International Review of Research on Mental Retardation (International Review of Research in Mental Retardation)

International Review of

RESEARCH IN MENTAL RETARDATION VOLUME 17

Consulting Editors Ann M. Clarke THE UNIVERSITY OF HULL

J. P. Das THE UNIVERSITY OF ALBERTA

H. Carl Haywood VAN D E R B ILT U N I V E R S I T Y

Ted Nettelbeck T H E UNIVERSITY OF A D E L A I D E

International Review of RESEARCH IN MENTAL RETARDATION

EDITED B Y

NORMAN W. BRAY CIVITAN INTERNATIONAL RESEARCH CENTER A N D DEPARTMENT OF PSYCHOLOGY T H E UNIVERSITY OF A L A B A M A AT BIRMINGHAM BIRMINGHAM, A L A B A M A

VOLUME 17

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Contents

Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

vii

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ix

The Structure and Development of Adaptive Behaviors Keith F. Widaman, Sharon A. Borthwick-Duffy, and Todd D. Little

I. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11. The Structure of Adaptive Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111. The Life-Span Development of Adaptive Behaviors . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV. Factors Moderating the Life-Span Development of Adaptive Behaviors . . . . . . . . . . . . V. Summary and Conclusions . . ........................................ References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

I 4 19 40

41 48

Perspectives on Early Language from Typical Development and Down Syndrome Michael P. Lynch and Rebecca E. Eilers 1. Introduction . . . . . . . . . . . . . . . . . . . . . 11. Perception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111. Production . . . . . . . . . . . . . . . . . . . . . . ...........

IV. Relationships between Perception and Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V. Conclusions . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

55

56 66 16 80 83

The Development of Verbal Communication in Persons with Moderate to Mild Mental Retardation Leonard Abbcduto 1. Introduction . . . . . 11. The Nature of Verbal Communication

......

....................................... 111. Research on the Verbal Communication of Persons with Mental Retardation . . . . . . . . IV. Verbal communication in Persons with Mental Retardation: Summary, Implications, and Future Rescarch . . . . . . . . . ............................ V. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . ........ ........................... V

91 92 93

I08 I10 I12

vi

CONTENTS

Assessment and Evaluation of Exceptional Children in the Soviet Union Michael M. Gerber, Valery Perelman, and Norma Lopez-Reyna 1. Introduction .................................. 11. Interpretive and Empirical Framework for the Survey . . . . . . . . . . . . . . . . . . . . . . . . . . 111. Survey of Recent Literature ..................................

IV. Discussion . . . . . . . . . . . . . References . . . . . . . . . . . . .

................................... ...................................

i17 121 128 144 147

Constraints on the Problem Solving of Persons with Mental Retardation Ralph P. Ferretti and Al R. Cavalier

I. Introduction . . . , . , . ,

153

11. Problem Solving and Information Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111. Self-Management Processes and Problem Solving . . . . . . . . . . . . . . .

155 158

IV. Persons with Mental Retardation Are Sometimes Strategic . , . , . , . . . . . . . . . . . . . . . . V. Persons with Mental Retardation Sometimes Transfer Strategies . . . VI. General Conclusions . ................... References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

171 176

179 182

Long-Term Memory and Mental Retardation James E. Turnure

I . Introduction . . . . . . . . _ . _ . _ . _ . _ _ _ . . _ . . . . . . _ _ _ . . _ . _ .193 _.__._. 194 11. Historical Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 111. Long-Term Retention with Exceptional Subjects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 IV. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

219

Contents of Previous Volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

23 I

Contributors

Numbers in parentheses indicate the pages on which the authors' contributions begin.

Leonard Abbeduto (9 1 ), Waisman Center and Department of Educational Psychology, University of Wisconsin-Madison, Madison, Wisconsin 53 705 Sharon A. Borthwick-Duffy (l), School of Education, University of California, Riverside, California 92521 Al R. Cavalier (153), Department of Educational Studies, University of Delaware, Newark, Delaware 19716 Rebecca E . Eilers (55), Departments of Psychology, Pediatrics, and Otolaryngology, University of Miami, Miami, Florida 33101 Ralph P. Ferretti ( 153), Department of Educational Studies, University of Delaware, Newark, Delaware 19716 Michael M . Gerber ( 1 17), Graduate School of Education, University of California, Sun ta Barbara, California 93106 Todd D . Little' ( l ) , Department of Psychology, University of California, Riverside, California 92521 Norma Lopez-Reyna ( 1 17), Department of Special Education, University of lllinois at Chicago, Chicago, Illinois 60680 Michael P. Lynch2 ( 5 3 , Department of Pediatrics, University of Miami, Mailman Center for Child Development, Miami, Florida 33101 Valery Perelman ( 1 17), Graduate School of Education, University of Californiu, Santa Barbara, California 93106 'Present address: Max Planck Institute for Human Development and Education, Center for Rychology and Human Development, D-1000 Berlin 33, Germany. 2Present address: Department of Audiology and Speech Sciences, Purdue University, West Lafayette. Indiana 47907. vii

...

Vlll

CONTRIBUTORS

James E. Turnure ( 193), Department of Educational Psychology, University of Minnesota, Minneapolis, Minnesota 55455 Keith F. Widaman ( l ) , Department of Psychology, University of California, Riverside, California 92521

Preface

As with previous volumes in this series, the articles presented here address current research issues important to behavioral scientists, educators, and clinicians concerned with the nature of mental retardation and its prevention and amelioration. The six contributors address four general areas: (1) the measurement of adaptive behavior from a life-span perspective; (2) the development of speech, language, and communication in mentally retarded children; (3) the assessment of psychological and educational functioning in the Soviet Union; and (4) cognitive processes in mildly retarded children and adults. In the first article Keith Widaman, Sharon Borthwick-Duffy, and Todd Little provide an integrative review of factor-analytic studies of adaptive behavior. They place research on adaptive behavior in a life-span context, reviewing the major cross-sectional, longitudinal, and semilongitudinal studies. They also present recently obtained data showing that differences in life-span developmental trends in adaptive behavior depend on the level of mental retardation. The article ends with a consideration of other factors that may contribute to the difference in life-span developmental trends. The next two contributions are concerned with the development of speech, language, and communication in mentally retarded children. Michael Lynch and Rebecca Eilers review research on the development of speech and language in Down syndrome infants and children. They present background information on the expected developmental functions for speech perception and language production for nonretarded children and place research on Down syndrome in this developmental context, noting that delays in babbling and early language production in Down syndrome infants may be due to moderating variables such as hearing loss and associated cognitive limitations. They also review the research on mother-child interactions with Down syndrome children, finding that these mothers are more directive than are those of typically developing childrenpossibly because Down syndrome infants tend to be more “passive” and “quieter,” and the mothers try to increase the communicative exchange. Next, Leonard Abbeduto reviews current research on verbal communication in mildly and moderately mentally retarded children. He focuses on managing verbal communication and places aspects of communication, such as turn taking, referential communication, speech acts, organizing topics, and conversational ix

X

PREFACE

repair, in the broader context of what is known about the developmental course of communication in typically developing children. Abbeduto concludes that mentally retarded children are somewhat deficient in each of these areas, but for some skills, such as turn taking, their abilities are nearly indistinguishable from those of their nonretarded peers. The clearest and most marked difficulties appear in referential communication and pragmatics. The fourth contribution, by Michael Gerber, Valery Perelman, and Norma Lopez-Reyna, reviews recent studies of assessment and evaluation of mentally retarded children conducted and published in the Soviet Union. The review is preceded by a discussion of the context of research on assessment in the Soviet Union and the general rationale for a qualitative approach. The literature reviewed includes several studies on neurophysiological, psychological, psychoeducational, and learning pote,ntial assessments never before available to English-speaking scientists. One surprising result of this review is that there is now movement toward the incorporation of more standardized and quantitative assessment in the Soviet Union. This trend runs counter to the movement toward more qualitative assessment in Western countries, a trend that has its roots in the Soviet Union and the work of Vygotsky. The last two articles are concerned with cognitive processes in mildly mentally retarded children and adults. Ralph Ferretti and A1 Cavalier review cognitive and behavioral studies on self-management skills, executive processes, and problem solving. They conclude that self-management skills, such as self-monitoring, result in little, if any, strategy transfer and suggest that variables such as task dificulty, comprehension of task demands, and content knowledge may influence strategy use. Their position is a departure from an emphasis on higher level executive processes. Ferretti and Cavalier suggest that limitations of working memory may underlie differences in strategy use in mentally retarded and nonretarded individuals. In the sixth article Jim Tmure reviews the recent literature on differences in long-term memory in mentally retarded and nonretarded individuals. He makes the point that the memory “deficits” observed in mentally retarded individuals are relatively mild compared to the exceptional deficiencies observed in amnesia patients and that many investigators have failed to put the magnitude of memory problems within this context. Turnure reviews recently obtained data showing that the magnitude of the difference in long-term memory functions in mentally retarded and nonretarded individuals depends on the relationship between the cues available at the time of original learning and the cues available at the time of test. Under some conditions mentally retarded and gifted students do not differ, suggesting that we have much to learn concerning the cognitive potential of mentally retarded individuals. As illustrated by these articles, this series will continue to publish integrative reviews on a wide range of current topics, including the psychological and social

PREFACE

xi

nature of mental retardation, the biological and neurological basis of behavioral and psychological problems associated with mental retardation, and the nature of problems of adaptation encountered by mentally retarded individuals. Reviews of both basic and applied research will be included. The majority are written by invitation, but unsolicited manuscripts will be considered. NORMAN W. BRAY

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The Structure and Development of Adaptive Behaviors KEITH F. WIDAMAN DEPARTMENT OF PSYCHOLOGY UNIVERSITY OF CALIFORNIA RIVERSIDE. CALIFORNIA 92521

SHARON A. BORTHWICK-DUFFY SCHOOL OF EDUCATION UNIVERSITY OF CALIFORNIA RIVERSIDE, CALIFORNIA 92521

TODD D. LITTLE’ DEPARTMENT OF PSYCHOLOGY UNIVERSITY OF CALIFORNIA RIVERSIDE. CALIFORNIA 92521

1.

INTRODUCTION

Since 1959 (Heber, 1959, 1961), adaptive behavior has been a major component in the classification of persons with mental retardation. In the most recent version of the classification manual by the American Association on Mental Retardation (AAMR; Grossman, 1983), adaptive behavior is placed on a virtually equal footing with intelligence in the diagnosis or classification of persons with mental retardation. Specifically, a person must exhibit not only “significantly subaverage general intellectual functioning,” but also concurrent “deficits in adaptive behavior” to be classified as having mental retardation (Grossman, ‘Present address: Max Planck Institute for Human Development and Education, Center for Rychology and Human Development, D-1000 Berlin 33, Germany. INTERNATIONAL REVIEW OF RESEARCH IN MENTAL RETARDATION, Vol. 17

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Copyright 0 1991 by Academic Ress. Inc. All rights of repduction in any form reserved.

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Keith F . Widaman et al.

1983). Although behaviors that are optimally adaptive at one age may signify less optimal adaptation at older ages, and vice versa, the role of adaptive behavior in defining and assessing mental retardation throughout the life span is unquestionable. About two decades ago, Clausen (1967, 1972) argued against the inclusion of adaptive behavior in the definition of mental retardation, focusing primarily on the inadequacies of extant measures of the construct. More recently, Zigler, Balla, and Hodapp (1984) renewed concerns regarding the definition of mental retardation, once again holding that the criterion of concurrent deficits in adaptive behavior should be deleted. Specifically, Zigler et al. argued (1) that the construct, or domain, of adaptive behavior (or social adaptation) is poorly defined, and (2) that the measures to assess adaptive behavior therefore “necessarily lack validity” (p. 226); both criticisms were aimed at foundational issues in the study of adaptive behavior. Partly in response to the continuing controversy, an AAMR committee was recently charged with reconsidering the definition of mental retardation and has forwarded a preliminary draft of a new definition that would reduce considerably the place of adaptive behavior in the classification of mental retardation (Staff, 1990). The purpose of this article is to consider the domain of adaptive behavior and to make strides toward resolving some of the problems noted by Zigler er al. Given the importance of the domain of adaptive behavior in the field of mental retardation, it is surprising that a clearer definition and more well-developed theory for this behavioral domain are not yet available. This observation should not be interpreted as discounting the previous work of researchers in the field of mental retardation. With Heber (1959, 1961), the domain of adaptive behavior was given a fledgling theoretical definition. With the construction and validation of the AAMR Adaptive Behavior Scale (ABS; Nihira, Foster, Shellhaas, & Leland, 1969, 1975), the domain of adaptive behaviors received an initial, implicit operational definition. Additionally, a number of authors have attempted to explicate the notion of adaptive behaviors, including Coulter and Morrow (1978), Leland (1973, 1978) and his associates (Leland, Shellhaas, Nihira, & Foster, 1967), and Mercer (1978), among others; however, we agree with others (cf., e.g., Bruininks, 1987; Bruininks & McGrew, 1987) that adequate answers to definitional and theoretical problems concerning adaptive behavior have lagged behind measurement concerns. By continuing to focus attention on these problem areas and to address the criticisms that are periodically directed at this research domain (e.g., Zigler et al., 1984), significant strides will be made toward an adequate understanding of the domain of adaptive behavior and of the development and aging of these forms of behavior across the life span. Regardless of its place in the official AAMR definition of mental retardation, the domain of adaptive behavior has great and far-reaching significance for the field. Although a commonly accepted criterion for “significantly subnormal

LIFE-SPAN DEVELOPMENT OF ADAPTIVE BEHAVIORS

3

adaptive behavior” has never been offered (Reschly, 1988), the assessment of adaptive behavior is commonly viewed as an important supplement to the results of an intelligence test (E. Horn & Fuchs, 1987) for defining and assessing mental retardation. That is, mental retardation may result primarily from subnormal intelligence or cognitive capabilities (Detterman, 1987; Zigler et al., 1984), but an individual’s adaptation to hidher environment is also influenced by many other nonintellective factors (MacMillan, 1983), and these nonintellective factors may be tapped by instruments assessing adaptive behavior. Moreover, measures of adaptive behavior are invaluable for a number of purposes. For example, measures of adaptive behavior assist in developing and assessing programs of instruction for individuals, in making judgments about the adequacy of different residential alternatives, and so forth (cf. Matson, 1987). Measures of adaptive behavior are also useful in distinguishing among characteristics of persons with mild, moderate, severe, and profound mental retardation, especially when one considers the restricted utility for tests of intelligence to differentiate among persons falling at the lower extremes of intellective functioning. As a result, despite problems in its theory and measurement, the domain of adaptive behavior remains of central importance for the field of mental retardation. The main purpose of this article is to review the adaptive behavior domain; however, a secondary goal is to note implications of extant research for theory development. In approaching the task of framing such implications in an initial approximation to an adequate theory of the life-span development of adaptive behaviors, the first step is to identify the problem areas that must be confronted by such a review. Although not an exhaustive list, the following three areas are reviewed, noting implications for theory development: 1. Determining the structure of adaptive behavior. Here, the number and

identity of the dimensions of individual difference spanning the adaptive behavior domain are the central concern. 2. Estimating the age-related trends for the life-span development of adaptive behaviors. By describing the results of studies of the growth and life-span development of adaptive behaviors, along with the methodological issues that arise in such studies, a framework for understanding the life-span development of adaptive behaviors is presented. 3. Investigating factors that moderate the life-span development of adaptive behaviors. This issue represents a general concern for contextual factorsintrapersonal, environmental, interpersonal, and familial-that influence the life-span development of persons with mental retardation. The remaining sections of this article focus, in turn, on the three issues outlined above. In each section, we discuss concerns that arise in the topic area and present pertinent research findings.

Keith F. Widaman et al.

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II.

THE STRUCTURE OF ADAPTIVE BEHAVIOR

At least two approaches have been used to characterize the structure of behavioral domains; one approach is more rational or definitional in nature, the other more empirical. These two approaches may be contrasted in research on intelligence, or mental abilities. Regarding the definitional approach, since 1900, a large number of definitions of intelligence have been offered, yet a consensus of opinion on intelligence has not been achieved. In an early symposium published in the Journal of Educational Psychology (Thorndike et a l . , 1921), 14 of the leading experts on intelligence were asked to define their conception of intelligence, describe how best to measure it, and outline the next important steps for research; looking across contributions, the discrepancies in views were more impressive than the agreements. More than 60 years later, Sternberg and Detterman (1986) put the same question to 24 current experts on intelligence. Although much has been learned over the past six decades, profound differences in opinions still remain, seeming rather more pronounced than do the convergences. The differences that persist represent many issues, some as basic as whether intelligence is a single entity or a collection of multiple, irreducible dimensions. Regarding mental retardation, Zigler et al. (1984) criticized the adaptive behavior domain on the grounds that experts lack agreement on its basic definition. But, this criticism is not a singular, defining problem; for example, Sternberg and Detterman (1986) document the considerable lack of agreement by experts on the definition of intelligence-the construct that provides the operational definition of mental retardation (cf. Kamphaus, 1987)! Circumventing the definitional morass that beclouds research on intelligence, many researchers have taken the second, more empirical approach. Here, the domain of interest was widely sampled, attempting to ensure that all aspects of the domain were represented within a set of observed measures. Then, a technique, usually factor analysis, was used to identify the dimensions of individual difference that represented variability in common among the observed measures. The structure of the mental ability domain has undergone considerable revision and expansion since the early studies by Spearman (1927) on general intelligence and those by Thurstone and his associates (e.g., 1938; Thurstone & Thurstone, 1941) on the Primary Mental Abilities, which usually numbered around 7 to 9 dimensions. Thus, considerable consensus is now emerging that from 25 to 30 dimensions may be needed to span the primary ability domain (Carroll, 1989) and that the intellectual ability domain is a hierarchically structured set of abilities of varying breadth, from quite narrow to rather general (Gustafsson, 1984; J. L. Horn, 1986, 1988; J. L. Horn & Hofer, in press). The relative utility of the empirically based, factor-analytic approach continues to be demonstrated for the intelligence domain and the implications for the adaptive behavior domain are no less significant.

LIFE-SPAN DEVELOPMENT OF ADAPTIVE BEHAVIORS

5

Similar approaches to the investigation of the domain of adaptive behavior have been utilized. Research on adaptive behavior, pursued in earnest for about 20 or 30 years, is in its infancy relative to research on intelligence. As a result, one might expect that conclusions drawn regarding the adaptive behavior domain would be less firm, given the smaller research base. Although much work remains to be done, some areas of agreement on the structure of adaptive behavior are discernible.

A.

Rational Approaches

Virtually every instrument that assesses adaptive behaviors constitutes yet another attempt to define a structure of the adaptive behavior domain. For example, the AAMR Adaptive Behavior Scale (ABS; Nihira et al., 1969, 1975), one of the most widely used inventories, contains one major division of behaviors, between forms of adaptive behavior (assessed within Part I of the instrument) and maladaptive behaviors (assessed within Part 11). Within Part I, distinctions are drawn among 10 domains of adaptive behavior, including Independent Functioning, Physical Development, Economic Activity, and Numbers and Time. Certain of these domains are further subdivided into subdomains; for example, the Language Development domain is broken down into subdomains of Expression, Comprehension, and Social Language Development. Other domains, such as Numbers and Time or Socialization, are not broken down into subdomains. The maladaptive behaviors assessed by Part I1 of the ABS are categorized into 14 domains, such as Antisocial Behavior and Withdrawal, and none of these domains is further divided into subdomains. This domain structure of the ABS is one attempt to characterize the structure of adaptive and maladaptive behaviors; however, to verify the validity of a conceptual structure, several patterns should be evident in empirical data. First, the items within a subdomain should be consistent, having high internal consistency and similar relations with other variables, to justify their placement within a single subdomain. Second, the subdomains within a given domain should obey somewhat different psychological laws, to justify the distinction among the subdomains; but the subdomains should still exhibit some “family resemblance” in their relations with other variables, to justify their placement within a single domain. Finally, domain scores should exhibit differential relations with outside variables, or follow different psychological laws, to justify the conceptual distinctions between the several domains. To our knowledge, careful, systematic investigations to demonstrate the patterns of empirical findings proposed above have not been undertaken with the ABS. As a result, the structure of adaptive behavior implicitly proposed in the form of the ABS is a most interesting one that has yet to be fully supported by empirical investigation. In their authoritative review of the assessment of adaptive behaviors, Meyers,

Keith F . Widaman et al.

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Nihira, and Zetlin (1979) summarized the types of behavioral domains included in existing measures of adaptive behavior. On the basis of this review, Meyers et al. suggested that seven domains of adaptive skills and competence are commonly represented in adaptive behavior scales: 1. Self-Help Skills, including the abilities to satisfy personal needs such as feeding, dressing, toilet training, and grooming. 2. Physical Development, assessing development and coordination of basic perceptual-motor skills, which likely are antecedent to the acquisition of specific self-help skills. 3. Communication Skills, including articulation, expression, comprehension, social interaction, and negotiation with others. 4. Cognitive Functioning, involving, among other skills, those of reading, writing, and ability to deal with numbers and time. 5 , Domestic and Occupational Activities, including such chores as cleaning, cooking, and washing, and such occupational activities as assembly of parts, operation of machinery, and job search skills. 6. Self-Direction and Responsibility, dealing with the originating and engaging in purposive activity based on the person’s own volition, which relates to assessment of autonomy and motivation. 7. Socialization, assessing the degree of interaction and cooperation with others, considerations for and helping others, and participation in group activities.

More recently, Kamphaus (1987) offered a five-domain structure of the types of behavior assessed by major adaptive behavior inventories, which consists of a slight rearrangement of the domains posited by Meyers et al. The five domains cited by Kamphaus, together with reference to similar domains from Meyers et al. listed above, are given here:

I . Motor/Physical, essentially the Physical Development domain from Meyers et al. 2. Self-Help/Independence, similar to the Self-Help domain in Meyers et al. 3. InterpersonaVSocial,corresponding to the Socialization domain of Meyers et al. 4. Responsibility/Vocational,largely a combination of the Domestic and Oc-

cupational Activities domains and the Self-Direction and Responsibility domains from Meyers et al. 5 . Cognitive/Communication,a combination of the Communication and Cognitive Functioning domains proposed by Meyers et al.

LIFE-SPAN DEVELOPMENT OF ADAPTIVE BEHAVIORS

7

The structure of maladaptive behaviors was a simpler matter for Meyers et al. (1979) to characterize. Across a number of studies, there appeared to be two general types of maladaptive behavior:

I . Social Maladaption, covering aggressive, destructive, and antisocial types of behavior in which other persons or others’ property is in danger of harm or damage. 2. Personal Maladaption, representing self-aggressive and autistic behaviors. Because of the comprehensive nature of their reviews, the five to seven domains that Kamphaus (1987) and Meyers et al. (1979) outlined merit consideration as a first cut at the “primary” dimensions for the adaptive behavior domain, as are the two dimensions characterizing the maladaptive behavior domain. The next, necessary step is to determine whether these conceptual distinctions are reflected in empirical data, a topic to which we now turn.

B.

Empirical Approaches

At present, two major positions on the structure of adaptive behaviors may be identified, a unifactorial position and a multifactorial one. These positions parallel the distinction in the intellectual ability domain between the two-factor theory of Spearman, in which a single factor termed g was hypothesized to be the single source of common variance among tests of ability, and multifactorial positions proposed by several researchers, such as the Primary Mental Abilities of Thurstone (1938) and the theory of fluid (G,) and crystallized (G,) intelligence of Cattell (1963, 1971) and J. L. Horn (1986, 1988; J. L. Horn & Hofer, in press). According to multifactorial theories, several or many factors are required to represent the intellectual ability domain, in contrast to the Spearman hypothesis. The same contrast is found in studies of the domain of adaptive behavior. In this section, we undertake a somewhat selective review of factor-analytic studies of the adaptive behavior domain. The selectivity of our review is shown primarily in the weight given various studies. Recently, McGrew and Bruininks (1987, 1989) reviewed factor-analytic studies of this domain, providing a useful summary of the samples, analytic methods, variables analyzed, and general findings from the set of 16 studies considered. We will not attempt to duplicate their efforts here. McGrew and Bruininks did not emphasize differences across studies with regard to potentially crucial aspects of the investigations, such as the sample size or the nature of the variables analyzed. Instead, they attempted to discern whether empirical studies more strongly supported the unifactorial position or the multifactorial one, with little consideration of the strength of the evidence provided by each study. Moreover, McGrew and Bruininks (1987,

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Keith F . Widaman et al.

1989) stressed the difference between levels of measurement of adaptive behavior, distinguishing between single items, parcels (the sum of a small number of items, e.g., from two to five items), and subscales (the sum of many items). McGrew and Bruininks then attended primarily to studies that analyzed data at the subscale level, essentially ignoring investigations analyzing item- or parcellevel data. As these decisions may have led to a biased summary of findings, we offer another view of published investigations that used factor analysis to represent the structure of the domain of adaptive behavior. 1. UNIFACTOR STUDIES

Nihira (1969a, 1969b) was perhaps the first to propose a single-factor conception for the adaptive behavior domain. In these two studies, Nihira analyzed the 10 adaptive and 12 maladaptive domain scores from the Adaptive Behavior Checklist, an early version of the ABS. Data were obtained for three samples of children and adolescents (with N's ranging from 102 to 107) and one sample of adults (N = 919). For each of the four samples, Nihira reported that a single factor, labeled Personal Independence, represented the relations among the 10 adaptive behavior domain scores, although two factors, Social and Personal Maladaption, were required to represent the 12 maladaptive domain scores. More recently, Bruininks, McGrew, and Maruyama (1988) analyzed data from seven samples of subjects, including several samples of persons without mental retardation. The five age-graded samples of persons without mental retardation spanned the range from preschool (under 4 years of age) through adulthood (over 18 years of age), and the sample sizes were fairly large (median N = 460). The two samples of individuals with mental retardation were children (mean age = 10.0 years) and adolescents/adults (mean age = 25.9 years), samples that were relatively smaller (N's = 110 and 178, respectively). The variables analyzed were the 14 subscales of the Scales of Independent Behavior (SIB; Bruininks, Woodcock, Weatherman, & Hill, 1984). The general outcome of these analyses was that the single-factor hypothesis received the strongest support, as Bruininks et al. reported that only a single factor was found in four of the seven samples. In two of the remaining three samples, a two-factor solution appeared to describe the data best, but the resulting factors exhibited such poor simple structure that characterization of the factors was problematic. Finally, for the seventh sample, a three-factor solution was accepted, which had moderately good simple structure. Across all seven samples, even in those samples for which more than a single factor was extracted, Bruininks et al. claimed that a General Development or Personal Independence factor was a dominant feature, providing support for a single major dimension of adaptive behavior across the multiple samples. The study by Bruininks et al. (1988) is, however, limited by at least two features. First, the SIB offers a somewhat unfortunate set of scales on which to

LIFE-SPAN DEVELOPMENT OF ADAPTIVE BEHAVIORS

9

base a factor analysis. Some scales seem rather broad (e.g., Social Interaction), whereas other appear quite narrow (e.g., Eating, which often is either an item or a subscale on other measures of adaptive behavior). Also, certain domains, such as Social Interaction, are represented by only a single scale, so that isolation of a common factor for the Socialization domain of Meyers et al. (1979) is precluded. The relation of the remaining SIB subscales to the domain structures proposed by Meyers et af. and Kamphaus (1987) is unclear, but it seems that few of the hypothesized domains would be represented by at least three SIB subscales, the minimum number usually recommended to identify a common factor (e.g., Bentler, 1980). Second, Bruininks et af. used analytic procedures-component analysis, retaining only components with eigenvalues over 1 .O, and varimax orthogonal rotation-that may be ill-advised for a domain such as adaptive behavior. In studies of the ability domain, in which factors are typically moderately correlated, orthogonal rotations are rarely used, as they provide poor simple structure. In multifactor studies of the adaptive behavior domain, to be reviewed below, oblique rotations resulted in far superior simple structure. Moreover, Bruininks et af. (1988) noted that their procedures may have led to “conservative estimates of the number of possible factors” (p. 268), yet the failure to extract a sufficient number of factors is usually considered far more problematic than the extraction of too many factors (Gorsuch, 1983; Rummel, 1970). Thus, the results presented by Bruininks et al. provide only weak, qualified support for the singlefactor hypothesis. At least three additional studies have reported that a single factor represented the relations among the subscales of one or another adaptive behavior measure (Hug, Barclay, Collins, & Lamp, 1978; Katz-Garris, Hadley, Garris, & Barnhill, 1980; Millsap, Thackrey, & Cook, 1987); however, these studies evince an array of problems. For example, Katz-Garris et al. and Hug et af. provided such brief discussions of the factor-analytic methods used that a careful evaluation of their work is not possible. Also, the Hug et al. and Millsap et al. studies used instruments containing subscales that ( I ) are relatively small in number, and (2) do not, at least on the surface, provide multiple indicators of domains hypothesized by Meyers et al. (1979) and Kamphaus (1987), limiting considerably the factorial structures that could be found. 2. MULTIFACTOR STUDIES On the other hand, a number of studies have provided rather strong support for a multiple-factor conception of the domain of adaptive behavior. For example, Nihira (1976) analyzed the 25 subdomain scores from the AAMR Adaptive Behavior Scale obtained on eight samples of persons with mental retardation. The eight samples spanned the ages 4 years to 69 years; sample sizes were fairly large, with a median N = 400 and a total sample size of 3354 persons. Nihira found that three comparable factors represented the subdomain scores across the

10

Keith F . Widaman et al.

eight samples of subjects, although a fourth factor was required at the youngest age levels. The three factors were named Personal Self-Sufficiency, Community Self-Sufficiency, and Personal-Social Responsibility. Although the three factors reported by Nihira (1976) appear to be replicable and interpretable, they unfortunately bear no simple relation to the seven domains posited by Meyers et al. ( 1979). In 1987, Widaman, Gibbs, and Geary described the results of their analyses of data from 14 samples of persons who had mild, moderate, or severe mental retardation. Widaman et al. used scores on the Client Development Evaluation Report, an instrument developed by the California State Department of Developmental Services (1978). Widaman er al. followed a two-step analytic strategy, employing 2 derivation and 14 cross-validation samples. The two derivation samples each consisted of over 3000 persons who obtained services from a single regional center in Southern California. Factor analyses at the item level were conducted on these two samples, and similar six-factor structures were obtained for both samples. On the basis of the results from these derivation samples, three parcels of items were developed for each factor. The item parcels were the simple sum of items loading on each factor; item parcels were developed so that an approximately equal number of items appeared in each parcel, and each item was assigned to only a single parcel. The result was a set of 18 parcels, 3 parcels for each of the six factors. Once the item parcels were formulated, the second step in the analysesanalyses of data from the 14 cross-validation samples-commenced. The 14 samples were drawn from a statewide sample of 68,000 persons cross-classified on the basis of residence (institution, community, or health facility), age (0-1 1 years, 12-19 years, or 20+ years of age), and level of mental retardation (mild, moderate, or severe). This 3 X 3 X 3 classification yielded 27 cells; 14 of these cells contained at least 200 persons, and these 14 cells yielded the samples for the cross-validation analyses. The 14 cross-validation samples ranged in size from 200 to lo00 persons, for a total of 9464 persons across the 14 samples, or an average of 676 persons per sample. In each of the 14 samples, the majority of tests for the number of factors indicated the presence of six factors, the number hypothesized. Oblique rotation of six factors led to rather replicable factors across the 14 samples. The average factor pattern and factor intercorrelations across the 14 samples are shown in Table I. Inspection of Table I reveals that there are three high loadings on each factor, and the nondefining loadings are rather small. The numbers in parentheses are the standard deviations of the parameter estimates across the 14 samples; in general, these standard deviations are rather small. Given the cross-sample replication of the factors, the factor interpretations are of great theoretical importance. Four of the factors represented dimensions defined by adaptive behavior items. The first factor was labeled Motor Develop-

LIFE-SPAN DEVELOPMENT OF ADAPTIVE BEHAVIORS

11

ment; Parcels 1-3 consisted of items measuring gross and fine motor skills, ambulation, and basic eating and toileting skills. The second factor was termed lndependent Living Skills, as Parcels 4-6 were based on items assessing skills in completing household chores, dressing, bathing, making food, and washing dishes. Cognitive Competence was chosen as the label of the third factor; Parcels 7-9 were made up of items assessing receptive and expressive language, reading and writing skills, handling money, ordering food in public, and others. Finally, Parcels 10-12 included items covering the making and maintenance of friendships, interaction with others, and participation in group activities, so Social Competence was the factor label chosen. The remaining two factors were defined by parcels of items assessing maladaptive behaviors. Parcels 13- 15 included items assessing aggressive behaviors, the tendency toward resistiveness or destruction of others’ property, temper tantrums, and negative reactions to frustration; whereas Parcels 16-18 were based on items indexing frequency and severity of self-injurious behavior, hyperactivity, and presence of repetitive body movements. Thus, the two factors represent, respectively, Social Maladaption and Personal Maladaption, the two factors discussed by Meyers et al. (1979) as spanning the maladaptive behavior domain. The replications of factors across the 14 samples were quite good, with coefficients of congruence between like-named factors falling above .90, and corresponding coefficients between differently named factors falling closely around .OO. As a result, the Widaman et al. (1987) study provides very strong evidence that the adaptive and maladaptive domains of behavior are both multidimensional (see also Widaman, Stacy, & Borthwick-Duffy, in press). The correlations among the six factors, presented in the bottom of Table I, also deserve mention. The four dimensions of adaptive behavior, Factors 1 through 4, are moderately intercorrelated, but the correlations are sufficiently low to suggest that the four dimensions of behavior must be distinguished when characterizing the domain of adaptive behaviors. The two dimensions of maladaptive behavior are also moderately correlated, but once again the correlation is not so large as to indicate that the two dimensions are identical. In a recent study, Widaman, Geary, and Gibbs (1991) attempted to replicate the above findings in six samples of persons with profound mental retardation. The first four factors, representing dimensions of adaptive behavior, were well replicated across the six samples. In contrast, variables assessing forms of maladaptive behaviors collapsed onto a single factor. These findings suggest that it is possible to distinguish among the four types of adaptive behavior even in persons with profound mental retardation. But, if a person with profound mental retardation tends to exhibit socially maladaptive behavior, she or he is also very likely to exhibit personally maladaptive behaviors as well. The preceding studies were characterized by McGrew and Bruininks (1989) as having been based on parcels of items. Multifactor studies have also been pub-

TABLE I SUMMARY OF OBLIQUELY ROTATEDSIX-FACTOR SOLUTIONS ACROSS 14 SAMPLES OF NONPROFOUNDLY MENTALLY RETARDED PERSONSO Factor Variable

1

4

5

6

-.008(.061) .038(.069)

.028(,056) .003(.029) -.010(.064)

2

3

-.008(.035) - .OO9(.023) .022(.054)

-.030(.040) .005(.019) .033(.048)

- .010(.O29)

Primary factor pattern

Parcel I Parcel 2 Parcel 3

.858(.119) .881( .060) .787(.09 1 )

-.020(.068) .002(.033) .036(,050)

Parcel 4 Parcel 5 Parcel 6

-.038(.049) - .027(.059) . I 16(.088)

.808(,068) .89/(.077) .786(.079)

.066(.061) -.030(.048) -.018(.051)

.006(.036) -.007(.030) - .011(.035)

-.012(.046) .019(.042) - .020(.036)

.038(.047) - .O I6( .038) -.021( ,042)

Parcel 7 Parcel 8 Parcel 9

-.013(.028) .032(,053) -.OO4(.025)

.028(.042) - .OO4(.060) -.018(.038)

.9/2(.043) .851(.092) .908(.054)

-.042( ,024) .027(,048) .025(.033)

- .049(.017) .030(.044) .022(.028)

.039(.025) -.020(.033) - .023(,024)

Parcel 10 Parcel 1 1

- .026(.024) .040(.028)

- .008(.033) -.039(.031)

.002(,037) -.007(.021)

.910(.034) .9J 7( .029)

-.052(.042)

.046(,028) - .043(,046)

.007(.043)

Parcel 12

-.021(.029)

Parcel 13 Parcel 14 Parcel 15

.002(,025) .022(.027) -0.84(.102)

Parcel 16 Parcel 17 Parcel 18

-.014(.037)

.056( ,065) -.048(.100)

.062(,056)

.008(,050)

.020(.050)

- .013(,032)

- .032(.048)

.OI 2( ,024)

.056(. 110)

.012(,062)

- .054(.078) -.001(.035) .071(. 107)

- .064( .064)

.023(.026) .037(.063)

.766(.

Om

.090(,039)

.003(.041)

.084(,037) - .068( . O W - .072(.059)

.872(.035) .87O(.045) .533(.I5 1)

- .W2(,040)

.030(.051) -.052(.026) .101( ,059)

.090(. 168) .038(.078) - .130(.071)

.661(. 185) .767(.078) .629(.098)

.02 1(.073) .245(. 147)

Factor intercorrelations

Factor I Factor 2 Factor 3 Factor 4 Factor 5

1 .Ooo

.604(.058) .439(. 108)

.334(. 128) .071(.165) .1511.1631

Factor 6 ~

1.Ooo

.634(,095) .509(.096) .260(. 159) ,3281.127)

1 .Ooo

.530(.110) .159(. 122) ,2681.095)

1.OOO

.375(.124) .410(.083)

1.Ooo

.7 I8(.080)

I .Ooo

~~

oFactor 1 = Motor Development, Factor 2 = Independent Living Skills, Factor 3 = Cognitive Competence, Factor 4 Social Competence, Factor 5 = Social, or Extrapunitive, Maladaption, and Factor 6 = Personal, or Intrapunitive, Maladaption. Tabled values are mean factor loadings or mean factor intercorrelations with standard deviations (calculated across the 14 samples of subjects) for mean estimates in parentheses. Italicized factor loadings identify parcels defining each factor. =

14

Keith F . Widaman et al.

lished that relied on either item-level or subscale-level data, but several of these studies are difficult to evaluate. Considering item-level analyses, at least six studies have appeared (Levine & Elzey, 1968; Nihira, 1978; Reynolds, 1981; Silverman, Silver, Lubin, & Sersen, 1983; Sparrow & Cicchetti, 1978, 1984). Of these, perhaps the strongest was the study by Reynolds (198 l), who analyzed the 20 items of a scale he developed to assess adaptive competence (e.g., motor and independent living skills), cognitive competence, and affective behavior (e.g., getting along with others). Based on a sample of 613 residents of group homes, a factor analysis led to the isolation of the three hypothesized factors; however, the set of 20 items was rather restricted in nature, not allowing the distinction between motor and independent living skills and failing to include any maladaptive items. On the other hand, the factorial separation of the items onto the three factors was very clear and easy to interpret. Of the remaining item-based studies, most used items that were not representative of the complete domain of adaptive behavior. For example, Levine and Elzey (1 968) analyzed the 30 items of the San Francisco Vocational Competence Scale. As a result, it is unclear whether the resulting four factors, which were interpreted in rather general terms (e.g., Cognitive competence, Cognitive-Motor Ability), represent broad dimensions of adaptive behavior or the subdomain structure within the Vocational domain. In another study, Silverman et al. (1983) performed analyses on the 80 items constituting the four scales from Form C of the Minnesota Developmental Programming System-Behavioral Scales. The 20 items on each scale were graded for difficulty during the development of the scale, and the eight factors that emerged in analyses consisted primarily of one easy and one difficult factor for each of the four scales. As McGrew and Bruininks (1989) noted, the Silverman et al. results may have resulted from differences in the difficulty level of items, rather than representing eight substantively important factors. In an early study, Sparrow and Cicchetti (1978) reported initial results on a behavioral rating instrument of their design. The factor analysis was based on the assessments of a sample of 45 persons with mental retardation; 41 items were factor analyzed. As a 5 : 1 or 10 : 1 ratio of subjects to variables is frequently recommended to ensure stability of results (e.g., Gorsuch, 1983), the reasonably clear factor structure should not be given great weight unless replication were attempted. Such a replication was reported by Sparrow and Cicchetti (19841, based on a considerable sample size. Further, the factors reported in their earlier study were replicated quite well in this latter study. The Sparrow and Cicchetti (1984) study therefore provides strong evidence for at least three factors of adaptive behavior-Psychomotor, Cognitive, and Social-and one factor of maladaptive behavior-Control, which appears to correspond to the Social Maladaption domain of Meyers et al. (1979). In neither study, however, did Sparrow

LIFE-SPAN DEVELOPMENT OF ADAPTIVE BEHAVIORS

15

and Cicchetti provide explicit details about the factor-analytic methods on which their reported results were based, leading to some difficulties in interpreting aspects of their results. Finally, Nihira (1978) analyzed the correlations among the 66 items of the ABS in three samples, so the adaptive behavior domain was widely represented by the set of items. The three samples were also fairly large, consisting of 750 children (aged 4-9 years), 947 adolescents (aged 10-18 years), and 734 adults (aged 19-67 years). Nihira largely succeeded in reconstituting the domain structure of the ABS, although there were some deviations from the a priori domains posited during the development of the ABS. The Nihira results were presented in little detail, however, and it is unclear whether to interpret the factors as substantively different factors or as fractionated constructs at a lower level. Turning to studies based on subscale-level analyses, at least five studies have resulted in multiple factors for the adaptive behavior domain (Guamaccia, 1976; Lambert & Nicoll, 1976; Owens & Bowling, 1970; Song et al., 1984; Walsh & McConkey, 1989). Unfortunately, results from the majority of these studies are difficult to interpret. The strongest of these studies appears to be the study by Walsh and McConkey (1989). They assessed 408 persons with mental retardation, ranging from 14 to 61 years of age, receiving day-care services in Dublin, Ireland. The assessments were based on the Pathways to Independence checklist, consisting of 365 items grouped within 36 skill areas. Walsh and McConkey factor-analyzed the 29 skill area scores that showed sufficient levels of variance to be entered into analyses. The three factors that emerged from analyses were labeled Personal Care, Daily Living, and Community, and seem to correspond moderately well to the Motor Development, Independent Living Skills, and Cognitive Competence factors from Widaman et al. (1987). The difficulty in making more confident matches between factors stems from the skill areas on the Pathways to Independence checklist, which includes few basic motor items. Also, apparently none of the items on the checklist assessed social competence or types of maladaptive behavior, thus representing a rather restricted assessment of the adaptive behavior domain. Of the remaining studies, the Lambert and Nicoll (1976) was the most ambitious. Lambert and Nicoll analyzed the Public School version of the ABS in three samples of students-regular class ( N = 1 157), EMR (N = 880), and TMR (N = 185). The variables analyzed were the 9 adaptive and the 12 maladaptive behavior domain scores on the Public School version of the ABS. Lambert and Nicoll reported that the same factor structure characterized all three groups. The structure contained two adaptive behavior factors, labeled Functional Autonomy and Social Responsibility, and two maladaptive behavior factors, labeled Interpersonal Adjustment and lntrapersonal Adjustment (similar to the Social Maladaption and Personal Maladaption domains, respectively, of Meyers et al.,

16

Keith F . Widaman et al.

1979). The use of rather nonstandard methods of analysis and the incompleteness with which results were reported, however, lead to an inability to evaluate their results in depth. The Song et al. (1984) study analyzed the correlations among the 11 subscales of the Wisconsin Behavior Rating Scale in each of two samples. One sample consisted of 325 persons with mental retardation, ranging in age from 1 to 72 years and residing in an institution, and the other sample consisted of 184 nonretarded children, ranging in age from 2 weeks to 48 months. In the two samples, roughly similar two-factor solutions were obtained, with a Psychomotor factor subsuming motor, eating, dressing, and toileting scales, and a Cognitive factor representing language, socialization, and domestic skills. Although the cross-sample replication of the factors was moderately good, the number and identity of the subscales of the instrument precluded the finding of a more differentiated structure. The remaining two studies also lead to problematic conclusions. In a study of 100 residents of state institutions, ranging in chronological age from 2.5 to 12.5 years, Owens and Bowling (1970) analyzed the eight scales from the Preschool Attainment Record. A wide range of chronological ages were represented in the sample as were a wide range of levels of attainment. Thus, although a two-factor solution was required for the data, the failure to control for age may have resulted in a solution of lower dimensionality than would otherwise have been found. Finally, the results reported by Guarnaccia (1976), who analyzed the 10 domain scores from the ABS along with earnings, were based on such a small sample (N = 40) that the factors described are difficult to consider in depth.

