' :llso Cnk 1995). McDaniel and EnlSlclII {I 992) n-pon normal prospective remcrnhcrmg ofJ. 10i paired be-pc:rformed task III the <'ldcrly. whcreu Cockburn :md Smith (1991) found m
prospective rel1lel1lbe�ing in old lX'ollle. 7. For a revJew ofbr.ull chanK<'S with aging, Srt h'Y et al. (1992).Je�mg;1Il et aI. (1991) rn provide MRI evidence ()fage-rda1t:d dencaK'$ in the volume of the medl,1.1 tempo lobes :md cortical asso cialion are.1$. 8. For a I1.'Vlew of research on neunm loss and al;lI1l;, see Albert and Mos� (in pn.'$S). 9. The �lUdy of hippocampal lll'urons is by West el aL ( 1994).Albe.rt and Mms (in presii) loss in the I'oim OUI th.u stud,,�:s of humans and mOTlh'Ys show liltle or no neuron CA 1. CA2. and CAl fields that COIlSlJlute the core of the hippocampus. where:r.s there IS wme eVld",,,ce of neuron loss in the output pathway of the hipp
the subiculum. 10. For hippocJompal atrophy :md memory perforlTUnce. sec Golomb 1'1 :II. (1994).Albert ';ew evidence on neuron loss in the b:u:r.1 fOTl:'br�lIl. ,, and Moss (in prCSii) .. I I . For changes In fiullla l lobe physiology "';Ih �S". R'e BastIOn: (I99J).lvy et al. (1'J'J2). and Mmenbcrg et :II. (1989). For elderly .1dults' performance on testS sensiove 10 fronl:ll iobe lesions. !IN' MllIenberg et al. (1989), M05CO'VItch and Wmocur (1992). :r.nd Whehhan :md Lesher (1985). 12. For cvldence that frontal lob.:.'1 are more rdev:r.nt to recdl than recogllltlon, temporn see the order memory than span al memory. and cer{;lin prospective memory t�sks,
R'V1<-Wl; by Schacter (1 9R7b) and Shimal11ura (1995). 13. The PET study was arricd out in colbbOr::ltion with Marilyn Albert, N�t Alpert. Scott Rauch. and Cary S:lvage. The comparison that yielded impaired right frontal ..ctiv;1. lion in older �dults invoked one condition where participants provid.'d the fi�t ,,�)rd dlat cnne to mind in mponse to thl'«' Io:-uo:-r word begll1lungs. and another where they tried to remember words that h�d appeared in a �hallow encodmg condmon dur ing study list eXpo'lure. In .1ddltlon to the cle:r.r-tu! agt'-rebted dlffen:nces III right fronti.! activOltion. then: WOlS � lillliiar. albel! less obvious, dlffeTl:'ncl' m left frontal aco area Vluon. Older �dults also !ended to show greater activ:r.!loll thOln young III Broca; perhaps on. cti u rod p guage n a l n i d ke uwo S I h c ll wi regIon. fron{;l! left r o i r e t pos the 111 reRecting � greater reli�llce on phonetIC retrieval strateglt'S III old than young. Th�re 1:.0 a�'-reblt'd differenCe< m J br:lin region known u the lnterior cillgubtt'. wert' .. which is oflen activJted when young people are re{l\lired to pay active attention 10 a urget stimulus. For discmSlon of the frontal and Clllb'1"bt(' con tributions 10 retriev:r.l .