C. Summary of the Structure of Adaptive Behavior As a set, the findings from the studies reviewed above are sufficiently divergent that one must conclude that there is as yet no final consensus on the dimensional structure of adaptive behavior. This should not be surprising, as the factor-analytic structure of intellectual abilities, after almost 90 years of empirical investigation, i s only now beginning to reach some resolution (e.g., J. L. Horn & Hofer, in press). Moreover, we will propose an organizing principle that may begin to resolve the apparent differences across studies in the factorial structures promoted for the adaptive behavior domain. First, however, we note that the evaluation of factor-analytic studies must involve at least four aspects of such studies: the samples of subjects used, the variables analyzed, the analytic methods chosen, and the results obtained. Although one may be tempted to proceed directly to a summary of results, these may have been affected in important ways by other aspects of the study. For example, more stable results should be expected from larger samples of subjects; this is a well-known phenomenon. But, at least as important is the presence of

LIFE-SPAN DEVELOPMENT OF ADAPTIVE BEHAVIORS

17

heterogeneity in the sample, which can impinge on results. Hence, Widaman et af. (1987; Widaman, Geary, & Gibbs, 1991) and Bruininks et af. (1988) partialled chronological age from the correlations among variables prior to factor analysis, to reduce or eliminate this form of bias on results. Further, by design, Widaman et af. (1987; Widaman, Geary, & Gibbs, 1991) also partialled the effects of level of mental retardation, by analyzing data separately for persons at the different levels of mental retardation. In contrast, Bruininks et al. (1988) did not have sufficient numbers of subjects with mental retardation to perform separate analyses by level of mental retardation and did not partial level of mental retardation from the variables analyzed. The resulting heterogeneity represented among their samples of persons with mental retardation may have been one reason why Bruininks et al. tended to find solutions in low dimensionality (i.e., one or two factors). With regard to the variables analyzed, the number and psychometric properties of the variables are clearly of great importance. As noted above, McGrew and Bruininks (1 989) emphasized the different levels of analysis represented by items, parcels, and subscales, a point also made by Widaman et al. (1987); however, the number of items in an index, which may range from one (for items) to many (for subscales), may be only a superficial and far less crucial property than other aspects of the index, most especially the breadth of behavior assessed by the index. For example, eating behavior is a subscale, measured by several or many items, in some inventories (e.g., the SIB), but is only a single item within a more generic subscale in other inventories (e.g., the ABS). Clearly, factor analyses of subscales from inventories with such differences in the breadth of scale definition cannot lead to fully compatible factors. Moreover, factoring the subscales from existing instruments may not be a reliable way to approach the structure of adaptive behavior in the first place. The subscales for an instrument may be less than optimally constituted, or the instrument may contain few or no items from certain aspects of the adaptive behavior domain, as mentioned throughout our review. Hence, the factors derived from analyses of such subscales are only as valid as the measured variables-the subscales-on which they are based. Moreover, at least three measured variables are required to identify a factor well; the set of subscales from extant instmments often contains only a single subscale for an important part of the adaptive behavior domain, precluding the finding of a common factor representing that part of the domain. The particular analytic methods used may also affect the results obtained. In their review, McGrew and Bruininks (1989) did not distinguish between the use of principal axes and principal components for the extraction of factors. This may have been for any of several reasons, not the least of which is the ambiguity with which authors typically describe their procedures; however, among others, Bentler and Kano (1990), McArdle (1990), and Widaman (1990, in press) demonstrated differences arising from use of principal axes and principal compo-

18

Keith F . Widaman et al.

nents. For example, in many common research situations, the use of principal components frequently leads to much higher loadings of variables on factors than does the use of principal axes. In addition, the choice of the number of factors to retain and the selection of a rotation may also have profound effects on the factoranalytic results obtained. As a result, certain differences across studies may have arisen solely from the differences in factor-analytic methods employed. Given the preceding caveats, the results of the factor analyses of indices of adaptive behavior seem to support fairly strongly the presence of multiple factors for the domain. In addition, the domain structures discussed by Meyers et al. (1979) and by Kamphaus (1987) received fairly strong support. Looking at the studies by Widaman et a f . (1987; Widaman, Geary, & Gibbs, 1991), there may not be a one-to-one relation of the four Client Development Evaluation Report factors with the seven adaptive behavior domains posited by Meyers et af.,but there are clear relations between the two structures (cf. Widaman et al., 1987). Moreover, the four Client Development Evaluation Report factors correspond rather well to four of the five domains posited by Kamphaus; only the Responsibility/Vocational domain is not represented on the Client Development Evaluation Report. Hence, the Widaman el a f . (1987; Widaman, Geary, & Gibbs, 199 1) studies provide strong empirical evidence for the rational distinctions among domains of adaptive and maladaptive behavior presented by Meyers et a f . and Kamphaus. Also, other studies provide support for one or more of the Meyers et al. and Kamphaus domains, although usually based on more restricted sampling of variables from the domains. Additional research is clearly warranted on the structure of adaptive behaviors, but the future trends appear clear. As with the domain of human abilities, a multifactorial approach seems to hold the most promise; however, the presence of a number of studies that isolated only a single, general Personal Independence dimension must be acknowledged. Thus, it is likely that the structure of the adaptive behavior domain is similar in form to the structure usually posited for the domain of mental abilities-a structure that is hierarchical in nature, with broader or more general factors at higher levels in the hierarchy and narrower or more specific factors at lower levels. Indeed, the resolution of the unifactorial and multifactorial positions may reside in concluding that both are correct, to a certain extent; it simply depends on the level of the structure at which a study is undertaken. Consider the multiple factors identified by Widaman et al. (1987; Widaman, Geary, & Gibbs, 1991), which exhibited moderate intercorrelations. The correlations among the four adaptive behavior factors may signify the presence of a single, general Personal Independence dimension that is a higher-order factor, and that a higher-order General Maladaption factor could account for the correlations between the Social and Personal Maladaption factors (cf. Amdt, 1981). On the other hand, the presence of higher-order factors for the adaptive

LIFE-SPAN DEVELOPMENT OF ADAPTIVE BEHAVIORS

19

and maladaptive behavior domains may be contraindicated by certain patterns of data. That is, just as with the human ability domain, research of various types must be brought to bear on the decision regarding the most appropriate structural representation of adaptive behaviors. With this in mind, we turn to the topic of the development and aging of adaptive behaviors, as this topic might well impact on decisions concerning the optimal structural representation of the adaptive behavior domain.

111.

THE LIFE-SPAN DEVELOPMENT OF ADAPTIVE BEHAVIORS

Investigating the growth and life-span development of adaptive behaviors can serve both basic and applied goals. Regarding basic research aims, life-span trends can help resolve questions about the structure of adaptive behavior. Specifically, if a researcher maintains that two or more dimensions are required to represent a domain like adaptive behavior based on factor-analytic evidence, then research on the life-span development of behaviors on the multiple dimensions should be consistent with this judgment. That is, finding that different dimensions of behavior exhibit differential life-span trends of growth and decay would lend support to the multifactorial conception of the structure of adaptive behaviors. In contrast, charting development on a single, general dimension would mask and therefore misrepresent the age-related changes on different forms of adaptive behavior. Turning to more applied goals, research on the life-span development of adaptive behaviors will be useful for a number of purposes. One beneficiary of such work would be state agencies and residential settings of various types that provide services for persons with mental retardation. Given knowledge of the likely developmental status of persons at various stages of the life cycle, these agencies would be able to plan in a more informed way for future programming for these persons. Parents of persons with mental retardation would gain needed information about the likely developmental progress of their children. Such information should enable parents to plan with greater certainty for the future living situations for their children, replacing the ambiguity of potential developments by their child with some notions of the likely range of functioning they can expect for their child. Given the array of aims that may be satisfied by the study of the life-span development of adaptive behaviors, the accurate estimation and description of developmental trends is a most important enterprise. We turn now to the design, interpretation, and empirical issues surrounding the study of the life-span development of adaptive behaviors.

20

A.

Keith F. Widaman et al.

Design Issues

The study of development across the human life span typically involves the investigation of behavior (B) as a function of chronological age (A), or B = f(A). Traditionally, two types of developmental design have been used to gather data for determining age-related trends; these two types of design are the crosssectional and the longitudinal. More recently, semilongitudinal designs have been proposed that alleviate several of the shortcomings associated with the two traditional approaches. Each of these designs is described briefly, as are the problems arising in their use. 1. TRADITIONAL DEVELOPMENTAL DESIGNS a . Cross-Sectional Designs. Under a cross-sectional design, samples of subjects are chosen so that the samples differ systematically in chronological age. For example, subjects might be chosen who are 0-9 years of age, 10-19 years, 20-29 years, and so forth, to study the life-span development of behaviors of interest. The various samples of subjects are then tested at a single point in time (e.g., during a certain quarter of the school year or during a single calendar year). Analyses of data from a cross-sectional design take on a rather direct form: the differences in levels of behavior between the samples of subjects are attributed to the differences in their ages; thus, the observed age differences are presumed to reflect the expected age-related changes one would observe as individuals develop. b. Longitudinal Designs. The second traditional developmental research design is the longitudinal design. With this design, a single sample of subjects is identified and is then assessed on behavioral measures of interest at several points in time. As a result, the sample is assessed when the subjects are at different chronological ages. Then, the investigator may map directly the age-related changes in behavior of the persons in the study, rather than infer likely agerelated changes from the age differences based on independent samples of subjects as is done in a cross-sectional design. c . Problems with Traditional Designs. The attribution of age-related differences to the causal influence of chronological age using either cross-sectional or longitudinal designs is beclouded by several threats to the validity of the two designs. Briefly, as discussed by Baltes (1968), conclusions based on the two traditional research designs may be invalid, as any of the following problems may influence the findings: (1) selective sampling, resulting in samples that are differentially representative of the population; (2) selective survival, with decreases in representativeness of samples if survival is related to the behavioral variables of interest; (3) selective dropout, as those remaining in a longitudinal study for its duration tend to be different from those who drop out; and (4) retest effects, which arise simply from the retaking of a given test.

LIFE-SPAN DEVELOPMENT OF ADAPTIVE BEHAVIORS

21

A fifth problem with traditional research designs is the possibility of generation, or birth cohort, effects (Baltes, 1968). That is, birth cohorts differ systematically in many factors, including (1) the historical time during which they passed certain developmental milestones, and (2) any secular, or historical, trend that varies with historical time (e.g., mean length of education has increased steadily since 1870). If these generation effects are systematically related to the behavioral variables of interest, then both of the traditional designs may lead to biased results. The possibility of cohort effects is generally considered one of the most important sources of bias in life-span studies of behavioral development.

2. SEMILONGITUDINAL DESIGNS One way of attempting to circumvent the problems associated with the traditional developmental research designs is through the use of one or another type of semilongitudinal design. Types of semilongitudinal design have been discussed since 1953 (e.g.. Bell, 1953, 1954; Fisher & Zeaman, 1970); however, Schaie (1 965) provided a systematic explication of semilongitudinal designs that may be used as a point of departure. Schaie distinguished three components of a general developmental model, noting that measurement of persons may be distinguished by the person’s age ( A ) when measured, the time of measurement (T), and the birth cohort (C) to which the person belongs. Thus, according to the general model, behavior may be seen to be the result of the combination of age, cohort, and time of measurement, or B = f ( A , C , T ) . As a result, the attribution of changes in behavior to the effects of chronological age must be made while explicitly noting the potential confounding factors of cohort and time of measurement. A considerable literature has arisen over the past 20 years that has dealt with the testing of cohort effects and the testing of the external validity of semilongitudinal designs (e.g, Baltes, 1968; Baltes, Cornelius, & Nesselroade, 1978; Labouvie, Bartsch, Nesselroade, & Baltes, 1974; Nesselroade & Baltes, 1974). Although specific suggestions will not be reviewed in detail here, the fact that cohort effects are alternative explanations of age-related trends identified using either cross-sectional or longitudinal designs cannot be overemphasized. As a result, research studies that enable the estimation and testing of cohort effects are most valuable, and our understanding of the life-span development of adaptive behaviors will be furthered more by such investigations than by the continued accumulation of age differences documented using cross-sectional designs. a. Interpretation of Cohort Effects. The issue of the presence or absence of cohort effects seems much less problematic than does the interpretation of cohort effects, even in nonretarded populations. The differences noted between results yielded by cross-sectional and longitudinal studies across several domains (e.g., Damon, 1965; Kuhlen, 1963) led to the initial questioning of the comparability of results from the two types of design. In general, cohort effects are frequently

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attributed to the different life histories of the cohorts contrasted. For example, cohort differences on variables (e.g., length of schooling) that might affect the behavioral variables of interest (e.g., mental abilities) are invoked as potential explanations of the differences in levels or trends in behavior exhibited by cohorts. Indeed, the explicit operationalization of such cohort differences has been proposed as one way of identifying cohort effects (Hogan, 1984; Jagodzinski, 1984). But, there remains far more ambiguity in interpreting cohort effects than in determining that such effects are present. If cohort effects are problematic to interpret in samples of persons without mental retardation, the situation becomes even more difficult when considering samples from populations with mental retardation. In the latter populations, similar explanatory problems arise concerning cohort effects as with nonretarded populations, but additional problems may arise. Consider, for example, the typical large-sample study of development and aging of adaptive behaviors (e.g., Eyman & Widaman, 1987; Nihira, 1976; Zigman, Schupf, Lubin, & Silverman, 1987). In these studies, the investigators were able to analyze data routinely collected on persons with mental retardation. The samples on which these studies were based, then, did not consist of random and representative samples from some specifiable population. Rather, the samples represented populations of subjects that were possibly differentially representative of their own birth cohorts and of birth cohorts to come. The theoretical population of persons with mental retardation in a given birth cohort is affected by classification issues, such as classification on the basis of an IQ of 85 or below (the old standard) or an 1Q of 70 or below, the present standard (see MacMillan, 1989). Moreover, the population of persons with mental retardation may change across historical periods because of various types of changes in medical and programming practices. For example, cohort effects in studies of persons with mental retardation could arise from any of the following sources, among others: ( I ) cohort effects may represent a change in composition of the types of individuals who fall into certain levels of retardation, as medical breakthroughs may lead to significant changes in the incidence and/or prevalence of persons with certain etiological problems; (2) cohort effects may represent better education and/or training for retarded individuals across time, as a result of improvements suggested by current or previous research and theory; (3) cohoit effects in persons living in certain settings may arise from the differential rates across cohorts in the movement of persons residing in large state residential facilities into community placements; (4) cohort effects may represent changes in definition or diagnosis of persons falling in the various categories of mental retardation; or (5) cohort effects may result from systematic, differential representation of the population cohort at a given point in time, because of differential identification of persons with mental retardation or selective survival.

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Any of these potential causes of cohort effects may be involved in main or interactive effects. More importantly, certain patterns of cohort effects may be consistent with certain explanations and inconsistent with others. The specification of different cohort comparisons that provide crucial contrasts among explanations is a worthy task for research, but this task may have to be undertaken anew in different behavioral domains, as cohort contrasts that are considered crucial in one domain may be less crucial or useless in another. Our intent here is simply to illustrate the potential utility of the specification and estimation of cohort differences.

B.

An Interpretational Framework for Empirical Findings on the Life-Span Development of Adaptive Behaviors

In this section, a small number of principles or hypotheses are listed that provide a framework for understanding the development of adaptive behaviors across the life span. That is, the development and aging of adaptive behavior should follow certain trends to justify the hypothesis that the domain of behaviors is subject to psychological laws of a specifiable nature. On the basis of previous life-span research on other domains, for example, the ability domain (J. L. Horn & Hofer, in press), the following hypotheses are proposed:

Hypothesis 1: For persons at each level of mental retardation, the different dimensions of adaptive behavior will exhibit diyerent life-span developmental trends. If this hypothesis is confirmed, the multifactorial representation of the structure of adaptive behavior will be supported, as collapsing the multiple factors into a single score would misrepresent the development and aging of adaptive behaviors. Hypothesis 2: As a corollary of the preceding hypothesis, the aging of adaptive behaviors will vary systematically as a function of certain qualities, such as the novelty or the speeded nature, of the behaviors subsumed. One tenet of the G,G, theory of J. L. Horn (1986, 1988; J. L. Horn & Hofer, in press) is that certain types of behavior are maintained without evidence of decline until relatively late in the human life span, whereas other behaviors exhibit much earlier declines. Specifically, measures that require highly speeded responses or that require novel forms of response seem to show evidence of developmental declines at relatively early points in the life span. In contrast, measures that assess well-learned material or performances in situations in which speed of response is not required begin to reveal developmental declines later in life. Hypothesis 3: For each dimension of adaptive behavior, differential life-span developmental trends will be shown by persons at different levels of mental

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retardation. This hypothesis embodies the expectation that level of mental retardation places constraints on expected development, and that these constraints vary systematically as a function of mental retardation level. Hypothesis 4: Cross-sectional and semilongitudinal methods of estimating life-span developmental curves may yield divergent information. This is a most important point, as differences in trends yielded by the different methods may lead to serious questioning of the results from cross-sectional studies. Moreover, cohort differences are confounded with age differences in both cross-sectional and longitudinal designs, so semilongitudinal designs that allow the estimation of cohort effects may prove especially useful in the understanding of the life-span development of adaptive behaviors. Hypothesis 5: Certain factors will be found to moderate the life-span trends of development and aging of adaptive behaviors. Although it is impossible at present to specify these factors with any assurance, certain categories of variables noted by Grossman (1983), such as etiology, prenatal and perinatal factors, congenital factors, demographic factors, and features of the residential environment, are all potential variables that moderate the development and aging of adaptive behaviors.

To the extent that extant data conform to the preceding hypotheses, our initial set of hypotheses, based on previous life-span research in other domains, will be supported. In all likelihood, future research will reveal that the above hypotheses were too simplistic or too general to be confirmed or disconfirmed with clarity. If, however, this state of affairs occurs at some time in the future, the above framework will have served its purpose-to spur on research efforts to demonstrate the ways in which the initial hypotheses were deficient, leading to more accurate representations of the life-span development of adaptive behaviors.

C. Empirical Studies of the Life-Span Development of Adaptive Behaviors 1. STUDIES OF UNRESTRICTED SAMPLES OF PERSONS

WITH MENTAL RETARDATION a. Cross-Sectional Studies. In perhaps the first large-scale study of the lifespan development of adaptive behaviors, Nihira (1976) plotted the levels of behavior exhibited by over 3300 persons with mental retardation ranging in chronological age from 4 through 69 years. The samples of persons were distributed across five levels of mental retardation, from borderline through profound, and life-span growth curves were plotted for each of the three factors identified by Nihira: (1) Personal Self-Sufficiency, covering basic skills such as eating, toileting, and grooming; (2) Community Self-sufficiency, including more

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cognitive skills such as communication and economic activity; (3) PersonalSocial Responsibility, subsuming an array of motivational attributes. The life-span growth trends from the Nihira (1976) study differed across both level of retardation and domains of adaptive behavior. Regarding the most basic domain of behavior, Personal Self-Sufficiency, persons at the mild and moderate levels of mental retardation showed a rapid increase through childhood, reaching an asymptote at about 12 to 15 years of age, after which little change was noted. In contrast, severely retarded persons had a prolonged period of growth, reaching an asymptote at about 25 years of age; profoundly retarded persons exhibited steady growth throughout the life span. On the second factor, Community SelfSufficiency, slower rates and later asymptotes were shown by all four groups, with asymptotes at approximately 14, 17, 25, and 40 years of age for mildly, moderately, severely, and profoundly retarded persons, respectively. For the Personal-Social Responsibility factor, persons with mild retardation exhibited rapid growth during childhood, reaching an asymptote at about 8 or 9 years of age; those at the moderate and severe levels showed slower growth of a similar pattern, with an asymptote at around the mid-20s; whereas persons with profound retardation showed rather slow but continued growth throughout the life span. Although not stressed by Nihira (1976), there was some suggestion of slight declines for persons with mild and moderate mental retardation after the age of 50 years on the Personal Self-Sufficiency and Community Self-Sufficiency factors, but it is not clear whether these declines were significant. Aside from Nihira (1976), few studies have attempted to document the development of adaptive behaviors during the childhood and adolescent years using cross-sectional designs. However, several studies have investigated development during this age span using longitudinal or semilongitudinal methods; these studies are discussed in a later section. On the other hand, there has been a good deal of research interest in documenting the maintenance and possible declines in adaptive behaviors during adulthood and old age. In one of the first studies, Seltzer, Seltzer, and Sherwood (1982) described the behavioral characteristics of 153 adults with mental retardation who had been released from a state institution in Massachusetts. The primary aim of the study was to contrast the older adults, aged 55 years and older (N = 25), with the younger adults, aged 18-54 years ( N = 128). Despite the lack of group differences on IQ or level of mental retardation, Seltzer et al. found that the older adult group exhibited lower levels of functioning than did the younger adults on the number of community living skills they had mastered, the regularity with which they performed those community living skills, and their motivation for independent performance. The older adults also were initially placed into less independent residential settings and continued to live in less independent settings when compared with the younger adult group. The Seltzer er al. results imply that independent living and cognitive skills exhibited by persons with mental

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retardation decline after the age of 55 years. But the presence of preexisting differences between the two groups-the older adults had been institutionalized, on average, twice as long and fewer of them were formally discharged from the institution relative to the younger adult group-leads to difficulty in attributing the group differences on adaptive behavior skills solely to the effects of aging. The Seltzer et al. (1982) study was followed up in a large-scale investigation by Janicki and MacEachron (1984) of persons served by the New York State Office of Mental Retardation and Developmental Disabilities. Janicki and MacEachron reported on a large array of personal, behavioral, and service characteristics of over 7800 adults with mental retardation who were 53 years of age or older. Janicki and MacEachron arrayed their data several ways, presenting simple aging trends as well as aging trends as a function of level of mental retardation and placement. Apparent aging-related decreases in motor and independent living skills were found, especially after the age of 73 years. These trends, however, seem to have arisen from the age-related trends in numbers of persons living in institutional settings; that is, as age increased, a greater proportion of persons lived in institutional settings rather than community settings, and persons in institutional settings tend to have lower levels of functioning. When Janicki and MacEachron arrayed their data by residence type (community vs. institutional), essentially no age-related changes in levels of adaptive behavior skills were evinced, except for a decline in mobility and an increase in eating skills which were shown only for residents of institutions and after the age of 73 years. The failure to report tests of significance in this study, however, limits the ability to draw conclusions regarding the statistical significance of the various trends reported. In at least two large studies, older adults were found to be more competent and less dependent than adults who were in the middle years of the life span. Hauber, Rotegard, and Bruininks (1985), based on data from a nationwide study, used an overall index of independence in adaptive skills and found that older adults (i.e., those over 62 years) showed greater independence, or higher levels, of independent living skills than did adults in the middle years from 40 to 62 years of age. As expected, institutionalized adults showed lower levels of independence than did those living in community settings, but similar age-related trends relating increased independence with increased age were reported for residents in both settings. In the second study, similar age-related trends were found by Krauss and Seltzer (1986), who compared the medical, functional, and behavioral characteristics of 530 adults between the ages of 22 and 54 years of age with those of 555 adults in the age range 55-91 years. Krauss and Seltzer found that the older adults were less cognitively impaired, as indexed by level of mental retardation, and were correspondingly significantly higher functioning in adaptive behaviors, as measured by the Minnesota Developmental Programming System, when com-

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pared with the younger adults. These findings were replicated in a smaller study by Linter (1986) of 63 adults with mental retardation above the age of 20 years residing in a hospital setting in England. Linter reported that the 25 older adults, aged 60 years and older, were the most able of the three age groups on the selfcare skills of eating, bathing, and dressing, and exhibited the highest levels of communication skills relative to the two groups of younger adults. But the findings from this study are limited by a lack of significance testing of trends and the possibility that changes in admission policy underlie the findings. In a study of over 10,500 adults with mental retardation over the age of 45 years, Janicki and Jacobson (1986) presented data on persons receiving services from the New York State Ofice of Mental Retardation and Developmental Disabilities. The aging trends were reported for the eight domains of a short form of the Behavioral Scales from the Minnesota Developmental Programming System and for two aggregate scores based on the eight domains. The domains represented were gross motor, toileting, dressing/grooming, eating, language, reading and writing, quantitative, and independent living; the first four scales were also aggregated into a daily living composite, and the latter four into a cognitive composite. Janicki and Jacobson then reported on age-related trends on these 10 indices of adaptive behavior for two general levels of mental retardation, mild/moderate and severe/profound. The findings indicated that adults with mild or moderate mental retardation showed slight declines in mean levels of performance after the age of 50 years in gross motor and independent living skills, whereas either stability or increases in mean level occurred as a function of age for the remaining six domains through the age of 70 years, after which some declines were noted. Adults with severe or profound mental retardation also showed declines in gross motor skills after the age of 50 years; however, on the remaining seven domains, age-related increases were found until at least the age of 75 years for the adults with severe and profound mental retardation. The daily living skill scales tended to exhibit decreases in mean levels of performance after the age of 75 years, but the cognitive scales continued to increase through at least 80 years of age before showing some declines. More recently, Haveman, Maaskant, and Sturmans (1989) described the results of a cross-sectional study of 509 adults with mental retardation living in both community and institutional settings in The Netherlands. The subjects were described as having severe mental retardation, but, with IQs below 50, would fall in the moderate to profound range of retardation according to the American Association of Mental Deficiency (AAMD) guideline (Grossman, 1983). Adults without Down syndrome showed a small decline in motor functioning after the age of 50, but adults with Down syndrome showed much larger motor and mobility problems after age 50. Differential patterns for adults with and without Down syndrome were also shown on two scales that appear roughly comparable to the Independent Living Skills and Cognitive Competence factors of Widaman

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et al. (1987), although the latter scale was restricted to linguistic skills. On both of these scales, adults without Down syndrome showed either little change in mean level or slight increases across the age levels from 20 to 60+ years of age. In contrast, adults with Down syndrome exhibited clear declines in Independent Living Skills after the age of 50, and showed smaller, but still noticeable, declines in linguistic skills after the age of 60 years. Haveman and Maaskant (1989) reanalyzed the data from Haveman et al. (1989) to determine whether their differential aging patterns held as a function of placement. They reported that adults over 50 years of age living in institutions had significantly worsened motor problems, a pattern not shown for those living in sheltered homes. There was some drop in Independent Living Skills by adults after age 50, but linguistic skills continued to improve across the life span; neither of these two trends was moderated by placement. In another study, Maaskant and Haveman (1989) studied 416 adults with mental retardation living in group homes in The Netherlands. They found some decrease in motor competence among adults after the age of 60 years, but essentially no significant changes in independent living skills or linguistic skills across the ages from 20 to 60+ years. An item analysis revealed some agerelated declines in certain independent living skills, such as dressing, making one’s bed, and setting the table. But, these were apparently offset by increases in other types of independent living skills. In a study of 99 adults with mental retardation over the age of 65, Day (1987) reported a substantial age-related increase in mobility problems; however, there were rather small and nonsignificant age-related trends in the degree of dependence shown by these adults. Finally, Janicki (1989) studied 883 older adults with both mental retardation and cerebral palsy. Janicki reported age-related declines in a variety of motor and independent living skills, including mobility, toileting, eating, and dressing and grooming skills, but these skills tended to show the greatest declines later in life, after the age of 75 years. b. Longitudinal or Semilongitudinal Studies. In a semilongitudinal study of development during the childhood and adolescent years, Schlottmann and Anderson (1982) presented data on the growth of adaptive behavior between the ages of 7 and 20 years, based on data from 200 institutionalized persons. Unfortunately, Schlottmann and Anderson presented their results using only a single, summary adaptive behavior composite score, so that comparing their results with the differential aging trends during this age span reported by Nihira (1976) is not possible; however, Schlottmann and Anderson reported largely linear growth trends between the ages of 7 and 20 years. Furthermore, these linear trends differed systematically as a function of level of mental retardation, with persons with mild mental retardation showing the fastest growth in adaptive behaviors and persons with profound retardation the slowest rate of growth. Eyman and Arndt (1982) attempted to plot the life-span aging of adaptive

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behaviors for persons with mental retardation living in institutional (N = 3457) and community (N = 312) settings. Each client had been followed for four consecutive years, and behavioral assessments were based on the Behavioral Development Survey, a shortened version of the AAMR Adaptive Behavior Scale. Similar to Schlottmann and Anderson (1982), Eyman and Arndt used a single overall index of adaptive functioning. Client ages ranged from 5 to 47 at the first time of measurement, so growth curves were plotted from 5 to 50 years of age. Across this age span, Eyman and Arndt reported that persons in institutional settings exhibited growth up to about age 12, then an asymptote until about age 45 years, after which there was possibly a decline in adaptive functioning. Persons residing in community placements showed growth until about age 15 years, after which mean levels of behavior were largely unchanged, although there were fluctuations after age 35, probably as a result of small sample sizes. No significant differences in the shape of the growth functions for institutionalized and community-placed persons were reported. The preceding study was followed up by Eyman and Widaman (1987), who analyzed data on over 30,000 persons served by the California State Department of Developmental Services. These persons had been assessed for four consecutive years using the Client Development Evaluation Report, for which the factorial structure was obtained by Widaman et al. (1987). Of the sample, about 6400 persons were residents of large state institutions, and the remaining 24,000 persons lived in a variety of community settings. Eyman and Widaman demonstrated large differences between cross-sectional and semilongitudinal estimates of age-related trends for the Motor Skills factor, differences that were most pronounced for persons in the severe and profound levels of mental retardation. Because of their greater validity, Eyman and Widaman concentrated on the results revealed by the semilongitudinal data. Here, significantly different growth curves were found as a function of level of mental retardation, as expected, and rather different growth trends were found for each of the four dimensions of adaptive behavior (Motor, Independent Living, Cognitive, and Social) and the two dimensions of maladaptive behavior (Social Maladaption and Personal Maladaption). Furthermore, significant differences were found in the growth trends for persons residing in institutional and community placements, controlling for level of retardation. In a current study, Widaman, Little, and Borthwick-Duffy (1991; Little & Widaman, 1991) explored the fit of an array of structural models to data from over 36,000 persons with four annual surveys using the Client Development Evaluation Report. The 36,000+ persons were divided into 18 birth cohorts at each of the four levels of mental retardation from mild to profound. The resulting 72 cohort samples ranged in size from 123 to 1221 persons, with an average sample size of 506 subjects. The first 16 cohorts are 3-year birth cohorts; the first cohort contains infants aged 0-2 years at the first time of measurement, and the

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sixteenth cohort contains adults aged 45-47 years at the first time of measurement. Because of the decrease in sample sizes over the age of 47 years, the seventeenth cohort included adults aged 48-54 years at the first time of measurement, and the final cohort contained adults aged 55 years and older at the first time of measurement. Three-year birth cohorts were employed so that persons in one cohort at the fourth time of measurement would be approximately the same mean age as the persons in the next cohort at the first time of measurement. The discrepancies that arise from the use of cross-sectional and semilongitudinal estimates of aging trends are illustrated in Fig. 1A and 1B. These figures were prepared using data from the first time of measurement on the 36,101 individuals with mental retardation. For simplicity, data from only two samples for only a single factor were plotted: Fig. 1A shows the plots of the cross-sectional and semilongitudinalgrowth in Cognitive Competence across the life span for persons with mild mental retardation, and Fig. 1B gives a similar plot for persons with severe mental retardation. As shown in Fig. l A , the crosssectional plot reveals a somewhat positively biased estimate of life-span growth in Cognitive Competence, but a similar trend is revealed, with consistent increases in competence between the ages of 1 and about 20 years, with relative stability thereafter. A rather different picture is revealed in Fig. 1B. Here, the cross-sectional curve provides not only a positively biased estimate of growth, but a different looking curve as well. Based on the cross-sectional curve, one would conclude that the persons with severe mental retardation would exhibit continued growth in Cognitive Competence between the ages of 1 and about 27 years, with relative stability thereafter; however, the semilongitudinal curves suggest that there is little in the way of age-related changes in Cognitive Competence shown by persons with severe mental retardation. The differences between the cross-sectional and semilongitudinalcurves are due to cohort differences, the precise meaning of which remains to be determined. Widaman, Little, and Borthwick-Duffy (1991; Little & Widaman, 1991) plotted life-span development for persons at each of the four levels of mental retardation between the ages of 1 and 67 years on each of the six dimensions underlying the Client Development Evaluation Report (cf. Widaman et al., 1987; Widaman, Little, & Borthwick-Duffy, 1991). The semilongitudinal life-span curves for Motor Development revealed that both growth rate and asymptotic level are systematically related to level of mental retardation. Thus, moving from the mild to the profound level of mental retardation, growth rate between the ages of 1 and 6 or 7 years of age slows greatly and the asymptotic level of performance is greatly lessened. Interestingly, persons at all levels of mental retardation reach their asymptote at about the same age, between the ages of 7 and 10 years. Also, all growth curves tend to reveal some declines associated with aging, with the more profoundly mentally retarded showing the earlier and larger declines.

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FIG.I . Illustration of differences between cross-sectional and semilongitudinal estimates of lifespan growth curves in Cognitive Competence for persons with mild mental retardation (A) and for persons with severe mental retardation (B).

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The semilongitudinal growth curves for the Independent Living Skills factor also showed that growth rate and asymptotic level were directly related to level of mental retardation. Persons with mild or moderate mental retardation showed increases in competence through about 16 years of age, whereas those at the severe and profound levels showed little and no noticeable change during this age span, respectively. Approximate stability, with slight declines, in mean levels was exhibited by persons at all levels of mental retardation between the ages of 16 and 45 years. Thereafter, persons with moderate to profound mental retardation had declines in competence after the age of 50, whereas important declines in Independent Living Skills by persons with mild mental retardation were exhibited only after the age of 63 years. To illustrate the appearance of semilongitudinal life-span trends, the growth trends for the Cognitive Competence factor are presented in Fig. 2A by level of mental retardation. Here, growth rate, asymptotic level, and age at asymptote all appear to be related to level of mental retardation. Persons with mild retardation show rather fast growth during childhood and adolescence, reaching an asymptote at around 20 years of age, and show essentially no changes in mean levels until at least the mid-60s. Persons with moderate mental retardation reveal slower growth, an asymptote in performance reached at about 18 years of age, and some declines in performance after the age of 50 years. Persons at the severe and profound levels of mental retardation show some small changes during the first decade of life, reaching an asymptote in performance between 7 and 10 years of age, and show little or no change in performance during the remainder of the life span. The semilongitudinallife-span growth curves on the Social Competence factor are presented in Fig. 2B. As with the Cognitive Competence factor, all aspects of the growth trends appear to be related to level of mental retardation. For persons with mild retardation, the fastest growth occurs before the age of about 10 years, but some increases continue until the early 20s; after the age of about 30 years, declines begin, which are relatively small but steady thereafter. Persons with moderate retardation exhibit gains in Social Competence until about 10 years of age, after which there is approximately 15 years of stability in mean levels before declines begin in the mid-20s. Persons with severe and profound mental retardation show some gains until about 8 years of age; after a period of stability in mean level for about 10 years, declines in Social Competence ensue, with a faster rate of decline for persons with profound retardation than for persons with severe retardation. To contrast the life-span developmental trends of adaptive behavior, the semilongitudinal life-span trends for Social Maladaption are shown in Fig. 2C for persons at each of the four levels of mental retardation. The most striking aspect of these curves is the rather similar and steady age-related increase in socially maladaptive behavior across the ages included in this study. During the first 6 or

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8 years of life, there is no notable difference in levels of social maladaption among persons at the four levels of mental retardation. After the age of about 9 years, however, persons at the mild and profound levels of mental retardation continue to exhibit relatively low levels of social maladaption, but persons at the moderate and severe levels show some increases in social maladaption. After about the age of 20 years, persons at all levels of mental retardation exhibit steady and parallel increases in levels of social maladaption throughout the remainder of the life span. Finally, the semilongitudinal life-span trends in Personal Maladaption are presented in Fig. 2D. These estimates reveal a somewhat different trend than did the curves for Social Maladaption. Specifically, persons at the mild level of mental retardation have the lowest level of Personal Maladaption, continuing to exhibit very low levels of this form of behavior through the early 20s, after which they show small but steady increases in Personal Maladaption. Persons at the moderate level exhibit somewhat higher levels of Personal Maladaption, deviating from those at the mild level during the ages from 1 through about 12 years, after which they show small, parallel increases in maladaptive behaviors. Persons with severe mental retardation exhibit consistently higher levels of Personal Maladaption than do any other group. They show a faster growth rate for these behaviors from about 1 to 20 years of age, after which they show a reduced rate of increase that approximately parallels the increases shown by persons at the mild and moderate levels of retardation. Persons at the profound level of mental retardation show age-related increases in Personal Maladaption that are very similar to those for persons at the moderate level throughout the life span. This study is the only one of which we are aware that has estimated cohort effects for measures of adaptive behavior. The general form of these cohort effects is as follows: For subjects at the mild, moderate, and severe levels of mental retardation, there are positive cohort effects for the first three to six cohorts, and then nonsignificant cohort effects across the rest of the life span. This is consistent with differential identification of persons with mental retardation, as only the lowest functioning persons at the mild, moderate, and severe levels are identified at early ages, whereas less impaired persons at these three levels are identified only at later ages. In contrast, for persons with profound mental retardation, there were no significant cohort effects during the first several cohorts, but then significant and positive cohort effects were found after about the fifth cohort. These cohort effects may reflect differential survival of persons with profound mental retardation. Initially, in the first few cohorts, virtually all persons with profound mental retardation are identified, so there is an absence of cohort effects. With increasing age, however, the more medically compromised persons with profound mental retardation have higher probabilities of dying, resulting in later cohorts of persons with profound retardation that consist of only the healthier, less medically fragile portions of their population.

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2. DIFFERENTIAL LIFE-SPAN DEVELOPMENT OF PERSONS WITH DOWN SYNDROME From before 1970, researchers have investigated the hypothesis that persons with Down syndrome exhibit patterns of life-span development different from those of persons with other forms of mental retardation. A central impetus for this research area is the finding, on autopsy, that the neuropathological signs of Alzheimer’s disease, such as neurofibrillary tangles and senile plaques, have been present in virtually all persons with Down syndrome who died over the age of 35 years (e.g., Wisniewski, Wisniewski, & Wen, 1985). In nonretarded populations, the onset of Alzheimer’s disease is accompanied by a wide array of behavioral deficits, such as memory loss and disorientation. If persons with Down syndrome develop the neurological signs of Alzheimer’s disease to a much greater extent than do mentally retarded persons without Down syndrome, then persons with Down syndrome should exhibit differential, steeper declines in behavioral skills during the aging period relative to other persons with mental retardation. Interestingly, many persons with Down syndrome who had the neurological signs of Alzheimer’s disease did not show the expected declines in behavioral skills that are the concomitants of the neuropathology in nonretarded populations (Wisniewski et a l . , 1985);however, the apparent link between Down syndrome and Alzheimer’s disease has spurred considerable work on the possibility of differential declines in adaptive behaviors by persons with Down syndrome. a . Cross-Sectional Studies. Differential development across the life span for persons with Down syndrome was investigated by Silverstein, Herbs, Nasuta, and White (1986). Restricting their attention to persons residing in institutional settings, Silverstein et al. compared the development of 413 persons with Down syndrome with that of 413 persons without Down syndrome, matched for relevant attributes such as age. Six age groups were defined: 0-19, 20-29, 30-39, 40-49, 50-59, and 60+ years. The assessments of adaptive behavior were the Client Development Evaluation Report evaluations of these persons for a single calendar year, and analyses were performed at the item level. Only 4 of 62 Client Development Evaluation Report items revealed statistically significant Age X Diagnostic Group interactions. Three items-assessing rolling and sitting, crawling and standing, and eating-showed relative declines after age 60 by persons with Down syndrome; the three items all fall on the Motor Skills factor of Widaman et al. (1987). For the fourth item, writing skills, a relative increase in performance by persons with Down syndrome was found after age 50, contrary to the differential decline hypothesis. The preceding study was followed up by Silverstein et a l . (1988), who reported the results of three studies, two of which were cross-sectional in design. In the first of these, Silverstein et a1. reanalyzed the data from Silverstein et al.

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(1986) at the scale (or factor) level, using the six factored scales described by Widaman et af. (1987), arguing that item-based analyses may have been of insufficient power to ensure the detection of findings of practical importance. With the same subjects and age categories used by Silverstein ef al. (1986), an Age X Diagnostic Group interaction was found only for the Motor Skills factor; a differential decline by persons with Down syndrome was found after the age of 60 years, consistent with Silverstein et af. (1986). Silverstein et al. (1988) also reported the results of a second cross-sectional study (termed Study 3 in their article), investigating whether their findings on persons living in institutional settings would generalize to those living in community settings. In this study, the life-span development of 399 persons with Down syndrome and 399 mentally retarded persons without Down syndrome matched on relevant characteristics, all of whom lived in noninstitutional settings, was contrasted. Six age levels were again defined, beginning with 0-9 years and ending with 50+ years of age, and analyses were performed on the six Client Development Evaluation Report factor scores. Once again, an Age X Diagnostic Group interaction was shown only for the Motor Skills factor. Persons with Down syndrome had higher levels of motor skills than did persons without Down syndrome at all age levels except the 50+ level; in the latter group, the pattern was reversed, and persons with Down syndrome exhibited lower levels of motor skills. Thus, for persons residing in both institutional and noninstitutional settings, Silverstein ef al. (1988) found that persons with Down syndrome showed a differential decline only in motor skills and at some point after 50 years of age. In a large study of middle adulthood and aging, Zigman et af. (1987) obtained a sample of 2144 persons with Down syndrome between the ages of 20 and 69 years. The comparison group consisted of 4172 persons without Down syndrome, matched on age, sex, residential placement, and level of mental retardation. Five age groups were defined, corresponding to the age decades from the 20s through the 60s. Adaptive behavior scores were derived from the short form of the Behavioral Scales of the Minnesota Developmental Programming System, also used in the Janicki and Jacobson (1986) study discussed above. Based on a factor analysis, Zigman et af. formed two composite scores: (1) Daily Living Skills, a composite of five scales (gross motor, eating, dressing/grooming, toileting, and independent-living); and (2) Cognitive Skills, a composite of the remaining three scales (language, reading/writing, and quantitative). Analyses were performed only on the two composite scores, and statistically significant Age X Diagnostic Group interactions were found for each composite. On the Daily Living Skills composite, persons with Down syndrome scored above persons without Down syndrome during every age decade from the 20s through the 50s; but this pattern was reversed in the age group 60-69 years, with the persons with Down syndrome scoring lower. The results for the Cognitive composite were fairly similar; the largest mean difference in performance as a function of

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diagnostic group was shown in the group 60-69 years, with the persons with Down syndrome scoring lower than those without Down syndrome. Interestingly, the relative decline in performance from the 50s to the 60s for persons with Down syndrome was much larger for the Daily Living Skills composite than for the Cognitive Skills composite. In a later paper, Zigman, Schupf, Silverman, and Sterling (1989) reanalyzed the Zigman et al. (1987) data at the scale level, employing identical subjects and age and diagnostic groupings. Statistically significant Age X Diagnostic Group interactions were found for all eight scales; on each scale, the largest difference in performance was found for the persons aged 60-69 years, where persons with Down syndrome scored below persons without Down syndrome. But the relative declines from 50-59 years to 60-69 years were most pronounced for the most basic skills-gross motor, toileting, dressing/grooming, and eating. In comparison, the relative declines for the cognitive skills-language, reading/writing, and quantitative-were rather small, only about one-third to onehalf the magnitude of the relative declines shown in the basic skills. The relative decline in independent living skills fell between those for the basic skills and the cognitive skills. Schupf, Silverman, Sterling, and Zigman (1989) used data on 99 deceased adults with Down syndrome, who had died between the ages of 20 and 69 years, and 99 deceased persons without Down syndrome, matched for relevant characteristics such as age at death and level of mental retardation. Schupf et al. analyzed a single overall adaptive behavior score, derived as a composite of the eight behavioral scales from the Minnesota Developmental Programming System. They found that, over the 3 years before their death, the persons with Down syndrome exhibited greater declines in adaptive behaviors than did their matched controls, but only after the age of 50 years. Unfortunately, because Schupf er a f . used only a single composite score, determining whether the differential declines stemmed primarily from declines in motor skills or were more general in nature is not possible. Two additional cross-sectional studies have reported results on the behavioral functioning of persons with Down syndrome, but both were based on relatively small sample sizes. In one study, Fenner, Hewitt, and Torpy (1987) studied a group of 39 persons with Down syndrome between the ages of 19 and 49 years of age; in the other, Hewitt, Carter, and Jancar (1985) obtained a sample of 23 persons with Down syndrome over the age of 50 years. In both studies, the authors concluded that there was no noticeable relationship between chronological age and level of self-care skills, the only type of adaptive behavior assessed; however, the small sample sizes resulted in low power to detect relationships, so the results of these studies are inconclusive. b. Longitudinal or Semilongitudinal Studies. Only a small number of longitudinal or semilongitudinal studies have investigated the differential development of persons with Down syndrome. In the lone life-span study, Silverstein et af.

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(1988, Study 2) obtained four years of longitudinal data on 192 of the 413 persons with Down syndrome that were the subjects in their earlier study (Silverstein et al., 1986). The life-span development for these persons was contrasted with the development of their matched control subjects. Because of the smaller sample size, only four age groups were defined: 0-19, 20-29, 30-39, and 40+ years. Silverstein et al. (1988) reported that the Age X Diagnostic Group X Occasion interaction was nonsignificant on all six Client Development Evaluation Report factors, suggesting that the declines in adaptive behaviors were similar for persons with Down syndrome as for those without Down syndrome. Three recent studies have reported longitudinal or semilongitudinal data on persons with Down syndrome: Lai and Williams (1989), Evenhuis (1990), and Brown, Greer, Aylward, and Hunt (1990). The former two used prospective designs, whereas the last study used a retrospective design. The Brown et al. study had the largest sample size (N = 130) and used standard measures of adaptive behavior (e.g., the Vineland Social Maturity Scale or the Vineland Adaptive Behavior Scales: Interview Edition). Using only an overall adaptive behavior composite, Brown et al. found fairly stable levels of adaptive behavior through much of the adult years, with a large drop after 50 years of age. In the other two studies, less standard measures of adaptive behavior skills were used, based primarily on unspecified interviews with nursing staif. In all three studies, important declines in various types of self-care skills were found, but the lack of a comparison group of persons without Down syndrome compromises attempts to test the differential decline hypothesis, that the aging declines are uniquely associated with persons with Down syndrome. D.

Summary of Empirical Studies of the Life-Span Development of Adaptive Behaviors

Looking across the varied studies of life-span developmental trends for adaptive behaviors, several generalizations are possible. First, supporting the multifactorial approach to the representation of the domain of adaptive behaviors, the different dimensions of adaptive behavior exhibited rather different life-span trends. Collapsing all forms of adaptive behavior into a single Personal Independence dimension would lead therefore to a misrepresentation of the differential growth, maintenance, and aging of different types of adaptive behavior. At present, the strongest evidence for aging declines is in the area of motor skills; more studies have reported declines in motor skills than in any other area. The domain of Independent Living Skills also exhibited some declines in a number of studies. Interestingly, the cognitive skills assessed by measures of adaptive behavior appear to show smaller and later declines than do skills in the other areas. This is an easily interpreted finding: the cognitive skills represented in adaptive behavior scales tend to be of the crystallized variety, abilities that show less of an age-related decline in nonretarded populations (J. L. Horn & Hofer, in press).

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Finally, few studies have looked at social skills; in the Widaman, Little, and Borthwick-Duffy (1991) study, social skills showed earlier and more consistent declines across all levels of mental retardation than did any other dimension of adaptive behavior. Second, persons at the four levels of mental retardation exhibit rather different life-span trends for acquisition, maintenance, and decline of adaptive behaviors. In general, the more profound the level of mental retardation, the less the growth during childhood and adolescence, the shorter the period of growth (the sooner an asymptote in performance is reached), the lower the asymptotic level of behavior, and the sooner and larger the aging declines. These generalizations necessarily misrepresent the trends for certain dimensions of adaptive behavior, but the life-span trends revealed in the Widaman, Little, and Borthwick-Duffy (1991) study suggest that the modifiability of adaptive behaviors is probably inversely related to the profoundness of a person’s level of mental retardation. Third, several studies have shown differences in developmental curves based on cross-sectional and semilongitudinal methodologies (e.g., Eyman & Widaman, 1987; Widaman, Little, & Borthwick-Duffy, 1991). Because they trace the development of the same individuals across time, semilongitudinal results probably portray aging trends more accurately than do cross-sectional studies. Researchers should be encouraged to exploit opportunities for conducting semilongitudinal analyses, as the field of mental retardation would benefit from a larger array of studies of this type. Fourth, research on the differential development of persons with Down syndrome, although encouraging, has reached somewhat conflicting results. Crosssectional studies have tended to find that persons with Down syndrome exhibit somewhat stronger aging declines in adaptive behaviors than do persons without Down syndrome; however, such issues as the age at which the differential decline commences and whether decline occurs for the adaptive behavior domain in general or for specific adaptive behaviors within the domain are unclear. In studies that have analyzed more differentiated instruments, the differential aging of persons with Down syndrome has been most pronounced and most consistently documented for the motor skills area; other types of adaptive behavior exhibit rather smaller differential declines. As few longitudinal studies have been performed on this topic, firm conclusions regarding the validity of the differential development hypothesis must await further longitudinal study.

IV. FACTORS MODERATING THE LIFE-SPAN DEVELOPMENT OF ADAPTIVE BEHAVIORS

In this section, we discuss several types of factors that may influence the development and aging of adaptive and maladaptive behaviors by persons with mental retardation. For convenience, these factors are grouped under the head-

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ings of characteristics of the individual, physical or structural features of the residential environment, and interpersonal features of the residential environment. The topics covered in this section constitute the contextual factors that moderate the normative trends for the life-span development of adaptive behaviors.

A.

Characteristics of the Individual

Certain characteristics of individuals with mental retardation may moderate the acquisition, maintenance, and decline of adaptive behaviors across their life span. To date, perhaps the most widely studied form of personal characteristic is level of mental retardation, followed by etiology, particularly the differential declines in adaptive behaviors shown by persons with Down syndrome relative to other aging persons with mental retardation. Research on the differential aging of persons with Down syndrome was reviewed in a previous section; this research tended to show that individuals with Down syndrome exhibit earlier declines in adaptive behaviors than did persons with other etiological classifications. As noted above, research on persons with Down syndrome is still preliminary; the differences across studies in the extent and generality of the aging declines reported, and the cross-sectional findings reported in several studies by Zigman and his associates (e.g., Zigman, Adlin, & Silverman, 1990; Zigman ef al., 1987) should be supplemented by longitudinal investigations that validate these findings; however, this research area illustrates the utility of including etiology as a factor when studying the development and aging of adaptive behaviors. Unfortunately, the reliable identification of groups of persons with other etiological diagnoses is more problematic than is the case for persons with Down syndrome (Chaney & Eyman, 1982). But the current findings for persons with Down syndrome support the position that a complete theory of the development and aging of adaptive behaviors must ultimately determine the differential effects of an array of etiological factors on life-span development of adaptive behaviors. Several other personal characteristics seem to be likely candidates as moderators of development. For example, gender and ethnic status are frequently used as personal moderator variables in studies of the development of nonretarded populations; however, previous research on populations of persons with mental retardation has failed to reveal important or significant effects of either gender or ethnicity (e.g., Eyman & Amdt, 1982; Eyman & Widaman, 1987; Schlottmann & Anderson, 1982). The possibility exists that previous studies have not asked the “right” questions about gender and ethnicity, leading to the apparent nonsignificance of these factors. Thus, the consideration of gender and ethnicity as potential moderators of developmental progress and decline and the encouragement of other researchers to test for such effects should be continued. Only a body of repeated failures to find effects will ensure that these characteristics are not moderators of the development of adaptive behavior. In addition to the preceding factors, an array of other personal characteristics

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remain viable possibilities as moderators of developmental progress and decline in the domain of adaptive behaviors. For example, such factors as coexisting medical or sensory impairments (e.g., the Janicki, 1989, study of persons with cerebral palsy and mental retardation), the presence of psychiatric problems, and socioeconomic status, among others, are possible developmental moderators. A comprehensive theory of adaptive behaviors must determine whether these personal characteristics influence the development of adaptive behaviors; clearly, much work remains to be done to investigate these potential influences. B.

Physical or Structural Features of the Residential Environment

1. NORMALIZATION OF THE RESIDENTIAL SETTING

The emphasis on moving persons with mental retardation to less restrictive residential environments led to attempts to examine the impact of normalization on changes in adaptive behavior. One commonly used measure is the Program Analysis of Service Systems (Wolfensberger & Glenn, 1975). In one study, Eyman, Demaine, and Lei (1979) found that certain indices of normalization, including the location and proximity of services, as well as the comfort and appearance of the family care and group homes, were associated with improvements in adaptive behavior. In a later study, Eyman, Borthwick-Duffy, and Sheehy (1987) reported that global characteristics of the residential environment had weak, but significant influences on both adaptive and maladaptive behavior scores of residents. Furthermore, studies of life-span development (e.g., Eyman & Widaman, 1987) have found different developmental curves for groups of persons living in different types of residential settings. These finding suggest that placement or selection bias and additional characteristics of persons may provide alternative explanations of reported influences of residential settings.

2. PERSON-ENVIRONMENT FIT Recently, Landesman (1987) investigated the possibility that the goodness of the “behavior-environment fit” between an individual with mental retardation and his or her residential setting may moderate development of adaptive behaviors. In this study, matched trios of persons with mental retardation were randomly assigned to three residence types: group homes on the grounds of a state institution, similarly structured group homes in the community, and residential wards in a large state institution. Thus, two of the three residential settings offered reduced staff-to-resident ratios and more normalized living settings. Certain results of this study failed to confirm a priori hypotheses. For example, despite notable improvements in physical settings and management practices, Landesman concluded that the daily behaviors of the residents had not changed accordingly. Moreover, there was no evidence from this study that reduced staffto-resident ratios led to increased interactions between staff members and resi-

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dents. In fact, the results were consistent with previous findings (Balla, 1976) that staffing patterns do not necessarily influence the quality or frequency of personal interactions. Indeed, many residents in the less institution-like settings were found to spend more time alone than had been the case before their relocation. Landesman (1987) speculated that there may be an interaction between individual characteristicsand the effects of different residence types. After clustering individuals into behavioral types based on baseline data, Landesman concluded that there was an interaction between characteristics of people and their environments. That is, similar environments had markedly different effects on different types of persons. For instance, residents with the highest levels of social and verbal functioning prior to their relocation failed to show significant behavioral changes in any setting, whereas residents who were initially more passive and dependent seemed to benefit from smaller living units; however, Landesman concluded that none of the settings used in the study, even the new physical structures, could be considered cognitively stimulating, thus providing a partial explanation for the lack of significant behavioral changes. These findings do speak, however, to the notion of normalization, specifically that judgments regarding the most appropriate and least restrictive environment must be made in conjunction with an appraisal of the characteristics of the individual being placed.

3. ARCHITECTURAL FEATURES OF THE HOME ENVIRONMENT Recently, Thompson, Robinson, Graff, and Ingenmey (1990) evaluated the homelikeness of different residential settings. Thompson er al. concentrated on the architectural features of residential settings, arguing that even seemingly rather minor variations across settings in various architectural features may impact behavior. Hence, rather than relating to the global features tapped by an instrument such as the Program Analysis of Service Systems, behavior may be more strongly a function of the presence of homelike architectural features. In their study, Thompson et al. found that a sample of persons without mental retardation agreed quite well on the homelikeness of a variety of features of living environments. Future research must be undertaken to determine whether the cognitive discriminations by persons without mental retardation among features of residential settings have causal influences on the behavior of persons with mental retardation.

C. Interpersonal Features of the Residential Environment In addition to the research focus on physical aspects of residential settings, research on interpersonal features of residences has also been undertaken. Prime examples of research of this sort are the studies by Mink and Nihira (1986,

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1987). These studies were guided by the general hypothesis that the affective climate of the home may influence the development of adaptive or maladaptive behaviors by the child with mental retardation and that the child’s behavior may, in turn, influence the climate of the home. In the first of these studies, Mink and Nihira (1986) studied 218 families with a child labeled as EMR or educationally handicapped. First, a cluster analysis of the families was undertaken to isolate different types of families. Then, within the three clusters of families with sufficient sample sizes, cross-lagged panel correlations were computed to determine the preponderance of causal impact among family and child variables. In learning-oriented families, the child tended to influence the family more than the reverse. Thus, the child’s social adjustment influenced the intellectual/ recreational orientation of the home; the child’s personal/social responsibility affected both the intellectual/recreational orientation and the provision of a supportive environment for school learning; and the child’s level of social maladaption led to lower levels of community involvement by the parents and a lower intellectual/recreational orientation of the home. In contrast, in achievementoriented families, the family tended to influence the child. In these families, parental expressiveness influenced the child’s social adjustment, and community involvement by the parents led to lower levels of both socially and personally maladaptive behavior by the child. Finally, in other-directed, low-achievement families, there were some instances of the child influencing the family and some of the reverse pattern of influence. For example, the child’s personal self-sufficiency tended to influence parental openness and improved quality of the residential environment. Parental achievement orientation influenced the child’s social adjustment inversely, but the intellectual/recreational orientation of the home led to improved community self-sufficiency for the child. In the second study, Mink and Nihira (1987) followed a similar design, using data on 115 families with children labeled as TMR. Once again, three clusters of families had sufficient size to warrant further analyses. In one family type, cohesive families, the family tended to influence the child. In these families, the quality and safety of the residential environment influenced the child’s social adjustment, and both parental language stimulation and parental openness influenced the child’s self-esteem with regard to physical size and power. In the other two family types, the child tended to influence the family. In control-oriented families, child psychological adjustment affected parental pride, affection, and warmth, whereas child personally maladaptive behaviors led to parental conflict. In the child-oriented families, child psychological adjustment influenced parental cohesion, and child personal/social responsibility led to improved quality of the physical environment and higher levels of parental academic stimulation. Another example of the investigation of interpersonal influences is our longitudinal study of the bidirectional influences between parents and their children with mental retardation (Borthwick-Duffy, Widaman, & Carson, 1990; Widaman &

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Borthwick-Duffy, 1990). Baumrind (1967, 1971) has long studied the influences of parents on their children, using children without mental retardation as subjects. Baumrind has stressed the parenting styles exhibited by parents and the influences that these parenting styles have for the developmental outcomes of the children. Our study was designed to determine whether the Baumrind findings would generalize to families having a child with mental retardation. In this study, we have been making annual visits to the homes of families that have a mentally retarded child, making detailed observations of behaviors during the hour around dinner. In addition, the mothers fill out several questionnaire measures that deal with parenting styles and are rated for their differential use of seven parenting styles. With data from the first 2 years of data collection, cross-lagged regression analyses were performed between parenting style measures and child adaptive and maladaptive behaviors as assessed by the six factors of the Client Development Evaluation Report. One of the more interesting outcomes that was confirmed across the four adaptive behavior factors was the interactive nature of parenting effects. In these interactive models, the mother’s level of maturity demands was the strongest and most consistent form of parenting style. Mothers who score high on maturity demands tend to provide relatively consistent encouragement for the child to exhibit behaviors that are as mature as the child can sustain; mothers scoring lower on maturity demands are less insistent or consistent in their demands of the child, at times doing things for the child if the child balks at undertaking a difficult task. As one example, consider the patterns shown in Figs. 3A and 3B, which show the results for the Motor Development factor. In Fig. 3A, the data are based on children with mild or moderate mental retardation. As shown in the figure, motor development during the second year of the study was influenced by both the mother’s level of maturity demands and the child’s level of motor skill during the first year of the study. For children who had rather high levels of motor skill during the first year of the study, maternal maturity demands had little influence on their later levels of motor skills. On the other hand, the lower the initial level of motor skills by the child, the stronger the influence of maternal maturity demands. The results for children at the severe and profound levels of mental retardation, shown in Fig. 3B, reveal a notable, if disappointing, contrast. For these children, maternal demands have no influence on behavior; the behavior exhibited by the children in the first year of the study is basically the same as that shown in the second year of the study. Results for other dimensions of adaptive behavior have certain similarities to and certain differences from those shown in Figs. 3A and 3B. For example, on Cognitive Competence, only mildly retarded children with relatively high scores during the first year of the study were positively influenced by maternal maturity demands. The lower scoring children with mild mental retardation and children at the other three levels of mental retardation were relatively uninfluenced by

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High Y 1

x

\ Med Y 1

---------

Low

High

Maturity Demands

LOW

Low Y 1

High

Maturity Demands

FIG. 3. Level of Motor Development at Year 2 (Y2) as a function of Motor Development at Year I (Y I ) and maternal maturity demands for persons with mild and moderate mental retardation (A) and for persons with severe and profound mental retardation (B).

maternal maturity demands. These results once again reinforce the multidimensional nature of the adaptive behavior domain. The differing life-span trends for the four dimensions of adaptive behavior imply that forms of behavior will be more malleable at different points in the life span. To understand the impact of parental styles on behavior, we must therefore consider the current capabilities of the child, the child’s level of mental retardation, the parental behavior exhibited, and the current malleability of the behavior under consideration.

D.

Summary of Factors Moderating the Life-Span Development of Adaptive Behaviors

This section, dealing with the factors that moderate the life-span development of adaptive behaviors, is the least comprehensive of the sections of this chapter. This is as it should be, as some agreement must be reached on what we are studying (i.e., the behavioral dimensions that constitute the structure of the domain) and expected development on those dimensions before questions regarding factors that moderate expected development can be explored fully. However, evidence is accumulating that personal characteristics, such as level of mental

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retardation and etiology, and the interpersonal features of the person’s living situation may play particularly important roles in moderating or modifying changes in levels of adaptive or maladaptive behavior. Less evidence has accumulated that physical or structural aspects of the living situation are of great importance, yet research should continue to study these effects. The concerns reviewed in this section are among the most challenging, as these focus on the contextual factors that influence nonnative trends of life-span development. Perhaps most challenging is the possibility that the moderating effects on behavioral development may vary across contextual factors and across the life span. That is, certain factors such as etiology or level of mental retardation may moderate development across the life span. In contrast, other factors may influence behavioral development only across more restricted age spans. For example, parenting styles may moderate behavioral development primarily during the first 20 years of life, during the period of greatest growth in adaptive behaviors, whereas the biological degeneration that is concomitant of aging would likely influence behavioral declines primarily during the later years of the life span. A great deal of work remains to be done to understand the workings of the myriad moderating factors as they affect the life-span development of adaptive and maladaptive behaviors.

V.

SUMMARY AND CONCLUSIONS

The primary aim of this chapter was to review findings that will constrain the form of adequate theories regarding the development and aging of adaptive behaviors across the human life span. To accomplish this aim, we reviewed research on three major topics with which such theories must deal. These topics were (1) determining the structure of adaptive behaviors, (2) estimating the lifespan developmental trends for the growth, maintenance, and aging of adaptive behaviors, and (3) investigating factors that may modify or moderate the development and aging of adaptive behaviors. By way of a general summary, the research investigations we reviewed point toward a number of conclusions. First, a multidimensional representation of the adaptive behavior domain, including several adaptive behavior factors and at least two factors of maladaptive behavior, seems more adequate than does a unifactorial structure. Second, this multifactorial structure was strengthened by the finding that different types of adaptive behaviors exhibit different life-span developmental trends. Given the varying life-span trends for the several dimensions of adaptive behavior, to collapse measures of adaptive behavior into a single Personal Independence composite would misrepresent the growth, development, and aging of forms of adaptive behavior. Finally, several categories of factors exist-some representing characteristics of the individual and others

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constituting characteristics of the person’s living situation-that moderate in important ways the life-span development of adaptive behaviors. Considering all of these issues, especially as they relate to one another, will lead in the direction of a fuller understanding of the life-span development of adaptive and maladaptive behaviors. The issues dealt with in this chapter are considered preliminary and tentative for at least two reasons. First, although perhaps appropriate for early stages of theory development, the framework we offered has minimal specificity; future research should attempt to expand or modify our hypotheses in the light of additional information. Second, the set of issues discussed was restricted to the minimum number that a life-span theory should confront; future research may reveal important additional areas of concern that must be considered. With these caveats, the present framework is offered as a way of structuring the thinking and future research on the life-span development of adaptive behaviors. ACKNOWLEDGMENTS The present work was supported in part by Grants HD-21056 and HD-22953 from the National Institute of Child Health and Human Development to the first two authors, and by Grants GOO8530208 and H023C80072 from the U.S. Ofice of Education (Donald MacMillan, Principal Investigator). The insightful comments by Richard Eyman and Donald MacMillan on a previous version of this article are gratefully acknowledged, as is the help of Art Silverstein. We also acknowledge the assistance of Karen Fleck at many points in our work on this article. This article was written while the first author was on sabbatical leave at the Department of Psychology, University of Trier, Trier, Germany; the support, in various ways, provided there by Professor Leo Montada, Maria Haas, and Manfred Schmitt is also gratefully acknowledged. REFERENCES Arndt, S. (1981). A general measure of adaptive behavior. American Journal of Mental Deficiency, 85, 554-556. Balla, D. A. (1976). Relationship of institution size to quality of care: A review of the literature. American Journal of Mental Deficiency, 81, 1 17- 124. Baltes, P. B. (1968). Longitudinal and cross-sectional sequences in the study of age and generation effects. Human Development, I I , 145- 17 I . Baltes, P. B., Cornelius, S. W., & Nesselroade, J. R. (1978). Cohort effects in behavioral development: Theoretical and methodological perspectives. In W. A. Collins (Ed.), Minnesota symposia on child psychology (Vol. 1I , pp. 1-63). Hillsdale, NJ: Erlbaum. Baumrind, D. (1967). Child rearing practices anteceding three patterns of preschool behavior. Generic Psychology Monographs, 78, 43-88. Baumrind, D. (1971). Current patterns of parental authority [monograph]. Developmental Psychology, 4 , 1-103. Bell, R. Q . (1953). Convergence: An accelerated longitudinal approach. Child Development, 2 4 , 145- 152. Bell, R. Q. (1954). An experimental test of the accelerated longitudinal approach. Child Devefopment, 25, 281-286.

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Manuscript submitted for publication. Widaman, K. F., Stacy, A. W., & Borthwick-Duffy, S. A. (in press). Construct validity of dimensions of adaptive behavior: A multitrait-multimethod evaluation. American Journal on Mental Retardation.

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Perspectives on Early Language from Typical Development and Down Syndrome MICHAEL P. LYNCH’ DEPARTMENT OF PEDIATRICS UNIVERSITY OF MIAMI MAILMAN CENTER FOR CHILD DEVELOPMENT MIAMI, FLORIDA 33101

REBECCA E. EILERS DEPARTMENTS OF PSYCHOLOGY, PEDIATRICS, A N D OTOLARYNGOLOGY UNIVERSITY OF MIAMI MIAMI, FLORIDA 33101

I.

INTRODUCTION

Although the above title is appropriate for this article, it might just as easily have been named “Early Typical Language Development, with a Comment on Down Syndrome.” Considerable progress has been made in the description of early (up to about 4 years of age) language development in typically developing infants and children, but, despite many years devoted to inquiry, only limited descriptive progress has been made concerning Down syndrome. This situation is dismaying because Down syndrome is obvious from birth, and populations of Down syndrome infants and young children have been the focus of many developmentally oriented studies of language acquisition. Innate capacities for speech perception and the effects of linguistically specific experience on perceptual and productive abilities have been documented in typically developing infants and children, but the dearth of information in these areas concerning Down syndrome has at least two important disadvantages. One ‘Present address: Department of Audiology and Speech Sciences, h d u e University, West Lafayette, Indiana 47907.

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is that few of the language-related disabilities that are specifically related to Down syndrome are known. In fact, it was not until the past 5 years that compelling evidence for particular language deficits related to Down syndrome has been available. The other disadvantage is that opportunities for a deeper understanding of typical language development have not been fully exploited by studying the effects of a disorder such as Down syndrome on this development early in life. This article provides a broad introduction to perceptual and productive abilities of typically developing infants and children for language in the first few years of life. It also incorporates what is known about language development in this age period for Down syndrome to highlight potentially important descriptive gaps. In the perceptual domain, the review will include psychoacoustic studies of speech perception, with a brief introduction to newly obtained converging evidence from music perception to broaden the general scientific perspective on perceptual development. In the production domain, infant vocalizations, as well as early semantic development, syntactic development, and relationships with language comprehension, will be discussed. Additionally, cry, perhaps the first avenue of communication for infants, will be covered briefly. Finally, the link between perception and production will be considered in a synopsis of research on communicative interaction between caregivers and infants and children. This review of perception, production, and adult-child interactions is designed to bring the reader an integrated perspective on relationships between acquisition of language in typical and Down syndrome infants and to point out gaps in our knowledge of effects of Down syndrome on early communicative development. 11.

A.

PERCEPTION

Auditory Sensitivity

Hearing is crucial to the development of speech and language (Jaffe, 1977). The importance of hearing is evident as early as the end of the first year of life, when profoundly deaf infants fail to establish production of mature syllables (e.g., ba, da), but their 7 - to 10-month-old normally hearing counterparts are producing large proportions of mature (canonical) syllables (Kent, Osberger, Netsell, & Hustedde, 1987; Oller & Eilers, 1988; Oller, Eilers, Bull, & Carney, 1985). Additionally, when deaf infants begin babbling, the phonetic content appears more restricted than that of normally hearing infants, and the speech features produced by deaf infants are typically those that may be visible on the lips of adult speakers. For example, deaf infants tend to produce more bilabial sounds than normally hearing infants (Stark, 1972; Stoel-Gammon & Otomo, 1986). Although hearing is certainly critical for the timely development of mature

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syllable production, alternative sensory systems may be brought to bear on accomplishing communicative goals. Lynch, Oller, and Steffens (1989) found that an “acochlear” child, a child born without the organ of hearing and, therefore, totally deaf, achieved mature syllable production by the late age of 32 months when the aid of speech information provided through the sense of touch via tactile speech aids (see Lynch, Oller, & Eilers, 1989; Weisenberger & Miller, 1987) and specialized speech training. The tactile aids seemed to provide critical timing information needed for the production of mature syllables. Studies of effects of hearing impairment on early vocal production have served to demonstrate the importance of audition in early language development. Without an accurate acoustic representation of the speech signal, either as produced by others or as feedback, infants and children with hearing impairment are hindered in the very earliest stages of language development. A child need not be deaf to show effects of hearing loss on communication development. Down syndrome infants do not necessarily receive an accurate acoustic representation of speech because they are at greater risk for hearing loss than are typically developing infants (Downs, 1980; Gordon, 1987; Kaga & Marsh, 1986; Northern & Downs, 1984). Reasons for this increased risk include otitis media (Dahle & McCollister, 1986) and middle ear anomalies (Balkany, Berman, & Simmons, 1978). Thus, although the extent of hearing loss can vary considerably across individuals, many Down syndrome persons begin life with incomplete or distorted auditory input. As a result, the nature of the speech code is obscured, predisposing infants to delays in language development. Hearing loss is also a problem in older Down syndrome children (Fulton & Lloyd, 1968) and adults (Keiser, Montague, Wold, Maune, & Pattison, 1981; Widen, Folsom, Thompson, & Wilson, 1987). What is not clear at this point, however, is the nature of the relationship between hearing loss and specific patterns of language delay (Miller, 1988) in Down syndrome. €3.

Innate Capacities for Speech

The importance of hearing in the development of language is evident not only in the productive realm, but also in the perceptual realm. Spoken language is a highly complex acoustic signal perceived in real time. Infants and children cope with a potentially baffling array of acoustic characteristics by extracting key invariant properties of the acoustic signal that correspond to categories of speech sounds. These acoustic characteristics include, among others, voice onset time, which is important for determining whether a consonant is voiced (e.g., /b/as in back) or voiceless (e.g., /p/as in pack); formant frequency relationships, which are concentrations of acoustic energy along the frequency continuum that cue vowel identity, as well as other speech features; and formant transitions, which are the interim slopes of energy concentration between speech segments that are

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important cues to segment identities (see Denes & Pinson, 1963, for a more complete description of speech acoustics). That adults are capable of processing the acoustic complexities of speech came as no surprise because adults are, in typical circumstances, very capable perceivers of the speech signal (MacMillan, Kaplan, & Creelman, 1977). What came as quite a surprise, however, was the demonstration by Eimas, Siqueland, Jusczyk, and Vigorito (197l), using the high-amplitude sucking paradigm, that I - and 4-month-old infants were capable of perceiving the voicing distinction between /pa/ and /ba/ in a categorical-like manner. This result paralleled findings from adults’ perception of speech and suggested at the time that infants were born with mature speech perceptual abilities for a variety of speech sounds. In the high-amplitude sucking paradigm, a repeating background stimulus (e.g., ba) is presented to an infant, who is also provided with a nonnutritive nipple on which to suck during testing. Once the infants’ baseline sucking rate is established, the infant learns to suck in order to hear a targeted speech sound. After a period of several minutes habituation occurs, followed by a change in the background stimulus (e.g., changed to pa). If infants reliably increase their sucking rate from habituation levels following the stimulus change, then a reasonable inference is that the infants were able to discriminate between the two stimuli. Infants’ categorical perception of speech sounds may be inferred from their relative difficulty in discrimination of speech sound changes that are within the same adult category (e.g., a change from a prototypical ba to a ba with a shorter voice onset time and, thus, less voicing) in comparison to their discrimination of changes that cross adult speech sound category boundaries (e.g., from ba to pa). The work of Eimas er al. (1971), in addition to work that followed up and expanded upon it both in terms of the variety of speech contrasts tested and the methods used (e.g., Eilers, Wilson, & Moore, 1977; Eimas & Corbit, 1973; Kuhl, 1979; Trehub & Rabinovitch, 1972), suggested that typically developing infants are born with relatively sophisticated abilities for speech perception. These sophisticated perceptual abilities were initially interpreted as indications that infants are born with a speech-specific capacity to successfully perceive (i.e., discriminate) universally all of the world’s speech contrasts (also known as the “innateness hypothesis”). Much theoretical and empirical progress has been made since the early 1970s, however, and it is now apparent that categorical auditory perception is not specific to speech. Categorical perception has been demonstrated in music perception (Bums & Ward, 1978) as well as other nonspeech auditory patterns (e.g., Jusczyk, Pisoni, Walley, & Murray, 1980). In fact, infrahuman species, such as the Japanese quail, have also shown the ability to categorize speech contrasts (Kluender, Diehl, & Killeen, 1987; Kuhl & Miller, 1975), suggesting that categorical perception is nonspecific to speech and is not unique to humans.

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In addition to the speech- and species-specificity issues, progress has been made in evaluation of the universality issue. A survey of the literature covering speech perception of young typically developing infants reveals at least one obvious fact, that not all speech contrasts are inherently easy to discriminate (Best, in press; Eilers, Gavin, & Oller, 1982; Eilers, Morse, Gavin, & Oller, 1981; Eimas, 1974, 1975; Morse, Eilers, & Gavin, 1982; Trehub, 1976). For example, the [a:t-a:d] distinction was found to be readily discriminable by young infants but the [a:s-a:z] distinction was not (the colon denotes a lengthened vowel) (Eilers, 1977). It is possible that the relative salience of acoustic properties of the contrasts may account for perceptual difficulties with particular speech contrasts. Infants may have success in perception of speech contrasts as a function of how salient the contrasts are (Eilers, Wilson, & Moore, 1979), even if the contrasts are highly dissimilar from the speech contrasts infants are learning in the process of linguistic specialization, such as contrasts involving clicks found in Bantu languages as perceived by English-learning infants (Best, McRoberts, & Sithole, 1988). Although this overall picture of innate capacities for speech perception of typically developing infants has evolved by dint of considerable research effort since the early seventies, little effort has been devoted to investigation of the early speech perception abilities of Down syndrome infants. Only two studies have explored this area (Eilers, Bull, Oller, & Lewis, 1985; Eilers, Moroff, & Turner, 1985). These studies were focused on the hypothesis that difficulties experienced by other children with specific language deficits, specifically in the perception of rapid changes in the speech spectrum (Tallal, 1976), might also be experienced by Down syndrome children. In the Eilers et al. studies, Down syndrome infants and children (13-37 months old) experienced difficulties in processing of rapid spectral information relative to their ability to perceive events that occur over longer periods. In speech, rapid events such as formant transitions are critical in cuing the nature of consonants, for example, the difference between ba and ga. Down syndrome infants may have difficulty in establishing perceptual knowledge for speech because they have difficulty in tracking these acoustic properties that are important cues to consonant identity. In addition, hearing loss commonly associated with Down syndrome probably exacerbates this difficulty through one or more mechanisms. A lack of or degraded auditory experience with speech events could reduce sensitivity to rapid spectral changes in the auditory periphery or hinder development of more central processing capacities required for tracking of spectral changes that occur on the order of a few dozen milliseconds. Hearing status is, of course, only one factor that may contribute to speech processing deficits. Little is known about the specifics of Down syndrome itself or of the accompanying behavioral deficits, which might affect speech processing capacities.

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Linguistic Specialization

The process of linguistic specialization incorporates a broad variety of developmental processes. In this section, effects of linguistically specific experience on speech perception as explored in psychoacoustic studies during the first 18 months of life will be discussed. Other speech reception abilities related to perception, such as comprehension, will be discussed in the next section on Production. Adin and Pisoni (1980) sunimarized four models that have proved useful in a global sense in guiding interpretation of developmental effects on speech perception. These models were referred to as the universal, attunement, perceptual learning, and maturational theories. According to universal theory, infants are born with the ability to discriminate all of the speech contrasts of the world’s languages (cf. “innateness hypothesis” above). The ability to discriminate among native speech contrasts is maintained by linguistically specific experience, but the ability to process nonnative contrasts is lost. Artunemenr theory is a weaker form of universal theory. Attunement theory claims that infants are born with the ability to discriminate some proportion of the world’s speech contrasts. The role of linguistically specific experience is to sharpen, or tune, infants’ perceptual abilities for native speech contrasts. Perceptual ability for nonnative contrasts is left undeveloped. Perceptual learning theory suggests that infants need specific early experience with some speech contrasts within a critical time frame to induce development of perceptual ability for those contrasts, a concept similar to imprinting of ducklings on particular physical objects or persons (see Hess, 1972, for a review of imprinting). Finally, maturational theory proposes that infants develop perceptual ability for speech contrasts through a genetically predetermined schedule. The universal, attunement, perceptual learning, and maturational theories all have relevance in some respect to data obtained before and since their elaboration, but the perspective on relative contributions of the corresponding developmental processes of maintenance (universal and attunement theories), facilitation (attunement and perceptual learning theories), and biological maturation (maturation theory) have been broadened during the 1980s. Some of the most compelling empirical work on developmental processes in early speech perception has been conducted by Werker and colleagues (Werker, 1989; Werker, Gilbert, Humphrey, & Tees, 1981). This research suggests that perceptual reorganization for native speech sounds occurs in the first year of life. Infants approximately 6 months of age appear to be superior to 8-month-olds, 10month-olds, and adults in perception of certain nonnative speech contrasts while performing similarly to older subjects in perception of native speech contrasts. A logical inference that can be made in light of such findings is that lack of specific

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experience with nonnative contrasts results in decay of perceptual ability for these contrasts with development. The results of Werker’s studies point to the fact that perceptual loss plays a role in the development of speech perception and communicative development. In addition to perceptual loss, the facilitation of native speech contrast perception in comparison to the perception of nonnative speech contrasts has also been explored with infants (Eilers et a l . , 1982; Eilers, Gavin, & Wilson, 1979). In these studies, better perception of native contrasts by Spanish- and Englishlearning infants was found, suggesting that performance on the native contrasts was improved relative to performance on the nonnative contrasts with linguistically specific experience. Oller and Eilers ( 1983) explored cross-linguistic speech perception with older children (2-year-olds) and found results similar to those obtained with infants. These studies did not allow for clear interpretation of results concerning perceptual facilitation, however, because they were not developmental studies which would have allowed for the tracking of perceptual improvement on native speech contrasts over time if it did, in fact, occur. Perceptual facilitation is difficult to study because even if subjects of different age groups are tested under precisely the same conditions and with identical stimuli, better performance by older than younger subjects can always be attributed to nonperceptual factors, such as improved attention, memory, or different levels of interest in the testing procedure (see Kail, 1990). The identification of perceptual and cognitive factors that contribute to developments in speech perception is a primary challenge of research in this area. Instead of examining perceptual improvement versus perceptual loss, the recent work of Best and colleagues (reviewed in Best, in press) focuses on the perception of nonnative speech contrasts in an effort to further illuminate factors affecting perceptual ability for speech. In this work, nonnative speech contrasts have been classified according to their similarity in terms of articulatory gestures to native speech contrasts. Best er al. have conducted a series of studies suggesting that 1-year-olds’ perception of nonnative contrasts are somewhat influenced by linguistic experience. Apparently, nonnative contrasts may be assimilated to native contrasts once sufficient native perceptual experience has been acquired. Thus, listeners may attempt to process novel speech contrasts within the framework of their acquired knowledge for native speech contrasts. Although developmentally oriented psychoacoustic work has provided information as to the course of early acquisition of typically developing infants’ speech perception ability, almost no similar developmental information is available on Down syndrome infants and young children. Following up on the findings of Tallal (1976) and of Eilers, Bull et al. (1985) and Eilers, Moroff, and Turner ( 1985), which suggested that the language deficits accompanying mental retardation may result partly from difficulty in processing rapid spectral changes

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in speech, Eilers and Oller (1080) compared 3-year-old severely retarded children (two of the seven children had Down syndrome) with 7-month-old typically developing infants in perception of rapidly changing versus static acoustic properties of speech segments. In this study, speech contrasts involving discrimination of steady-state properties of vowels (beetl[bit] vs. bir/[bIt]) and discrimination of more rapidly changing speech formants of consonants (awa/[awa] vs. aral[ara]) were used. The typically developing and retarded subjects did not differ in perceptual ability for the rapid formant change contrast, but the retarded children were significantly better than the typically developing infants in perception of the vowel contrast. Although the developmental implications of this study are not entirely clear because typically developing and Down syndrome subjects were not matched for either chronological or mental age, these findings suggest that the retarded children found the perception of relatively static acoustic characteristics of speech (e.g., steady-state vowel formants) easier to process than rapidly changing formant transitions. This result is consistent with the two previously mentioned studies of speech perception by Down syndrome infants (Eilers, Bull er al., 1985; Eilers, Moroff, & Turner, 1985), which found that the infants had difficulty in formant tracking. Further studies that are designed, either longitudinally or cross-sectionally, to elucidate developmental trends in speech perception in the first few years of life by Down syndrome infants and children are needed, however, to describe effects of Down syndrome on perceptual development for speech. D.

From Ear and Eye

A relatively new area of study in early perceptual development for speech that may yield particularly exciting results when Down syndrome persons are studied involves the interaction of visual and auditory input. This area is of special interest when considering early language development in Down syndrome because some research has suggested that the visual and auditory modalities are not equally accessible to Down syndrome children. Scheffelin (1968) reported that 1 1-year-old Down syndrome children performed more poorly on paired-associative learning tasks involving an auditory stimulus with a vocal response than on tasks involving visual-vocal , auditory-motor, and visual-motor stimulus and response channels. Another study also suggested that Down syndrome children rely more heavily than typically developing children on gestures in imperative and declarative expression (Greenwald & Leonard, 1979). In imperative expression, 16- to 54-month-old Down syndrome children would often look at and reach for objects without accompanying vocalization, but typically developing children rarely performed an imperative without vocalizing. Kuhl and Meltzoff (1982) found that young typically developing infants (4-

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month-olds) preferred to look at a face that was performing articulatory gestures consonant with an auditory signal rather than a face producing a gesture that would not result in the accompanying auditory signal. Additionally, the findings of MacKain, Studdert-Kennedy, Spieker, and Stem (1983) suggested a role of left-hemisphere specialization in cross-modal speech perception because infants’ looking preferences were reliably stronger when they were looking at a face displayed on their right than on their left. These studies led to at least two important interpretations. First, infants are likely to use both auditory and visual information in their early acquisition of language knowledge. Second, the quality of input from the visual and auditory channels, as well as the level of integration between the two channels, might affect language development. In light of the findings of Scheffelin (1968) and of Greenwald and Leonard (1979) mentioned above, and, considering the fact that Down syndrome is present at birth, interaction of auditory and visual speech information in the development of early language of Down syndrome infants and children is an area much in need of study. Such research might result in description of abilities or disabilities related to Down syndrome not only for speech perception via audition but also for associative capacities across different sensory modalities that could affect language development from birth. Intervention with Down syndrome infants in processing bimodal speech information could, in fact, prove beneficial in their later development of language skills.

E.

Converging Evidence from Music Perception

The substantial body of research that has been devoted to describing early development of perceptual ability for speech has been quite fruitful in identifying some innate capacities and charting some effects of linguistic specialization. A nagging problem that has weaved its thread throughout this area, however, has been that researchers are often uncertain whether to attribute findings narrowly to the perception of speech only, such as in a speech or language module (e.g., see N o r , 1982; Liberman & Mattingly, 1989), or more broadly to general perceptual development. The study of early music perception is an area that has recently begun to receive serious attention as a source of information about general perceptual development complementary to speech perception research, because music and speech share certain global characteristics of structure. Speech and music both comprise universally employed features that have important differences in their use across cultures. For example, in speech, the consonant/vowel distinction is used in all of the world’s languages (Jakobson, 1941/ 1968). Specific languages, however, use only subsets of the universal inventory of consonants and vowels. A parallel structural organization obtains in music. In music, scales are used throughout the world (Dowling & Harwood, 1986). A musical scale is a finite set of pitches (usually five to seven), which are

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generally confined within an octave (acoustic frequency ratio of 2 : 1). Specific cultures, however, utilize different pitch sets for their scales, resulting in music that may sound dissonant, or off-key, to the nonnative listener. Thus, speech and music both have structures for which innate perceptual abilities may exist but for which cultural specificity develops with experience. Infants appear to possess some potentially innate capacities for perception of universal musical structure. A procedure that has proved useful in assessing music perception in infants has been an adaptation of the visually reinforced infant speech discrimination paradigm (Eilers et al., 1977). In this paradigm, a repeating background stimulus, such as a melody, is played repeatedly from a loudspeaker. Infants can be readily trained to look toward the loudspeaker when the stimulus is systematically manipulated (e.g., when the contour, or overall pitch direction, of a melody is changed from up-down to down-up) in anticipation of a visual reinforcer. Among the first innate perceptual capacities for music to be studied was the perception of melodic contour. Melodic contour is the overall configuration of successive directional changes in pitch within a melody (e.g., up-down, downup). Eight- to ten-month-old infants have successfully detected changes in melodic contour in a variety of stimulus settings, suggesting that they are able to mentally conserve the overall pitch configuration of a melody, even when the absolute pitch level of the entire melody has been changed (Chang & Trehub, 1977; Trehub, Bull, & Thorpe, 1984). This finding could be important when considering infants’ perception of prosodic characteristics of speech because the ability to notice the overall pitch configurations of utterances, which can be analogous to melodies in music, may be important in early language development (Fkrnald, in press; Papousek, Papousek, & Bornstein, 1984). Another potentially important parallel between speech and music involves rhythm. The perception of rhythm is crucial in both speech and music because it provides a means of “chunking” the stream of linguistically appropriate speech sounds or culturally appropriate musical pitches into potentially important temporal units. The first studies to shed light on processes of temporal perception involved testing adult subjects’ detection of changes in intertone time periods within prescribed temporal subgroups of a tone sequence or between subgroups. Adults were better perceivers of within-subgroup than between-subgroup changes, suggesting that the subgroups were perceptually cohesive (Fitzgibbons, Pollatsek, & Thomas, 1974; Thorpe, 1985). Thorpe, Trehub, Morrongiello, and Bull (1988) found that 6- to 8-month-old infants had similar relative success in perception of within-subgroup temporal changes as opposed to between-subgroup changes. This finding suggests that typically developing infants encode not only overall configurations of melodic pitches but also temporal characteristics of melodic pitches but also temporal characteristics of serially produced auditory events.

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Recent work has investigated the possibility that perception of auditory events in music can be affected by culturally specific listening experience. Lynch, Eilers, Oller, and Urbano (1990) tested 6-month-olds in perception of a melody based on two culturally familiar musical scales (Western major, Western minor) and a culturally foreign scale (Javanese pelog). The infant subjects were divided into two groups, one of which was trained on a culturally familiar scale (major) and one of which was trained on the culturally foreign Javanese scale. Both groups were able to notice a mistuning (acoustic frequency change) in one of the melody notes reliably better than chance in all three scale contexts, and there were no reliable differences in performance found across the scale contexts, suggesting that infants are born with an equipotentiality for the perception of a variety of pitch sets. This finding parallels the universality claim made in the area of infant speech perception (e.g., Eimas et al., 1971; innateness hypothesis mentioned above) and is consonant with findings from another music laboratory using a different stimulus set (Trehub, Cohen, Thorpe, & Morrongiello, 1986). Adult music perceivers in the Lynch et al. study did not show the same pattern of performance across pitch set contexts as the infants. Adults were reliably better perceivers of mistuning in the culturally familiar contexts than in the culturally foreign context, suggesting their performance was affected by acculturation with the musical interval patterns found in Western music (see also Lynch, Eilers, Oller, Urbano, & Wilson, in press). Two studies have now provided evidence that suggests that effects of culturally specific listening experience are present in the first year of life. In both of these studies, infants around 1 year of age were better able to detect alterations of melody notes when the melody was based on a culturally familiar pitch set than when it was based on a culturally unfamiliar set (Cohen, Thorpe, & Trehub, 1987; Lynch, Eilers, & Oller, 1990; Trehub, Thorpe, & Trainor, 1990). These studies suggest that perceptual specificity for culturally familiar pitch sets may begin to influence infants’ perception of music during the same time that similar specificity begins to occur in the perception of speech sounds (Werker, 1989). Another possibility is that the pitch sets that are native to Western music are inherently easier to process than other pitch sets, resulting in better Western perception by infants (Trehub ef al., 1990). Both the acculturation and the inherent processing advantage hypotheses require further study. An overall picture of perceptual development for speech and music emerges from this discussion of parallel findings in the two areas. vpically developing infants seem to be endowed with abilities to process coherent structure in auditory events, and these abilities may be influenced by experience as early as the first year of life. The dearth of information available on the similar developmental period for Down syndrome infants, however, makes it impossible to determine whether such abilities and experiential effects might be inherently affected by the disorder.

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Soraci, Barlean, Haenlein, and Baumeister (1986) suggested that retarded adults (non-Down syndrome) were less sensitive to changes in quasirandom sequences of musical pitches than nonretarded adults. In this study, subjects’ changes in heart rate from habituation levels were monitored in response to changes in pitches from a sequence. A general idea as to the retarded listeners’ absolute level of sensitivity to auditory discrepancy was thus obtained. The success of Eilers, Bull et al. (1985) Eilers, Moroff, and Turner ( 1985), and Soraci et al. indicates that methodologies exist to perhaps study processing of auditory relationships in young Down syndrome persons. Therefore, it would seem worthwhile to pursue a broad description of Down syndrome infants’ and childrens’ perception of auditory patterns, such as those related to music and speech. This line of inquiry might reveal basic differences in auditory processing related to Down syndrome that might be considered in development of early intervention programs with this population.