c
sec lluckner and Tulving (1995). 14. See Gndy et al. (1995). It must be noted that. in addilion to the recognition ,'enus reC:l.lI difference, thiS stud), dlffen from tho:- experimo:-nt by our group in tho:- respecl that we u:;ed words and Ihey uSC'd facd. Dlffo:-rellces III aCtl\'3t1om could reRect word e v enus f,lco:- differences as much as 1l.'<:,¥llIl!on versus reoll dlffen:nces. lnte�l1ngly. th g n TI U d s n cuo u n:d d e at rel ageshowed th�t 5truCtures die hIPPOC.1Il1PUS W:lS alllong encoomg in Grady et al.!. study. Because my colleagut'S and I found norm�l �clh';ltlon of the hlppOCalllp\l� during reuiev.d III old people, Ihese findmgs JH.llllt tow.ml possi . ble dlffeTl:'llct'S 111 l\lppocarnp�1 contnbutions 10 ..ncoding and retrieval But �g;lIn. Ihis
347
possibility I� tempered ">, dlffeTl:'nccs between wonk and f�ce5 In rhe two smdics. 15. See Willi: (1987) for the R.cag;1I1 anecdote. 16. For SOUT(;" memory dl'ficlU lnd :l1;1IIg. see Ferguson, H.uhlmudl, and Johnson (1992). Mcllllyn: �Ild Cr:llk (1 987), and Sc.h�cte� el a!. (1991). Thl'Se experrillents show dUI older adulu' recollection of so urce I1lformanon (:.111 be more or leu impaired in dif_ . f<:rent expernncnt.ll conditions. A rec..nt re"il'W and Illela-an:llysis. howen-r, re\'C�ls thaI on balallCl' source mem()ry (ends 10 be unpaired III dd<'rly adults (Spencer & Ita 1995). For links �e�wcen fron{;ll iobc Ullpairment and source memory impairrllenIS l� thl' eldl'rly, see Cralk el :1.1. ,<1990). Glisky, Polsll'r. �nd 1l0urhlC�ux (1995). alld Schac_ ter et aL (1 991). DY"'3Il, Segalowltz. and Williamson ( I 99�) h�\'e recently providl'd . dect,:,phYSlologlc:lJ eVidence indicating that the speCific a'peel offiun{;ll dysfunction assoct:lled wlth so�rct l'«'aJ\ erroN III older adults is dirT("relit from the sp"cific :l5pect of dysfunction rdated 10 perfornullce on probll'IIl-so1vlnG tl'$CS. TIll'Y also pro Vide e " ldence Ihat fromal dysfunction :r.lolI(" probably docs lIot �CCOUlit for all of older , adulcs .source: memory problems. 17. TIl(' �tudy 011 remembl'ring CQlriid("nti:l1 mformation was conducted in collaboration wnh Kathr)'n Angell and Suun McGlynn. 18. For false �m(' cffoxu in t�e eldmy,. see 1)y\. · � I � and).lCol')' (1990). TIl<" elderly arc susccp_ . tlbl<, to a nnubr kmd of IlIlIs on \\'nll un f a mili ar faces. Afi("r having secll a photograph of � a not famous fac(" ollce Of tWICe. olle week bier old.'r adults :lre milch 1II0re likdv 10 claim �hat the fue is f.1I110US dun are youllg adults (D:lrtlett. STr.lter, � fulton. 19<)1). The exper IIIl""t 011 false recognition "� conduC!l-d recently by Kenncth Nornun :md nle. 19. Cohen an� Faulkner (1 989). [n the relevant I'xpo::rim("m, old and )'Oung adul� wt're shown a �do:-()t:.lpt' of a kldnappmg. Late�. <;ome elderly adulu and JOme young adulu
;
fiull,:,,1
TCOId a
WTlttCll
sumnury of rhe ('vent th:lt conuined nusinformanon, lnd others �ad
an accurate summary, Old('r adults were more mfiuenced by Ihe
mmnformation lhan
"'�": yO\llger adult'!; the')' frequently cbim('d that the 1I11�lIlform�l1on w..� part of the
orrgmal Vl�dco{;lped "'Vent. 20. Ha.shtroudl.Johnson. and Chrosniak (1990). 2 1 . Parkm and Walter (1992). 22. For evi dence (;onn'rmng working memory and fromal lobe p�lienb. :;ee lladdcley (1986, 1994) and Shmlamu.ra (1995).The PET studies are by Petrides ct .11. (1993) and . _ I n addition SIl.uth I.'t aI. (199,,). t o frontal-lobe activ;nions, both studies a lso rev ..a!e" \'\'ldence of �ctiv.ltioll ,n po5lenor cortical region$ durmg performance of work mg memory la�ks, particularly the parie{;ll lobes. BaSC'd on studies of monkc)". Fnednun and Goldll1:r.n-Ralnc (1994) h;;r\'e elllph.ulzed that JpeClfic �reas wltlun the frontal and pUleul regions work c1OSC'ly t�ther :lnd are key dClllCnl5 of a dlJinbmed ne,,",'Ork of structul'l'S Ih:r.t subsen\' \\'Orklllg memory. 23. I�r rn�nkeys and "'OrkmG memory, see Goldman_Rakic (1994) and Wilson. a Sca b . dhe. :Inri Goldman- Rakrc (1993). The link hem\'en dop�mme receplors :r.nd working �elllo�y is shown by Wrlh�nls Jnd Goldman-R�k!c ( 1 995).The specific type of dopamme receptor Il11phcated in working memory IS knowll JS Ih<' " 0 I " rcceptor. Arnsten el al. (1994) show lhat Ih<' DI receptor IS impli(;�led in til<' working m ..mory deficits of :lged monkeys. and de Keyser et .11. (1990) proVide eVidence for Dl recep tor d�pletion in the fron{;ll lobes or eld"'rly people. P�rk and Holzman ( 1992) repon "'Orkmg mell\Ory defiCItS 11\ schizophremcs and Bradle)"Welch, and DICk ( 1989) show "'Orhng m�ll1ory deficits in P�rklllson's p:lnenn. For wor�mg memory :lnd aglllg, see re-news ">' Cralk et OIl. (1995) and Llghl ( 1991). ::I. For a re\'1ew ofsemantIC memory and inferenct' nukIng III older adulu, S('(' Light (1991). Clurness (1981) repoTU eKpenmenu 011 chess and agmg. For a sUillnucy of l'CS('arch . sh�m� hov.' ellcodmg �nd retrieval (';In belwfit (he elderly. !IN' BJcknun, Mantylli, and Herllt � ( 1 990). Name finding impairmellt'l III agmg �re commonly 0�T\t:d
;�.
d�nc\l\'"
Notes
348
Notes
the bm arc not well undcnt-ood. They nuy rt'bte to itllp�lI"d inhlbLlory proc� III th�n ddi!rlv' which 1 dIscuss d><.>whcre in the chapter. Oldcr �dult:l are sometime5 less able young people to suppress irrd",,-ml though ts and .ide:l.5 whel� curymg out a cognitive . task, :md tins Ill:l)' sometimes gel 111 the w�y of n-tnevmg .>pee.fie names.
�
26. SCI' U VOle :md LIght (199�) (or a systematic revIew of priming and aging. HOW" (1996) ;ma DJVIS and Bernstem (1992) also pr<:Jl,1dc revu:....'S ofilllpiicil mcmo� an
:l.ging. I bd.le\"e that some of the :.J.ppanom age-relat..d defi�1tS III prmullS an: ;lItnbut· . that do able to the \1st' of explicit reuie,';!l Str.l.lc:gte5 by young subjects III experiments not han' �dequalc proceduIT$ for ruling oUI"cont:umnauon" from explicit memory
al.. 1993). There is al50 some md.LC�tlOn of 1T10� �ro naunced age-related deficits when primmg d('pends on formmg novd ;l5SOClatlons do during a study osk. How:ard. Fry, and iJrune (1991) h ave. shown that older a.dulu not always dww normal pnTJllllS of new :aVloctations all a stem complellon tCSt. although thl")' p<'rform well when they are gJ-"Cn more time than the yo�ng to form (sec Schacu,r, Kih]strom,
('\
novel :LUOCllttons. In another recent study. SchaCler. Church. alld OSO\\'leclu (1994) ng examin..d auditory printing and found that older adulu failed 10 �how marc prinu. , ..r votce when thl.' speJker"s \'Oice was Ihc S
�
than with dilferem voices at study and If'St. HNring lms in th... elderly did not that account for their impaiTt'd auditory priming. However. there LS reason to beli...,."C a voice-specific priluing depenru on fornunS a new assocbnon ��'cen J word :md \'I$ual novd of pnmmg normal I and (:oUcagues My \'Oke. speaker's specIfic �me
re�ned
. Cooper (per l!I p sern. 19(2), but L ldi a i older adulu (&hancr. Cooper, & V object5 n elfe(:1 de(:"'ys prlllung Ihe that ound f reccntly has l cornmulllcauon. June 1995) ... son mort' qUICkly III oldcr than in younger adults. LaVoic :l.Ild light (1?94) notc thu Illeta
ana!ytk pro.;:ed\lr� do nOI indical� th�t priming of nO\'el is gcner:tlly Illore lI11pam:d . than simplc pruning of f�mih�r \�'Ord� in th. elderly. so Ih� ISSUI.' 15 �ot )"� �Itlcd:
, 27. The PET study of priming :md agLng was conducl..d in (:ollabor.lIlon .. lIh Manlyn Albt:rl, NlIt Alpt'rI. S.;:ott Rauch. �nd ClIry Sa\";lj.,-e. 1TI thl' ...Iderly. l.ee HO\\";lrd lind HO\\'.ml (1989).