Ill.

PRODUCTION

Considerable progress has been made in recent years in the description of speech production by typically developing infants and young children. Typically developing infants produce systematic vocalizations that are related in many ways to their first words. More research has been devoted to the description of Down syndrome individuals’ speech production abilities early in life than to their perceptual abilities. Several key differences between Down syndrome and typically developing infants and children are documented, in addition to noticeable differences in voice quality (Pentz, 1987; Pentz & Gilbert, 1983).

A.

Myths of Infant Vocal Development

To place the recent advances in understanding of infants’ and young childrens’ vocal development in historical perspective, it is useful to consider commonly relied upon misconceptions, or myths, about infant vocal development that have been pervasive over the years: methodology myth, discontinuity myth, babbling drift myth, deaf infants’ babbling myth, and McCarthy’s myth. These myths have, unfortunately, been referred to in standard texts on child development (e.g., Biehler, 1981) and have been accepted as truths, although there are no data to support their claims and considerable data that contradict them. The methodology myth relies on the assumption that infant vocalizations are so different from mature speech that the only reasonable description of infant speech is accomplished via acoustic analysis (Lynip, 1951). Certainly, acoustic descriptions of infant speech and adult speech are valuable and can be obtained concerning a variety of characteristics, for example, formant frequencies, temporal

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features, and amplitude envelopes, but there is no theoretically convincing manner of determining what acoustic differences between infant and adult speech actually mean developmentally. Oller (1986) proposed a “metaphonological” approach, now referred to as “infraphonological” (Oller, 1991; Oller & Lynch, in press), combining acoustic description with the developmental categorization of infant vocalizations according to their relationships to mature speech. Essentially, this approach describes vocalization types on a developmental continuum from nasal-sounding, gruntlike quasiresonant sounds, which are the predominant vocalizations of early infancy, to adultlike syllables, which are reliably produced by typically developing infants beginning at 6-10 months of age. The infraphonological description of infant vocalizations will be discussed further in the treatment of stages of infant vocal development below. The discontinuity myth, which claims that infant speech and adult speech are unrelated, was fueled by extreme theoretical stances born of unsophisticated descriptive technology. Among these stances were that infant babbling is utterly random and unorganized (Jakobson, 194111968; Lenneberg, 1962), infants babble the sounds of all languages (Jakobson, 194111968; Osgood, 1953), and there is no phonetic relationship between babbling and young childrens’ speech (Jakobson, 1941/ 1968). Information is now available, however, that contradicts each of these stances. First, it is apparent from a number of studies of infant vocal development through the first 18 months of life that the vocalizations of infants proceed through a developmental sequence from production of developmentally primitive sounds to the onset of substantial production of mature syllables, for example, buba and mama (Oller, 1986; Stark, 1980). Second, infants certainly do not babble the sounds of all of the world’s languages. There are many sounds that infants have not been reported to make in any quantity, such as lingual trills (with tongue tip), consonant clusters, and final consonants. Finally, several studies have reported that there is, indeed, a phonetic relationship between babbling and young childrens’ speech. The core units of babbling (e.g., pa, ba, ma) are among the predominant sounds used in early meaningful speech (Cruttenden, 1970; Menyuk, 1968; Oller, Wieman, Doyle, & Ross, 1976; Vihman, Ferguson, & Elbert, 1986). Babbling drift, which presumes that infant babbling gradually comes to resemble the phonology of the child’s language community, is not strongly supported by available data. Infants tend to prefer and produce most often those sounds that are relatively universal (Oller et a l . , 1976), and infants who will eventually learn different languages do not appear to babble differently as perceived by observers who are blind to the infants’ language community (e.g., Atkinson, MacWhinney, & Stoel, 1969; Preston, Yeni-Komshian, & Stark, 1967; Thevenin, Eilers, Oller, & Lavoie, 1985). Some recent evidence from a study of acoustic summaries (long-term spectrum analyses) of adult and child utterances from French, Algerian, Arabic, and Cantonese linguistic environments, however, is suggestive

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that babbling drift may subtly affect infant vowel productions between 8 and 10 months of age (de Boysson-Bardies, Sagart, Halle, & Durand, 1986). This work has reopened investigation of the babbling drift issue, and further work may clarify babbling drift effects on infant vocal production. The deaf babbling myth is possibly the most egregious of the myths because it may have affected the vigor with which potential interventions were pursued. It has been widely believed that deaf infants babble similarly to normally hearing infants in the first year of life and then cease to do so (Lenneberg, Rebelsky, & Nichols, 1965; Mavilya, 1969:).Recent data have clearly indicated that deaf infants begin reliably producing mature syllables (baba, dadu) considerably later than do normally hearing infants, 6-10 months (Oller & Eilers, 1988). And, although hearing is not essential for the eventual development of mature syllable production (Lynch, Oller, & Steffens, 1989), it is definitely of great importance for the unhindered speech development early in life. McCarthy’s myth (McCarthy, 1952) simply attributed the quality of infant vocalizations to mechanical forces acting on the child’s vocal apparatus. This myth depended on the assumption that the child’s posture (e.g., upright or supine) would affect what kind of vocalizations the child produced. No data have been obtained in support of this view. A few studies have addressed this hypothesis by manipulating infants’ physical orientation (e.g., prone versus supine), but this manipulation did not appear to affect the types of syllables produced by typically developing children (Bosma, 1972; Oller, 198 1; Stark & Nathanson, 1974). This myth has been investigated only with typically developing infants, however, and, considering the hypotonia that generally accompanies Down syndrome, it is possible that physical orientation could affect the vocalizations of Down syndrome infants. McCarthy’s myth should be explored in greater detail with disordered populations in empirical work. This review of widely believed myths is intended to serve two purposes. One of these is to identify these beliefs as unfounded so that the reader will be aware of their lack of empirical support. Another is to provide a backdrop for the description of the vocal development of typically developing and Down syndrome infants and children.

B.

Maturation and Experience

The development of early vocal production can be divided into three primary accomplishments. In the first year or so of life, infants progress from production of mostly developmentally primitive vocalizations to the reliable production of mature, prototypical syllables. Soon after the accomplishment of mature syllable production, the first words generally appear, intermingled with babbling. Finally, at some point in the third year of life, words are combined, suggesting the child is acquiring some degree of syntactic knowledge. Each of these periods will be surveyed here for typically developing and Down syndrome infants and children.

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1. DEVELOPMENT OF MATURE SYLLABLE PRODUCTION Oller (in press) summarized the increasing agreement that is being reached concerning the course of vocal development for typically developing infants. Five important levels of vocal development in the first 18 months have been observed for infants in a number of different laboratories and observational settings (Elbers & Ton, 1985; Oller, 1986; Stark, 1980; Stoel-Gammon & Cooper, 1984; Vihman & Miller, 1988). These stages, of course, involve overlap in ages to account for individual differences, but the predominant vocalizations produced by infants at each age level generally conform to those indicated for each stage. The vocalizations of each stage are described here along the lines of an infraphonological approach (Oller, 1991; Oller & Lynch, in press), combining the classification of vocalizations into categories, such as quasiresonant or canonical, with acoustic description. The phonation srage (0-2 months) involves the production of quasiresonant sounds, which are characterized by normal phonation (no distortion) with the vocal tract in a relatively at rest position. Quasiresonant sounds are very nasal sounding, mostly because of their composition of predominantly low-frequency acoustic energy. The primitive articulation stage (1-4 months) involves the production of quasiresonant sounds accompanied by articulations in the back of the vocal tract. These sounds are commonly referred to as goos, coos, or gurgles. The expansion stage (3-8 months) involves the production of a much wider variety of sounds than the previous two stages. In this stage, the reliable production of vowellike sounds marks the child’s beginning capacity to approximate mature speech sounds. These vowellike sounds differ from quasiresonant sounds in that they consist of acoustic energy across a relatively broad range of the frequency spectrum and are, therefore, less nasal. In this stage, infants tend to experiment with the pitch range by producing high-pitched squeals and lowpitched growls, experiment with loudness by producing yells and whispers, begin to produce raspberries (labial lingual and bilabial), and attempt to combine consonant-like articulations with their newly acquired vowellike sounds. Attempts at consonant/vowel combinations, however, generally result in syllables in which transitions from consonants to vowels are slower than in prototypical syllables. These slowed-transition syllables have been termed marginal babbles because they are almost, but not quite, like mature syllables. The canonical syllable stage (5- 10 months) is characterized by the first reliable production of prototypical syllables (e.g., ba, pa). Mature syllables such as these have been termed canonical because they are syllables that are commonly used in adult speech as the building blocks of words. The chief improvement that infants make in progressing to reliable production of canonical syllables is control over production of the transition from consonant-like elements to vowellike elements, resulting in more rapid transitions that often generate mature-sounding syllables.

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Finally, the integrative stage (9- 18 months) involves the combination of canonical babbling with first words. Additionally, long strings of babbling occur that can be adult-sounding because of their prosodic characteristics (termed variously jargon and gibberish). The development of this stage model has accomplished at least two important goals that facilitate study of disabled populations, such as Down syndrome infants and children. First, it has provided a detailed account of early speech in typically developing infants, thus providing a framework for interpreting the early speech development of Down syndrome infants and children. Second, it has resulted in the development of a descriptive framework for analysis of a broad range of infant vocalizations so infant utterances may be classified in terms of their developmental status. In an early attempt to study the early speech development of Down syndrome infants, B. L. Smith and Oller (1981) conducted a longitudinal study of Down syndrome and typically developing infants by collecting vocalization samples for each group at 3-month intervals from birth to 15 months of age. This study did not reveal any systematic differences between the groups in onset of reduplicated babbling (e.g., bababa) or patterns of place of articulation of consonant-like elements. Both groups generally produced more back consonants (e.g., goos) than other consonants early in the study and more front consonants (e.g., [ba] and [da]) than other consonants later in the study. An additional analysis did not reveal differences between the Down syndrome and typically developing groups in vowel height. Both groups produced more low (e.g., [a] as in bother) and mid (e.g., [el as in bake) vowels than high (e.g., [i] as in “beer”)vowels across the study. The findings of B. L. Smith and Oller (1981) agreed very broadly with those of Dodd (1972), who failed to find differences between typically developing and Down syndrome infants in overall vocal output. Older Down syndrome children (3-4 years), however, appear to be delayed in comparison to typically developing children in application of several phonological processes. Down syndrome children appear to require a longer time to reduce certain phonological errors in their speech, for example, final stop devoicing (e.g., changing Bob to bop) and initial cluster simplification (e.g., changing star to far)(B. L. Smith and StoelGammon, 1983; Van Borsel, 1988). Additionally, Down syndrome childrens’ general phonological abilities have been found to be commensurate with their general language ability (Stoel-Gammon, 1980). It should be kept in mind that Down syndrome childrens’ absolute levels of both phonological and language abilities were delayed in comparison to those of typically developing children matched for chronological age. Dodd ( 1976) suggested that Down syndrome childrens’ phonological errors may be more likely to occur in spontaneous than imitative vocalizations because of difficulty in planning of articulatory movements. Recent work by Tager-

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Flusberg and Calkins (1990), however, suggests that imitation does not provide a benefit to Down syndrome children, albeit in a different speech realm (syntactic development). The possible benefits of imitation on phonological development clearly require further study. Such research with Down syndrome children could potentially describe sources of delays in developmental patterns of phonological processes. One of the admitted limitations on interpretation of the results of the study of prelinguistic vocal development by B. L. Smith and Oller (1981) was that their Down syndrome subjects were enrolled in a special educational program that may have optimized their vocal development. This arrangement may have obscured differences between typically developing and Down syndrome infants that may be apparent in more common circumstances. In an attempt to further study potential differences in the vocal development of Down syndrome and typically developing infants, Lynch, Oller, Eilers, and Basinger (1990) studied typically developing and Down syndrome infants who were not enrolled in special educational programs. The major findings of this study were that the onset of substantial production of canonical syllables for Down syndrome infants (mean age at onset = 9 months) was delayed in comparison with typically developing infants (mean age at onset = 7 months). Perhaps more importantly, once the onset of substantial canonical production was noted, the Down syndrome infants were less consistent in maintaining their levels of canonical production through the end of the first year than the typically developing infants. This finding suggests that perhaps the delays in motor development characteristic of Down syndrome infants and children (see Gibson, 1978) may result in problems with control over mature syllable production once this production has been established. These infants have continued to be followed longitudinally, and data on their vocal and motor development will eventually be available through at least 30 months of age.

2. FIRST WORDS AND SYNTACTIC DEVELOPMENT A number of recent studies (e.g., Cardoso-Martins, Mervis, & Mervis, 1985; Miller, 1988; Miller, Miolo, Sedey, Pierce, & Rosin, 1989; Miller, Miolo, Sedey, & Rosin, 1990; Miller, Rosin, Pierce, Miolo, & Sedey, 1989) have explored in detail the vocal production of Down syndrome children from the end of the first year through 4 years of age. These studies have illuminated some intriguing asymmetries in development among verbal and nonverbal capacities in Down syndrome children. Miller and his colleagues are investigating longitudinal relationships among language, nonverbal cognition, and speech motor control in Down syndrome infants and children from 0 to 60 months in chronological age. In the studies completed thus far, language production and comprehension were assessed in terms of such measures as mean length of utterance in morphemes, number of

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different words produced in free speech samples, phonetic inventory, percentage of consonants correct, Peabody Picture Vocabulary Test, and the Test of Auditory Comprehension of Language. The children’s developmental status as examined by these language measures was compared with their mental age as determined by a number of standardized procedures, such as the Bayley Mental Scale, Stanford-Binet Revised (nonverbal subscales), and Symbolic Play assessments. The analyses conducted in the Miller et al. studies are complex, and details can be found in Miller (1987, 1988). The broad developmental patterns that have emerged from these analyses, however, are of considerable topical interest to the present discussion. One of the most intriguing findings to arise from this work is that children with Down syndrome appear to have a specific deficit in language development. Mental age-matched Down syndrome and typically developing children score similarly in tests of nonverbal cognition up to about 4 years of chronological age, but Down syndrome children lag behind typically developing children in this age period in productive and receptive language (Miller, 1987). Cunningham, Glenn, Wilkinson, and Sloper ( 1983, Greenwald and Leonard (1979), and L. Smith and von Tetzchner (1986) obtained findings suggesting that this disparity between language and nonverbal cognition tended to become worse with age from early to late childhood. Many factors could potentially contribute to a specific language deficit in Down syndrome (see Miller, 1987; Stoel-Gammon, 1990), perhaps the most influential of which is hearing status, which could affect language without influencing nonverbal cognition. The possibility that the hearing loss typically experienced by Down syndrome children might be partially responsible for a specific language deficit cannot be underestimated and warrants further investigation. Another contributing factor might be speech-specific motor difficulties. Down syndrome children often have structural differences in comparison to typically developing children in the speech apparatus, such as small or retracted maxilla, occlusion and gaps between teeth, and tongue hypertrophy (Miller, 1988). These differences in structure could result in articulatory difficulties for Down syndrome children that may hinder language development. The contributions of motor difficulties to language development in Down syndrome will require further study to evaluate fully, but two studies have already provided hints that the overall motor skill status of Down syndrome children influences language. L. Smith and von Tetzchner (1986) reported a positive relationship between gross motor behavior at 2 years of age and language skills at 3 years for Down syndrome children. Lynch, Oller et al. (1990) found that once Down syndrome infants had begun production of substantial numbers of mature syllables (around 9 months of age), their levels of mature syllable production were erratic in comparison to typically developing infants, which suggests that difficulties with control over speech articulators may be evident early in life for Down syndrome children.

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In addition to the language specificity of delays in Down syndrome children in comparison to mental age, Miller and colleagues have discovered developmental asynchronies between different language abilities in Down syndrome children. Three profiles of relationships among language comprehension, production, and mental age emerged from studies conducted by Miller’s group. In Profile 1, language production and comprehension skills of Down syndrome children corresponded well with increases in mental age, which is similar to the profile of typically developing children. Note, however, that Down syndrome children were delayed when compared with typically developing children matched for chronological age. In Profile 2, language production was delayed relative to comprehension and mental age. Profile 1 accounted for 50% and Profile 2 accounted for 25% of the children studied. In a third profile, the remaining 25% of the children had delays in both production and comprehension relative to mental age. When the children with the three profiles were followed longitudinally for 24 months, Profiles 2 and 3 (particularly Profile 2) began to account for a greater proportion of the children in the study. This finding suggested that, with increasing age, language development, especially language production, did not keep pace with progress in nonverbal cognition. Miller and colleagues also have studied relationships between mean length of utterance in morphemes (MLU) and vocabulary size. The MLU has been widely used as an indicator of syntactic development because it is simple to obtain but correlates well with early syntactic milestones (Brown, 1973). Typically developing children first begin to combine morphemes when they put together words in the latter half of the second year. From that point MLU is highly correlated with age and, consequently, vocabulary growth (Miller & Chapman, 1981). MLU is also highly correlated with age in Down syndrome children (Rondal, Giotto, Bredart, & Bachelet, 1988). Down syndrome and typically developing children differ, however, concerning relationships between age and vocabulary growth, as well as between MLU and vocabulary growth. The different age and vocabulary growth relationships of typically developing and Down syndrome children were studied by Cardoso-Martins et af. (1985). In this study, Down syndrome and typically developing children in the second year of life progressed similarly through Stages 5 and 6 of sensorimotor development (e.g., attainment of object permanence and acquisition of means-end relations). The Down syndrome childrens’ receptive and productive vocabularies, however, were both delayed in comparison to those of the typically developing children at completion of each stage of sensorimotor development. The different MLU and vocabulary growth relationships of typically developing and Down syndrome children were studied by Miller, Budde, Bashir, and LaFollette (1987; see also Miller, 1988). When typically developing children 20 months of age and older were matched with Down syndrome children on mental age, the typically developing children produced a greater number of different

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words in speech samples than the Down syndrome children. Parent reports of vocabulary use agreed with this finding. When the typically developing and Down syndrome children were matched for MLU, however, a different pattern emerged. The Down syndrome children produced approximately 25% more unique words than the typically developing children, suggesting the Down syndrome children had larger vocabularies than MLU-matched typically developing children. These findings indicate that Down syndrome childrens’ nonverbal mental age is not predictive of either semantic development, as measured by vocabulary size, or syntactic development, as indicated by growth in MLU. Additionally, it seems that semantic development outstrips syntactic development in Down syndrome children because their vocabulary size is greater than that of typically developing children when MLUs are equivalent. These developmental asynchronies between nonverbal cognition and language, and also between semantic and syntactic development, highlight the variegated nature of effects of Down syndrome on communicative abilities. Language development in Down syndrome should not be treated as a generic problem. In this vein, it should be noted that the developmental asynchronies uncovered thus far have been observed for language production only. Therefore, these asynchronies could arise in part because of productive difficulties, such as speech motor control, which would not necessarily be directly associated with the child’s internal language knowledge. If such asynchronies are found to exist in language comprehension, it would more conclusively indicate that the language learning capaciries of young Down syndrome children differ in comparison to those of typically developing children. The analytic approach taken by Miller’s group holds promise in elucidating such parallels that might exist between production and comprehension. Their research may also lead to effective interventions based on the specific language capacities of Down syndrome persons.

C. Infant Cry Cry is possibly the earliest form of communication used by infants. Infants use cry as a means of communicating their biological state (e.g., hunger, distress). Thus, in addition to prosodic characteristics (e.g., duration, intensity, pitch) that might be used to communicate affect, cry has a referential component. This combination of prosody and reference parallels the structure of later meaningful speech. Through transmission of information via cry, infants engage in communicative interaction with their caregivers. Therefore, cry can serve a number of functions, including promotion of proximity with caregivers (Bowlby, 1969), expression of survival needs, and also as a medium for learning canons of interaction (Lester, 1984). In fact, Bell and Ainsworth (1972) found that mothers who responded more quickly to their infants’ crying in the first year had infants

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who cried less in the second year than later-responding mothers, suggesting that the foundations for interaction patterns may be established early in life. Cry has been studied from two general perspectives that constitute an overall biosocial model. One of these perspectives has been as a window on the biological integrity of the infant because cry is the manifestation of complex interactions between the central nervous system, respiratory system, peripheral nervous system, and various muscles (see Golub & Corwin, 1985). The other perspective has been as an influence on the infant’s caregiving environment (see Lester, Corwin, & Golub, 1988). Cry as an indicator of biological integrity has particular relevance to Down syndrome because of the hypotonicity that accompanies the syndrome. Acoustic studies revealed that Down syndrome infants’ cries had longer latencies, lower pitch, flatter pitch contours, greater distortion, greater stuttering, and more nasality than typically developing infants’ cries (Fisichelli & Karelitz, 1963; Karelitz & Fisichelli, 1962; Lind, Vuorenkoski, Rosberg, Partanen, & WaszHockert, 1970). These acoustic characteristics are consistent with the idea that Down syndrome infants’ hypotonicity would affect the laryngeal musculature. In an effort to understand effects of cry on parents and, thus, the caregiving environment, studies of adults’ perception of infant cry samples have been conducted. These studies have indicated that adult listeners respond to infant cries along a number of dimensions, such as urgency, distress, sickness, arousal, discomfort, among others, and several acoustic correlates of cries have been associated with these dimensions (Gustafson & Green, 1989; Zeskind & Lester, 1978). Specific to Down syndrome, Freudenberg, Driscoll, and Stem (1978) found that adult observers rated Down syndrome infants’ cries as more “unpleasant” than those of typically developing infants. This response on the part of adults to cries of Down syndrome infants might conceivably affect parenting behavior toward these infants by functioning as a negative reinforcer. Freudenberg et al. also found that typically developing infants’ cries were interpreted to mean that these infants were in greater need of attention than the Down syndrome infants. Therefore, caregivers of Down syndrome infants may be motivated to stop their infants’ crying, but not necessarily in an immediate fashion because the infants’ need for attention may not be conveyed. Further studies of the cries of Down syndrome infants would require particular attention to methodology because these infants do not spontaneously cry as much as typically developing infants (Lind et al., 1970). An often-used procedure is to obtain samples of pain cries by audiotaping infants’ cry responses to routine medical procedures, such as the heel stick applied in evaluating infants for phenylketonuria (Lester et al., in press). Another means of obtaining samples of pain cries is to audiotape infants’ vocal responses either to injections or to removal of electrodes from the skin following heart rate or respiratory monitoring (B. M. Lester, personal communication, 1991).

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An alternative to analyzing pain cries might be to monitor Down syndrome infants’ cries during administration of the Neonatal Behavioral Assessment Scale (Brazelton, 1984). This scale involves elicitation of a series of infant reflexes, which progressively disturb infants and sometimes result in crying. This crying, like that in response to a pain stimulus, would not be spontaneous. It would be analogous to the types of crying infants generally produce during typical caregiving (e.g., diaper changing). Once Down syndrome infants’ cry samples are collected, many technological advances, such as real-time spectrography, could be exploited to further describe characteristics of cry that are specifically related to Down syndrome (see Lester & Boukydis, 1985, for reviews of analysis techniques). Additionally, recent evidence suggests that acoustic characteristics of cry could be used as predictors of developmental outcome (Lester, 1987), and the possibility that specific cognitive or linguistic outcomes might be predicted by cry characteristics of Down syndrome infants should be investigated.

IV.

A.

RELATIONSHIPS BETWEEN PERCEPTION AND PRODUCTION

“Motherese”

Recently, Fernald and colleagues have made progress in describing the nature of “motherese,” which is the syntactically, semantically, and phonologically altered form of speech that adults use when speaking to infants (Snow, 1977). Motherese is important because it makes up a large part of the linguistic input received by infants and may, therefore, serve to influence the foundations of language development. It may also, like cry, be important in forming the basis for caregiver-child interactions because it could serve also to draw the infant’s attention to the speaker. This possibility was raised by Femald (1985), who demonstrated that typically developing infants preferred to listen to motherese rather than adult-directed speech. Additionally, Fernald and Simon (1984) and krnald and Kuhl (1987) examined the prosodic characteristics of motherese and found that the fundamental frequency pattern, or pitch contour, of motherese was particularly important in determining infant auditory preference. This finding is intriguing in light of Trehub, Bull, and Thorpe (1984), who suggested that infants were able to perceive melodic contours in music. The perception of pitch contours may be an innate capacity that developed in response to the infant’s potentially instinctive need to communicate without having acquired the ability to use words. It would be very interesting to study Down syndrome infants’ preferences for motherese, as well as to study Down syndrome infant-directed speech of adults, to better describe the early communicative experience of Down syndrome infants.

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Adult-Infant Interaction

Given infants’ melodic perception abilities as demonstrated for music and their preference for listening to motherese, it is not surprising that infants interact with adults as a function of the adults’ production of different pitch contours in speech (see Papousek et al., 1984, for a review). Adults use a small number of distinctive pitch contours in infant-directed speech, such as a sharply rising contour and also a sharply rising contour with a gradual fall in pitch (see Papousek et a l., 1984). Bornstein (1981) suggested that the finite set of intonation contours in infant-directed speech may serve to establish them as perceptual prototypes, once learned, allowing infants to extract more detailed information as to the content of the adult message, such as phonetic segment characteristics. Recent work on the perception of musical phrases (Krumhansl & Jusczyk, 1990) and phrasing in speech (Kemler-Nelson, Hirsh-Pasek, Jusczyk, & Wright-Cassidy, 1989), in which infants preferred to hear well-phrased rather than ill-phrased music and speech, also suggests that gestalt characteristics of the communicative acoustic stream may be broken down perceptually by infants in accordance with universal principles of phrasing. Although adults address infants using some version of motherese, the adultinfant communicative link is bidirectional, as suggested by the tendency of infants to imitate facial gestures (Meltzoff & Moore, 1977) and to imitate adult behavior as well as speech (Papousek e? al., 1984), and their ability to match sung pitches (Kessen, Levine, & Wendrich, 1979). Thus, typically developing infants are capable not only of receiving information through the perceptual channel but also of forming schematic notions of response and interplay. Interactions between caregivers and Down syndrome children differ in many respects from those between caregivers and typically developing children. Several investigations have reported that mothers of Down syndrome infants talk faster and with greater overall density to their 1- to 2-year-old children than do mothers of chronological age-matched typically developing children (Buckholt, Rutherford, & Goldberg, 1978; Buium, Rynders, & Turnure, 1974). Jones (1977) also found a greater incidence of communicative overlap, or “vocal clashing,” with Down syndrome infants and young children than with typically developing children matched developmentally. Peskett and Wootton’s (1985) pilot study with four Down syndrome subjects (two less communicatively advanced, two more communicatively advanced relative to each other) suggested that occurrence of vocal clashing may be related to communicative ability, at least for 3-year-olds. Berger and Cunningham (1983) found in a longitudinal study an age-related increase in vocal clashing between 0- to 6-month-old Down syndrome infants and their mothers in comparison to typically developing infants. Thus, when Down syndrome infants and children are spoken to they receive a greater volume

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of speech stimulation and often clash and overlap with their mothers when vocalizing themselves. There are further interesting differences in the communicative interaction patterns between typically developing infants and their mothers and between Down syndrome infants and their mothers. Berger and Cunningham (1983) found that the average durations of their typically developing infants’ nonvegetative vocalization increased steadily over the first 4 months of life when the infants were engaged in face-to-face interaction with their mothers, with a marked decrease over the subsequent 2 months. The same pattern was not found for Down syndrome infants. The average durations of the Down syndrome infants’ vocalizations were considerably shorter than those of the typically developing infants over the first 3 months, with a marked increase over the subsequent 3 months. This finding is intriguing because it raises the possibility of a cylical pattern of vocal output in mother-infant interactions, which might serve some purpose in the child’s developing ability to process and produced speech. Infants may proceed through periods of high vocal output in interaction as a means of exercising a communicative instinct. Periods of lower interactive vocal output may occur as they restructure their schemas for speech and pay greater attention to adult speech models. Another possibility is that schema development in nonspeech realms, such as those regarding motor skills, could influence the potential cycling of vocal output. Typically developing infants may begin life in a “high-output mode” for the first 4 months and subsequently proceed to a “low-output mode.” The results of Berger and Cunningham suggest that the pattern for Down syndrome infants may be reversed, beginning with low output. Differences in the manner in which mothers of typically developing and Down syndrome infants interact with their children may serve to alter a potentially natural cycle of vocal output in interaction for Down syndrome infants. For example, the vocal stimulation provided by the mothers of typically developing infants generally decreased with age in the Berger and Cunningham study, but the opposite was true for Down syndrome infants. Additionally, communicative overlap, or “vocal clashing,” increased with age for the Down syndrome infants but not for the typically developing infants. Cardoso-Martins and Mervis (1985) also found that mother-child interactions were predominantly mother-directed for Down syndrome infants and young children but child-directed for typically developing infants. Mothers of Down syndrome children used more imperatives and fewer child-oriented labels for objects than mothers of typically developing infants and children. A longitudinal study expanding on the 0-6 months age range of Berger and Cunningham would clarify the issue of cycles in vocal output of typically developing and Down syndrome infants in interactive settings. In addition to the possibility of cycles of vocal output, studies of adult-child interactions involving Down syndrome and typically developing infants and chil-

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dren yield a recurrent theme consistent with the findings of Cardoso-Martins and Mervis (1985), that adults are more directing with Down syndrome youngsters (e.g., Buium et al., 1974). For example, mothers of Down syndrome infants and children will often use larger numbers of imperatives than mothers of typically developing children. The fact that vocal clashing is more prominent in Down syndrome child-mother interactions than in typically developing childrens’ interactions with their mothers suggests that perhaps parents notice that their Down syndrome infants have difficulty with turn taking and may need greater assistance and direction to take part in communication. It is also possible, however, that adults are predisposed to be more directive with Down syndrome infants and children because they assume that because the children are handicapped they will need greater direction in any circumstances. These issues could be studied further by combining laboratory observation methods, which could be used to verify results concerning vocal clashing and directiveness, and perhaps intervention studies, which may provide information regarding the effects of directiveness on communication. Studies of father-child interaction would also be of use in further describing the Down syndrome child’s communicative environment. Differences in communicative environments between typically developing and Down syndrome infants and children are of both theoretical and clinical interest. Such differences could, in addition to internal factors such as hearing loss and speech motor difficulties, partially explain a specific deficit in language development related to Down syndrome (Miller, 1988). This possibility is supported by the results of L. Smith and von Tetzchner (1986), who highlighted a positive relationship between the linguistic structure of mothers’ speech to their Down syndrome infants at I7 months of age and the childrens’ expressive and productive language at 3 years of age. In this study, mothers’ uses of WH- questions, sound expansions (repetition or adding to child utterances), imitations, and answers to Down syndrome childrens’ utterances were related to later expressive and productive language outcome. Thus, the richness of the linguistic content of a Down syndrome infants’ communicative environment may affect language development. The communicative environment of Down syndrome infants and children might also be used as an avenue of language intervention. Down syndrome infants are capable of some imitation of prosodic speech features (Reichle, Siegel, & Rettie, 1985), suggesting that communicative channels between adults and infants are open to at least some degree on a reciprocal basis. Additional encouragement for imitation as a potential tool in early language intervention with Down syndrome children was provided by Mahoney and Snow (1983). In this study, when mothers interacted with Down syndrome infants and children in a structured manner designed to increase vocabulary, the childrens’ expressive language improved. This finding was particularly intriguing in light of a relationship between pretraining sensorimotor development and eventual

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expressive language ability of the Down syndrome children at 3 years, which suggests that nonverbal cognitive status might be predictive of the potential effectiveness of language intervention early in life for Down syndrome children. The prospects for imitation therapy are not entirely positive, however, because the findings of Dunst (1988) suggested that Down syndrome infants’ development of imitation of speech segments and novel words was delayed for chronological age-matched Down syndrome infants in relation to typically developing infants. In spite of this potential limitation on Down syndrome infants’ imitative capacities for speech, imitation therapy holds considerable promise and deserves further investigation.

V.

CONCLUSIONS

Typically developing infants and children achieve major perceptual and productive developments in the first few years of life. Infants appear to be endowed with relatively sophisticated perceptual abilities for auditory events. Infants can perceive speech sounds in a categorical-like manner, combine visual and auditory input in speech perception, and extract underlying rhythmic and musical interval structures from tone sequences. With sufficient perceptual experience, infants develop specialized knowledge of the speech sounds of their native language and at least some aspects of their native musical structure. In the productive realm, typically developing infants achieve substantial production of mature (canonical) syllables by about 7 months of age on the average. First words appear in the second year, and, once words are combined beginning in the latter half of the second year, mean length of utterance in morphemes is highly correlated with age and, thus, cognitive development, up to about 3.5 years. Studies of early language development in Down syndrome children can be divided into several categories based on differences in approach. The few studies of infancy have been conducted in two areas, psychophysically oriented investigations of dynamic versus static information in the speech spectrum (e.g., Eilers, Bull et a l . , 1985) and studies of premeaningful speech, or babbling (e.g., B. L. Smith & Oller, 1981; Lynch, Oller er a l . , 1990). These studies have suggested a basic speech processing capability (better processing of static than dynamic spectral information) and the onset of mature syllable production at about 9 months of age in Down syndrome infants, but many questions regarding speech perception and production in the first 2 years of life remain unanswered. In the perceptual realm, it has proved difficult to test Down syndrome infants younger than 1 year in speech tasks using available methodologies. For example, in the visually reinforced infant speech discrimination paradigm (Eilers et al., 1977), Down syndrome infants younger than 1 year seem unable to establish the necessary connection between a change in the auditory stimulus (e.g., from awa

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to ara) and the presentation of a visual reinforcer. In other words, it is difficult to train Down syndrome infants to perform the basic responses required in the procedure, even with easily discriminable speech contrasts (e.g., ba versus wa). Therefore, little is known about the perceptual abilities of Down syndrome infants in the first year of life. Additionally, Down syndrome infants may experience difficulty in the integration of sensory information across different modalities, such as vision and audition, which could hinder their processing of speech information at very early stages of development. New methodologies, perhaps similar to the heart rate monitoring procedure used by Soraci et al. (1986), which will allow for testing of young Down syndrome infants in a variety of perceptual tasks, are needed to clarify the capacities of Down syndrome infants. In the productive realm in infancy, there are no unequivocal accounts for the later onset of mature syllable production in Down syndrome than typically developing infants. Down syndrome infants may begin canonical babbling late because of hearing loss or possibly as a function of difficulties in speech motor control. These two factors could interact, influence babbling development in isolation, and of course be influenced themselves by individual differences across children. Additionally, the transition from babbling to meaningful speech is an area that has just begun to attract research attention. Once a credible account of this developmental period has been obtained for typical development, a description of this period should be investigated for Down syndrome children. Beyond the first year or so of life, a number of studies of language development in Down syndrome children have attempted to describe a distinct overall pattern of development related to Down syndrome (e.g., Greenwald & Leonard, 1979; Miller, 1988; L. Smith & von Tetzchner, 1986). Down syndrome children appear to have a specific language deficit because they lag behind typically developing children on a number of language measures when matched with these children on measures of nonverbal cognition. Relationships among chronological age, mental age, semantic development (vocabulary size), and syntactic development (measured by mean length of utterance in morphemes) are being investigated longitudinally in Down syndrome children through the first 4 years (studies of Miller and colleagues). These studies are providing information about the course of early language development in Down syndrome children, and other investigators are studying older Down syndrome children (e.g., Fowler, 1988). In addition to studies of language development patterns from infancy to 4 years, a third major area of inquiry regarding Down syndrome has focused on mother-child interactions (e.g., Berger & Cunningham, 1983; Cardoso-Martins et al., 1985). These studies have suggested that mothers of Down syndrome children are more directive and less prone to use child-appropriate labels in interactive situations with their children than are mothers of typically developing children,

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Reasons for interactive differences between Down syndrome and typically developing child-caretaker dyads are manifold. Cardoso et al. (1985) reported that the Down syndrome children in their study seemed more “passive” than the typically developing controls. Perhaps mothers sense this passivity and attempt to remedy it by aggressively stimulating their children. Greenwald and Leonard (1979) and L. Smith and von Teuchner (1986) both indicated a generally lesser amount of overall vocalizing in their Down syndrome subjects. Lind et al. (1970) also noted that Down syndrome infants did not cry as often as typically developing infants. This general “quietness” could contribute to the perception of Down syndrome as passive and also perhaps result in these children appearing less communicative than typically developing children. Both passivity and quietness on the part of their Down syndrome children could possibly motivate mothers to stimulate their children to increase the overall communicative interchange. The factors contributing to different interaction patterns between Down syndrome and typically developing child-mother pairs should be studied further in an attempt to understand the communicative environment of Down syndrome children. Studies of perception and babbling in the first year of life, overall patterns of language development across a variety of verbal and nonverbal cognitive assessments, and mother-child interaction represent three main foci of research on early language development of Down syndrome children. Other areas studied to some degree have been vocal quality (e.g., Pentz, 1987) and cry (e.g., Lind et a l . , 1970). The work on patterns of language development has provided the greatest insights into early language in Down syndrome children, and this ongoing work promises to yield additional important information. Other areas, however, have been largely neglected and are not the focus of intensive inquiry at this time. It has been obvious for some time that persons with Down syndrome experience considerable difficulties with language (see Gibson, 1978), and early language intervention can be of benefit for other handicapped groups, for example, the deaf (see Oller, Eilers, Vergara, & Lavoie, 1986). Therefore, description of the early language difficulties of Down syndrome children could result in the development of effective strategies for augmenting the language development of these children that may not be possible later in life. This reason, aside from the basic theoretical interest of the study of early language in disordered populations, is sufficient for the devotion of a substantially greater research effort in this underinvestigated area. ACKNOWLEDGMENTS Preparation of this work was supported by NIH/NIDCD Grant l-ROl-DC00484 (D. K . Oller, Principal Investigator). The authors are grateful for helpful commentary on earlier versions of the article from Dr. Barry Lester, Dr. Jon Miller, and Michele L. Steffens.

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Future directions for research. I n J. Miller (Ed.), Research on child language disorders: A decade of progress. Austin, TX: ProEd. Oller, D. K. (in press). Development of vocalizations in infancy. In H. Winitz (Ed.), Human communication and its disorders. Norwood, NJ: Ablex. Oller, D. K., & Eilers, R. E. (1983). Speech identification in Spanish- and English-learning 2-yearolds. Journal of Speech and Hearing Research, 2 6 , 50-53. Oller, D. K., & Eilers, R. E. (1988). The role of audition in infant babbling. ChildDevelopment. 59. 441-449. Oller, D. K., Eilers, R. E., Bull, D. El., & Carney, A. E. (1985). Prespeech vocalizations of a deaf infant: A comparison with normal metaphonological development. Journal of Speech and Hearing Research, 28, 47-63. Oller, D. K., Eilers, R. E., Vergara, K., & Lavoie, L. (1986). Tactual vocoders in a multisensory program training speech production and reception. Volta Review, 88, 21-36. Oller, D. K., & Lynch, M. P. (in press). Infant vocalizations and innovations in infraphonology: Toward a broader theory of development and disorders. In C. Ferguson, L. Menn, & C. StoelGammon (Eds.), Phonological development. Parkton, MD: York Press. Oller, D. K . , Wieman, L. A., Doyle, W. J., & Ross, C. (1976). Infant babbling and speech. Journal of Child Language, 3 , I - 1 I . Osgood, C. E. (1953). Methodand theon, in experimenralpsychology. New York: Oxford University Press. Papousek. M., Papousek, H., & Bomstein, M. H. (1984). The naturalistic vocal environment of young infants: On the significance of homogeneity and variability in parental speech. In T. M. Field & N. Fox (Eds.),Social perception in infants. Norwood, NJ: Ablex. Pentz, A. L. (1987). Formant amplitude of children with Down syndrome. American Journal of Mental Deficiency. 92. 230-233. Pentz, A. L., & Gilbert, H.(1983). Relation of selected acoustic parameters and perceptual ratings to voice quality of DS children. American Journal of Mental Deficiency, 88, 203-210. Peskett, R., & Wootton, A. J. (1985). Turn-taking and overlap in the speech of young Down’s syndrome children. Journal of Mental Dej7cienc.y Research, 29, 263-273. Preston, M. S., Yeni-Komshian, G., & Stark, R. E. (1967). Voicing in initial stop consonants produced by children in the prelinguistic period from different language communities. Johns Hopkins University School of Medicine, Annual Report of Neurocommunications Laboratory. 2 , 305-323. Reichle, J., Siegel, G., & Rettie, M. (1985). Matching prosodic and sound features: Performance of Down’s syndrome preschoolers. Journal of Communication Disorders, 18, 149- 159. Rondal, J. A., Ghiotto, M., Brkdarl, S., & Bachelet, J. F. (1988). Mean length of utterance of children with Down syndrome. American Journal on Mental Retardation. 93, 64-66. Scheffelin, M. (1968). A comparison of four stimulus-response channels in paired-associate learning. American Journal of Mental Deficiency, 73, 303-307. Smith, B. L., & Oller, D. K. (1981). A comparative study of premeaningful vocalizations produced by normally developing and Down’s syndrome infants. Journal of Speech and Hearing Disorders, 46, 46-5 I . Smith, B. L., & Stoel-Gammon, C . (1983). A longitudinal study of the development of stop consonant production in normal and Down’s syndrome children. Journal of Speech and Hearing Disorders, 48, 114-1 18. Smith, L., & von Tetzchner, S. (1986). Communicative, sensorimotor, and language skills of young children with Down syndrome. American Journal of Mental Deficiency, 91, 57-66. Snow, C. E. (1977). Mothers’ speech research: From input to interactions. In C. E. Snow & C. A. Ferguson (Eds.), Talking to children: Language input and acquisition. Cambridge: Cambridge University Press.

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Soraci, S. A,, Barlean, J. L., Haenlein, M., & Baumeister, A. A. (1986). Lower sensitivity to alterations of auditory relational information in mentally retarded than in nonretarded adults. Physiological Psychology, 14, 146- 149. Stark, R. E. (1972). Some feature of the vocalizations of young deaf infants. In J. F. Bosma (Ed.), The mouth of the infant. Springfield, IL: Thomas. Stark, R. E. (1980). Stages of speech development in the first year of life. In G. Yeni-Komshian, J. Kavanagh, & C. krguson (Eds.), Childphonology: Vol. I : Producrion. New York Academic Press.

Stark, R. E., & Nathanson, S. N. (1974). Spontaneous cry in the newborn infant: Sounds and facial gestures. In J. F. Bosma (Ed.), Fourrh symposium on oral sensation andperception: Development in the fetus and infant. Bethesda, MD: US. Department of Health, Education, and Welfare. Stoel-Gammon, C. (1980). Phonological analysis of four Down’s syndrome children. Applied Psycholinguistics, I , 3 1-48, Stoel-Gammon, C. (1990, September). Down syndrome: Effects on language development. ASHA, 32, 42-44. Stoel-Gammon, C., &Cooper, J. A. (1984). Patterns of early lexical and phonological development. Journal of Child Language, I I , 247-271. Stoel-Gammon, C., & Otomo, K. (1986). Babbling development of hearing-impaired and normally hearing subjects. Journal of Speech and Hearing Disorders, 51, 33-41, Tager-Flushing, H.,& Calkins, S. (1990). Does imitation facilitate the acquisition of grammar? Evidence from a study of autistic, Down’s syndrome, and normal children. JOWMI of Child Language, 17, 591-606. Tallal, P. (1976). Rapid auditory processing in normal and disordered language development. Journal of Speech and Hearing Research, 19, 561-571. Thevenin, D. M., Eilers, R. E., Oller, D. K., & Lavoie, L. (1985). Where’s the drift in babbling drift? A cross-linguistic study. Applied Psycholinguisrics, 6, 3- 15. Thorpe, L. A. ( 1985). Auditory-temporal organization: Developmenral perspectives. Unpublished doctoral dissertation, University of Toronto. Thorpe, L. A., Trehub, S. E., Morrongiello, B. A., & Bull, D. (1988). Perceptual grouping by infants and preschool children. Developmental Psychology, 24, 484-491. Trehub, S. E. (1976). The discrimination of foreign speech contrasts by infants and adults. Child Development, 47, 466-472. Trehub, S. E., Bull, D., & Thorpe, L. A. (1984). Infants’ perception of melodies: The role of melodic contour. Child Development, 55, 821-830. Trehub, S. E., Cohen, A. J., Thorpe, L. A., & Morrongiello, B. A. (1986). Development of the perception of musical relations: Semitone and diatonic structtm. Journal of Experimental Psychology: Human Perception and Performance, 12, 295-301. Trehub, S. E., & Rabinovitch, M. S. (1972). Auditory-linguistic sensitivity in early infancy. Developmental Psychology, 6 , 74-77. Trehub, S. E., Thorpe, L.A,, & Trainor, L. J. (1990). Infants’ perceptionof good and bad melodies. Psychomusicology, 9, 5- 19. Van Borsel, J. (1988). An analysis of the speech of five Down’s syndrome adolescents. Journal of Communication Disorders, 21, 409-421. Vihman, M. M., Ferguson, C. A., & Elbert. M. (1986). Phonological development from babbling to speech: Common tendencies and individual differences. Applied Psycholinguisrics. 7 , 3-40. Vihman, M. M., & Miller, R. (1988). Words and babble at the threshold of language acquisition. In M. D. Smith & J. L. Locke (Eds.). The emergenr lexicon. San Diego, CA: Academic Press. Weisenberger, J. M., & Miller, J. D. (1987). The role of tactile aids in providing information about acoustic stimuli. Journal of the Acoustical Society of America, 82, 906-916.

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Development of Verbal Communication in Persons with Moderate to Mild Mental Retardation LEONARD ABBEDUTO WAISMAN CENTER AND DEPARTMENT OF EDUCATIONAL PSYCHOLOGY UNIVERSITY OF WISCONSIN-MADISON MADISON, WISCONSIN 53705

1.

INTRODUCTION

Spoken language is involved in most types of social interaction and in classroom instruction; thus problems in verbal communication will have negative effects on many facets of an individual’s mental and behavioral functioning. It is not surprising, therefore, that problems in verbal communication have figured prominently in work on mental retardation. A deficit in the area of adaptive behavior is an important component of the definition of mental retardation endorsed by the American Association on Mental Retardation (Grossman, 1983), and behaviors involved in verbal communication fall within the domain of adaptive behavior. Moreover, the intelligence tests most often used to identify persons with mental retardation (i.e., the Stanford-Binet and the Wechsler scales) include numerous items whose solution requires the use of language. This means that performance on such tests, and thus the diagnosis of mental retardation, can be affected by an individual’s expertise in the area of verbal communication. Comprehensive interventions for young children with or at risk for mental retardation include language behaviors involved in communication as targets (e.g., Zigler & Hodapp, 1986), and speech and language therapy is included in many special education programs at the elementary school level (N. Robinson & Robinson, 1976). In this article, I summarize existing data on the nature, extent, and causes of the problems in verbal communication associated with mental retardation. I also identify ways in which our understanding of these problems is incomplete. INTERNATIONALREVIEW OF RESEARCH IN MENTAL RETARDATION. Vol. 17

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It should be noted at the outset that the present review does not include a consideration of all facets of communication and language in persons with mental retardation. First, the focus is on communication through spoken language. There is no attempt to review research on prelinguistic communication or nonlinguistic behaviors that persons with mental retardation use to supplement their spoken communication. Second, because persons with severe to profound mental retardation often develop little, if any, spoken language, they are not represented in most of the articles reviewed. Thus, the conclusions reached in this article should be seen as generalizable only to persons with less severe impairments. Third, there is no attempt to review the large literature on differences between the language environments of persons with and without mental retardation. Instead, the focus is on descriptions of the verbal communicative behavior of individuals with mental retardation, and on the knowledge and skills on which those behaviors depend. This focus reflects my own research interests, and should not be seen as a denial of the importance of environmental factors in the development of verbal communication. Fourth, although studies on the relation of impairments in linguistic (i.e., phonological, syntactic, and semantic) competence to performance in spoken communication are reviewed, I have not described the acquisition of linguistic competence per se. Instead, the emphasis is on the use of language to communicate with other people.

II. THE NATURE OF VERBAL COMMUNICATION Communication is more than the transmission of information to others. The cry of a newborn, for example, is informative (Zeskind & Marshall, 1988), but it differs in a fundamental way from the behaviors that occur in conversations, lectures, debates, or other activities that most of us call communication. Because the newborn’s cry is a reaction to an internal state, it occurs (and in the same form) whether or not there is someone present to respond to it. In contrast, when we utter Can you close the window? to a friend, we do so because of a belief that these words will influence our friend’s behavior in a particular way. Similarly, when we request a signature from our boss by saying Would you mind signing this? rather than Sign rhis, we do so because of a belief that the latter will be seen as impolite. Unlike the newborn’s cries, true communicative behaviors not only convey information, but are motivated and shaped by a consideration of the other participants in the activity (Whitehurst & Sonnenschein, 1985). Becoming competent in spoken communication, then, involves more than the acquisition of linguistic competence. Language users also must learn, among other things, how to (1) take turns at talking (Sacks, Schegloff, 8z Jefferson, 1974), (2) formulate their utterances so that their referents are clear to the other participants (Whitehurst & Sonnenschein, 1985), (3) use language to perform

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various social functions or speech acts, such as making a promise to someone (Abbeduto & Benson, in press), (4) contribute in meaningful ways to the topic or task of interest to the other participants (Dorval& Eckerman, 1984), and ( 5 ) deal with situations in which participants have failed to understand each other’s messages in the ways intended (Garvey, 1977). In short, the development of competence in verbal communication is, in large measure, the process of acquiring knowledge about how to use and understand language in ways that are sensitive to the goals, beliefs, feelings, and capabilities of the other participants. Such knowledge typically is referred to as pragmatic knowledge (Levinson, 1983). In the next section, I review research that has been designed to determine which types of pragmatic knowledge are and are not displayed in the verbal behavior of persons with moderate to mild mental retardation.

111.

RESEARCH ON THE VERBAL COMMUNICATION OF PERSONS WITH MENTAL RETARDATION

Research on the development of verbal communication in persons with mental retardation has been motivated largely by practical concerns about their adaptive functioning. Researchers have examined those verbal behaviors that have been identified by work on nondisabled children and adults as being crucial to the success of a wide range of communicative encounters. The assumption has been that deficits in these areas will seriously limit an individual’s ability to participate in and benefit from interactions with others. Five areas of verbal communication have received the most attention: turn taking, establishing referents, managing speech acts, contributing to the conversational topic, and conversational repair. In each area, successful performance requires that a participant adjust his or her language behavior on the basis of a consideration of the other participants. The nature of the adjustments, and thus the pragmatic knowledge required, however, differs across areas. We consider below whether persons with mental retardation are less adept in some of these areas than in others.

A.

Taking Turns at Talking

To facilitate the transmission of information among participants, all communicative interactions are governed by rules for taking turns at talking (Sacks et al., 1974). Turn taking is evident in the earliest interactions between infants and their mothers (Snow, 1972), although this organization is due entirely to the adjustments of the latter to the former. By the preschool and early school years, however, children are adept at turn taking even when engaged in peer interactions (Gallagher & Craig, 1982; Garvey & Berninger, 1981). Most of the transitions from one speaker to the next are managed smoothly in such interactions, with 5

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to 10% of these transitions involving errors (e.g., one speaker interrupting another or two or more speakers beginning to talk simultaneously). This rate approximates the 5% rate estimated for the conversations of nondisabled adults (Levinson, 1983). A near-adult level of performance is not achieved at such an early age in most of the other areas of verbal communication considered in this article. This suggests that the skills and experiences needed to acquire and use the pragmatic knowledge underlying turn taking are fairly minimal, and thus, this may be an area of verbal communication in which many persons with mental retardation do reasonably well. Although there have been few studies of turn taking involving individuals with mental retardation, studies to date have been consistent with this prediction. Studies of turn taking by persons with mental retardation typically have involved an analysis of the occurrence of errors in speaker change, such as one speaker interrupting another or two speakers talking simultaneously. Tannock (1988) examined the speaker changes that occurred when children with Down syndrome, some of whom were prelinguistic, were engaged in free play with their mothers. The rate of turn-taking errors in these dyadic interactions was compared with that occurring in the interactions of nondisabled children and their parents, with the two groups of children being matched on measures of linguistic competence and mental age. Tannock found the rate of turn-taking errors to be quite low, with no differences between the groups. A similar finding was obtained by Davis, Stroud, and Green (1988) in their analysis of parent-child talk during free play and instructional episodes. The children with mental retardation in the Davis et al. investigation ranged in chronological age from 19 months to 5 years and were heterogeneous with respect to etiology. Davis and Oliver (1980) also found a low rate of turn-taking errors in their study of the free play of parents and their children with mental retardation. Thus, although the development of turn-taking knowledge and skills may be delayed in children with mental retardation, their interactions with their parents are highly systematic and organized in terms of speaker change. It is important to recognize, however, that the parents of children with mental retardation, like the parents of nondisabled children (Snow, 1984), probably work hard at adapting to their children’s limitations so as to ensure that speaker change is systematic. Therefore, although many children with mental retardation are relatively good at taking turns with their parents, these children might be less adept at taking turns in interactions with peers. Unfortunately, there are no published data on turn taking in the peer interactions of children with mental retardation. A study by Abbeduto and Rosenberg (1980), however, provides data on the turn-taking organization of the peer interactions of adults with moderate to borderline mental retardation. These investigators examined the mealtime conversations of triads of acquainted peers and found that turn-taking errors occurred on

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only 10% of the speaker changes. This figure is not appreciably greater than the rate for the conversations of nondisabled adults (Levinson, 1983), which suggests that turn taking is not a major problem for many adults with mental retardation.

6.

Establishing Referents

The success of any communicative interaction depends on the participants’ clearly establishing the persons, places, and things being referred to in each others’ utterances (Whitehurst & Sonnenschein, 1985). Consider the confusion that would occur if a participant began a conversation with He did it again and offered the other participants no clue as to who he was or to what action if referred. Because of the impact that such referential failures can have on social interaction (Whitehurst & Sonnenschein, 1985), referential communication has been a popular topic of research both in developmental psychology and in mental retardation. In contrast to the case of turn taking, the development of nondisabled children in the area of establishing referents is protracted. Although preschoolers recognize the need, as speakers, to make adjustments based upon the sensory and information processing capabilities of their listeners (Maratsos, 1973), much of the pragmatic knowledge needed to establish referents is not acquired until well into the school years (Whitehurst & Sonnenschein, 1985). For example, it is only near the age of 7 that nondisabled children recognize the need to produce messages that distinguish their referent from other similar entities in the environment (Whitehurst & Sonnenschein, 1985). Moreover, even late in the elementary school years, nondisabled children’s pragmatic knowledge remains fragile and is not applied in many situations in which it is relevant (Whitehurst & Sonnenschein, 1985). Such findings suggest that the task of acquiring the pragmatic knowledge relevant to referential communication is demanding, in terms of the nature of the skills and experiences involved, and thus, this may be a task that is especially problematic for many individuals with mental retardation. Most of the work involving subjects with mental retardation, especially the early work, has made use of a procedure originally developed by Glucksberg and Krauss (1967) in their research with typically developing children. In this procedure, a speaker and a listener are separated by an opaque partition. The speaker is given a set of stimuli, one of which is arbitrarily designated as the referent. The listener receives the same stimuli but is not informed which stimulus is the referent. The speaker’s task is to produce a message that fits only the referent, whereas the listener is to select the referent on the basis of the message that the speaker produces. Longhurst (1974) used the Glucksberg and Krauss procedure to study the referential skills of dyads of institutionalized adolescents with moderate to bor-

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derline mental retardation. The stimulus sets were composed of meaningless geometric designs. Longhurst found that the efforts of even dyads of people with IQs above 70 seldom culminated in the selection of the referent by the listener. This was due in large measure to inadequacies in the performance of these adolescents as speakers rather than as listeners. The evidence for this claim was the finding that nondisabled adults were seldom able to select the referent when they were given the messages produced by the subjects with mental retardation. The subjects with mental retardation, however, could select the referent when given messages generated by nondisabled adults (see Rueda & Chan, 1980, for a similar result). The Longhurst study has been criticized on the grounds that the results may tell us more about the subjects’ ability to process unfamiliar, meaningless designs than about their referential skill (e.g., Rosenberg, 1982). In studies by Beveridge and Tatham (1976) and Rueda and Chan (1980), however, meaningful, familiar stimuli were used in a variant of the Glucksberg and Krauss task. The stimuli were trios of simple scenes (e.g., a girl cutting a cake) in the former study and pairs of objects differing on a single dimension (e.g., a clown with a flower and an identical clown without a flower) in the latter. In both investigations, the adolescents with moderate mental retardation produced inadequate messages at a high rate. This suggests that these individuals find it difficult to produce adequate messages whatever the nature of the objects to which those messages refer. Beveridge and Tatham’s study also demonstrated that the referential inadequacies that characterize the speaking performance of adolescents with mental retardation are not simply the result of a lack of linguistic competence. The subjects in this study were pretested to ensure that they could produce and comprehend verbal descriptions of the simple scenes used as stimuli. Despite passing this linguistic pretest, the subjects performed poorly in the referential communication task. Problems in acquiring or using pragmatic knowledge, in contrast, may account for at least some of the referential difficulties experienced by speakers with mental retardation. In particular, Beveridge, Spencer, and Mittler (1979) present evidence that at least some children with mental retardation do not recognize that the success of any communicative exchange hinges on the quality of the messages produced. In the Beveridge et al. investigation, the subject and experimenter alternated as speaker and listener in the standard Glucksberg and Krauss task. The experimenter purposely produced ambiguous messages when in the role of speaker and selected the wrong stimulus in response to adequate messages when in the role of listener. A number of the children consistently blamed the listener for the failure (whether they or the experimenter assumed that role). This suggests that they did not understand that a message can be inadequate, a finding that also characterizes nondisabled children who are younger than 6 or 7 (Whitehurst & Sonnenschein, 1985). Consistent with expectations, then, the research on non-face-to-face referential

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communication suggests that persons with mental retardation, even high-functioning,older individuals, display limited pragmatic knowledge in their referential performance. It is difficult from this research, however, to determine precisely the extent to which development in this area is delayed. This is the case because neither chronological age-matched nor developmental level-matched nondisabled comparisons have been included in these studies (Abbeduto & Rosenberg, 1987). Nevertheless, research on typically developing children has indicated that 10-year-oldsperform quite well in the speaker role in Glucksberg and Krauss-type situations (Glucksberg, Krauss, & Higgins, 1975; E. J. Robinson & Whittaker, 1986). In contrast, persons with mental retardation who have mental ages near 10 years produce inadequate messages at a high rate (Longhurst, 1974). This suggests that in the area of establishing referents, adolescents with borderline to moderate mental retardation may perform at a level below that expected on the basis of their cognitive ability, at least in non-face-to-face situations; however, comparisons of individuals with and without mental retardation within a single study are needed to confirm this claim. It is important at this point to recognize two limitations of studies using a Glucksberg and Krauss-type procedure. First, although there will be instances in the lives of persons with mental retardation in which they must engage in nonface-to-face talk about referents (e.g., talking on the telephone), face-to-face interactions are certain to predominate. There is no guarantee that speaking performance in the former situation predicts success in the latter (Abbeduto & Rosenberg, 1987). Second, the Glucksberg and Krauss procedure is designed so that a dyad can succeed consistently only if (1) the speaker produces messages that completely and unambiguously specify his or her intended referents, and (2) the listener selects a referent solely on the basis of the speaker’s words. In everyday conversation, however, speakers often produce utterances that are referentially ambiguous if considered in isolation (Clark, Schreuder, & Buttrick, 1983). Listeners typically are able to resolve this ambiguity by relying on the context in which the utterance occurs and, moreover, are expected to do so by speakers (Clark et af., 1983). The results of the studies discussed to this point, therefore, may tell us nothing about the ability of persons with mental retardation to deal with the ambiguity typical of everyday conversation. Researchers interested in mental retardation have only recently begun to address these limitations of the Glucksberg and Krauss procedure. We now turn to these studies. The referential performance of persons with mental retardation in face-to-face situations was the focus of a study by Kernan and Sabsay (1987). These investigators asked adults with moderate to mild mental retardation to retell the story depicted in a previously seen film. The subjects made more errors in their use of definite and indefinite articles to introduce referents than did nondisabled college students. Kernan and Sabsay interpreted these errors as reflecting a lack of referential skill on the part of adults with mental retardation.

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In contrast to the findings of Kernan and Sabsay, however, Rosenberg and Abbeduto (1987) found that adults with mild to moderate mental retardation seldom made errors with the articles a , an, and rhe. In the Rosenberg and Abbeduto study, the spontaneous use of these articles was examined within the context of the naturally occurring mealtime conversations of the subjects. The information processing demands in such a situation are minimal compared with those involved in retelling a story. Thus, the results of the Kernan and Sabsay investigation may reflect more about the ability of their subjects to encode and retrieve a story from memory than about their referential skill. Face-to-face referential speaking performance also was examined in a study by Loveland, lhnali, McEvoy, and Kelly (1989). Loveland er al. asked each subject to explain a game he or she had learned to an experimenter. The experimenter asked questions (e.g., What hrrppens next?) when the subject failed to provide critical information spontaneously. The adolescents and adults with Down syndrome who participated provided the necessary information to the experimenter without extensive questioning. The research questions addressed by Loveland et al., however, did not require that they include a nondisabled comparison. (They were interested in making a comparison between persons with autism and the subjects with Down syndrome.) As a result, we do not know whether the performance of their subjects with Down syndrome was chronological age- or developmental level-appropriate. These studies of face-to-face talk are a welcome addition to the literature on referential communication. As we have seen, however, their results have not been particularly informative. Moreover, it is important to recognize that not all face-to-face interactions are equivalent in their communicative and information processing requirements (Shatz. 1983). Establishing referents may be more difficult or proceed in a different manner, for example, when the listener is an acquaintance rather than a friend, when the referents are physically absent rather than present, and when the referents are embedded in an unfamiliar activity rather than in a highly routinized activity. The two studies discussed represent only a limited sampling of the face-to-face interactions that persons with mental retardation typically encounter. Clearly, more work on referential communication in face-to-face interactions is necessary. As mentioned previously, studies based on the Glucksberg and Krauss procedure do not indicate whether persons with mental retardation can deal with the ambiguity typical of everyday conversation. Abbeduto, Davies, Solesby, and Furman (1991) addressed this issue in their study of the listener side of referential performance. The subjects were children with mild to moderate mental retardation. Abbeduto et al. found that their subjects with mental retardation were as likely to use disambiguating context to resolve the ambiguity in the utterances they heard as were nondisabled 5- to 10-year-olds matched to them in terms of mental age (as determined by performance on a standardized nonverbal measure

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of cognitive ability). For example, if a speaker made clear that she was searching for a gift for a child, the subjects in both groups typically reacted to a request such as Show me rhar cup by selecting a child’s cup over an adult’s cup. This study, then, suggests that although individuals with mental retardation may be delayed in learning to use some types of disambiguating context, the magnitude of the delay is similar to that seen in the domain of cognitive functioning. It should be noted, however, that nondisabled listeners use many types of contextual information to disambiguate referential expressions (Ackerman, Szymanski, & Silver, 1990), only some of which were included in the Abbeduto et al. investigation. Thus, there is more work to be done in this area of the referential performance of individuals with mental retardation. In sum, the results of the research reviewed are consistent with expectations derived from work on the developmental course of referential skills in nondisabled children. Individuals with mental retardation exhibit developmental delays in many aspects of their referential performance. In fact, there is some evidence that suggests that they do less well in the speaker role than would be expected on the basis of their mental ages, at least in non-face-to-face situations.

C.

Managing Speech Acts

The production of a linguistic expression during a social interaction constitutes a social act; that is, it is an attempt to influence the other participants in the interaction. For example, the utterance of That’s u collie would be an attempt to inform the other participants about a belief that the speaker holds, whereas the production of Is rhar a collie? would be an attempt to indicate to the other participants that the speaker needs a particular piece of information. These linguistically conveyed social acts are referred to as speech ucts (Austin, 1962). Problems in producing and understanding speech acts can affect not only the transmission of information among the participants in an interaction but also the ways in which they react to and evaluate each other (Abbeduto & Benson, in press). As is true in the area of establishing referents, nondisabled children’s acquisition of knowledge about speech acts is not complete until well into the school years. For example, although the basic social acts that can be performed through language are recognized by the age of 2 or 3, even 8- and 9-year-olds sometimes fail to select an appropriate linguistic means of expression for their speech acts (Abbeduto & Benson, in press). Such findings raise the possibility that some aspects of the task of acquiring and using knowledge about speech acts may depend on skills that are beyond the ken of many persons with mental retardation. Intense research on speech acts and mental retardation over the last decade has borne out this prediction. Several investigations in this area were designed to determine whether indi-

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viduals with mental retardation use language to express the same types of speech acts, and with the same relative frequencies, as do nondisabled speakers. This question has been addressed most often through an analysis of the linguistic utterances expressed by persons with mental retardation in the course of an interaction with one or more parent, peer, or teacher during loosely structured situations such as free play, cleanup, or mealtime. In conducting this type of analysis, each of the subject’s utterances is placed into one or more categories of speech act on the basis of the words spoken and the context [e.g., the previous discourse, the physical activities accompanying the utterance, the reactions of the other participant(s) to the utterance]. Different classification systems have been employed across studies, but in all cases the speech acts scored have been those thought to occur in the spontaneous speech of nondisabled speakers. This line of research indicates that children with mental retardation are delayed in the early stages of speech act development. The support for this claim comes from two studies of dyadic free play involving children with Down syndrome and their parents (Coggins, Carpenter, & Owings, 1983; Owens & MacDonald, 1982). The subjects ranged from 2 to 7 years in chronological age across the studies. In each investigation, the relative rates at which these children expressed various speech acts (e.g., requests for information, comments about objects) were compared with the rates seen for nondisabled children as they interacted with their parents in dyadic free play. The nondisabled children were matched to the subjects with Down syndrome on mean length of utterance ( M U ) , a gross measure of young children’s level of productive linguistic competence, in both studies. The results indicated that children with Down syndrome expressed the same types of speech acts, and with the same relative frequencies, as did the nondisabled comparison group. Despite these early delays, by adulthood individuals with mental retardation eventually come to produce all of the basic categories of speech act evident in the speech of nondisabled adults (Abbeduto & Rosenberg, 1980; Owings & McManus, 1980; Owings, McManus, & Scherer, 1981; Zetlin & Sabsay, 1980). Abbeduto and Rosenberg (1980), for example, found that their adult subjects, whose retardation ranged from moderate to borderline, produced assertions, questions, directives, expressives, and commissives. These are the same categories used by linguists to describe the speech of nondisabled adults (e.g., Bach & Harnish, 1979; Searle, 1969). Similar findings have been obtained by Owings and his colleagues (Owings & McManus, 1980; Owings et al., 1981) and by Zetlin and Sabsay (1980) despite the fact that the subjects and settings in their studies were very different from those in the Abbeduto and Rosenberg investigation. In the work of Owings and co-workers, the subject was a 28-year-old male with moderate mental retardation who was observed in a variety of naturally occurring encounters with the staff and residents of the group home in which he lived, whereas Zetlin and Sabsay observed adolescents with moderate mental retardation within the context of daily cleanup activities. Such findings demon-

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strate that, eventually, many persons with mental retardation are motivated to perform the same basic social acts as are nondisabled adults, and they evidently come to see language as the tool by which those acts can be performed. This is perhaps not surprising in light of the fact that, as mentioned previously, nondisabled children demonstrate such motivation and knowledge as preschoolers (Abbeduto & Benson, in press). Language not only makes possible the expression of numerous social acts; it provides a number of different forms for expressing any given act (Levinson, 1983). For example, Sign this, I want you to sign this, Could you sign this?, and Would you mind signing this? could all be used to make the same request. Not only requests, but assertions and other speech acts also can be expressed in a variety of ways. Abbeduto (1984) examined this aspect of speech act expression in 6- to 9-yearolds with moderate to borderline mental retardation by eliciting requests in response to hypothetical situations. On one trial, for example, each subject was told to imagine that another child was tearing some of the subject’s books, and the subject was asked to say something to end the destructive behavior. The subjects did not rely only on the imperative, which is the prototypical form for requesting. Instead, they also on occasion used various interrogative forms (e.g., Could you play with me?). In fact, they used as many different request forms as did a group of nondisabled kindergarten children matched to them in terms of mental age (as determined by their performance on a standardized nonverbal intelligence test) and productive linguistic competence. This suggests that children with mental retardation do learn that speech acts map onto linguistic forms in a one-to-many fashion, although their development in this regard may be slower than that seen for nondisabled children. In selecting among the alternative forms for an intended speech act, speakers are guided by, among other things, a desire to maintain good social relations with the other interactants (Brown & Levinson, 1978). For example, a speaker who is concerned with maintaining good social relations would be more likely to say Do you have another pen? than Give me a pen. The former is polite, whereas the latter is impolite and thus not likely to be viewed with favor by the addressee. A study by Nuccio and Abbeduto (in press) suggests that persons with mental retardation are not always adept at expressing their speech acts in ways that are conducive to the maintenance of good social relations. In this study, children and adolescents with mild to moderate mental retardation and nondisabled children matched to them in terms of mental age were prompted to request objects from an adult experimenter. The nondisabled children were found to use polite, interrogative forms such as Can I have another toy? almost exclusively. The subjects with mental retardation, in contrast, relied heavily on impolite, noninterrogative forms such as Another toy. This was true despite the fact that the subjects with mental retardation were capable of producing many of the interrogative forms

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used by the nondisabled children. It may be that students with mental retardation know less about the social acceptability of the various forms in their repertoires than do nondisabled children. The fact that parents of children with mental retardation make relatively greater use of the impolite imperative when speaking to their children than do parents of nondisabled children (Cardoso-Martins & Mervis, 1985) may contribute to the former’s problems in this area of speech act management. In selecting a linguistic form for a speech act, competent speakers also consider the context in which that act will be embedded (Abbeduto & Benson, in press). For instance, the maintenance of good social relations requires more linguistic politeness in some contexts than in others. Thus, a speaker might select an extremely polite form for a request addressed to someone who is angry, but a moderately polite form for a more cheerful and accommodating addressee (e.g., May I please have this one? in the former case and Can you give me this one? in the latter case). Further, there may be contexts in which speakers are not concerned with maintaining good social relations, as might be the case when requesting the return of an object taken without permission. Persons with mental retardation learn to attend to important dimensions of the context when deciding on the linguistic form their speech acts should take, albeit at a later age than do typically developing individuals. Abbeduto (1984), in a study described previously, elicited requests to hypothetical situations and found that children with mental retardation varied the politeness of their requests as a function of the following factors: the addressee’s age (i.e, the addressee was a child or adult), the cause of the request (i.e., the subject needed a favor or was reacting to the addressee’s behavior), and the goal of the request (i.e., the subject sought an action, termination of an ongoing action, or initiation of social interaction). Bliss (1985) used a similar methodology and found that children and adolescents with mild mental retardation were more polite when making a request of an unfamiliar adult than of a familiar adult. In the study by Nuccio and Abbeduto (in press) described previously, the children and adolescents with mental retardation attended to the experimenter’s affective state and activity level, such that their requests were most polite when the experimenter was both sad and busy. In each of these studies, however, the subjects with mental retardation did not perform as well as would be expected on the basis of their chronological ages; instead, they performed in a manner similar to that of their nondisabled mental age-matches. Researchers also have been interested in the comprehension of speech acts by individuals with mental retardation. Comprehending speech acts is complicated by the fact that many linguistic utterances can be intended in different ways in different contexts. That’s mine, for example, would be a request for the return of an object if addressed to a child who had taken one of the speaker’s possessions without permission. If, however, this same sentence was uttered by a business

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person who was giving a tour of the properties he or she owned, the speech act performed would be that of assertion. Listeners, therefore, often must rely not only on what a speaker says but also on the context in which it is said to decide which of several possible speech acts is actually intended (Abbeduto & Benson, in press). Persons with mental retardation have been found to be delayed in their comprehension of speech acts. Abbeduto, Davies, and Furman (1988) were interested in the comprehension of sentences that can be intended as yes-no questions or as requests for action, such as Can you make the pencil roll? These investigators manipulated the context such that the sentence was best interpreted as a request for action on some trials and as a yes-no question on other trials. The procedures and materials ensured that accurate comprehension could be achieved only by considering both what the speaker said and the context in which he or she said it. The performance of a group of children and adolescents with moderate to borderline mental retardation was found to be worse than expected on the basis of their chronological ages, but similar to that of nondisabled children matched to them on mental age (as indicated by a nonverbal test of intelligence). This was true despite the fact that the subjects with mental retardation had less well developed receptive language (i.e., syntax and vocabulary) than did their nondisabled mental age-matches. Delays in speech act comprehension also have been documented in observational studies involving children with mental retardation. The approach in these investigations has been to determine whether or not and how the children responded to the speech acts conveyed by their mothers’ utterances within the context of dyadic free play. Comparisons of preschoolers with mental retardation to nondisabled mental age-matched children have indicated similar levels of responsiveness to parental requests for actions in the two groups (Hanzlik & Stevenson, 1986; Sigman, Mundy, Sherman, & Ungerer, 1986). In addition, Leifer and Lewis (1984) found that toddlers and preschoolers with Down syndrome responded appropriately to their mothers’ requests less often than did chronological age-matched nondisabled children, but more often than MLUmatched nondisabled children. Despite these initial developmental delays, persons with mental retardation eventually develop the expertise to deal with at least some of the situations in which they must understand the speech acts of other people. In particular, adolescents and adults with mild to moderate mental retardation typically respond appropriately to the speech acts performed by familiar peers and adults during familiar or highly routinized activities. For example, Abbeduto and Rosenberg (1980) found that adults with moderate to borderline mental retardation appropriately responded to more than 90% of those speech acts that required a response (e.g., questions, requests for action) during mealtime conversations with their peers.

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It is important to recognize that adults with mental retardation may be successful in familiar situations because a detailed analysis of the speaker’s words and the context is not always required (Abbeduto & Rosenberg, in press). For example, the speech acts performed in such activities may be highly predictable from the context, and thus a listener need conduct only a superficial analysis of the speaker’s utterance (Abbeduto, Furman, & Davies, 1989a). Whether adults with mental retardation eventually evidence competence in unfamiliar situations that require consideration of both the speaker’s utterance and its context remains to be determined. In sum, consistent with what would be expected on the basis of the research on nondisabled children’s development, individuals with mental retardation exhibit delays in all aspects of speech act management investigated to date. In fact, there are areas of speech act management (e.g., using language in ways designed to maintain good social relations) in which the delay is greater than would be predicted from measures of their cognitive functioning. There also is evidence, however, that persons with mental retardation eventually manage speech acts quite well in familiar situations associated with minimal cognitive and linguistic demands.

D. Topic Organization The participants in a conversation typically identify a topic (or series of topics) of mutual interest and then produce utterances that focus on that topic and help it advance (i.e., move toward some resolution or closure). The talk even of nondisabled 18-month-olds displays some organization at the level of topic in that their utterances are contingent on their partner’s preceding conversational turn (Bloom, Rocissano, & Hood, 1976); however, the toddler’s utterances often are made to fit the syntactic not the semantic and pragmatic characteristics of their partner’s prior turn (Shatz, 1983). In fact, there is evidence that the pragmatic knowledge required to produce turns that expand on the content of a previous speaker’s turn continues to be acquired well into adolescence (Dorval & Eckerman, 1984). These data suggest that acquisition of the pragmatic knowledge underlying the production of topically coherent discourse poses a special challenge to nondisabled language users and, thus, may be an area in which we see particularly poor performance by persons with mental retardation. Abbeduto and Rosenberg (1980) found that for the three triads of adults with mental retardation they studied, the number of consecutive turns on the same topic averaged from 7 to 21 across the triads. Further, the longest topic, in terms of number of consecutive turns, ranged from 36 to 57. This would seem to suggest that the topic skills of adults with mental retardation are well developed. Such a conclusion, however, is not warranted for two reasons. First, without a comparison group of nondisabled adults it is impossible to determine whether the

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performance of Abbeduto and Rosenberg’s subjects was chronological age-appropriate. Second, topic length may not be a good measure of topic quality. This is demonstrated nicely by the results of a recent study by Warne and Bedrosian (cited in Bedrosian, 1988). Wame and Bedrosian found that although the adults with moderate mental retardation in their study stayed on topic, their utterances often did little to help the topic progress. Subjects often stayed on topic by acknowledging the prior speaker’s utterance with responses such as oh and mmhmm. Such responses have no semantic content and thus add no information about the topic (Dorval & Eckerman, 1984). Abbeduto and Rosenberg noted that acknowledgments were frequent in the conversations of their subjects as well. Thus, adults with mental retardation have problems in the area of topic development and these difficulties are not reflected in measures that tap their topicrelated persistence. The only published study of topical organization in children (Tannock, 1988) also relied exclusively on topic length. Thus, although limited, research in this area suggests that even adults with mental retardation find it difficult to contribute to the conversational topic in ways that help its progression. This is consistent with what would be expected on the basis of the development of nondisabled children.

E.

Conversational Repair

Communication does not always proceed in a problem-free manner, even when the speaker and listener are nondisabled adults. For instance, listeners may not attend to a speaker’s utterance, and speakers sometimes assume that the referents of their utterances can be identified when in fact they cannot. Repair devices such as Huh? and Which one do you mean? are available to resolve such problems. A failure to use or respond to repair devices can have serious consequences for an interaction. Listeners who do not indicate that there is a problem to be repaired can fail to grasp the speaker’s message and inadvertently respond to the speaker in inappropriate ways, whereas speakers who ignore requests for repair may not get their message across. By the age of 3, nondisabled children have been found to produce and respond appropriately to a variety of repair devices. Some types of repair devices, however, are more problematic for nondisabled children than are others (Shatz, 1983). In addition, even 5- and 6-year-olds fail to recognize many of the situations in which repair devices are useful (E. J. Robinson & Whittaker, 1986). This leads us to expect that although persons with mental retardation may evidence some skill in dealing with repair requests quite early in their development, there may be some types of repair device, or some situations in which they are used, that are never mastered by many of these individuals. Individuals with mental retardation often produce repair devices during conversation. Zetlin and Sabsay (1980), for instance, report that requests for repair

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(e.g., Where? in response to There’s apple right there) were frequent in an interaction between three adolescents with moderate mental retardation and their teacher. These investigators, however, did not indicate the rate at which these requests were produced. In their study, Abbeduto and Rosenberg (1980) found that 5% of the responses that adults with borderline to moderate retardation made to their partners’ turns were requests for repair. Thus, by adolescence, many persons with mental retardation are willing to request repair in familiar interactions associated with minimal social and information processing demands. The fact that persons with metal retardation are willing to use repair devices does not mean that they use them in all, or only in, circumstances in which their use is required. In fact, there is evidence that these individuals often fail to request repair of the communicative problems that arise during an interaction. Abbeduto et al. (1991) found that children with moderate to mild retardation seldom produced clarification requests (e.g., Which one?) when they encountered a request that was ambiguous (i.e., it could refer to either of two physically present objects). The children instead guessed at the referent of the request. Mental age-matched nondisabled children, in contrast, frequently made requests for clarification. In a similar vein, Rueda and Chan (1980) observed few instances in which their adolescent subjects with mental retardation requested clarification of the inadequate messages addressed to them in a non-face-to-face referential task. Warne and Bedrosian (cited in Bedrosian, 1988) found that their adult subjects with moderate mental retardation were more likely to produce repair devices when the speaker referred to a physically absent referent that was unrelated to the current topic than when he or she stayed on topic and referred to an absent entity. The results of these studies, then, suggest that although persons with mental retardation request repair, they do so in only a limited set of situations. Such variation across situations could be explained in terms of competence limitations; that is, these individuals may not have learned the circumstances in which repair devices are useful. It is also possible that this variation reflects performance rather than competence limitations. In the Abbeduto er al. (1991) study, for example, the speaker was a nondisabled adult. The children with mental retardation in this study may have recognized that a request for clarification was in order, but refrained from making the request because they feared it would be seen as a threat by the adult (i.e., as questioning his or her skill). Whatever its source, it is important to recognize that across-situation variation in verbal communication is not unique to persons with mental retardation; young nondisabled children exhibit similar variation in their communicative performance (Shatz, 1983). Researchers also have investigated the ability of persons with mental retardation to respond to requests for repair of their own inadequate messages. Coggins and Stoel-Gammon (1982) and Scherer and Owings (1984), for example, examined the responses that 5- to 6-year-olds with Down syndrome made to the requests for repair directed to them by a nondisabled adult during naturally

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occurring dyadic interactions such as free play, picture book reading, and mealtime. These children responded at a rate and in a manner similar to that reported for typically developing preschoolers (Gallagher, 1977; Garvey, 1977). Thus, individuals with mental retardation are slow to develop the competencies needed to respond to other people’s requests for repair. Consistent with the results of studies of typically developing individuals, children and adolescents with mental retardation find some repair devices more difficult to respond to than others. This is suggested by Longhurst and Berry’s (1975) investigation. The subjects in this study were a group of children and adolescents with moderate to borderline mental retardation. Longhurst and Berry examined the ability of these subjects to respond to three types of request for repair: (1) explicit verbal (i.e., Tell me something else about the picture), ( 2 ) implicit verbal (i.e., I don’t understand), and ( 3 ) nonverbal (i.e., a puzzled facial expression). These researchers found that most of their subjects responded at a high rate to explicit verbal requests, which made the response requirements clear. Only the subjects with the highest IQs, however, responded appropriately to the other two types of request, neither of which made explicit the response requirements. By adulthood, persons with mental retardation are highly skilled in responding to a number of different types of repair device. Abbeduto and Rosenberg (1980), for example, found that the adults with moderate to borderline mental retardation in their study appropriately responded to nearly all of the requests for repair addressed to them by their peers during mealtime conversations. Further evidence is provided by Paul and Cohen’s (1984) finding that the adults with moderate to borderline mental retardation who they studied responded in some way to all of the different requests for repair addressed to them. This included requests for confirmation (e.g., You watched “Dynasry” last night?), for repetition of an utterance (e.g., What?), and for repetition of a specific constituent (e.g., You leji what?). Moreover, these adults tailored their responses appropriately to the type of repair request directed to them. For instance, they repeated a specific constituent from their original utterance in response to 75% of the requests for repetition of a specific constituent, but never did so in response to a request for repetition. It should be noted that the research questions of interest to Paul and Cohen and Abbeduto and Rosenberg (1980) did not require the inclusion of a nondisabled adult comparison group. As a result, although the rate at which the subjects in these two studies responded to repair devices was quite good, we do not know whether it was chronological age-appropriate. Moreover, these studies did not examine all types of repair device (e.g., they did not include nonverbal requests such as those studied by Longhurst & Berry, 1975); thus, we cannot rule out the possibility that there are repair devices that continue to cause problems for persons with mental retardation throughout their adult lives. In summary, persons with mental retardation evidence developmental delays in

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producing and responding to repair devices; however, they have more problems producing repair devices in some situations than in others, and they find it more difficult to respond to some types of repair device than to others. This is similar to the pattern seen for nondisabled children.

IV. VERBAL COMMUNICATION IN PERSONS WITH MENTAL RETARDATION: SUMMARY, IMPLICATIONS, ANDFUTURERESEARCH In the studies reviewed, the verbal behavior of persons with moderate to mild mental retardation was examined for evidence of their acquisition and use of various types of pragmatic knowledge. This research has uncovered developmental delays in every facet of the verbal communication of these individuals. Delays are seen in taking turns, establishing referents, managing speech acts, contributing to the conversational topic, and repairing conversational breakdowns, and in both speaking and listening performance. Further, the delays consistently have been found to be as great or greater than the delays seen in the domain of cognitive functioning. Such findings validate the notion that deficits in verbal communication are a defining feature of mental retardation and should figure prominently in assessments of adaptive behavior (Grossman, 1983). The research reviewed, however, also suggests that some areas of verbal communication pose more of a problem for persons with mental retardation than do others. lhrn taking, for example, appears to be an area of relative strength for these individuals. In fact, the turn-taking performance of adults with moderate to borderline mental retardation (at least as indexed by the occurrence of overlaps and interruptions) has been found to approach that of nondisabled adults (Abbeduto & Rosenberg, 1980). In the area of establishing referents, in contrast, below-mental-age-level speaking performance appears to characterize this population. For the most part, these developmental asynchronies have been predictable from work on the course of pragmatic development in nondisabled persons. Those areas in which the bulk of the relevant pragmatic knowledge is acquired early by nondisabled children (presumably because that acquisition requires minimal skill and experience) are the least problematic for individuals with mental retardation. The most problematic areas of verbal communication for persons with mental retardation are those in which the development of nondisabled individuals continues into middle childhood or beyond. This pattern suggests that the mechanisms by which pragmatic knowledge are acquired are probably similar for persons with and without mental retardation. The fact that persons with mental retardation eventually achieve a high level of performance in some aspects of verbal communication but not others has impor-

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tant implications for assessment and intervention. First, because some communicative problems continue into adulthood, there is a need for lifelong programs of assessment and intervention in verbal communication. Currently, many such programs end once the client with mental retardation leaves high school, and sometimes even before. Second, interventions involving children with mental retardation may need to devote the most resources to treating those areas of verbal communication in which they can be expected to attain the lowest final level of achievement. Despite intense research into the verbal communication of persons with mental retardation over the years 1970-1990, additional data are needed. For example, there is a need for more data regarding situational variations in verbal communication. Nondisabled children show more consistency in their communicative performance across situations as they grow older (Shatz, 1983). This suggests that an important part of development in verbal communication consists of learning the situations in which specific pragmatic knowledge is applicable and of acquiring the skills needed to apply that knowledge consistently. The verbal communication of persons with mental retardation, therefore, must be examined across the range of situations in which they typically participate, so as to identify the situations that are most and least problematic for them (Abbedato & Nuccio, 1989). This has seldom been done. In addition, there is a need for research to distinguish between problems in verbal communication that reflect a lack of pragmatic knowledge and those that reflect a failure to apply existing pragmatic knowledge. Although in most studies the poor communicative performance of persons with mental retardation has been taken to reflect a lack of pragmatic knowledge, a recent study by Abbeduto, Nuccio, Short, Benson, and Maas (1990) suggests that not all problems in verbal communication can be explained in this way. These investigators were interested in the ability of children and adolescents with mild to moderate retardation to recognize the implications of a speaker’s choice of words. A non-face-face situation was employed in which the speaker requested, via telephone, information about which versions of a novel toy the subject possessed. The speaker’s choice of noun phrase varied over trials in a way that implied an interest in different versions. For example, Do you have Boppo Number One? implied an interest in only the one version named, whereas Do you have any of the Boppos? implied an interest in more than one kind of Boppo (Clark, 1979). Abbeduto et al. found that the subjects recognized the implications of different noun phrases if the experimenter told them in advance to attend to the speaker’s choice of noun phrase. If the subjects were not given this advance instruction, they failed to recognize the implications carried by the different noun phrases. Because the advance instruction did not specify the implications carried by particular noun phrases, it appears that it merely prompted the subjects to apply pragmatic knowledge that they possessed but did not use spontaneously. This “prosthetics”

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approach (Shatz, 1983) could be used to examine other areas of verbal communication in persons with mental retardation. Research on verbal communication must also be designed with greater attention to the heterogeneity of the population of persons with moderate to mild mental retardation. In the research described in this article, these individuals have been treated largely as a homogeneous group. There are likely to be subgroups, however, that differ in their profiles of strengths and weaknesses across different aspects of verbal communication. Some subgroups may be defined in terms of etiology. This is suggested by recent evidence of differences in nonverbal communication between children with Down syndrome and those with other forms of organically based mental retardation (Mundy, Sigman, Kasari, & Yirmiya, 1988). Other subgroups may reflect variations in environment. It may be, for example, that more directive parents lead their children with mental retardation down different paths in terms of their communicative development than do less directive parents. Regardless of the source of such subgroups, their identification will help to increase the effectiveness of assessment and intervention in verbal communication.

V.

CONCLUSION

Why do persons with mental retardation have problems acquiring and using pragmatic knowledge? Although we are a long way from being able to answer this question in detail, I believe that the research reviewed in this article provides some clues. The cognitive impairments of persons with mental retardation appear to place particularly strong constraints on their acquisition and use of pragmatic knowledge. The evidence for this claim comes from studies that have involved comparisons between subjects with mental retardation and nondisabled subjects matched to them on measures of cognitive functioning (i.e., mental age). I have identified nine such studies, all of which have been described in the foregoing review (Abbeduto, 1984; Abbeduto etal., 1988, 1991; Bliss, 1985; Davis et al., 1988; Hanzlik & Stevenson, 1986; Nuccio & Abbeduto, in press; Sigman et al., 1986; Tannock, 1988). Despite differences in the subjects, procedures, and aspects of communication investigated, the results of these studies are remarkably similar. In no study did the level of communicative performance of the group with mental retardation exceed that of the cognitive ability-matched nondisabled group. This contrasts with studies in which the groups with and without mental retardation were matched on measures of maturity in other domains (e.g., linguistic competence). This pattern of results suggests that there are important cognitive prerequisites for many of the pragmatic achievements that occur over the course of development.