28. For s.equen(:e learning
29. For the Tower of H�noi task in agmg lIml �mnl'Sie patIentS,
5('('
the papcr.; by D�\'1S
and lkrnstl.'ln (1992) lind S.;ullt-Cyr and Taylor (1992). \-Iov.";lrd and Wigt,,"i (1993) pto vide ;a gelleral discus.ion of pro.;:cdural Icarnmg alld lIging. inclu�ing dLscmslOll of . Howard's expentllenu showing all intJct form of impli(:l1 learnmg m thc dd...rly. hlk elllL (1994) show that older adults retain g�'ncr.tl but nOI speclfk lISPCelS ofa pcrcep
mal skill
n
wcll
;l5
o
y ung people. For diSCUSSIon of gcller.t1 !.Iowmg ;and older �dults,
see S:Llthou!C (1991). For discussion of inhtbmon :md the from;al lobc:s,.sa S�I
al 11Ura . (1995). �nd for �lden(:r: Imkmg memory impalr1ll�nt ;and UJlp,llrt'd mlnbnory �
pro.;:� 111 the eldcrly. se... Stolu:fus et aI. (1993).
30. For fbshbulh memom."S and ;oglng, see Cohen, Conw�y. and Maylor (1994). C:mteltsell and Turk-Charles (1(94) showed that older adults rcmembe:r more from thc emotionally
n�ner (1988) failed to
arousing parts ofa ,;t0l)' Ihan tram the neutral parts Cohell and Fau
find an :woaation dderly.
octwecn the vivl{lnt'SS of a memory and emotional aromal 111 the
31. Kldder (1993), p. 184. 32. The quotn lire from an unpubhshed manus.;:ript b)' Rosemary PlfUlun. pl'O\'1ded to me by the MIA Gallcry, Seattle. For bLographial mfornutlon OIl Pittman, see R� nak and Rosenak (1m). pp. 244-245.
33. The quote is frotn Hufford, Hum. and Zeitlin (1987). p. 42, who pro-llde nutllcro1l5 examplcs of other ddl.'Tly memory pamters and folk artim.
34. Dobrof (1984). p. xVl1i. See Kaminsk)' ( 1 98"*) for a rt'VI�'W of Iht llUcencc therapy.
.
11Icr.tturr:
. on renu
349
35. For reviews of hfl' revIew and rermuilCence in the cldl'rly, see Coleman (1986), Moli n�ri and R.clchhn (1985), and Thornton and \JrolCh.e (1987). For Ihl.' (hficremial ben efits of dilferent ty� of Tl'miniS("ellce. see Wong ami Watt (1991).
36. For stl1dif'S of the remmL$Cence bump, !Ce Fitzger.tld (1988. 1992). 37. Owt:n (1992), p. 82. 38. The fa(;1 th�1 (:uemg only n.rc:ly e\'Okl'd tnemones of UJtrec�llcd expcrien(:f
'S suggest5 th,ll the rele\";L11I engrams had d«a}"Cd or deterior.ttM cOlLsldcr,lh ly. Im"'R'Stingly. Ihc Holfm,llls omcr.,..d that ""In order to lI(:Ceq Ihis lseellllngly forgotten] 1l1aleriai. II was nccl'SSlLry to find a \"Cry sp<"Cific (:"c. and thaI seemed to be: largely a hIt-or-miss aR;ur" (Hoffiuan &- HolTmUl, 1990. p. 145).This observ.tdon fiu wit h � point Ihat ! stressed earlier: when the engrJnl is impoverished or degr.tdcd. only a seleci 5('1 of highly spe cific cues wLlI pro\'lde a sutTtciently good rn�tch to yield a sub jecli\"C cx]X'"ricn(:c of rell1cmbe:ring.