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Although the studies mentioned above point to the existence of cognitive prerequisites, they do not tell us the specific cognitive skills that function as prerequisites for particular achievements in the pragmatic domain. The reason for this is that in these studies, verbal communication was examined only in relation to mental age, which provides a summary of performance across numerous and, oftentimes, unknown cognitive skills. Identifying the cognitive prerequisites for verbal communication will require an examination of the relationship between specific achievements in the pragmatic domain and the acquisition of specific cognitive skills. In addition to their cognitive impairments, persons with mental retardation evidence developmental delays in the domain of linguistic competence (Rosenberg, 1982). In fact, their impairments in syntax and some aspects of semantics often are more severe than their cognitive impairments (Abbeduto, Furman, & Davies, 1989b; Abbeduto & Nuccio, in press; Chapman, 1981; Miller & Chapman, 1984). Nevertheless, in several of the studies I have described, persons with mental retardation were found to be better at verbal communication than would be expected on the basis of their linguistic competence (Abbeduto et al., 1988, 1991; Leifer & Lewis, 1984). This suggests that not all impairments in linguistic competence invariably result in pragmatic problems. What we do not know from these investigations is which linguistic achievements constrain the acquisition and use of pragmatic knowledge and which do not. This is due to the fact that in these studies, verbal communication was examined in relation to measures that, like MLU, summarized performance across several facets of linguistic competence. In the future, researchers will need to examine the relationships between impairments in specific linguistic skills and particular achievements in the pragmatic domain. Factors besides linguistic and cognitive impairments no doubt constrain the acquisition and use of pragmatic knowledge by persons with mental retardation. Because communication is by definition a social activity, the impairments in social knowledge and skill that characterize these individuals (Simeonsson, Monson, & Blacher, 1984) may also play a role in their pragmatic problems. In addition, parents and other adults may interact with individuals with mental retardation in ways that are less than optimal for acquiring pragmatic knowledge (Abbeduto & Rosenberg, 1987). Unfortunately, the contributions of these factors to pragmatic development have not been adequately investigated (Abbeduto & Rosenberg, in press). Thus, there is a definite need for more work on the causes of the pragmatic problems that have been described in this article. ACKNOWLEDGMENTS Preparation of this manuscript was supported by Grant HD-24356 awarded by the National Institute of Child Health and Human Development to L. Abbeduto and by Grant 03352 from the

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National Institute of Child Health and Human Development to the Waisman Center on Mental Retardation. I thank Sheldon Rosenberg; the many collaborations and discussions he and 1 have had over the years have had a great impact on the ideas expressed here. I also thank Terry McMenamin, Glenis Benson, and Katherine Short for their helpful comments on earlier drafts of this article.

REFERENCES Abbeduto, L. (1984). Situational influences on mentally retarded and nonretarded children’s production of directives. Applied Psycholinguistics, 5 , 147- 166. Abbeduto, L., & Benson, G. (in press). Speech act development in nondisabled children and individuals with mental retardation. In R. Chapman (Ed.), Child talk: Performance processes in child language development. Chicago, IL: Mosby Yearbooks. Abbeduto, L.. Davies, B., & Furman, L. (1988). The development of speech act comprehension in mentally retarded individuals and nonretarded children. Child Development, 59, 1460- 1472. Abbeduto, L . , Davies, B., Solesby, S., & Furman. L. (1991). Identifying the referents of spoken messages: The use of context and clarification requests by children with mental retardation and by nonretarded children. American Journal on Mental Retardation, 95, 55 1-562. Abbeduto, L . , Furman, L., & Davies, B. (1989a). Identifying speech acts from contextual and linguistic information. Longuage and Speech, 32, 189-203. Abbeduto, L., Furman, L., & Davies, B. (1989b). Relation between the receptive language and mental age of persons with mental retardation. American Journal on Mental Retardation, 93, 535-543. Abbeduto, L., & Nuccio, J. (1989). Evaluating the pragmatic aspects of communication in schoolage children and adolescents: Insights from research on atypical development. School Psychology Review, 18, 498-508. Abbeduto, L., & Nuccio, 1. (in press). The relation between receptive language and cognitive maturity in persons with mental retardation. American Journal on Mental Retardation. Abbeduto, L., Nuccio, J., Short, K.,Benson, G., & Maas, F. (1990). Communicative development of persons with mental retardation: Recognition of pragmatic implications. Manuscript in preparation. Abbeduto, L., & Rosenberg, S. (1980). The communicative competence of mildly retarded adults. Applied Psycholinguisrics, I , 405-426. Abbeduto, L., & Rosenberg, S . (1987). Linguistic communication and mental retardation. In S. Rosenberg (Ed.), Advances in applied psycholinguistics: Vol. I . Disorders of first language development (pp. 76- 125). Cambridge: Cambridge University Press. Abbeduto, L . , & Rosenberg, S. (in press). The development of linguistic communication in persons with mental retardation. In S. Warren & J. Reichle (Eds.), Perspectives on communication and language intervention: Development, assessment and remediation. Baltimore, MD: Brookes. Ackerman, B. P., Szymanski, J., & Silver, D. (1990). Children’s use of the common ground in interpreting ambiguous referential expression. Developmental Psychology, 26, 234-245. Austin, J. L. (1962). How to do things with words. Oxford: Oxford University Press. Bach, K., & Harnish, R. M. (1979). Linguistic communication and speech acts. Cambridge, MA: MIT Press. Bedrosian, J. L. (1988). Adults who are mildly to moderately mentally retarded: Communicative performance, assessment and intervention. In S . N. Calculator & J. L. Bedrosian (Eds.), Communication assessment and intervention for adults wirh mental retardation ( pp. 265-307). Boston, MA: College-Hill Press.

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Beveridge, M., Spencer, J., & Mittler, P. (1979). Self-blame and communication failure in retarded adolescents.Journal of Child Psychology and Psychiatry and Allied Disciplines, 20, 129- 138. Beveridge, M. C., & Tatham, A. (1976). Communication in retarded adolescents: Utilization of known language skills. American Journal of Mental Deficiency, 81. 96-99. Bliss, L. S. (1985). The development of persuasive strategies by mentally retarded children. Applied Research in Mental Retardation, 6 , 437-447. Bloom, L., Rocissano, L., & Hood, L. (1979). Adult-child discourse: Developmental interaction between information processing and linguistic knowledge. Cognitive Psychology, 8 , 521-552. Brown, P., & Levinson, S. (1978). Universals in language usage: Politeness phenomena. In E. Goody (Ed.), Questions and politeness ( pp. 356-389). Cambridge: Cambridge University Press. Cardoso-Martins, C., & Mervis, C. B. (1985). Maternal speech to prelinguistic children with Down syndrome. American Journal of Mental Deficiency, 89, 45 1-458. Chapman, R. (1981, April). A clinical perspective on individual difierences in language acquisirion among mentally retarded children. Paper presented at the biennial meeting of the Society for Research in Child Development, Boston, MA. Clark, H. H.(1979). Responding to indirect speech acts. Cognitive Psychology, 1 1 , 430-477. Clark, H. H.,Schreuder, R., & Buttrick, S. (1983). Common ground and the understanding of demonstrative reference. JOUrMl of Verbal Learning and Verbal Behavior, 22, 245-258. Coggins, T. E.,Carpenter, R. L., & Owings. N. 0. (1983). Examining early intentionalcommunication by Down's syndrome and nonretarded children. British Journnl of Disorders of Communication, 18, 99- 107. Coggins, T. E., & Stoel-Gammon C. (1982). Clarification strategies used by four Down's syndrome children for maintaining normal conversational interaction. Education and Training of rhe Mentally Retarded, pp. 65-67. Davis, H., & Oliver, B. (1980). A comparison of aspects of the maternal speech environment of retarded and nonretarded children. Child: Care, Health and Development, 6 , 135-145. Davis, H., Stroud, A., &Green, L. (1988). Maternal language environment of children with mental retardation. American Journal on Mental Retardation, 93, 144- 153. Dorval, B., & Eckerman, C. 0. (1984). Developmental trends in the quality of conversation achieved by small groups of acquainted peers. Monographs of the Society for Research in Child Development. 49, No. 2 (Serial No. 206). Gallagher, T. (1977). Revision behaviors in the speech of normal children developing language. Journal of Speech and Hearing Research, 20, 303-318. Gallagher, T. M., &Craig, H.K. (1982). An investigation of overlap in children's speech. Journal of Psycholinguistic Research, 1 1 , 63-75. Garvey, C. (1977). The contingent query: A dependent act in conversation. In M. Lewis & L. A. Rosenblum (Eds.), Interaction, conversation, and the development of language ( pp. 63-93). New York: Wiley. Garvey, C., & Beringer, G. (1981). Timing and turn-taking in children's conversations. Discourse Processes, 4 , 27-57. Glucksberg, S., & Krauss, R. M. (1967). What do people say after they have learned how to talk? Studies of the development of referential communication.Merrill-Palmer Quarterly, 13, 309316. Glucksberg, S., Krauss, R., & Higgins, E. T. (1975). The development of referential communication skills. In F. D. Horowitz (Ed.),Review of child development research (Vol. 4 ) . Chicago, 1L: University of Chicago Press. Grossman, H. J. (Ed.). (1983). Manual on terminology and classification in mental retardation (3rd rev. ed.). Washington, DC:American Association on Mental Deficiency.

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Hanzlik, J. R., & Stevenson, M. B. (1986). Interaction of mothers with their infants who are mentally retarded, retarded with cerebral palsy, or nonretarded. American Journal of Mental Deficiency, 90,513-520. Kernan, K. T., & Sabsay, S. (1987). Referential first mention in narratives by mildly mentally retarded adults. Research in Developmental Disabilities, 8 , 361-369. Leifer, J. S., & Lewis, M. (1984). Acquisition of conversational response skills by young Down syndrome and nonretarded young children. American Journal of Mental Deficiency, 88, 610618.

Levinson, S. C. (1983). Pragmatics. Cambridge: Cambridge University Press. Longhurst, T. M. (1974). Communication in retarded adolescents: Sex and intelligence level. American Journal of Mental Deficiency, 78,607-618. Longhurst, T.M., & Berry, G. W. (1975). Communication in retarded adolescents: Response to listener feedback. American Journal of Mental Deficiency, 80, 158- 164. Loveland, K. A., lhnali, B., McEvoy, R., & Kelly, M.L. (1989). Referential communication and response adequacy in autism and Down’s syndrome. Applied Psycholinguistics, 10, 301-3 13. Maratsos, M. (1973). Nonegocentric communication abilities in preschool children. Child Development, 44, 697-700. Miller, J. F., & Chapman, R. (1984). Disorders of communication: Investigating the development of language of mentally retarded children. American Journal of Mental Deficiency, 88, 536-545. Mundy, P.,Sigman, M., Kasari, C., & Yirmiya, N. (1988). Nonverbal communication skills in children with Down syndrome. Child Development, 59, 235-249. Nuccio, J.. & Abbeduto, L. (in press). Dynamic contextual variables and the directives of persons with mental retardation. American Journal on Mental Retardation. Owens, R. E.. Jr.. & MacDonald, J. D. (1982). Communicative uses of the early speech of nondelayed and Down syndrome children. American Journal of Mental Deficiency, 86, 503-5 10. Owings, N. 0.. & McManus, M. D. (1980). An analysis of communication functions in the speech of a deinstitutionalized adult mentally retarded client. Mental Retardation. 18, 309-3 14. Owings, N. O., McManus, M. D., & Scherer, N. (1981). A deinstitutionalized retarded adult’s use of communication functions in a natural setting. British Journal of Disorders of Communication, 16, 119-128.

Paul, R., & Cohen, D. J. (1984). Responses to contingent queries in adults with mental retardation and pervasive developmental disorders. Applied Psycholinguistics, 5 , 349-357. Robinson, E. J., & Whittaker, S. J. (1986). Learning about verbal referential communication in the early school years. In K. Durkin (Ed.), Language development during the school years. London: Croom Helm. Robinson, N., & Robinson, H. (1976). The mentally retarded child (2nd ed.). New York: McGrawHill. Rosenberg, S. (1982). The language of the mentally retarded: Development, processes, and intervention. In S . Rosenberg (Ed.), Handbook of Applied Psycholinguistics: Major thrusts of research and theory (pp. 329-392). Hillsdale, NJ: Erlbaum. Rosenberg, S . , & Abbeduto, L. (1987). Indicators of linguistic competence in the peer group conversational behavior of mildly retarded adults. Applied Psycholinguistics. 8, 19-32. Rueda, R., & Chan. K. S . (1980). Referential communication skill levels of moderately mentally retarded adolescents. American Journal of Mental Deficiency, 85, 45-52. Sacks, H., Schegloff, E., &Jefferson, G.(1974). A simplest systematics for the organization of turntaking in conversation. Language, 50, 696-735. Scherer, N. J., & Owings, N. 0. (1984). Learning to be contingent: Retarded children’s responses to their mothers’ requests. Language and Speech, 27, 255-267. Searle, J. R. (1969). Speech acts. Cambridge: Cambridge University Press. Shatz. M. (1983). Communication. In J. Flavell & E. M. Markman (Eds.), Cognitive development.

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P. Mussen (Gen. Ed.), Carmichael’s manual of child psychology (4th ed., pp. 841-899). New York: Wiley. Sigman. M., Mundy, P., Sherman, T., & Ungerer, J. (1986). Social interactions of autistic, mentally retarded and normal children and their caregivers. Journal of Child Psychology and Psychiatry, 27, &17-656. Simeonsson, R. J., Monson, L. B., & Blacher, I. (1984). Social understanding and mental retardation. In P. Brooks, R. Sperber, & McCauley (Eds.), Learning and cognition in the mentally retarded (pp. 389-417). Hillsdale, NJ: Erlbaum. Snow, C. E. (1972). Mother’s speech to children learning language. Child Development, 43, 549565.

Snow, C. E. (1984). Parent-child interaction and the development of communicative ability. In R.L. Schiefelbusch & J. Pickar (Eds.), The acquisition of communicative competence (pp. 69- 107). Baltimore, MD: University Park Press. Tannock, R. (1988). Mothers’ directiveness in their interactions with their children with and without Down syndrome. American Journal on Mental Retardation, 93, 154- 165. Whitehurst, G. J., & Sonnenschein. S. (1985). The development of communication: A functional analysis. In G. I. Whitehurst (Ed.), Annals of child development (Vol. 2 , pp. 1-48). Greenwich, CT: JAI. Zeskind, P. S., & Marshall, T. R. (1988). The relation between variations in pitch and maternal perception of infant crying. Child Development, 59, 193-196. Zetlin, A. G., & Sabsay, S . (1980, March). Characteristics of interaction among moderately retardedpeers. Paper presented at the Gatlinburg Conference on Research in Mental Retardation, Gatlinburg, TN. Zigler, E., & Hodapp, R. M. (1986). Understanding mental retardation. Cambridge: Cambridge University Press.

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Assessment and Evaluation of Exceptional Children in the Soviet Union MICHAEL M. GERBER AND VALERY PERELMAN GRADUATE SCHOOL OF EDUCATION UNIVERSITY OF CALIFORNIA SANTA BARBARA. CALIFORNIA 93106

NORMA LOPEZ-REYNA DEPARTMENT OF SPECIAL EDUCATION UNIVERSITY OF ILLINOIS AT CHICAGO CHICAGO. ILLINOIS 60680

I.

INTRODUCTION

Education in the U.S.S.R., as in the United States, is a complex blend of political, ideological, cultural, historical, and educational components. Not surprisingly, very different intellectual and cultural-political environments also have produced extremely different approaches to providing special education. These differences reflect, in part, the fact that for most of this century it has been impossible for Soviet psychological research to separate itself from a narrow, organic view of developmental disabilities. In addition, again largely on ideological grounds, Soviet researchers traditionally have rejected use of psychometry and other quantitative methodology in conducting inquiries on educational topics; however, despite narrowness of outlook, or maybe because of it, Soviet psychology has developed a strong clinical tradition of qualitative analysis in which clinical inference is more often theory driven than data driven. On the other hand, Western psychologists and special educators in recent years have expressed increasing interest in the clinical assessment and intervention practices associated with Soviet approaches to individuals with disabilities (see, e.g., Budoff & Friedman, 1964; Campione & Brown, 1987; Campione, Brown, & Ferrara, 1982; Holowinsky, 1973a, 1973b, 1973c, 1976, 1980, 1984-1985; INTERNATIONAL REVIEW OF RESEARCH IN MENTAL RETARDATION. Vol. 17

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Minick, 1987; Rothman & Semmel, 1990). Western educators, reacting to mounting criticism of historical reliance on psychometric procedures, now express great interest in developing a broader array of assessment strategies, including various qualitative approaches, case study methods, and dynamic clinical assessment techniques. On their part, Soviet psychologists and educators are increasingly interested in developing greater expertise in psychometry and testing technology to assist in solving their own assessment, identification, and policy problems. Therefore, it is timely to begin considering how our divergent experiences in solving common assessment problems might valuably inform all concerned. The main purpose of the present article is to make a contribution to such a beginning. The ideas of a few Soviet psychologists, such as Vygotsky (1973, 1978, 1983a, 1983b) and Luria (1963a, 1963b, 1969, 1975), already receive prominent mention in Western literature and have exerted clear influence on Western special education (e.g., Balla & Zigler, 1969; Borkowski & Wanschura, 1974; Brown & Ferrara, 1985; Gallagher, 1974; Meichenbaum, 1977; Zigler & Balla, 1971). For example, Meichenbaum’s highly influential work, drawing explicitly on theoretical and conceptual postulates developed by Sokolov (1968) and Vygotsky (1983a, 1983b), has stimulated a wide variety of innovative thinking in Western special education. As a result, researchers have generated a variety of broadly applicable, cognitive-behavioral training techniques (see, e.g., Gerber, 1986; Larson & Gerber, in press). Such techniques share with those described in Soviet sources a common belief in the ability of teachers to restructure learning-related cognitive activity of handicapped students through direct training of a chain of strategic, self-regulating verbalizations and behaviors. Unfortunately, the Soviet literature tends to be remote because of the relative inaccessibility of original Russian sources, general unfamiliarity with the Russian language, and the philosophical frames of reference for much of its reported research. Nevertheless, the effort to overcome such obstacles may be worthwhile. Despite difficulties of accessibility and translation, older Soviet work has had a demonstrably beneficial impact on current Western special education practice. Further exchange and development are problematic, though, unless we exert greater effort to access and integrate Soviet literature. For example, the work of Vygotsky is frequently cited as a significant source for much cognitive training-oriented intervention research. But Vygotsky’s work is not contemporary; he died in 1934. At least 30 years passed before his work was known in America, then by only a narrow group of researchers, and only now are translations and interpretations widely available. Yet, very little is really known about those who followed Vygotsky or about what ideas mark contemporary trends in Soviet psychoeducational assessment and evaluation. Although some of Vygotsky’s students and co-workers, such as Alexander Luria, are fairly well known in the United States and the West, others, such as Leont’ev,

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Zaporazhets, Zinchenko, Elkonin, Galperin, and Bozhovich, are less often cited because they are less known. Therefore, this review has two goals. First, if offers an interpretive framework for understanding the potential value of Soviet contributions. We hope that expanded understanding will foster new and mutually beneficial exchange and dialogue. Second, both to illustrate points made in the first section and to better orient readers to specific Soviet research content and trends, this article also presents results of a systematic survey of recent Soviet journal literature on exceptional child assessment.

A.

Problems in Reading Soviet Research Literature

Soviet psychologists have a long history of developing methods of assessment that intend to capture the qualitative nature of performance. In stark contrast to traditional Western approaches, Soviet psychologists and educators have spent decades developing clinical tasks and techniques for collecting and analyzing detailed observations of children’s problem solving as a preferred means for assessing cognitive functioning of disabled learners. But, for Western scholars, much of the richness of Soviet experience remains hidden by the relative inaccessibility of source material. Ordinarily, this problem might be corrected by conducting systematic review of studies published in the Soviet Union in appropriate scientific journals. Practically speaking, a truly integrative review of Soviet special education assessment and evaluation research is complicated, if not impossible, because very little source material is published in English. In addition to the absolute difficulty of obtaining source materials, very few Soviet journals are devoted topically to special education independent from related issues in general psychology. It is true that the general topic of psychological assessment is addressed more often in Soviet journals. Implications for special education practice either are discussed indirectly or must be inferred by a knowledgeable reader. Other, more complex barriers to gaining an understanding of Soviet literature exist. Most notably is the Soviet style of reporting research. It is, in both form and content, very different from Western, or even most European, publication traditions. Americans, in particular, tend to be impatient with what appears to be lack of adherence to those canons of normal science expected in psychological research. Most foreign, and discouraging perhaps, to Western readers is the fact that published Soviet research tends to be so suffused with subtle (or not so subtle) philosophical and ideological content. However curious and confounding the style of Soviet reporting may seem to Western scholars, this body of Soviet research is not without significant substance and insight. Thus, although future exchange with Western researchers might eventually influence the reporting style and general accessibility of this

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literature, some effort is still required to study and integrate the published work that already exists. To accomplish this goal, it is first necessary to understand how several theoretical, practical, and ideological levels of abstraction are addressed simultaneously in Soviet publications. Published papers cannot be taken at face value, as Kozulin (1984) points out, but rather as “rough material for subsequent distillation and decoding.” 6.

Previous Reviews

Since 1973, several reviews of Soviet special education literature have been reported in Western journals, mostly by one scholar-Holowinsky (l973a, 1973b, 1973c, 1974, 1976, 1977, 1980, 1981, 1982, 1983, 1984-1985; also, see Wozniak, 1975). Some of these earlier reviews have briefly discussed specific theoretical and practical principles underlying Soviet assessment and evaluation of children with disabilities (e.g., see Holowinsky, 1973a, 1973b, 1973b, 1976, 1980, 1984-1985). As Holowinsky acknowledges, it is difficult to state explicit standards for judging the quality of previous reviews of Soviet research (see, e.g., Holowinsky, 1981). Unavoidably, previous attempts to review Soviet research have inherent limitations. It has been especially difficult to systematically accumulate a large enough body of related studies so research trends can be estimated and research paradigms described. In general, Western reports on Soviet research make little attempt to explain how studies were sampled, collected, or examined and what selection or review criteria were used. The nature of source materials, that is, the publications themselves, are rarely, if ever, described. (An important exception to both of these points is found in Holowinsky, 198I .) It is therefore difficult to have confidence that previous reviews have been comprehensive, integrative, or representative and that they have critically examined a particular body of Soviet research. Even readers who do read Russian and who do possess broad knowledge about Soviet society or special education, experience difficulty inferring the often unstated principles and theories that structure reporting of Soviet assessment and evaluation research. Without such a frame of reference, though, we are naturally at risk for conceptually distorting or frankly erring in any attempts to apply Soviet concepts to our own assessment problems. Consider, for example, how the key idea of assisted activity within a “zone of proximal development” is specified in many contemporary studies. Most often, it is employed as a conceptual rationale or link for building more dynamic, “qualitative” assessment techniques, a legitimate goal, to be sure. However, some critics have suggested that some of the major applications of this important concept now being developed in Western research are simply “inconsistent” with Vygotsky’s theory (Minick, 1987, p. 118). This does not make them “wrong,”

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of course, but it should cause us to question whether a more rigorous interpretation of Soviet work might lead to stronger and more useful modeling. Some, such as Holowinsky, correctly caution that strong philosophical and ideological considerations affect Soviet assessment procedures themselves, not merely reporting of their application; however, it has been rare for previous reviewers to present results of literature surveys and simultaneously explain what interpretive framework should or might be used by readers to better understand the implications of Soviet work. The following section offers such a framework that we feel is important for understanding current Soviet work.

II.

INTERPRETIVE AND EMPIRICAL FRAMEWORK FOR THE SURVEY

As shown by Kozulin (1984), Soviet ideology itself is cast in two different perspectives: one as an existing body of ideas and beliefs, and another as a censored version of these beliefs produced by official ideologists. All research in the Soviet Union has political implications because virtually every published document conforms to an ideological standard. An important principle of interpretation for readers of Soviet research is to distinguish between actual conditions and subjects of a particular research study, on one hand, and the secondary interpretation invented and offered by the researcher to present these conditions in ideologically coherent forms, on the other hand. This enduring tension between objective reporting and ideological interpretation causes problems in translating research into practice. It is historically characteristic of Soviet psychology, as the case of Vygotsky illustrates, that one and the same set of ideas can be considered at one moment appropriately dialectical and materialistic, only to be condemned as pseudoscientific and “bourgeois” a few years later (Kozulin, 1984). Soviet researchers frequently use concepts that are unfamiliar and cumbersome to many Western scientists. To deal with these and other problems of interpreting Soviet research on assessment and evaluation, this section supplements and frames the literature survey to follow. That is, a review of key concepts is offered as a guide to understanding the published literature we have selected for discussion. Unlike other reviews, our literature survey will be treated empirically. Approached in this way, published Soviet studies are a “population” to be sampled and constitute the major source of information pertinent to questions about trends in Soviet assessment. A discussion of “results” entails critical integration of findings from our sample in an attempt to identify major trends. The final portion of the article summarizes our perception of the implications of Soviet work for addressing current Western special education problems.

Michael M . Gerber et al.

A.

Key Philosophical Concepts

I . DIALECTICAL MATERIALISM Dialectical materialism theory holds that the material processes of the nervous system and the cognitive processes of consciousness are one aspect, not two aspects, of the working brain. Only the external material world is a source of sensation, perception, and thought. Nothing can exist in consciousness that is not the reflection, representation, or imprint of some aspect of that external, material world. Despite its philosophical underpinnings and political overtones, this Soviet view is not incompatible with recently articulated neuroscience theories, especially those offered as alternatives to older (i.e., linear) information processing models of cognition. In Gerald Edelman’s theory of neural Darwinism, for example, a developmental mechanism is posited that explains why and how neural organization represents a real interpenetration of the external, sensed environment and the anatomical-physiological principles of the human brain (Edelman, 1987).

2. HUMAN LABOR AND BEHAVIOR Through labor, human beings create their own environment. Broadly understood, Soviet psychology views intellectual development as a product of children’s purposeful, mutually transforming transactions with their environment. Development is propelled and conditioned by important aspects of their their social context, including the history and conditions of adult caregiving and the omnipresence of language used to both represent and structure perception as well as activity. Thus, to Soviet psychologists interested in child development and disabilities, cognitive life is a very direct result and reflection of social life. Cognitive processes are taken as producrs of a developmental process that has social, as well as individual, history. Development of language is the chief mechanism by which external phenomena are gradually transferred and represented as mental functions (Luria, 1963a, 1963b). This sociolinguistic view of language as a force for development has begun to significantly influence fundamental assumptions in Western special education thought as well (Stone, 1989; Stone & Wertsch, 1984; Turnure, 1987). Vygotsky thought that new forms of cognitive activity were created while using tools in a rich linguistic environment. Caregivers use language to encode children’s tool-using activity, which generates a basis for future development in the same way that human language in general provided a means for society to further collective development (Luria & Majovski, 1977).

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3. THEORY OF KNOWLEDGE Soviet psychologists attempt to gain an understanding of the characteristics of human thinking and knowledge by seeking to analyze intelligent activity, assuming that the structure of activity literally becomes the structure of thought (Davydov & Radzikhovsky, 1980a, 1980b; Rubinstein, 1983). Most critically, psychologists believe that changes in the social and linguistic structure of activity lead to changes in the organization of cognitive processes. This last idea particularly invests special education with critical importance in the process of developing intellectual potential. In the United States, researchers interested in mental retardation similarly have come to understand the relative importance of investigating intelligent behavior over scores on intelligence tests (see, e.g., Campione et al., 1982). Indeed, there has been demonstrably greater interest in investigating children’s problem solving outside the laboratory and in the contexts of applied school tasks; however, even recent Western work that claims to be “Vygotskian” in perspective tends to be quite narrow in how it conceptualizes the ability of language to lead and organize developing cognition (e.g., Minick, 1987).

4. “LEADING ACTIVITY” Leading activities are the basic factors defining a given developmental period in children’s psychological progress. “Activity” refers to a developmental construct, not to observable behavior. It is associated with the particular psychological process that is currently emerging and being transformed. The climax of these emergent activities determines and prefigures the emergence of the next leading activity. The formal concept of “activity” is, in many ways, understood as an irreducible whole. Attempts to hold some components constant to study others naturally distorts or limits the validity of information remaining in the system. For example, Western research often attempts to study child variance by making the simplifying assumption that teacher, situational, and teaching variance can be held constant. Or, conversely, we assume that it is possible to hold child differences constant in studies of teacher or school effectiveness without realizing that “effectiveness” changes in relationship to differences in children being taught and the purposes for teaching them. A “law” of human activity was first formulated in 1930 by Vygotsky. He wrote that higher forms of mental activity actually emerge on the developmental stage twice: first in the form of collective social activity, and second as an individual activity (Vygotsky, 1983a, 1983b). That is, adults provide encoded models of the meanings and purposes of their own social experience in their use of language to direct and communicate with their children (Elkonin, 1976). At the beginning of an individual’s cognitive development, “language” exists

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in the signal (i.e., social communication) value of external behaviors, and gradually is transformed and internalized as children’s primary means of cognitive self-development. This process is impelled by a hierarchy of various stages of activity, with the dominating, or “leading,” activity most readily evoked. That is, although children naturally engage in many activities simultaneously, their cognitive status is not reflected in the simple sum of these various activities. Instead, some types of activity always play a more dominant role than others at a given period in life. Consequently, every period of human development is motivated and predicted in some sense by a particular leading activity. The change from one leading activity to another also reveals intrapersonal changes that are interpretable as evidence of transition from one stage to the next. For example, when assessing infants, Soviet psychologists would naturally examine relationships between babies and mothers. The determining role of such relationships in the child’s development is seen in the period when a so-called voluntary (conscious) action is formed in the child. Normally, a voluntary action begins with the mother’s initiation and instruction that result in a movement of the child’s hand. In effect, this action initially requires a social unit, the mutual activity on the part of the mother, who begins the action, and that of the child, who continues it. Therefore the social nature of a human action is the source of what later becomes voluntary and conscious. In the beginning, the child only follows the mother’s encouragement, but in time, the child meditates its own behavior, so he or she firstfollows modeled action and laterprecedes these actions. This approach to analysis of the genesis and organization of voluntary action enables Soviet psychologists to assess many forms of conscious self-regulation. No contradiction exists between social determinant views and dialectical materialism. Whereas the development of complex forms of mental activity (perception of categories, voluntary attention, active memorizing, abstract thinking) is ultimately determined by the requirements of the social organization of human life, the nervous system forms a dynamic constraint in the form of temporarily integrated circuits (Davydov, 1982, 1983). 5 . MENTAL RETARDATION AND SPECIAL EDUCATION

When considering instances of developmental disability, the Soviet view directs attention to the natural history of childhood. The historic changes in how context influences sociopsychological development and changes even in succession of developmental periods suggest that innate endowment is only one condition of future development, a condition that does not determine either the level particular children may reach or the precise stages through which they will pass. Actual levels and stages are achieved only in relation to the social environment (i.e., levels and stages of society) and to the success the child achieves in adopting the culture of that society.

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According to Luria (1963b), D’iachkov (1965), and Pevzner (1966), mental retardation or oligophrenia can be understood and defined as the underdevelopment of higher forms of psychological activity, which is a result of organic disorder of the central nervous system in the different stages of intrauterine development of the fetus or in the earliest period of the child’s life. As a result of this disorder, permanent defects of cognitive activity emerge, such as defects of abstraction and generalization. Only the deep pathology of brain activity that affects higher nervous processes is the physiological essence of mental retardation. Only children with such symptoms could be considered mentally retarded and sent to the auxiliary schools. Special education in the Soviet Union has two major educational goals: (1) general education and (2) specific vocational training in special schools to maximize development of children’s capacity for socially useful labor; however, special school placement can occur only on the basis of clinical, neurological, psychological, and psychoeducational evaluations (Luria, 1963b; Pevzner, 1966). The Scientific Research Institute of Defectology of the Academy of Pedagogic Science in the Soviet Union is the primary agency responsible for planning and coordinating research on learning and teaching of handicapped children. This institute is an interdisciplinary organization with a wide spectrum of clinical, neurophysiological, psychological, and educational researchers who have experience in the coordination of psychoeducational research and the desired curricula in a full system of special schools for children with different types of handicapping conditions. Development of children with developmental disabilities is viewed not as a single, spontaneous process characterized by simple quantitative increases, but by the appearance of successive stages of new mental and behavioral qualities and properties, each contingent on achievements at previous stages. Soviet psychologists consider differentiation of primary signs and secondary complications in psychological development to be extremely important. In their view, it is incorrect to conclude that all symptoms and all psychological characteristics of mentally retarded children stem from a basic neurological defect. Rather, it is in the process of development that the individual’s characteristics and potential are to be found, although in an exceedingly complex relationship with the major cause (S. L. Rubinstein, 1970). According to Vygotsky, the underdevelopment of higher mental abilities is the most frequent “complication” resulting from the general syndrome of mental retardation. This means that developmental problems related to higher forms of memory, thought, and personality originate and form in the process of the child’s social development, and are not predetermined (Vygotsky, 1983a, 1983b). Soviet defectologists accept an important lesson from Vygotsky: mentally deficient persons are often capable of greater development and achievement, but are

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impeded frequently by a form of cultural deprivation and underdevelopment because of their unique history of development. To better understand what the “unique history of development” of the mentally retarded means, there needs to be discrimination between cultural (psychological) and biological processes of development. For a normal child, these two streams merge, but it is different in the case of a mentally deficient child. Vygotsky (1983a) expressed this important point in this way: This connection and this orientation of one or another stage of development toward a certain time of organic maturity originated over millennia and led to a merging of both processes so that child psychology ceased to differentiate one process from the other and became confirmed in the idea that the mastery of cultural forms of conduct is just as natural a symptom of organic maturity as various physical forms. As a result, these symptoms came to be viewed as an actual content of organic development. At first, it was noted that deficiency in the development of speech and the inability to mastcr writing at a ccrtain age was frequently a symptom of mental deficiency. Consequently, these phenomena were taken for the actual substance of a state for which they could be symptoms under certain conditions. (p. 129)

In Soviet theory, the higher mental functions, such as memory, are more products of cultural development than certain consequences of biological maturity. The psychological development of mentally retarded children occurs under conditions of inadequate sensory-perceptual development, underdeveloped speech, and limited practical activity. Thus, their mental operations develop more slowly and possess features possibly unique to the retarded (Pevzner, 1966; Vygotsky, 1983a, 1983b). Soviet psychologists consider communication and cooperation key factors in the psychological habilitation of mentally retarded children. They emphasize the importance of the child’s collective for developmental outcomes. Without intervention, however, the mentally retarded child is deprived of normal social interaction with normal persons, and then is often isolated in special schools. Critically important learning opportunities, for example, participation in collective, interactive games in which the child develops crucial language skills and pragmatic social knowledge, can be missed. Soviet researchers now suggest that an impoverished social environment, lacking forms of socialization and learning opportunities, can become the source of secondary complications and defects for mentally retarded children. In Soviet theory, underdevelopment of higher mental functions is therefore partly a consequence of these conditions and, for particular children, can have serious, negative consequences (Bozhovich, 1979a, 1979b). B.

Qualitative Approaches to Assessment

Qualitative dynamic approaches to assessment and evaluation of mentally retarded children are based largely on Vygotsky’s idea that the principal mental

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functions, such as complex perception, voluntary attention, and logical thinking, do not represent inborn abilities of children, but rather are shaped when children manipulate real objects while adults provide communicative guidance and social meaning (Bozhovich, 1979a, 1979b; Vygotsky, 1983a, 1983b). Adults not only provide interpretations and linguistic representations of children’s sensorimotor explorations; they also use language to guide and control those experiences. Language mediation of child-environment encounters is ultimately adopted by normally developing children themselves as a means for cognitively, socially, and physically navigating the world. Thus, a function that was previously divided and shared as a social process between two persons gradually becomes an internal psychological process mediating the child’s own activity. The general notion of dynamic assessment, then, stems from an attempt to create such an adult-mediated, task-oriented “problem” that both a child and helping adult can address cooperatively. In conducting clinical assessments, psychologists attempt to distinguish signs of retardation and secondary symptoms (S. La. Rubinstein, 1970; Zeigarnik & Rubenstein, 1983) while interacting with a particular child during their performance of puzzles, tasks, and simple problems. They pay special attention to the fact that serious, sometimes fundamental changes in the development of abnormal children could have arisen from very particular and seemingly insignificant functions, which nevertheless have a strong impact on further formation of the higher mental activity. Genetic and systematic analyses of defects in abnormal children are thought to yield differential diagnoses of externally similar, but quite different, defects. Thus, Soviet defectologists believe that a case-building, dynamic approach based on careful observation can facilitate discovery of proper therapeutic and pedagogical intervention (Pevzner, 1966). The purpose of assessment and evaluation, therefore, is not merely to differentiate characteristic deficiencies observed in child development, but also to investigate and report, even if only anecdotally, methods for compensating for observed deficiencies. This approach to psychoeducational assessment, unusual for U .S. researchers, owes much to Vygotsky ’s conceptualization of “zones of potential development” (Minick, 1987; Vygotsky, 1983a, 1983b). The “zone of proximal development” consists of two related developmental levels or boundaries. A first level of development, actually defined by mental functions that are already mature, is probed and recognized by assessors by use of problems that children can solve independently. The second level is defined by psychological functions and mental abilities that are in the process of maturation. Receptiveness to the help of adults and ability to transfer former experiences to the new problem are indicators of this level of mental development of the child. For Soviet psychologists, peculiarities of processes by which new knowledge and skills are obtained are more significant than the actual knowledge and skills that a particular child

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already possesses. For example, it is not enough to know the extent of a child’s vocabulary; it is more important to know how the child acquires new words and how the child uses grammatical and lexical structures in verbal contexts. According to Soviet defectologists, assessment and evaluation of abnormal children must consist of four components: First, the peculiarity of early development of a child can be determined from medical history. The investigation of somatic conditions can provide an opportunity to evaluate a number of pathological symptoms in child development. Second, the analysis of neurological conditions provides data about diffuse versus local involvement of the nervous system and the nature of nervous activity development. Third, investigation of speech and hearing (logopedics) provides data on peculiarity and origin of defects of the organs of speech and hearing. Fourth, pathopsychological assessment is directed toward a complete examination of the psychological conditions of the child. A synthesis of all data provides an opportunity to understand the structure of the defects of a particular child (Bozhovich, 1979a, 1979b; D’iachkov, 1965). In sum, Soviet assessment comprehensively explores limits to children’s performance in various relevant situations and demand conditions. Accordingly, psychologists have developed and adopted clinical procedures calculated to permit systematic, dynamic study of developmental paths that are possible for children in the near term. Theoretically complex assessment procedures used in the Soviet Union do include collection and analysis of objective data from multiple sources, including a range of pertinent information assembled from medical and psychological histories; neurological examinations; physical examinations; tests of sensory acuity; electrophysiological evaluation of higher nervous activity; psychological assessments of performance on memory, attention, perception, and cognition tasks; pedagogical assessments; and observation of vocational skills (D’iackhov, 1965; Kalmykova, 1982). Unfortunately, it is dificult to describe and replicate these procedures simply and only on the basis of published clinical research. Soviet psychology has been so powerfully shaped by the key concepts described above, it has rarely entertained any fundamental reexamination in professional literature. Moreover, because use of normative data is rare, even Soviet readers need to rely on experience with theoretical interpretation and, when available, on specifics of any published descriptions of pertinent studies and research.

Ill.

SURVEY OF RECENT LITERATURE

The complexity and relative inaccessibility of Soviet literature seem to demand that we make our method of survey as explicit as possible. Therefore, in this section we explain the methods employed in our recent survey of Soviet literature as a prelude to interpreting and discussing the results.

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Sample

One of the preliminary tasks for the present survey was to establish an appropriate sampling frame. Boundaries (e.g., topics of published studies) of some type are necessary to aid analysis and infer generalizability of results. Typically, from a general collection of potentially relevant literature, it is possible to select a statistically representative sample. Soviet literature consists of a diverse collection of official, semiofficial, unofficial, and, to some extent, “underground” publications. One of the difficulties in studying Soviet published literature was that the true universe of study was not known, even in the Soviet Union; it is therefore possible that some critical studies might be overlooked. Another problem was that Soviet publications were difficult to access through conventional methods. Thus, to avoid overlooking important studies and to create a broader framework for analysis, a method likely to oversample Soviet journals available to us was adopted. The first step in collecting information was finding sources of research in the area of assessment and evaluation of exceptional children. Three journals were singled out for sampling because they are acknowledged to be the major professional publications dealing with education, psychology, and psychiatry of exceptional populations in the Soviet Union: Defectologia, Voprosy Psikhologii, and Zhurnal Nevropatologii i Psikiatrii. Defectologia [Defecfology]is an official publication of the Academy of Pedagogical Sciences of the U.S.S.R. and it is the principal theoretical and methodological source for special education in the Soviet Union. This journal publishes clinical neurophysiological, psychological, and educational research. New curricula, teaching and research methods, and textbook reviews find their way into this journal. The journal is intended for professionals working in special education (more precisely, in the areas of education of the blind, deaf, and mentally retarded) as well as for a broader, public audience. Voprosy Psikhologii [Problems of Psychology] is devoted to the major theoretical problems in general psychology and is intended for psychologists, teachers, physiologists, and philosophers. Zhurnal Nevropatologii i Psikiatrii [Journal of Neuropathology and Psychiatry] is a major journal for the Society of Soviet Neuropathologists and Psychiatrists, as well as for professionals working in these areas. It is also a main source for clinical and biological researchers, and often publishes clinical and theoretical studies in psychiatry, addressing issues concerning handicapped individuals.

B.

Procedures

The years 1975-1985, which overlap the first decade of implementation of Western special education reform pursuant to mtblic Law 94-142, were selected as a suitable sampling frame for published Soviet studies in the area of assessment. Moreover, many countries throughout the industrialized world, including

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YEAR

OF

TABLE I PUBLICATION AND NUMBER OF ARTICLES SELECTED FROM THREE RUSSIAN-LANGUAGE JOURNALS, 1977- 1985 Year

Journal

1977

1978

1979

1980

1981

1982

1983

1984

1985 Total

151 88

160

157

163 99

159 85

162

8311

104

156 89

160

97

104

-

1351 709

326 308

278

304

309

304 2Q4

334 25Q!

2717

549

571

548

600

333

4777

Voprosy

Psikhologii Defectologiab Zhurnal Nevropatologii i Psikhiatrii

565

565

539

431-

507

“Only 16 issues were available. %sues for 1985 were not available. 3 issues were available. d2 issues missing.

the U.S.S.R., considered or initiated major special education reform during these years. Publication data for journals sampled from 1977 to 1985 are presented in Table I. The tables of contents of the three journals were carefully examined. One way of organizing the collected information was to generate a set of relevant topics that included key words such as testirovnie ‘testing,’ otsenka ‘assessment,’ ‘evaluation,’ diagnos ‘diagnosis,’ difirintsirovannii diagnos ‘differential diagnosis,’ osobenestii rasvitia ‘abnormal development.’ Approximately 220 articles having these key words, or close variants, in their titles were ultimately selected on these criteria. The third and final step was to collect, review, and integrate only studies that fit the following self-explanatory criteria:

I . The article or report must be logically related to assessment issues. 2. The primary hypotheses stated in articles or reports also must be considered in the discussion of outcomes. 3. At least some discussion of probable validity and reliability of data must be given, especially if inferential statistical methods were used. For the purpose of review, therefore, 60 studies dealing with assessment and evaluation were chosen and read in Russian (see “Acknowledgment”). Articles found to contain trivial, ambiguous, or irrelevant information eventually were dropped by applying the following questions: 1. Is there evidence that the author(s) is an established authority in a particular

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field (e.g., editorial board, member of Academy of Pedagogical Sciences, member of well-established academic institution)? 2 . Is more than one article available from the same author? 3. Is the article and/or author frequently cited by others as authoritative (e.g., Pevzner, who is a leading figure in clinical assessment, is often cited as an authoritative source)? The final sample thus consisted of 41 major articles.

C. Analytic Strategy All articles were then sorted for analysis into four categories dependent upon their explicit approach to assessment. Use of categorical clusters simplified integration by ignoring superficial differences among studies and permitted a more general analysis. The four clusters obtained, using the following general descriptions, consisted of 5 to 18 articles each. 1. DYNAMIC CLINlCAL NEUROPHYSIOLOGICAL AND PSYCHOLOGICAL ASSESSMENT There were I8 articles dealing with dynamic clinical psychological evaluation (dinamicheskiiclinicheskii metod obsledovania). Dynamic clinical assessment is a major approach to assessment and evaluation in the Soviet Union, often involving multiple measures, instruments, methods of observation, and purposes. This type of assessment typically occurs over prolonged periods and does not orient around any particular measurement or task. It is important to note that Soviet psychologists use the word dynamic to refer to an active, flexible, but global, approach for evaluating particular children. The term dynamic as currently used in the United States has a more restrictive meaning, similar to that implied by our second and third categories described below. 2 . PSYCHOLOGICAL AND PSYCHOEDUCATIONAL ASSESSMENT Thirteen articles described psychological-psychoeducational assessment, a subset of assessment techniques used in the more global approaches described in the first category. Although these forms of assessment in the U.S.S.R. often rely upon tasks derived from standardized psychometric instruments, they rarely are concerned with traditional modes of psychometric interpretation. Rather, presentation of tasks is loosely structured and characterized by active, and contingent, involvement of clinicians in explaining, prompting, and assisting responses. Moreover, the outcome of such an assessment approach is more often a description of psychological process or developmental deficiencies than a quantitative index of performance.

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3. ASSESSMENT OF LEARNING POTENTIAL Five articles in this category dealt with a relatively new approach to psychological-psychoeducational assessment that emphasizes qualitative and quantitative estimation of children’s learning ability. This approach to assessment and evaluation operates under neo-Vygotskian concepts of learning potential (obsledovania potentsiala), such as “zone of proximal development .” It is characteristic of studies in this category that the qualitative aspects of assessment are highly formalized. This approach also attempts to integrate qualitative information with quantitative indices of performance. Contemporary Western conceptualizations of “dynamic assessment” are similar to those underlying approaches described in this and the second category. 4. USE OF STANDARDIZED ASSESSMENT DATA Five articles were categorized as being chiefly concerned with what Western psychologists would recognize as standardized assessment. Despite the small number of articles devoted to standardized testing, many believe that this may reflect an important trend in Soviet psychology (Gurevich, 1980, 1982). This division is not precise. as no category existed in pure form and treatments of topics overlapped; however, it indicates the distinguishing features of each group of studies and it provides an opportunity to trace general outlines of future trends in Soviet special education. To understand and meaningfully interpret Soviet studies, it is important to know that the concept of methodology has quite a different meaning for Soviet researchers than its conventional educational psychology usage in the United States. This term is not used by Soviet scientists to refer to a specification of experimental design or conditions; rather it is used to refer to employment of theoretical principles. In this sense, Soviet psychologists use the term methodology more like Western economists, say, use the term to refer to a process that theoretically grounds and structures an investigation. For Soviet psychologists, the dominant theory historically, of course, has been the dialectical materialism derived from Marxism-Leninism. Thus, comparing and interpreting Soviet studies from the standpoint of self-described “methodology” are often meaningless for Western audiences.

D.

Results of the Survey

Results of our survey yielded both quantitative and qualitative information. Table I presents the number of articles that were published in our three source journals between 1977 and 1985. The initial 220 articles we generated represented only 4.6% of all articles published in these journals. Sixty studies that fit the chosen criteria represented only I .2% of all published articles and reports. These data immediately reveal that only a very small proportion of all the studies

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was directly focused on issues of psychological and psychoeducational assessment of children with disabilities. They also may be interpreted to suggest that assessment research, as distinct from more general Soviet psychological research, was not (at least by 1985) a priority of Soviet special education. Nevertheless, because Western scholars have exhibited such interest in Soviet assessment, the literature that has been retrieved will be characterized in some detail in the following sections. Our approach is to present information from particularly representative studies within each category. 1. DYNAMIC CLlNlCAL NEUROPHYSIOLOGICAL AND PSYCHOLOGICAL ASSESSMENT

A distinctive feature of Soviet-style clinical methods of investigation is that they do not focus on one symptom or aspect of anomalous development or psychic function, but on the structure of a defect as a whole. A second and no less important feature of clinical methods of investigation is a principle requiring qualitative analysis of all findings obtained during observation of children and in the course of the study (Pevzner, 1966). The studies retrieved under this category underscored some other important features of dynamic clinical assessment as well (Kpyzhanowsky, 1980; Lebedinsky, Raisky, Nemirovsky, & Malzeva, 1980a, 1980b, 1982; Pevzner, 1980; Pevzner, Bertyn, & Mareva, 1979; Pevzner & Rastiagailova, 1981; Pevzner, Molchanovsky, & Davydov, 1983; Semke et al., 1982). First, to be diagnostically sound, all findings have to be evaluated in relation to their mutual interdependence (integration principle). Second, data must be concrete. An understanding of the basis of the defect could help. Third, the investigation must have a continual, dynamic aspect. This implies prolonged observation of the same child. The concept of zone of proximal development is a clear demonstration of the principle of continuity. According to Pevzner (1966), the zone of proximal development is extremely important because it directs clinical attention not only to previous development, but also to consideration and anticipation of changes likely to emerge in the course of future development. Pevzner et al. (1983) described an assessment process for a large group of mentally retarded children that could be regarded as typical of many Soviet research reports of this type. Their process included collection of medical history and genetic, sibling, somatic, neurological, psychopathological, and psychoeducational data. Data were also taken from X-rays and opthalmological and otolaryngology examinations. The Pevzner et al. article is a report of a complex clinical psychological and pedagogical investigation of mentally retarded children with severe vision problems. Two hundred eight children diagnosed as mentally retarded were the subjects of the investigation. Thirty-six were described as having deep disturbance of vision.

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Pevzner et al. (1983) conducted a detailed medical history with emphasis on parental and medical reports of possible complications during the pregnancy or birth (particularly toxemia or asphyxia), but it is not clear how many children had any of these complications. Somatic analysis shows that 15 children had abnormality of bone development. Physical development also was impaired in some children (though no specific data were cited). Somatic evaluation included an examination of the organs of vision. Five children had cataracts and eight children had evidence of optic nerve atrophy. Neurological pathology was reported for almost all subjects. Some were described as having one or more pathological neurological symptoms. Finally, clinical and psychoeducational data were analyzed and compared. The goal of evaluation was to assess ( I ) the level of cognitive development, (2) aspects of mental efficiency, and (3) the level of emotional-volitional development. To accomplish this goal, the investigators used a variety of psychoeducational tasks, including elementary puzzle construction (following patterns, and by memory), construction of geometric patterns, tasks for demonstrating an understanding of relationships between shape and size, and classification of geometric figures. All tasks depended on perception and perceptual-motor skills. To assess communication skills, children were asked to name objects and their characteristics and to describe pictures. Children also completed sentences referring to actions that were depicted in pictures. Researchers carefully observed (i.e., “dynamic” observation), the children’s activity during assessment. In this form of clinical observation observers freely interacted with children to discover how they communicate with the experimenter, how they use instructions, their ability to plan and exert self-control, and how they correct their mistakes. Together with psychological and psychoeducational assessment, a zone of proximal development was defined for each student. On the basis of the results of these procedures, Pevzner and his colleagues suggested that such dynamic clinical assessment procedures could help to detect deficiency in mental and neurophysiological development of mentally retarded children and, thus, could be a powerful adjunct to differential diagnosis. They asserted that such assessment and evaluation could differentiate primary defects (e.g., vision loss) from secondary complications such as maldevelopment of mental, perceptual, and motor functions. Unfortunately, details of assessment tasks and techniques are not reported. In other studies, psychometric methods were also frequently reported as being used to complement a dynamic approach in studies in this category (e.g., Burelov, 1980; Kozlovskaia, Kirichenko, Skoblo, & Budarezo, 1983; Kryzhanovsky, 1980; Lupandin, 1980; Semke, et af., 1982; Tepina, 1981). For example, Lupandin (1980) reported results of assessment of cognitive ability in 800 schoolchildren who were diagnosed with mild forms of intellectual insufficiency (intelektuulnaya nyedostatochnost). Lupandin collected and interpreted somatic,

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neurological, anthropometric, and developmental history data, including data concerning parents and siblings. Psychometric, logopedical, psychological, and psychoeducational [using an adapted version of the Wechsler Intelligence Scale for Children (WISC)] tests were also administered. Periodic observational data were collected for over 2 years on each subject. Using these tools and methods, Lupandin distinguished four types of intellectual dysfunction: mildly expressed personality-cognitive retardation, borderline forms of intellectual insufficiency, intellectual insufficiency resulting from functional brain disorders (e.g., some forms of mental retardation), and familialpedagogical neglect. Because no specific details concerning subject sample or analytical procedures are presented, however, it is difficult to further assess the reliability and validity of Lupanin’s subtypes. In all of these studies, procedures similar to traditional medicoclinical assessment were employed, such as customized questionnaires to evaluate microsocial environments, individual development and mechanisms underlying deficient behavior. Methods to probe particular cognitive abilities were also frequently used (e.g., semantic differentiation, cloze-type sentences, or questionnaires developed by other researchers). The authors, however, tended to report only simple listings of methods employed without much further description. Tepina (1981), for example, reported complex examinations of 396 mentally retarded subjects and analyses of their clinicopsychological and social peculiarities using an adapted form of the WISC. The author never specified how this adaptation method was developed and used. Instead of discussing psychometric properties or problems of statistical inference, the author only stated that a factor analysis and simple correlation procedures were performed and were statistically significant and that these analyses supported the conclusion that the nonverbal component of intellect was stronger than the verbal component. Another variation of the dynamic-clinical approach is devoted primarily to the use of physiological and biochemical methods of evaluation (e.g., Golod, 1983; Marinicheva, I98 1; Shorokhova & Sharabarin, 1980; Shuplezova, 1983). For example, Shorokhova and Sharabarin described a study of 338 twin pairs under 15 years of age in which blood analysis was used to define 131 monozygotic and 207 dizygotic twins. The authors do not specify how many children in these twin pairs were mentally retarded, but it is likely that all pairs had at least one retarded child. Soviet authors often compare their samples with “normal” groups without explaining any of the details of sampling or providing information about children in such samples. In this study, the authors simply reported that a significant correlation existed between order of birth and the first independent sitting and walking for both monozygotic and dizygotic twins for normal as well as for mentally retarded children. Another study using an approach called “ontogenetic” (to differentiate mental retardation according to time the brain was affected) was reported by Bliumina

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(1983), who analyzed the results of clinical genetic evaluations of 543 preschool children who were patients in the Institute of Defectology. The goal of this investigation was to differentiate children according to the time when the central nervous system was affected. The author analyzed etiology of prenatal and postnatal underdevelopment of children. The basis for this differentiation was a complex analysis of all collected data, which included medical history, clinical genetic data, biochemical examination, and psychopathological assessment. As result of this analysis, all patients were divided into two groups that could be characterized by specific etiological patterns. The results of this investigation were used to infer a genetic origin of mental retardation. Ninety-six percent of the sample belonged to the group in which psychological development was affected in the prenatal period. Bliumina, however, did not define the degree or level of severity among the mentally retarded subjects and, in fact, did not otherwise describe the sample. Therefore, the validity and generality of his conclusions are suspect by our standards, although a plausible argument is presented.

2. PSYCHOLOGICAL AND PSYCHOEDUCATIONAL ASSESSMENT

In this category of studies, psychological and psychoeducational assessment tasks were administered that concentrated on different psychological categories such as general knowledge, spatial organization, and cognitive function (Dunaeva, 1980; Ivanenko, 1984; Korobeinikova & Lubovsky, 198 I ; Korobeinikova & Poperechnaia, 198 I ; Umanskaia, 1977; Ustinova, 1980). This last category included general comprehension of spoken speech, comprehension of higherorder relations, classification, generalization, and memory. The goal of the Dunaeva (1980) survey was to investigate peculiarities of spatial organization development in children with learning disabilities. One hundred subjects ranging in age from 6 to 10 were divided into five age groups with 20 subjects in each group. Three forms of spatial organization were defined: form, size, and direction. All tasks were presented in standard format to children in each group. Tasks were administered in a sequence from simple to complex in the three domains of spatial organization (i.e., form, size, direction). Formrelated ability was assessed in a task requiring children to put different figures in a “form box,” using Seguin geometric form boards, and to reassemble pictures of varying complexity cut into pieces. To assess spatial organization, children were asked to indicate right and left sides on pictures of geometric figures varied in relation to child and to examiner. For assessment of spatial relationships, children followed verbal instructions to change positions of a handle in relation to a bowl, such as “under the bowl,” “in the bowl,” “to the left side and right side of the bowl,” “in front and behind the bowl.” A second task consisted of eliciting verbal descriptions of the examiner’s manipulations of the handle and bowl. Analysis of data was reported to show positive age-related development of

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spatial organization from preschoolers to third graders, all of whom were receiving special training and were attending special schools. According to the author, spatial organization concepts developed slowly, gradually, and with difficulty. Children in the study were described as experiencing special difficulties with verbal definition of spatial relationship among objects. On the basis of these data, Dunaeva suggested that correctional intervention could begin at the preschool age. Methods of other assessment-related psychological studies varied greatly among the Soviet defectologists whose work was surveyed (e.g., Korobeinikova & Lubovsky, 1981; Korobeinikova & Poperechnaia, 1981; Namazbaeva, 1982; Novak, 1983; Poperechnaia, Boiarshinova, & Kabachenko, 1980; Sak, 1983). For assessment of verbal development, Novak (1983) had children name objects that belong to defined classes in an object classification subtest. Children were required to provide definitions of the main events in a series of pictures and give verbal descriptions of each. To assess receptive vocabulary children had to write synonyms; expressive vocabulary was assessed using a number of different oral subtests, including free double verbal association, addition, saying the last word in sentences, and oral synonyms for vocabulary words. Children’s ability to understand sentences with different syntactic and semantic structure was determined with another specific subtest. Logical-verbal thinking was assessed using a subtest requiring the addition of absent conjunctions in complex sentences and the reorganization of sentences. According to Novak, performance data showed good measurement reliability and were treated by statistical inferential analysis and factor analysis; however, her description of her methods of analysis is too general and difficult for the reader to understand how reliable her data were or what percentage of total variability could be explained by derived factors. Dynamic observation, frequently an important tool of Soviet assessment and evaluation, was almost the exclusive focus of several articles (Domishkevich, 1977; Mironova & Lasareva, 1983; C. I. Peresleni, 1979; L. I. Peresleni & Podobed, 1982; Uranenko, 1984). These authors described their general approach as use of a “correction probe.” The goal of this class of methods was to investigate and form prognoses about the mental development of children. The core of this approach can be described as “guessing” events. Stimuli, say A and B, are presented in varying orders, for example, ABAB. The order is not known, but the child must recognize the correct order based on successive occasions of prediction and feedback. L. 1. Peresleni and Podobed (1982) studied normally developing (n = 16), learning-disabled (n = 181, and mentally retarded (n = 17) children, aged 10 to 1 1 , using three order conditions: ABAB, BB, and ABBABB. No information was provided to indicate how many trials of the task were administered. Results indicated that normally developing children made on average 4.7

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mistakes, whereas learning-disabled children made 14.9 mistakes. (The author indicates only that mentally retarded students overwhelmingly made errors on this task.) The authors interpreted their data to suggest that the difference between the three groups lay in both the number of trials required to obtain reliable predictions and the number of mistakes. There was also a difference in performance by normal versus performance by both learning-disabled and mentally retarded children. As a result, adequate prediction was reported for 95% of normal subjects, 63% of learning-disabled children, and no children with mental retardation. Despite a small sample, the size of observed differences among groups could mean, as the authors suggested, that this task might be useful for identification of level of mental development. To support this point, the authors reported examples from other unpublished studies in which the same methods were used. The authors claim that about 400 children have been tested clinically as part of normal treatment, although the details of specific clinical findings were not discussed in meaningful detail. 3. ASSESSMENT OF LEARNING POTENTIAL

In the Soviet Union, the concept of “learning potential” of children is viewed as that aspect of their psychological development that relates acquisition (i.e., learning) experiences to the processes of instruction. Accordingly, the demonstration of old (static) knowledge can be taken only as an indication of previous development. More important is the children’s ability to learn when explicitly taught new material, implying a need for a dynamic process. Soviet psychology regards abilities as individual, psychological peculiarities. Abilities help define successful achievement in different areas of activity. Ideally, abilities must possess qualitative characteristics, such as independence, depth, flexibility, steadiness, and consciousness of knowledge (Kalmykova, 1982). These qualities ensure easy and quick abstraction and generalization as well as self-regulation and reorganization of mental activity in response to situational demands (Novikova, 1977, 1979). The presence of these qualities indicates a high level of learning potential in particular children and, according to Kalmykova ( 1982), constitutes a reliable criterion for assessing level of mental development. Evaluation of learning potential usually takes the form of individual “teaching experiments.” During these experiments students must solve problems and acquire new knowledge independently or with assistance. For example, students can discover physics laws on the basis of their analysis of concrete situations, leading to potential transfer of this knowledge for solving other problems. (Kalmykova, 1977, 1978, 1981, 1982). One of the most developed variants of this group of assessment studies is based on a physics teaching paradigm (e.g., teaching students the law of equilibrium of a lever). Students are given a card with data about quantities of forces and the lengths of the arms of a lever. Pictures of levers with two different

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weights on the lever’s arms are reproduced on the card. Students are asked to make decisions about the presence or absence of balance. The correct answer is found on the reverse side of the card. Thirty problems of this kind, divided into six series, are presented. The clinical core of the assessment, however, concerns students’ abilities to verbalize descriptions and explanations as they discuss their answers with the examiner. After each series of problems, the students are asked to give a general definition of the problem. If at the end of the sixth series the problem has not been solved, students are offered very specific help on a continuum, described only as “minimal to maximum,” until either they are successful or the examiner determines the task is too difficult. The sense of the gradual increments in direct teacher assistance conveyed by this description captures the general approach taken by Soviet psychologists in estimating learning potential in a “zone of proximal development.” As in most studies of this type, a large amount of qualitative information is integrated with the general indications provided by correct answers. For example, successful problem solving means not only giving solutions to problem but also providing adequate verbal descriptions, with the highest evaluations reserved for children who show evidence of grasping the general principle embodied by the task. Indices for depth of thought used in this study were formulated from data about practical behavior, verbal-logical thinking, and conciseness of judgments (Kalmykova, 1978). From data generated by this study, Kalmykova defined five general levels (or depths) of problem solving to index what she judged to be qualitatively different levels of learning potential for this task. Kalmykova ( 1982) assessed 2000 students in the second and third grades using this method. Findings were interpreted to differentiate mentally retarded and learning-disabled students from normally developing peers in terms of depth of problem comprehension and solution. Handicapped children with delayed psychological development consistently displayed passive, shallow, concrete, and inert types of thinking and frequently needed, but could not solve all problems with, maximal assistance. Consequently, Kalmykova suggested that data collected by using this method were reliable and would be useful as an assessment procedure with special populations (e.g., learning-disabled, mentally retarded). Unfortunately, limited data or descriptions of her sample were given, so the generality of her findings is difficult to estimate. Another attempt to assess learning potential is described in studies by Novikova ( 1977, 1979). By “learning potential” (obuchiamost) Novikova means intellectual characteristics of children related to their facility for aquiring knowledge or skills. She studied second language learning in 50 children identified as having delayed psychological development (i.e., specific learning disability) who were enrolled in a special education school and 20 high-achieving peers from a regular school. She summarized the results of almost 500 individual assessment experiments, including several series of language-related tasks all

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intended to estimate learning potential in a manner similar to that used by Kalmykova. In the first series of experiments, children recalled word forms on 12 tasks (i.e., 6 in Russian, 6 in German), which Novikova related to short-term verbal memory. In addition, tasks were designed and administered so that students would progressively reveal their ability to use their general knowledge of a language’s grammatical logic when explicitness and linguistic-mnemonic demand of tasks varied. For example, students first selected nouns that could be used to tell a story about a family weekend with no demand for particular words or order. In successive tasks, however, the author restricted the class of words, the kind of story in which they would be used, and the order of their use in ways that revealed students’ abilities to mentally recall, construct, and manipulate sentences meaningfully in each language. A second series of tasks, designed to elicit similar opportunities to observe performance, involved selection, memory for, and manipulation of whole sentences. During the next phase of experimentation, the author sought to briefly teach (instruction plus examples) a number of grammatical principles in Russian, German, and Esperanto. Afterward, a series of probes were used to assess if students could correctly apply the principles they had been taught. In a final series of tasks, Novikova explored students’ abilities to complete partial syllables and cloze-type sentences and to discriminate speech sounds in the context of Russian and German words. On the basis of her analyses of these various experiments, Novikova generated a number of instructional treatment recommendations. Clearly, Novikova’s conclusions stem from an exhaustive analysis of observational records of each student’s quality of performance. These analyses undoubtedly were conducted with the general purpose of building a rich description of that particular child’s mode of performance under varying instructional conditions; however, she obviously could not detail such analysis or summarize it easily for the class of children considered handicapped. Thus, in summarizing the results of the cumulative experiments, she presents only simple descriptive statistical data (e.g., aggregate mean errors for students in each group across all tasks in a series) to support her case study conclusions. These conclusions were that (1) the school sample of learning-disabled students really represents four relatively discrete groups, one of which was not markedly different from normally developing students, and (2) most students in this group displayed particular difficulty in applying grammatical principles and in functions that appeared to be related in short-term memory. 4. USE OF STANDARDIZED ASSESSMENT DATA

Novikova’s studies nicely illustrate the problem faced by Soviet researchers who, building from an enormous base of observational case study data, lack

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parsimonious methods for forming rigorous comparisons and inferences about classes of handicapped students. According to proponents of standardized methods (Abramovich, 1979; Gilboukh, 1978, 1982; Gurevich, 1980, 1982; Novakova, 1983; Panasiuk, 1974; Ponariadova, 1979; Shaumarov, 1979; Shaumarov & Saidel, 1980), the use of standardized psychological techniques in the assessment of intellectual insufficiency is dictated by the same necessities that made psychometric techniques popular in Western countries, namely, desirability of objective assessment and improvement in the reliability and validity of conclusions. Some Soviet authors, moreover, argued that confidence in results should not depend on individual qualification and personal experience of researchers or should not vary from study to study. In a study by Panasiuk ( 1 974), a Russian version of the WISC was used. One hundred forty-two children aged 6 to 13 were examined. On the basis of the findings, 75 subjects were classified as normal and 67 were diagnosed as mentally retarded. One of the advantages of this test, in Panasiuk’s opinion, was that it provided a stable criterion for judging individual performance. Despite Western psychologists’ reasonable hesitations to use translated tests, Panasiuk nonetheless reported that scores obtained on a Russian WISC were highly correlated with clinical diagnosis, a critical and persuasive factor for Soviet defectologists. The translated WISC was also adapted to the Russian population whenever its items were judged not to correlate with specific historical, cultural, and social conditions of the Soviet Union. Because standardization research with the adapted forms ultimately appeared to demonstrate good reliability, some Soviet psychologists have concluded that existing normative data for the WISC can be used without significant changes (Shaumarov & Saidel, 1980). Shaumarov and Saidel (1980) tested 330 elementary school students from public school programs (probably referred as learning-disabled), special school students diagnosed as mentally retarded, and experimental school students diagnosed as learning-disabled with a Russian-language adaptation of the WISC (Panasiuk, 1974). One goal of the this study was to compare results of standardized testing with clinical identification procedures that had already resulted in placement of some children in special schools. Additionally, though, the authors sought to investigate how WISC data might be integrated with other sources of data to improve differential diagnosis of children’s learning-related developmental problems. Wechsler data were compared with clinical, achievement, psychological, and teacher report data for each group. Findings indicated an 89% overlap between criterion scores on the WISC and placement in special school programs for retarded children. Eleven percent of the sample children thought to be mentally retarded, however, received only borderline retarded scores. For a learningdisabled group enrolled in the experimental school, there was also an 89% overlap of scores with placement. The authors found that 56% of their public

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school sample did indeed received borderline scores, but the balance scored in the normal range. In interpreting these results, the authors argued that, whereas placement of special school students seemed to be valid, the public school group was quite heterogeneous and could not be differentiated only on the basis of the same clinical and psychological data. They conclude that the additional information provided by WISC scores is, therefore, valuable, especially if subtest scores are correctly analyzed to determine appropriate clinical profiles. Other researchers also report using such tests as the Stanford-Binet, Gessel, and Knobloch tests in translated form; however, conclusions are difficult to reach concerning these adaptations because very little description of these tests or how they are modified was given. Furthermore, few Soviet authors seem to have the sophistication or desire to clearly describe what psychometric or statistical analysis might be appropriate to use and report. An unusual counterexample was found in two studies by Ponoriadova (1979, 1982) who investigated attention of children with learning disabilities and mental retardation. In one of these studies (Ponoriadova, 1982), 333 students, in the first to fourth grades, were presented with a task that tapped visual discrimination, memory, and control of attention. Simple descriptive statistics and correlations were employed in a pseudoexperiment that compared stability with diffusion of attention measures across the four grade levels within two handicapped student groups. A logical inference of differences in attention between groups, favoring learning-disabled over mentally retarded, was argued, although no inferential statistical analysis apparently was used. Novakova (1983), in a study that employed inferential statistics, investigated different forms of thought as diagnostic indices of dysfunction in mental development. Three forms of thought investigated were visual-operational, visual-imagery, and verbal-logical forms. Three groups of children participated in this study. Thirty-three students (range = 6 years, 7 months to 8 years, 2 months; M = 7 years, 7 months) who were “good” achievers were selected from a regular school. Thirty-four students with delayed psychological development (zaderzhka psikologicheskogo razviria) were selected from a special school (range: 7 years to 8 years, 9 months; M = 7 years, 8 months). Another 32 children with mental retardation (oligophrenia) came from an auxiliary school (range: 7 years, 8 months to 9 years, 1 1 months; M = 8 years, I 1 months). All 99 students were in the first grade. Eight geometric puzzles were used to determine aspects of visual-operational thought. For visual imagery, problems similar to Raven’s Progressive Matrices were developed. Verbal-logical thought was assessed using an adaptation of the Stanford-Binet; however, unlike Western administration of standardized instruments, Novakova developed a complex system of prompts that were used during testing. In the initial stage problems are presented without aid and the examiner

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waits until children either solve or fail to solve an item on their own. If children fail, increasingly explicit prompts are given in a hierarchy of five levels or steps (etap) until a solution is reached. Means and standard deviations for completed tasks were computed and differences were analyzed using a simple t test to compare handicapped students with normal students. The author interpreted her results to suggest that both groups of handicapped children scored significantly lower than normal students on the number of spontaneously correct solutions. T tests were used to compare numbers of prompts required by students in each group for each problem administered without regard to risk for error associated with multiple comparisons. Data were interpreted to suggest that significant differences existed between handicapped and normal students. Despite serious methodological flaws, Novakova claimed that adaptive use of standardized instruments, such as the Stanford-Binet, can improve assessment of handicapped students. In the review of these studies several questions arise regarding possible changes in Soviet views on the use of standardized tests. One obvious question is, Is there a marked increase during the decade under review in the use of Westem-type statistical analyses? To answer this post hoc question, we employed the following procedures. First, a subsample of the most recent articles were selected; in this case, all the articles published during a 4-year period ( 1982- 1985)in the joumal Defectologia were counted, and the articles devoted to assessment and evaluation were identified. The same procedure was repeated with Zhurnal Nevropatologii i Psikhiatrii. Second, from this subsample, the studies that used either standardized tests or inferential statistical analysis as the main techniques were counted. Third, studies that used inferential statistical analyses as the main techniques were counted. The data are presented in Table I1 and show clearly that there is little evidence of significant change in the approach to reporting studies of assessment in Soviet journals. But in articles and monographs (e.g., Anan’ev, 1976; Volkova & Panasiuk, 1980), there is strong evidence of a greater use of standardized methods and tests as an adjunct to traditional clinical assessment and evaluation practices. These theoretical monographs and articles indicate the likelihood that some changes favoring Westem-style assessment might occur. Soviet psychologists appear to be increasingly arguing for standardized methods to provide greater reliability and valuable interpretive support for assessment (Anan’ev, 1976). It is worth noting that in almost half of the articles reviewed, the use of different standardized tests and statistical analysis was mentioned; however, it is chronically difficult to evaluate and describe these data because of a lack of evidence regarding their validity and reliability.

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USE

Year

1981 1982 1983 I984 1985"

TABLE I1 QUANTITATIVE TESTSA N D PSYCHOMETRIC ANALYSIS I N RECENT SOVIET JOURNALS

OF

Number of articles

Number using statistical tests

Number using standardized analyses

Zhurnal Newopatologii i Psikhiarrii, 1981 -1985 309 3 1 304 3 6 304 2 2 334 1 I 250 Defertologia, 1981-1985

1981 1982 19836 1984

94 85 43 104

-

-

-

-

-

1

-

-

uExcludes 2 missing issues. "Only 3 issues were available.

IV.

DISCUSSION

Increasingly, an international perspective on special education issues is emerging as more countries undergo reform of their special education policies and practices. These reform experiences provide potentially new perspectives on enduring issues that may broaden our own, often narrow, national perspective. This survey of Soviet assessment literature, a literature representing vastly different social, intellectual, and educational conditions, has revealed a professional orientation to assessment that relies heavily on skilled clinical methods and insights not only for purposes of social policy, but also for purposes of professional communication and knowledge accrual. Although details of methods are obscure for interested researchers who do not share the same political and professional sociology, careful and systematic review of Soviet literature may in the future prove to be a valuable source of methodological and interpretive insight as it has been in the past. Moreover, as Soviet psychologists relearn what advantages obtain in using quantitative models of analysis, but also seek integration of these methods with their fundamentally qualitative, individualized approach, we again may benefit from the new models that arise. Soviet experience underscores an emerging belief in the West that standardized test score comparisons must be treated as supplemental to teachers' or other situationally valid judgments about children's learning potential. Teachers' judg-

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ments have enhanced face validity, particularly if learning handicaps are viewed, as the Soviets do, more as products of socially situated, instructional transactions, not as causes of instruction failures. Rather, teachers might be taught to function as if they themselves were dynamic “tests” of learning ability under variable instructional conditions and constraints (also see, e.g., Gerber & Sernmel, 1984, 1985). Rather than viewing with suspicion teachers’ special education nominations of students who fail to make reliable gains after being given instructional effort, it is clearly arguable that such judgments are valid predictors of achievement outcomes in those same, unchanged, instructional circumstances. The fact that another teacher might do better does not invalidate the validity of the revealed relationship between a given effort and learning. Rather than view teachers’ judgments as idiosyncratic, it is reasonable to attempt to establish better principles (i.e.. theories) by which such judgments can be formed and defended. Recently, we have seen a wave of research that borrows such concepts as “zone of proximal development” from Soviet psychology to determine what principles might be used to construct more dynamic assessment models (e.g., Brown & Ferrara, 1985; Budoff, 1987; Campione et al., 1982; Delclos, Bums, & Kulewicz, 1985; Rothman & Semmel, 1990). In itself, this increase in research activity is evidence that Westerners are converging on the Soviet belief that learning potential should be assessed by considering the children’s modifiable responsiveness to instruction, and that the pertinent data for such assessment derive largely from direct observations of children’s attempts to solve difficult but solvable problems independently and with assistance (Campione et af., 1982; Rueda, 1987). This approach may offer potential solutions for a number of chronic, practical problems regarding diagnosis and placement, particularly with regard to ethnolinguistic minority (Rueda, 1987) and lower-socioeconomic-status children (Sewell, 1987). Budoff and his colleagues highlighted the importance of observing children’s performance under different conditions and through different modes several years before public policy drove identification issues to a crisis (e.g., Budoff, 1972; Budoff & Friedman, 1964; Budoff, Meskin, & Harrison, 1971). Only recently has dissatisfaction with standardized testing grown to the point that sustained programmatic research efforts have received widespread interest and support. Nevertheless, some Western models, although achieving important empirical support for more dynamic methods (e.g., Brown & Ferrara, 1985; Campione et al., 1982; Vye, Burns, Delclos, & Bransford, 1987), can be and have been criticized for overly narrow interpretations of the “zone of proximal development.” Minick (1987), for example, has argued strenuously that the “zone of proximal development” is not synonymous with the construct of “readiness” as it is used by some authors. Such simplified translations of the concept fail to

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capture the overarching importance accorded by Soviet psychologists to the sociolinguistic or sociocultural context of learning or teaching. As a result of the efforts by many researchers we are beginning to grasp the implications of Vygotsky ’s theoretical formulations from the 1920s and 1930s. They are dramatic and far-reaching, particularly for professionals and those involved in preparing professionals such as teachers, school psychologists, and other specialists who are involved directly with children’s learning. In this regard, Delclos et a l . (1985) have presented evidence that dynamic assessment can also affect teachers’ expectations for students. In their study, teachers expressed higher expectations after viewing videotapes of children undergoing a dynamic assessment than after viewing children’s performance during traditional, static testing. But much remains to be done. There is a need to better understand the core importance of culture and language during instruction, as well as how instructional use of language must necessarily differ from ordinary conversation in classrooms with students with disabilities. There is also need to discover if we can develop and convey to trainees replicable sets of clinical assessment procedures or at least theoretical principles to guide their design and construction ad hoc, so that similar results will obtain when applied by similarly trained individuals under similar conditions. Development of such capability awaits a more solid understanding of how culture and language transact with content knowledge in instructional settings to produce both the limits and the varieties of “normal” development. Viewing the development of assessment procedures in both the Soviet Union and the West from historical distance, we see ultimately the results of two very different natural experiments converging. The Soviets focused on clinical analysis because psychometric method was proscribed. Westerners focused on psychometric theory and standardized testing until special education policy forced us to acknowledge the identification, assessment, and instructional programming limitations inherent in such approaches. It appears that both traditions are slowly coming to a similar conclusion--that a purpose-specific balance between the use of quantitative and qualitative methods for obtaining assessment data must be fostered in policy as well as in practice. In the coming years it will be interesting to observe how and to what degree these trends in assessment continue to develop and, it is hoped, interact. ACKNOWLEDGMENT The second author translated all original Russian-language sources surveyed and discussed in this article. Mr. Perelman is a native of the Soviet Union who studied and worked at the Leningrad State Institute of Pedagogy, Department of Defectology (Special Education Department).

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REFERENCES I *Abramovich, M. ( 1979). Clinical differentiation of borderline mental insufficiency. Zhurnal Nevropatologii i Psikhiatrii, 9 , 403-407. *Anan'ev, G . ( 1976). Psychodiagnostical methods. Moscow, USSR: Nauka. Balla, D., & Zigler, E. (1969). Discrimination and switching learning in normal, familial retarded and organic retarded children. Journal of Abnormal and Social Psychology, 69, 664-669. *Bliumina, M. G. (1983). Ontogenetic approach to the diagnosis of mental retardation. Defectologia, 3, 19-24. Borkowski, I., & Wanschura, P. (1974). Mediational processes in the retarded. In N. Ellis (Ed.), International review of research in mental retardation (Vol. 7, pp. 1-54). New York: Academic Press. *Bozhovich, L. 1. ( 1979a). Stages of personality development in ontogenesis. Voprosy Psikhologii, 2, 47-56. *Bozhovich, L. 1. ( 1979b). Stages of personality development in ontogenesis. Voprosy Psikhologii. 4 , 23-34. Brown, A. L., & Ferrara, R. A. (1985). Diagnosing zones of proximal development. In J. Wertsch (Ed.), Culture. communication, and cognition: Vygotskian perspectives ( pp. 273-305), Cambridge, MA: Cambridge University Press. Budoff, M. (1972). Measuring learning potential: An alternative to the traditional intelligence test. In G. R. Gredler (Ed.), Ethical and legal factors in the practice of schoolpsychology: Proceedings of the f r s r annual conference in school psychology. Philadelphia, PA: Temple University. Budoff, M. (1987). Measures for assessing learning potential. In C. S. Lidz (Ed.),Dynamic assessmenf (pp. 173-195). New York: Guilford Press. Budoff, M., & Friedman, M. (1964). "Learning potential'' as an assessment approach to the adolescent mentally retarded. Journal of Consulting Psychology, 28, 434-439. Budoff, M., Meskin, J., & Harrison, R. H. (1971). Educational test of the learning-potential hypothesis. American Journal of Mental Deficiency, 76, 159-169. *Burelov. E. A. (I98 I). The attempt to separate some significant differential diagnostical indications in mental retardation and early residual organic disorder of brain with intellectual impairment on the identical stages of ontogenesis. Zhurnal Nevropatologii i Psikhiatrii, 2 , 374-378. Campione, J. C., & Brown, A. L. (1987). Linking dynamic assessment with school achievement. In C. S. Lidz (Ed.), Dynamic assessment (pp. 82-115). New York: Guilford Press. Campione, J. C., Brown, A. L., & Ferrara. R. A. (1982). Mental retardation and intelligence. In R. J. Sternberg (Ed.), Handbook of human intelligence (pp. 392-490). New York: Cambridge University Press. *Davydov, V. V. (1982). Meaning of works of Vygotsky for modern psychology. Sovetskaia Pedagogika, 6 , 84-87. *Davydov, V. V. (1983). Results and perspectives of scientific research in the USSR APS Scientific Research Institute of General and Educational Psychology. Voprosy Psikhologii, I , 93103. *Davydov, V. V. & Radzikhovsky, L. A. (1980a). Theory of Vygotsky and active approach in psychology. Voprosy Psikhologii, 6, 44-59. *Davydov, V. V., & Radzikhovsky. L. A. (1980b). Theory of Vygotsky and active approach in psychology. Voprosy Psikhologii, 6, 95- 101. Delclos, V. R., Burns, S . , & Kulewicz, S . J. (1985). Effecrs of dynamic assessmenf on reachers' 'Asterisk indicates original Russian-language source.

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Constraints on the Problem Solving of Persons with Mental Retardation RALPH P. FERRETTI AND AL R. CAVALIER DEPARTMENT OF EDUCATIONAL STUDIES UNIVERSITY OF DELAWARE NEWARK, DELAWARE 19716

I.

INTRODUCTION

Three beliefs that emerge from over three decades of empirical research occupy an almost axiomatic status in theorizing about the cognition of persons with mental retardation. First, these persons are not strategic in situations that call for active problem solving (cf. Belmont & Butterfield, 1969; Bray, 1979; Bray & Turner, 1986; Brown, 1974; Campione & Brown, 1987; Ellis, 1970; Spitz, 1966). Second, strategy instruction leads to large and rapid performance gains (cf. Bray & Turner, 1986; Brown, 1978; Butterfield & Belmont, 1977; Gerjuoy & Spitz, 1966). Finally, the strategies that are responsible for these gains are rarely used outside the training task; that is, the strategies do not transfer (cf. Belmont, Butterfield, & Ferretti, 1982; Blackman & Lin, 1984; Borkowski & Cavanaugh, 1979; Campione & Brown, 1984; Campione, Brown & Ferrara, 1982). For some, these facts simply illustrate the adaptive difficulties that are diagnostic of mental retardation (Grossman, 1983). The problems of strategy production and transfer are correlates of limited intelligence and poor adaptive functioning (Binet & Simon, 1916; Thorndike, Bregman, Cobb, & Woodyard, 1926; Wechsler, 1958). This belief, which is especially prevalent among professionals who use and interpret intelligence tests in schools and clinics (Ferretti & Belmont, 1983), is motivated by a “naive” theory of intelligence (cf. Brown, Campione, Webber, & McGilley, in press). This theory holds that intelligence is a general property of a person that is stable across time and over contexts, and that intelligence tests can be used to make simple predictions about later success. History shows that the motivation for Binet’s early investigations, namely, INTERNATIONAL REVIEW OF RESEARCH IN MENTAL RETARDATION, Vol 17

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universal compulsory education (Edwards & Richey, 1963), was largely responsible for these ideas. For the first time, a wide range of abilities was seen in educational institutions, and intelligence tests were used to rationalize educational decisions about children. The goal for school administrators was to measure a dispositional characteristic of an individual with a test that could be used to predict the child’s academic prospects (Charlesworth, 1979). The processes of intelligence were ignored and the product, an aggregate intelligence test score, was used to establish a unidimensional ordering of people (Ferretti & Belmont, 1983). In contrast, the early pioneers of psychometry were especially concerned about the processes of intelligence and the adaptive consequences of individual variation in them (Ferretti & Belmont, 1983). Binet and Simon (1916) argued, “there is fundamental faculty, the alteration or lack of which is of the utmost importance for practical life. The faculty is judgment . . . practical sense, intuition, the faculty of adapting oneself to circumstances. To judge well, to comprehend well, to reason well, these are the essential activities of intelligence” (p. 42). Spearman (1923) argued that “no serviceable definition can possibly be found for intelligence until after having firmly established at least the framework of the entire psychology of cognition” ( p. 23). Three transcendent principles described by Spearman (apprehension of experience, eduction of relations, eduction of correlates) attempted to subsume sensation, perception, memory, reasoning, judgment, and imagination in a psychology of cognition. Binet, Simon, Spearman, and others were clearly interested in both the processes and the products of intelligence (cf. Brown et a l . , in press). This interest gave way to the practical press to predict academic prospects. Contemporary efforts to understand intelligence have rediscovered the early interest in the processes of intelligence and adaptation (Ferretti & Belmont, 1983), and have placed strategy production and transfer at the forefront of theorizing about intelligence (Ferretti, 1989). This is due largely to a paradigm shift that took place in the late 1950s and early 1960s (H. Gardner, 1985). Prior to this time, the influential theories did not acknowledge the person’s contribution to the learning process. Simple associationistic concepts were imported from the study of infrahuman organisms and used to understand the behavior of persons who are developmentally young, intellectually average, and mentally retarded (cf. Brown, Bransford, Ferrara, & Campione, 1983). Theorists who emphasized the controllable aspects of behavior, especially the proponents of information processing theory (e.g., Miller, Galanter, & Pribram, 1960; Newell & Simon, 1972), challenged this position. According to this view, behavior could be understood as aspects of goal-directed internal transformations of information represented in memory. As a consequence, the processes that give rise to intelligent action became a principal focus of empirical study (cf. H . Gardner, 1985). The goal of this article is to critically review evidence about the strategy

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production and transfer of persons with mental retardation. We hope to show that the problem solving of persons with mental retardation is greatly influenced by constraints on functional working memory capacity. Before doing this, we briefly discuss basic concepts about problem solving and information processing to motivate a discussion about sources of intelligence-related variation in the problem solving of persons with mental retardation.

II. PROBLEM SOLVING AND INFORMATION PROCESSING Researchers who study strategy production and transfer are often unclear about what it means to be strategic (cf. Brown et al., 1983). That is, the term strategy is often used without an interpretive context afforded by theory. The term usually connotes planful activity on the part of the person rather than passive acquiescence during the learning activity (Bray, 1979). Nevertheless, confusion occurs because the relationship between a person’s activity and the task are often poorly defined. Further, strategy production and transfer depend upon a host of interrelated problem-solving skills that operate in a system architecture with real constraints. Problem solving theory provides an interpretive context for understanding strategy production and transfer in persons with mental retardation (Ferretti, 1989; Ferretti & Belmont, 1983).

A.

Problem Solving

A problem occurs when there is a discrepancy between the person’s current state and a goal state. In most studies, problem solving begins with a task environment that embodies an explicit goal and materials that may be used to achieve the goal. A complete account of the instructions and the materials that accompany the task’s presentation is usually sufficient to describe the task environment; however, problem solving does not occur in the environment as such, but in a problem space that results from the person’s internal representation of the task environment (Newell & Simon, 1972). This representation amounts to the problem solver’s understanding of the initial givens, that is, the instructions, goals, and materials. The problem space is a network of possible paths for transforming the initial understanding of the task into the goal (Newell & Simon, 1972). Two types of operations may be used by the problem solver as she traverses the problem space. The first is the specific computational procedures by which the problem solver successively transforms the initial understanding into the goal. This is what most researchers in the field mean by the term strategy: it embodies a set of processes that map the initial state into the goal state. For example, if the

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goal involves transferring an object from one point in space to another, and the object is at hand but the goal point is not in reach, then the computational solution may involve walking. Note that walking is a shorthand description for a procedure that involves a succession of constituent parts called steps. These constituents, the most basic of which are called elementary information processes (Newell & Simon, 1972; Simon, 1969), are the building blocks of all strategies (Frederiksen, 1984). Note also that other possible solutions exist (e.g., throwing), and it is up to the problem solver to judge the relative efficacy of alternative strategies. This point highlights the interdependence of problem solving, reasoning, and decision making (cf. Bransford, Sherwood, Vye, & Rieser, 1986). Strategies are said by some to be under the control of a second, more general set of operations, known as executive or self-management processes (Baddeley, 1986; Brown et a l . , 1983; Butterfield & Belmont, 1977). Self-management processes are thought to be responsible for the control and monitoring of subordinate information processing operations (cf. Belmont, Butterfield, & Ferretti, 1982; Borkowski & Kurtz, 1987; Brown, 1978; Brown et al., 1983; Butterfield, 1988; Butterfield & Belmont, 1977). Many information processing models attribute powerful responsibilities to the executive, including identifying the problem, planning strategies before problem solving, implementing strategies, monitoring the accuracy of implementation, and revising strategies in response to performance feedback. For proponents of these models, the executive holds an indispensable place in understanding strategic activity (cf. Brown et al., 1983). For others, these attributions render the executive a conceptual ragbag (cf. Baddeley, 1986) that should be banished from psychological theory (Anderson, 1983). To summarize, there are several implications of problem solving theory for the study of mental retardation. First, the theory explicitly assumes that behavior is goal directed and emphasizes the problem solver’s adaptive capabilities (Ferretti & Belmont, 1983). Thus, the theory is compatible with definitions of mental retardation that emphasize deficits in adaptive behavior (Grossman, 1983). Second, problem solving processes can be decomposed into constituent subsystems, allowing problem solvers to construct adaptive strategies from elementary information processes. Finally, focusing on the person’s mental processes and goals highlights the theory’s focus on artifactual systems (cf. Simon, 1969) from which new adaptations can be engineered. Problem solving is flexible within constraints imposed by the architecture of information processing. We now turn to a discussion of those constraints.

B.