39. For mldin showing be:ller �Iorylening m eld...rly peoplc than III young }>Copl.... st'c Kemper ct al. (1990) and Pr:m :md K.ohins (1991). For a�,.e-rebted probl...ms in telling unfamihar storin. 5('e Pr:m et aL (1989). Even when they lell reecntly Icarnl.'d starin. however. the elderly m�nagc 10 olTSCt Iheir poor memory to sollle extent by super imposing narr-dtl\"C Ihcm�"S, morals. or lessom On thcir reull of Story element5 to J grcalcr dl'gn.'�· thlm Ihe young do {A(bms ('I 31.. 1 990: Mergler, Faust. & Golrutein.
1984/1985). 40. SchleIfer. DJvis. �nd Mergler (1992. chlp. 3) addR'SS the cultural funcriom of story tdling in eld�rl)' adults and review relcv,lnt litcr:IUITt' on Ileg;m\"e stereotypes of aging in Wntern socle[),. Sec also Mersler !lon. SCl' Rubm (1995).
ct
al. (1984/1985). For memory and or.tl Ir:ldl
4 1 . Par " the rl.'mcmhering.'· SCI.' Sams and NtlS(:h (1991, p 57). For the Momaday . quote. see Hobson (1979, p. 1(3). 42. Hobson (1979) . p . 2 . 43. For a d1.swVlion o f Beam's ....,ork. 5('C Gr:l11de (1994). 44. DJnit'li (1988). 45. Danieli (1994). 46. IbId. 47. See Donald (1991) for a wldc-r.tnging dl!£IlSSl0n of extern�l s},mboh(: storagl.' �nd the e\'Ollll';on of nll'llIOry.
48. For a discmsion of the " (:fisi� of memory." see Lipsitz (1990). 49. For STudies of cheri,hed poSSCSSlOm and aging, 5('e Kaml'tltcr ( 1 9(1), Sherman and Newman (1977/1978). 3nd Wapner. Demick. and Redondo ( 1990). For the film and
(:amen memory mdusmo, .\l"(' Kuhn (1991) and Slatcr (1991). The phOto expernllcnu are ocing cOlldu(:led ....'lth Wilm� Kouut::lal, MafCI:.L John \On, Mara Grou, and Kathryn Angc-ll. In the 3(:t1l31 experimenta.l p:.Lr:ldlgm. people first vicw videonpes of several """erycUy scen:.Lrios th:.Lt we ""staged" ourselvo, each CoTll pnsed of a dozen or so milli-e\'t:nt5. In one of them, for examplc. a woman profl"$sor
goc.� about hcr bu,inns in hn office-working on a pap..r. talking on thc tckphonc, lending a modd br:lLlt to a colleague. and so forth. Soml'time after seeing Ihe laped scenarios. pcople return to the Iabor:ltory and look 31 photos of key mOl1tcnu from halfof Ihc C\"Cnu-the woman in thl' a(:\ ofhandmg the mooel br-Jin to hl'r collcague. . This is for lBun(:e i in nun)' w:ays slmlln 10 an cveryday situallon. whert' }'OU ,,'Ould phologr:lph only soml' of the events at a p�r[)' or 011 a tnp. later. however, ""c tt>il our expeTlmcntal p�rtlC:lpants' ability to recall and Tt'(:ognize all the e\'enu that wcrt' shown III Ihe origmal videot�pc.
50. The quotes from Ben Freeman arc in the exhihition (:atalog Nl'tll/lrtim 1994: 111<1/Og. mph)' OlwiJr Tmd" iOl' (p. 12), from th.. Currier GlIllcry of Arl Hampshire.
111
Manchester. New
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