Information Processing

Problem solving processes operate in real time and are constrained by a system architecture that is intrinsically limited (Atkinson & Shiffrin, 1968; Baddeley,

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1986; Miller, 1956; Newel1 & Simon, 1972). One such constraint is the widely recognized limitation on working memory capacity (Baddeley, 1986; Baddeley & Hitch, 1974). Virtually all contemporary theories of information processing recognize that goal-directed activity, that is, goal identification, strategy selection, implementation, and evaluation, requires the temporary storage and manipulation of information in memory (cf. Carr, 1984). The processing and storage demands associated with these activities often exceed the working memory capacity available to the problem solver, leading to performance trade-offs. The idea is that effortful problem solving requires the use of limited working memory capacity, and the limitations may constrain the effectiveness of problem solving. This analysis provides a straightforward account for two facts of experience: first, people often have difficulty when they perform two or more tasks concurrently, and second, complex tasks are often difficult to perform even without competition from other tasks (cf. Carr, 1984). In the former case, capacity is being distributed across too many activities, resulting in poorer performance on all or some of the tasks (Baddeley, 1986; Baddeley & Hitch, 1974). In the latter case, the demands imposed by the difficult task simply exceed the capacity available to the problem solver (cf. Lansman & Hunt, 1982). This analysis is complicated by the fact that constraints on working memory capacity can be affected by at least three factors. First, problem solving always requires the activation of information in long-term memory. This information is organized in a network of associatively linked conceptual clusters or chunks (Anderson, 1981, 1983; Kintsch, 1972; Schank & Abelson, 1977). When these chunks are activated, they enter working memory (Schneider & Shiffrin, 1977; Shiffrin & Schneider, 1977). Second, organized information requires less capacity to store and maintain in working memory than poorly organized information (Anderson, 1981, 1983), thereby increasing the functional capacity of working memory. People use a host of recoding and strategic processes to organize information in working memory (Atkinson & Shiffrin, 1968; Belmont & Butterfield, 1969; Ellis, 1970; Miller, 1956; Spitz, 1973). These processes serve to maintain information in working memory and to organize it more efficiently, effectively extending working memory capacity. Third, information processing can be made more efficient by automating the sequence of processes that are required for task performance (Schneider & Shiffrin, 1977; Shiffrin & Schneider, 1977). Automatic processing is possible when there is a consistent mapping of the task’s stimulus information and response requirements, that is, when the performance conditions are relatively invariant. When the conditions change, that is, when mapping among stimuli and responses is inconsistent, controlled processing is needed. In controlled processing, the activation of processes is under the control of the problem solver. Controlled processing is effortful and demanding of working memory capacity. Automating the processes of task performance increases functional working memory capacity. Differences in knowledge, strategies, or automaticity can contribute to perfor-

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mance differences among individuals or groups in any specific situation. Researchers often address this issue by taking care to use empirically validated diagnostic methods for measuring knowledge and strategies (e.g., Ferretti & Butterfield, 1986, 1989, 1991; Ferretti, Butterfield, Cahn, & Kerkman, 1985; Siegler, 1976, 19781, and by choosing tasks that are not conducive to the use of habitual or highly automated strategies; that is the task is not entrenched (cf. Charlesworth, 1976, 1979; Sternberg, 1981). It is important to recognize, however, that expert problem solvers will use their elaborate, specific, and highly interconnected knowledge (deGroot, 1965; Simon & Chase, 1973), and will quickly recognize patterns that are relevant to the performance of familiar tasks (Bransford et a / . , 1986). Experts can readily distinguish relevant and irrelevant patterns because they have stored large and well-organized chunks of information in long-term memory. There are two points to be noted about the importance of knowledge, strategies, and automaticity to problem solving proficiency. First, elaborate and wellorganized knowledge about situations exerts a powerful influence on problem solving (cf. Bransford e f a l . , 1986; Frederiksen, 1984) and automating much of that knowledge will aid the development of pattern recognition skills (Ericsson, Chase, & Faloon, 1980; Schneider & Detweiler, 1988 & Schneider & Fisk, 1982). In contrast, general problem solving heuristics are relatively less potent determinants of performance in any specific situation, unless their use leads to the compilation of specific rules for particular situations (cf. Anderson, 1987). Second, knowledge, strategies, and automaticity interact to determine functional working memory capacity in any given situation.

Ill.

SELF-MANAGEMENT PROCESSES AND PROBLEM SOLVING

We began this article by recounting the consensus opinion about strategy production and transfer among persons with mental retardation. The early work on strategy production attributed the poor performance of persons who are developmentally young or mentally retarded to their strategic passivity (e.g., Belmont & Butterfield, 1969; Brown, 1974; Ellis, 1970; Flavell, 1970). These findings were taken as support for Flavell, Beach, and Chinsky's (1966) production deficiency hypothesis, the confirmation of which depended upon two conditions: first, the person who failed to produce the appropriate strategy performed poorly, and second, the performance improved when the person was told to use the strategy. Unfortunately, the hypothesis is not a hypothesis at all, but another fact that needs interpretation (Bray & Turner, 1987; Paris & Lindauer, 1976; Turnure, Buium, & Thurlow, 1976). The essential theoretical question is not addressed. Why are people strategically passive when their prompted performance indicates competence'?

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Belmont, Butterfield, and Ferretti (1982) reviewed a number of instructional studies that appeared to facilitate strategy transfer in persons with mental retardation. It seemed to them that the instructions that were used in these studies taught self-management processes along with the task-specific strategies, and that these self-management processes were responsible for strategy transfer. This explanation attributes the production deficiency phenomenon to deficiencies in selfmanagement processes because, by implication, these strategies would not have been produced in the transfer situation; that is, they would not have transferred if self-management processes had not been taught (cf. Ferretti, 1989). Explanations of this sort are quite common in the mental retardation literature (Belmont, Butterfield, & Ferretti, 1982; Brown, 1978; Butterfield & Belmont, 1977; Campione et al., 1982; Whitman, 1987, 1990). They have wide appeal for at least two reasons. First, practitioners and researchers alike know that persons with mental retardation are very dependent upon others for structuring their environments and monitoring their behavior against performance standards (cf. Kurtz & Neisworth, 1976; Mahoney & Mahoney, 1976; Wehman, 1975; Whitman, 1987, 1990). Successful adaptation to normalized environments requires that persons with mental retardation become less reliant upon highly structured learning programs and increasingly independent (cf. Ferretti, Cavalier, Murphy, & Murphy, in press). Second, self-management processes map on the invariant characteristics of all tasks (cf. Ferretti, 1989). All problems involve goals and require the use of strategies whose outcomes must be monitored. Therefore, it is plausible to infer that self-management processes operate across situations to influence performance. The self-management deficiency hypothesis provides an elegant and intuitively plausible explanation for the adaptive difficulties of persons with mental retardation (Ferretti, 1989). A.

Instructional Studies of Self-Management

Instructional studies have played a valuable role in our understanding of the determinants of strategy production and provide some of the most widely cited evidence about the importance of self-management deficiencies in the problem solving of persons with mental retardation (cf. Belmont, Butterfield, & Ferretti, 1982; Blackman & Lin, 1984; Borkowski & Cavanaugh, 1979; Butterfield, 1981; Campione et al., 1982; Whitman, 1990). Consequently, it is important to consider the kinds of inferences that are permitted from instructional studies (cf. Brown & Campione, 1978), the degree to which the conditions necessary for such inferences have been met by instructional studies of self management, and the methodological soundness of studies that have attempted to train self-management skills in persons with mental retardation. The proponents of the instructional approach believe that instruction can be used to validate the researcher’s analysis of the cognitive determinants of performance (e.g., Belmont & Butterfield, 1977; Brown & Campione, 1978; Butter-

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field, 1981; Butterfield & Ferretti, 1991; Campione et a / . , 1982). The logic of instructional studies begins with a theory of performance about some intellectually interesting task that leads to specific predictions about the component processes that are responsible for individual or group differences in performance. To test these predictions, the instructional researcher trains performance-deficient clients to use the component processes that are presumably responsible for their poorer performance. If their performance improves to the level of proficient performers, the researcher’s theory of task performance gains credibility and the prediction about the source of performance variation is supported (cf. Campione et al., 1982). An implication of this reasoning is that training should have little effect on proficient performers: proficient performers are proficient because they presumably use the component processes that are putatively responsible for group differences in performance. In other words, the logic of the instructional approach requires that proficient as well as deficient groups receive the same instruction (cf. Butterfield, 1981; Campione et al., 1982). To our knowledge, these rigorous conditions have been met in only one instructional study (Butterfield & Ferretti, 1991) that was designed to validate a task-specific analysis of performance. There are, of course, a number of studies that show that the performance of persons with mental retardation improves after strategy instruction to the level of uninstructed persons without mental retardation (e.g., Butterfield, Wambold, & Belmont, 1973; Brown, Campione, Bray, & Wilcox, 1973); however, these studies provide inconclusive evidence about their performance theory because proficient persons were not trained. If proficient performers had been trained, their performance may have also improved (cf. Butterfield, 1981; Campione P I a / . , 1982) and thereby raised questions about the theory of group differences in performance. In principle, these conditions could be applied to instructional tests of theories of transfer. If self-management deficiencies contribute to transfer difficulties, and persons with mental retardation have self-management deficiencies, then training these processes should increase the breadth of transfer of persons with mental retardation. In contrast, the transfer propensity of proficient performers, who presumably use self-manag,ement processes, should be less affected by selfmanagement training. Of course, self-management deficiencies may only partly contribute to the transfer difficulties of persons with mental retardation. In this case, the performance gap between persons with and without mental retardation should at least be narrowed by self-management training (cf. Baumeister, 1967, 1984). In fact, we know of no studies in which persons with and without mental retardation received the same self-management instruction. There are, however, a number of studies that attempted to train self-management skills in persons with mental retardation (cf. Blackman & Lin, 1984; Borkowski & Cavanaugh, 1979; Borkowski & Kurtz, 1987; Ferretti et al., in press; Whitman, 1990). These studies fall into two broad categories corresponding to the cognitive and behavioral approaches to self-management (cf. Meichenbaum, 1990).

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1. COGNITIVE TRAINING STUDIES Belmont, Butterfield, and Ferretti (1982) described six components of selfmanagement that have been implicated in the problem solving difficulties of persons with mental retardation. These components include goal definition, strategy selection, strategy implementation, goal monitoring, strategy evaluation, and strategy revision. Most cognitive studies of self-management have focused on the last three components, each of which involves monitoring or evaluation processes (cf. Borkowski & Kurtz, 1987). Some of the earliest and most widely cited evidence for the effectiveness of self-management instruction with persons who are mentally retarded was reported by Brown (Brown & Barclay, 1976; Brown, Campione, & Barclay, 1979). Brown and Barclay taught younger and older mental age (MA) children with mental retardation to use one of three strategies for recalling supraspan lists. Children in the anticipation and rehearsal conditions were taught to label each item during the first pass through the list, and then either name each item before it was exposed (anticipation) or cumulatively rehearse exposed items (rehearsal) during subsequent passes through the list. These two conditions purportedly involved self-management instruction-albeit implicit-because both included a self-testing component. In the labeling condition, children were taught to label items as they were exposed but were not instructed to self-test. Following training, three posttests were administered. During the first, children were prompted to use the strategy, but they were not prompted on subsequent tests. Analyses of accuracy on the prompted posttest showed that young and old MA children showed marked gains as a result of anticipation and rehearsal training, but only marginal gains as a result of labeling. These gains persisted for the older children on the unprompted posttests, but the younger children quickly returned to their pretreatment level. Brown and Barclay attributed the success of anticipation and rehearsal training with older children to the self-testing component, and the absence of younger children’s maintenance to the failure to monitor the strategies’ etfectiveness. If self-testing were the effective component, it was not effective for the children who needed it the most. Observational data taken during the posttests suggest another possible explanation. These data showed about the same incidence of mnemonic activity for both young and old children with mental retardation. So, younger children were active, but this activity was not accompanied by changes in accuracy. Perhaps, then, younger children simply did not acquire the strategies as well as older children, and if they did, the strategies did not affect performance. Unfortunately, Brown and Barclay did not record information about performance during training. In the absence of this information, the data taken during the prompted posttest are most informative, and they show that younger children were not performing as well as older children. Brown ct al. (1979) administered maintenance and transfer tests to children

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who participated in Brown and Barclay’s (1976) study to see if older children maintained the strategies without prompting, if younger children used the strategies when prompted to do so, and if the strategies transferred to a new task. Children were seen for 4 days of maintenance testing, the first, second, and fourth of which were unprompted, and the third of which was prompted. The accuracy data from the unprompted posttests showed evidence of maintenance for the older children, but not for the younger children. Prompting improved performance for older and younger children, but the gain was much greater for younger children. These findings confirm the authors’ expectations about strategy maintenance. Six days of transfer testing were given. In the transfer task, children were asked to extract the main idea from prose passages and provide gist recall. The only apparent commonality between the training and transfer tasks was that both seemed to require a self-testing component. The younger children were not tested because they did not maintain the strategies without prompting. They were replaced by a group of naive subjects who were matched to the older children on the basis of chronological age, intelligence, and MA. Children were prompted to use various materials to highlight and summarize the texts to aid gist recall on the third and fourth days of testing. No prompts were given on the other days. The principal dependent measures were study times and the proportion of idea units recalled at each of three levels of idea importance. They found that children who received anticipation and rehearsal training recalled more idea units and studied longer than either the label or control children. So, it seems that very general improvements in problem solving were induced by implicit self-management training; however, pretests were not given on the transfer task before instruction and normative data on reading comprehension were not reported, so we do not know if there were preexisting group differences in gist recall performance. Doubt about the replicability of this study is cast by the findings of Borkowski and Varnhagen (1984). They studied the effects of traditional strategy instruction and self-management training on the strategy maintenance and transfer of children with mild mental retardation. Children in both conditions were taught an anticipation strategy for serial recall of pictures and a paraphrase strategy for gist recall of sentences. Both strategies included the self-testing component studied by Brown et af. (1979), and in addition, children in the self-management training condition received Meichenbaum’s ( 1977) self-instructional questions. So, both groups were given self-management training, although one group had an especially explicit form of it. The Brown et al. (1979) transfer task, which required gist recall for prose passages, was given along with maintenance tests at the completion of instruction and at the end of each training session. The results of maintenance testing showed that children in both instructional conditions were more active and accurate than uninstructed children, but did not differ from each other. Further, no differences in accuracy or processing were seen between the

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two instructed groups and the uninstructed control group on four of the five transfer tests. In this study, neither indirect self-management instruction nor explicit self-management training influenced the gist recall of children with mental retardation. Brown, Campione, and Murphy (1977) tried a different tact for studying transfer. They directly instructed span estimation because the monitoring of one's memory limitations seems prerequisite to change. Two groups of children with niental retardation, one younger and the other older, were first asked to predict their recall of an array of ten pictures. Children were deemed to be realistic or unrealistic estimators on the basis of the consistency between their prediction and recall accuracy. Unrealistic estimators were then given training during which they first predicted their accuracy and then attempted recall. Half the children at each age level were given explicit feedback about their predictions and accuracy, and the other half simply predicted and recalled without explicit feedback. Maintenance was assessed at 1 day, 2 weeks, and 1 year following instruction. Young children showed immediate improvement over their pretest performance, but quickly reverted to their uninstructed level. Older children fared better than younger children on the immediate test, and the effect was more durable over time. Explicit feedback was essential for maintenance with younger children at each interval, but was less important for older children, except for the final maintenance test. On balance, the training effects were more durable and less dependent upon feedback for older children. Two transfer tasks were administered. The first task involved span estimation using the seriated method of presentation. Rather that presenting the array in its entirety, children judged their ability to recall arrays of increasingly larger size. The second task was essentially a digit span estimation task, much like the task used during the pretest. For both tasks, children were deemed to be realistic or unrealistic by contrasting their estimations with their recall accuracy. The results were strikingly clear. Children who were realistic on the pretest were realistic on the transfer tests, but children who became realistic as a result of training were not realistic on the transfer tasks. In other words, self-management instruction was ineffective in promoting transfer among children who were unrealistic before training. Belmont, Butterfield, and Borkowski (1978) tried to show that instructing children with mental retardation on two ordered-recall tasks faciiitated transfer when the tasks' strategic commonalities were compared and contrasted. Two groups were distinguished by the kind and number of instructional episodes. Children in the single-instruction condition were given an uninstructed pretest on a 3/4 circular recall requirement, specific instruction on a cumulative rehearsalfast finish strategy for the 3 / 4 requirement, and then extended uninstructed experience with a 4 / 3 requirement. The children in the self-management condition were given the same sequence, except that after receiving a few uninstructed trials, they were given instruction with the 4 / 3 requirement. During this training,

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they were led to consider the similarities and differences between the recall requirements and rehearsal strategies for both tasks. Finally, all children were given maintenance tests for the 314 and 413 requirements and transfer tests on a 2/5 recall requirement and a 7-item position probe task. The pause patterns for both groups showed evidence of rehearsal but the twicetrained group showed a twofold advantage in recall accuracy. On the 2/5 transfer test, the twice-trained group actively rehearsed and had a recall advantage over the singly trained group, which was passive. Finally, the twice-trained subjects recalled nearly twice as much as the singly trained subjects on the position probe task, but the pause patterns of both groups were flat. The authors concluded from these data that the twice-trained group transferred the strategy, and attributed the effect to the deliberate comparing and contrasting of the strategies for two tasks; however, the twice-trained group not only received self-management instruction but also twice as much instruction with two different strategies. Hence, this study confounded the self-management manipulation with both the quantity and type of instruction, and it is well documented that extended training with multiple exemplars can result in transfer (Engelmann & Carnine, 1982; Stokes & Baer, 1977; Stokes & Osnes, 1989). The results of Burger, Blackman, Clark, and Reis (1982) appear to contradict the findings of Belmont et al. (1978). The purpose of this study was to compare the effectiveness of self-management training on a single task with the same instruction on multiple tasks. The self-management instruction was the same as that of Burger, Blackman, and Clark (1981) except for the addition of a selftesting component. In the single-format condition, children were taught selfinstructional questions along with the verbal abstraction strategy for use with picture triads. Children in the multiple-format condition were taught the selfinstructional questions and the abstraction strategy, but they were also taught to generate exemplars and to sort pictures of different conceptual classes. The children in these conditions received the same amount of instruction. Their performance was contrasted with two control conditions, in which children received uninstructed experience with either one or many tasks. Transfer was assessed on the verbal dyads and multiple classification tasks. Instructed children outperformed the control condition on the verbal dyad task, and the effect did not depend upon the number of tasks. There were no differences among conditions on the multiple classification task. The instructional effect on the dyad task cannot be attributed to self-management instruction because the task-specific instructional control was not included, and convincing differences between these conditions were not obtained. Knapczyk and Livingston (1974) observed that many children with mental retardation fail to ask questions when confronted with a difficult task. As a result, they fail to understand the task and often engage in inappropriate behavior. The authors studied the effects of teacher prompts to ask questions on the reading

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comprehension performance and on-task behavior of two children with mild mental retardation. Both children rarely asked questions of their teacher, had poor comprehension skills, and were rarely on task. The instruction amounted to a prompt to “ask a question if there is a word you don’t know or a direction you don’t understand.” Observations taken during training revealed an increase in the amount of question asking, as well as increases in the percentage of on-task behavior and the accuracy of reading comprehension. These findings have been interpreted as evidence for the importance of training monitoring and evaluation processes in persons with mental retardation (cf. Belmont, Butterfield, & Ferretti, 1982; Borkowski & Kurtz, 1987), but the training procedure actually assumed the child’s awareness rather than instilling that awareness. Instead, the procedure simply taught children what to do when they were aware that they did not understand. As a result of learning this simple strategy, to ask someone when you don’t understand, children secured information that enabled comprehension. In aggregate, the results of cognitive training studies of self-management are inconclusive. Attempts to explicitly manipulate self-management processes have not always shown convincing evidence for transfer. Some studies that seemed to induce transfer are subject to serious methodological and interpretive problems. Attempts to implicitly manipulate self-management processes have produced a range of outcomes from complete failure to modest success. None of these studies met the inferential conditions required by cognitive instructional studies; that is, both proficient and deficient groups receive training. Finally, some studies that were not designed to test the self-management deficiency hypothesis have been interpreted in support of it. Although post hoc interpretations are often useful in guiding instructional tests of a hypothesis, they do not substitute for direct empirical confirmation of the hypothesis. More and better instructional research needs to be conducted on the question. 2. BEHAVIORAL TRAlNlNG STUDIES Many researchers have recently argued for the importance of training persons with mental retardation to use self-management skills (cf. Ferretti et ul., in press; Whitman, 1990). One reason for this growing interest is that the integration of persons with mental retardation requires that they be less reliant on highly controlled environments and more responsible for setting goals and monitoring their performance (cf. Ferretti et a l . , in press). There are many potential practical advantages to teaching self-management skills to persons with mental retardation. They include the increased dignity and responsibility accorded persons with mental retardation as a result of successful self-management performance (Jackson & Boag, 1981; Nelson, Lipinski, & Black, 1976), the promotion and development of highly individualized treatment programs (Whitman & Johnston, 1983), the ethical press to adopt nonpunitive client management strategies (W. I. Gardner, Cole, Berry, & Nowinski, 1983;

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Guess, Helmstetter, lbrnbull, & Knowlton, 1986; LaVigna & Donnellan, 1986; Turnbull, 1988), the reduction in behavioral costs and increase in economic benefits resulting from a decrease in supervisory requirements (Lauth, 198 I; Mahoney & Mahoney, 1976), and the potential for recipients of self-management training to live and work in a broader range of settings with limited supervision (Ackerman & Shapiro, 1984; Helland, Paluck, & Klein, 1976). Clearly, selfmanagement training holds the promise of improving the functioning of persons with mental retardation. This literature can be divided into two groups of studies. The first group, which we call self-instruction studies, models its procedures after Meichenbaum and Goodman (197 I), attempting to establish verbal mediation of a chain of selfmanagement skills. This chain often includes goal setting, strategy selection, self-monitoring, self-evaluation, and self-consequation. Studies in the second group attempt to isolate one or two components of this chain of self-management skills. This voluminous literature is reviewed elsewhere (Ferretti et a l . , in press); here we offer some observations that characterize the general pattern of findings. In self-instruction training, clients are taught to overtly recite verbalizations that focus on defining the problem, sequencing solution steps, directing attention, slowing and evaluating responses, coping with errors and frustration, and consequating responses. This training has generally been shown to improve taskspecific performance (e.g., Ackerman & Shapiro, 1984; Burgio, Whitman, & Johnson, 1980; Guralnick, 1976; Hanel & Martin, 1980; Howell, Rueda, & Rutherford, 1983). However, it is often difficult to interpret these improvements because planned or unplanned external contingencies for changes in the target behavior often accompany self-management training, the training procedures are multicomponential, few clients are given training, and these clients usually are persons with mild or moderate mental retardation (e.g., Burgio et a l . , 1980; Guralnick, 1976; Johnston, Whitman, &Johnson, 1980; Lauth, 1981; Peters & Davies, 1981; Whitman & Johnston, 1983) and possess relatively good functional language (cf. Burgio et al., 1980; Kendall, 1990). There is a dearth of evidence about the durability of performance changes brought about by self-instruction training (e.g., Burgio et a l . , 1980). More surprisingly, there is little evidence about these techniques’ effectiveness in promoting transfer, and that evidence is mixed (cf. Burgio er a l . , 1980; Guralnick, 1976; Lauth, 1981; Peters & Davies, 1981). In most of these studies, multipletask exemplars were used to illustrate the self-management procedures (cf. Ferretti et al., in press), and performance changes may have been the result of this rather than the self-instruction training. Much more detailed research is needed before we can be confident about the durability and generality of effects engendered by self-instruction training (cf. Ferretti et a l . , in press; Whitman, 1987, 1990).

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The second group of self-management studies usually targeted the monitoring and evaluation components using nonverbal techniques (e.g., Ackerman & Shapiro, 1984; Connis, 1979; Homer, Lahren, Schwartz, O’Neill, & Hunter, 1977; Howell et al., 1983; Jackson & Patterson, 1979, 1980; Litrownik, Franzini, Geller, & Geller, 1977; Litrownik & Freitas, 1980; Litrownik, Freitas, & Franzini, 1978; Nelson, Lipinski, & Black, 1976; Nelson, Lipinski, & Boykin, 1978; Shapiro & Ackerman, 1983; Sowers, Verdi, Bourbeau, & Sheehan, 1985). In self-monitoring studies, clients are often taught to externally record a target behavior’s occurrence. In self-evaluation studies, clients are taught to evaluate a target behavior according to predetermined criteria, and sometimes, to administer reinforcers or punishers based on the outcome of self-evaluation. In contrast to self-instruction training, self-monitoring and self-evaluation training has frequently been conducted with persons who are more severely intellectually impaired and nonverbal. A widely sought-after outcome of self-monitoring training is reactivity, which is a change in the client’s behavior merely as a result of the self-recording process (cf. Nelson & Hayes, 1981). There are at least two competing explanations for this phenomenon. Kanfer (1980) believes that self-monitoring begins a feedback loop that includes untrained self-evaluation and self-consequation, the latter of which serves to change the frequency of the monitored behavior. Baer (1984), S. C. Hayes and Nelson (1983), and Rachlin (1974) also believe that self-monitoring may lead to self-evaluation and self-consequation; however, the function of monitoring and evaluating behavior is to increase the salience of cues and behavior associated with the consequences. The latter interpretation suggests that selfmonitoring training focuses the client on the information that should be monitored (cf. Knapczyk & Livingston, 1974). Research indicates that reactivity is a common therapeutic concomitant of selfmonitoring (e.g., Connis, 1979; Howell et al., 1983; Jackson & Patterson, 1979, 1980; Joachim, 1977; Litrownik & Freitas, 1980; Nelson er al., 1976; Sowers et al., 1985; Zegiob, Klukas, & Junginger, 1978; Zohn & Bornstein, 1980), but failures to observe reactivity have also been reported (e.g., Shapiro & Ackerman, 1983). There is little evidence about the generalizability of reactivity effects, and the available evidence is mixed (Litrownik, Freitas, & Franzini, 1978; Sowers et al., 1985; Zegiob et al., 1978). Reactivity does not seem to be a function of the accuracy and reliability of monitoring the target behavior (Rosenbaum & Drabman, 1979). Some studies report dramatic reactivity despite very poor accuracy or low reliability of recording (Nelson er al., 1976; Zegiob et al., 1978) and others report little or no reactivity despite highly accurate and reliable self-monitoring (Howell et al., 1983; Shapiro & Ackerman, 1983; Zohn & Bornstein, 1980). Moreover, clients in these studies were neither trained nor observed to self-consequate performance of the target behavior, although coach-

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ing, praising, value counseling, physical and verbal prompting, and other forms of external monitoring and consequation (Nelson & Hayes, 1981) were used by trainers in these studies. It is impossible to discount or even estimate the relative contribution of the trainers’ monitoring and administration of reinforcers or punishers to reactivity because componential analyses have not yet been done. The work of Ackerrnan and Shapiro (1984) suggests that self-recording is effective in maintaining behavior change first established with external contingencies. Despite the uncertainty about the importance of external contingencies in promoting reactivity, there is suggestive evidence that the cue properties of the self-recording device or procedure influence reactivity in persons with mental retardation (Connis, 1979; Nelson et a l . , 1978; Sowers et a l . , 1985). We concur with Nelson and Hayes’ (198 1) contention that the entire self-monitoring procedure, including instructions from the instructor and the self-recording materials, rather than the specific self-monitoring response, is most likely responsible for the reactivity effects. A number of studies used nonverbal techniques to train self-evaluation and self-consequation in persons with mental retardation. According to Bandura ( 1977), effective self-management requires that the client use objective standards to evaluate her or his behavior. In self-evaluation training, a client is often taught to use a performance criterion for evaluating her or his behavior, and is sometimes taught to administer consequences on the basis of that evaluation (e.g., Brodsky, LePage, Quiring, & Zeller, 1969; Fredericksen & Fredericksen, 1975; Helland et a f . , 1976; Homer et a l . , 1977; Litrownik et a l . , 1977; Litrownik, Freitas, & Franzini, 1978; Robertson, Simon, Pachman, & Drabrnan, 1980; Zohn & Bornstein, 1980). These studies generally show that persons with mental retardation can be taught to use externally established performance standards to control the delivery of rewards. There is little evidence about the durability of these effects (Litrownik, Lecklitner, Cleary, & Franzini, 1978) or the degree to which they transfer to other tasks or behaviors. In our discussions of self-instruction and self-monitoring training, we noted that it is usually impossible to disentangle the effects of self-management training and external performance contingencies. This conclusion is also applicable to the self-evaluation literature. In general, external consequences were given for the self-evaluation response, unplanned consequences often followed the target behavior, and the target behavior was often trained prior to self-evaluation training. Under these conditions, it is very difficult to interpret the effects of self-evaluation training. In summary, the behavioral training literature is inconclusive about the effects of self-management training on the performance of persons with mental retardation. Most of the studies show that self-management training can be effective in maintaining behavior change first effected by external control procedures. This

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conclusion is based on three recurring observations from these studies: ( I ) the target behavior was almost always in the client’s repertoire prior to self-management training, (2) external consequences for the target behavior were usually employed prior to the introduction of self-management training, and (3) external consequences were usually administered for the self-management skills or target behavior during self-management training. This packaging of self-management skills is not surprising because it probably increases the likelihood for a successful therapeutic outcome; however, it also makes it very difficult to evaluate the independent contribution of self-management training. We noted a rather striking pattern in the client selection for self-management training. Persons with mild or moderate mental retardation were almost always selected for self-instruction training. While persons with mild or moderate mental retardation were often selected for self-evaluation and self-monitoring training, persons with severe or profound mental retardation were also selected for participation in these studies. We suspect that the cognitive characteristics of persons with mental retardation may help account for this subject-selection effect. Self-instruction training relies heavily on the client’s functional language skills. Many persons with severe and profound mental retardation have little or no expressive language, and thus would be poor candidates for self-instruction training. Moreover, the discussion of self-management skills has ignored the possibility that there may be intelligence-related constraints on functional working memory capacity that may affect the use of self-management procedures (cf. Meichenbaum, 1990). These constraints could limit ( 1 ) the complexity of the tasks performed by persons with mental retardation, especially if self-management is not given some highly salient external referent, and (2) the complexity of the self-management procedures used successfully by persons with mental retardation. The literature is replete with examples of instructional arrangements that have the effect of reducing the information processing demands associated with the use of self-management procedures. For example, Nelson et al. (1978) had clients use hand-held counters to monitor their behavior. Connis (1979) and Sowers et uf. (1985) used pictures of the target task to prompt self-monitoring behavior. In addition, self-management training has usually been done to change the frequency of behavior already in the clients’ repertoire. As far as we know, self-management procedures have never been taught at the same time persons with mental retardation were learning the target behavior. We suspect that this happens because the aggregate burden of learning both the self-management procedures and the target behaviors would prove too difficult for many persons with mental retardation. This issue has not yet been systematically addressed in the mental retardation literature; however, a recent study by Kanfer and Stevenson ( 1985) showed that intellectually average children’s self-monitoring performance degraded as the number of to-be-monitored components increased. We

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would expect an even greater impact of this manipulation on the performance of persons with mental retardation.

3. CONCLUSIONS We draw five overarching conclusions from the preceding analysis of cognitive and behavioral training studies of self-management skills. First, transfer is not a ubiquitous outcome of self-management training. Some of these training studies fail to show any evidence of transfer, and those that succeed usually show modest effects. Findings such as these have motivated contemporary theorists to increasingly emphasize the situational determinants of transfer (cf. Bransford, Goldman, & Vye, in press; Brown et al., in press; Singley & Anderson, 1989). Second, the interpretation of many cognitive and behavioral training studies is hampered by methodological and procedural problems. Many of the cognitive training studies have been compromised by confounded treatment conditions, missing control groups, and the possibility of preexisting group differences in performance. On the other hand, the behavioral training studies often taught multicomponential self-management packages that included prompting and external consequences for the self-management processes and the target behaviors. Behavioral training studies are rooted in the tradition of applied behavior analysis (Baer, Wolf, & Risley, 1968; Wolf, 1978), so they have a strong focus on socially validated clinical change. It is not surprising, then, that many of the behavioral studies clustered treatment components to maximize the likelihood of a successful intervention. This decision, however, raises serious interpretative difficulties for those interested in determining the unique contribution of self-management training to behavior change. A systematic program of componential analyses is sorely needed. Third, we cannot find any convincing attempts to fully interweave the training of specific target skills along with a comprehensive set of self-management skills. A few studies have embedded one or two components, such as selftesting, within task-specific training (e.g., Brown & Barclay, 1976; Brown et al., 1979). Typically, self-management instruction assumes that the task-specific skill is in the client’s repertoire or is done after the person acquires proficiency with the task-specific behavior. We believe that the seamless integration of the target and self-management skills is prerequisite to successful training outcomes, but we understand that the concurrent training of two sets of skills places very heavy demands on the client’s functional working memory capacity. The acquisition of the self-management skills alone is probably very demanding of functional working memory capacity, and this may help account for the use of materials and devices that serve to reduce the working memory load (e.g., Bates, Renzaglia, & Clees, 1980; Connis, 1979; Nelson et al., 1978). Fourth, most cognitive and behavioral self-management training studies have been conducted with persons with mild or moderate mental retardation. There are

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a few behavioral self-management studies that targeted persons with severe or profound mental retardation (e.g., Bates er al., 1980; Keogh, Faw, Whitman, & Reid, 1984; Morrow & Presswood, 1984; Shapiro, Browder, & d’Huyvetters, 1984; Wehman, Schutz, Bates, Renzaglia, & Karan, 1978), only one of which used self-instruction training (Keogh et al., 1984). We believe that this is due to the heavy demands that self-instruction training places on the client’s language competence and functional working memory capacity. The exploration of creative means by which these problems could be avoided, such as through the use of augmentative and alternative communication systems (cf. Blackstone, 1986; Romski & Sevcik, 1988), will help us better understand the constraints on training self-management skills to persons with mental retardation. Finally, there is a pressing need for studies in which proficient and deficient problem solvers receive self-management training. If self-management deficiencies are at least in part responsible for performance differences between proficient and deficient performers, then deficient performers should benefit more from self-management training.

IV.

PERSONS WITH MENTAL RETARDATION ARE SOMETIMES STRATEGIC

We concluded that the success of self-management training may depend in part upon the client’s functional working memory capacity. This conclusion was based upon three observations. First, persons with mild or moderate mental retardation were usually selected as candidates for self-management training. Second, self-management training was usually administered after the target behavior was established in the client’s repertoire. Third, the self-management procedures were sometimes augmented by the use of devices or external prompts that served to minimize the burden on functional working memory capacity. There is additional evidence in the literature that points to the importance of working memory limitations in the problem solving difficulties of persons with mental retardation. We now turn our attention to that evidence.

A.

Empirical Evidence

Bray (1979; Bray & Turner, 1986, 1987) and Ferretti (1989) reviewed a number of studies that showed clear evidence of strategy use by persons with mental retardation (e.g., Belmont, Ferretti, & Mitchell, 1982; Borys, Spitz, & b r a n s , 1982; Bray, 1973; Bray, Goodman, & Justice, 1982; Bray, Justice. & Simon, 1978; Brown, 1972, 1974; Spitz & Borys, 1977, 1984; Spitz & Webreck, 1972; Spitz, Webster, & Borys, 1982). Despite the widely varying tasks and performance conditions, it is possible to extract two factors that help account for

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these surprising findings. A third factor, derived from the developmental literature, also has important implications for the study of the strategy production of persons with mental retardation. In brief, persons who are developmentally young or mentally retarded can be strategic when the task is not too difficult, they comprehend the task requirements, and they possess the necessary content knowledge. We argue that each of these factors is affected by constraints on functional working memory capacity.

I . TASK DIFFICULTY Persons with mental retardation are more likely to generate strategies when the task is not too difficult (cf. Bray & Turner, 1987). For example, Spitz and Borys (1984) studied the performance of persons with mental retardation on problems that varied in complexity. In these well-defined problems, such as the Tower of Hanoi (cf. Klahr, 1978; Klahr & Robinson, 1981; Newell & Simon, 1972), it is possible to explicitly describe and manipulate the complexity of the problem space that must be traversed by the problem solver. Spitz and Borys (1984) found that performance on these problems was related to intelligence and the complexity of the problem space. Persons of all ability levels solved the problems equally well when the problem solution required only two or three steps; however, less intelligent persons performed much worse than more intelligent persons on problems that required more than three steps. Spitz and Borys (1984) concluded that limitations in working memory constrained the depth of problem search of persons with mental retardation. 2. COMPREHENSION OF TASK REQUIREMENTS Persons with mental retardation are also more likely to generate strategies when they understand the task requirements (cf. Bray & Turner, 1987; Ferretti, 1978, 1982) directed forgetting research is the 1989). Bray’s (1979; Bray et d., most analytic in the literature about the conditions that are conducive to spontaneous strategy production by persons with mental retardation. In the directed forgetting task, a list of items is presented for possible recall. During list presentation, a cue signals the person to forget all previous items and remember subsequent ones. When standard instructions about the task requirements are given, persons with mental retardation do not use selective rehearsal strategies that minimize interference from the to-be-forgotten items (Bray et a / . , 1982); however, when especially explicit instructions are given about the significance of the cue to forget, then persons with mental retardation spontaneously devise a strategy for eliminating interference. Bray’s work shows that persons with mental retardation are strategic when they comprehend the task’s requirements. 3. CONTENT KNOWLEDGE

A third determinant of strategy production has received considerable attention in the developmental literature (cf. Ferretti, 1989), but little attention in the

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mental retardation literature (cf. McFarland & Wiebe, 1987). Content knowledge about the task exerts a powerful influence on the early emergence of strategies in children of average ability (cf. Bransford, et al., in press; Bray & Turner, 1987; Brown et al., 1983). A particularly good example of the relationship between strategies and content knowledge is seen in Siegler’s research on children’s strategy choices in arithmetic (Siegler & Jenkins, 1989; Siegler & Shrager, 1984). When confronted with problems such as What is 3 plus 2?, the child first tries to directly retrieve the answer from memory. In other words, she or he tries to recall an answer that is associatively linked to the problem. This is an especially efficient-strategy for children who have previously practiced solving these problems (cf. Goldman, Mertz, & Pellegrino, 1989; Goldman, Pellegrino, & Mertz, 1988). If the associative strength of the answer exceeds some criterion, the child responds. If not, the child either attempts to elaborate the representation of the problem, for example, use fingers to represent the numbers, or resorts to an algorithm to compute the answer. Content knowledge obtained through experience with specific problems is an important determinant of children’s strategy choices in arithmetic and other domains (cf. Bransford er al., in press). 6.

Working Memory and Strategy Production

Task difficulty, the comprehension of task requirements, and content knowledge influence the strategy production of persons who are developmentally young or mentally retarded (cf. Bray & Turner, 1987; Ferretti, 1989). Any account of problem solving in persons with mental retardation must explain their effect on strategy production. We propose that limitations on functional working memory capacity underlie the effects of these variables on the strategy production of persons with mental retardation. First, consider task difficulty. Spitz’s work, which was mentioned above, shows that the complexity of the problem space has a powerful impact on the problem solving of persons with mental retardation. He attributed the differential effects of task complexity to intelligence-related limitations in working memory capacity. The meager empirical base for this conclusion is bolstered by considering the developmental and individual differences literatures. For example, Pellegrino (1985) and his colleagues (Holzman, Glaser, & Pellegrino, 1976; Holzman, Pellegrino, & Glaser, 1983) have done extensive analyses of the determinants of series-completion problem difficulty. These problems measure the induction of serial patterns, an important component of many intellectual achievements (cf. Pellegrino, 1985). Not surprisingly, these problems are found on many aptitude and intelligence tests. In series-completion problems, the person is shown a string of elements (usually letters or numbers) that are related by specific rules. The person’s task is to discover and apply the rules to continue the string. To solve these problems, the person must detect the rules that relate individual elements to each other, dis-

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cover the number of elements that constitute a complete cycle of the pattern, that is, the period length of the cycle, generate a rule that describes the elements of a period, and then use the rule to extrapolate the string. The pattern-description rules for series-completion problems dramatically differ in the number of slots required to represent the pattern in memory (cf. Pellegrino, 1985) and problem difficulty is highly correlated with the working memory requirements of the problem (cf. Holzman et al., 1976; Kotovsky & Simon, 1973). Further, the performance of adults and children is much worse for problems that place greater demands on working memory. This effect is moderated by the person’s age and ability level. Children of average ability are most affected, children of high ability are somewhat less affected, and adults are least affected by the working memory demands of more difficult problems (cf. Holzman et a l . , 1983). These results are consistent with the conclusion that age- and intelligence-related limitations on working memory capacity affect the problem solver’s representation of series-completion problems and are also important determinants of problem difficulty. Limitations on working memory capacity also affect comprehension processes (cf. Baddeley, 1986; Daneman & Carpenter, 1980; Just & Carpenter, 1987; Kintsch & van Dijk, 1978). Daneman and Carpenter (1980) devised a readingspan test that required subjects to read a group of unrelated sentences and recall the final word of each sentence at the end of the group. Readers were presented with groups of sentences that ranged from two to seven sentences in length. Reading span was defined as the largest group size for which the reader could recall all of the final words. They found that the reading span of college students was strongly correlated with reading comprehension test scores, and these correlations approached unity for some specific comprehension processes. In a second study, Daneman and Carpenter had college students read passages that contained a pronoun that was related to a referent that appeared in a previous sentence. Between two and seven sentences intervened between the referent and the pronoun. College students with larger reading spans were much better in assigning the pronoun to the correct referent than students with smaller spans, and this difference grew as the number of intervening sentences increased. These findings suggest that persons with a larger functional working memory capacity can integrate and store a greater number of propositions during reading comprehension. This process is essential to creating a referential representation of the to-be-understood information (cf. Just & Carpenter, 1987). Problem solving theory predicts a relationship between working memory and the comprehension of task instructions. This is because the comprehension of instructions produces an internal representation of the problem along with a set of operations for manipulating that representation (J. R. Hayes & Simon, 1974; Simon & J. R. Hayes, 1976). If the representation is mistaken or incomplete because of working memory limitations, then comprehension will be poor and

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strategy production will be adversely affected (Newell & Simon, 1972). Said differently, the person may fail to produce a task-appropriate strategy if she does not understand the task requirements because of working memory limitations. The acquisition and compilation of knowledge are also affected by working memory operations (cf. Anderson, 1983; Baddeley, 1986; Schneider & Detweiler, 1987). Knowledge acquisition and compilation necessitate keeping instructions and task-relevant information in memory while performing aspects of the task. For example, consider children’s learning of balance scale strategies (cf. Butterfield & Ferretti, 1984; Butterfield & Nelson, in press; Day & Hall, 1988; Ferretti & Butterfield, 1991). In the balance scale task, children see a teeter-totter that contains weights placed at varying distances from a centrally supporting fulcrum. In one version of this task, their goal is to predict whether the scale will fall to one side or the other side, or stay level. Children use at least five different strategies to solve this problem and these strategies are related to development and intelligence (cf. Ferretti & Butterfield, 1986, 1989; Ferretti et al., 1985; Siegler, 1976, 1978). Suppose the child is learning the following strategy: “If one side has more weights and the other side has its weights farther from the middle, then the side that has the big difference in weight or distance will go down” (cf. Case, 1985; Ferretti & Butterfield, 1986, 1989). When children are learning this strategy, they usually first verbally rehearse the rule (cf. Anderson, 1983; Fitts, 1964; Schneider & Detweiler, 1987) and then check the input conditions: Does one side have more weight‘?Does the other side have its weight farther from the middle? Is there a big weight difference on either side? Is there a big difference in distance’?After checking the input conditions, the child can match them to the output. This requires controlled processing (cf. Schneider & Detweiler, 1987) and places heavy demands on working memory. As knowledge becomes proceduralized, less working memory capacity is required because the input (the problem) can directly activate the output (the answer) without intervening processing, that is, verbal rehearsal and controlled matching of input and output. Knowledge acquisition and compilation place demands on working memory capacity.

C. Conclusions There are three important conclusions to draw from the preceding analysis. First, persons with mental retardation produce strategies when the task is not too difficult, they understand the task requirements, and (more speculatively) they have the specific knowledge needed to fashion effective strategies. Second, each of these determinants of strategy production is affected by and in turn affects functional working memory capacity. This suggests that functional working memory limitations may play an important role in the spontaneous strategy

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production of persons with mental retardation. Third, these findings show that persons with mental retardation may produce strategies when the interaction of the task requirements and their processing capacities are taken into account. Unfortunately, direct evidence about the relationship between functional working memory capacity and strategy use in children with mental retardation is lacking; however, the developmental literature shows a relationship between estimates of functional working memory capacity and strategy use. For example, Guttentag (1 989) recently reviewed the developmental literature about performance in the secondary task paradigm. This paradigm, which is the most frequently used for measuring functional working memory capacity (cf. Baddeley, 1986; Baddeley & Hitch, 1974; Guttentag, 1989), assumes that capacity limitations are seen when two or more tasks compete for limited working memory capacity. Therefore, this paradigm requires the person to concurrently perform a primary task and a secondary task. To the degree that the requirements of the primary task consume the capacity available to the person, performance on the secondary task will suffer. The developmental studies show a fairly consistent pattern of findings (Guttentag, 1989). When performance of the primary task is comparable at each developmental level, then age-related differences in secondary task performance are almost always seen. Said differently, the secondary task performance of younger children is worse than that of older children when they must also perform a primary task that is equally difficult for both groups. The magnitude of these dual-task costs is related to strategy production (cf. Bjorklund, 1985; Bjorklund & Hamishfeger, 1987; Guttentag, 1984; Kee & Davies, 1988). In each of these reports, children of different ages were instructed to use rehearsal, elaboration, or organizational strategies while performing a secondary task. The use of these strategies was generally much more disruptive of younger children’s secondary task performance than of older ones’ performance. In each case, the authors interpreted their findings in terms of age-related differences in the functional capacity available to use these strategies. It seems, then, that age-related differences in functional working memory capacity are related to intellectually average children’s strategy use (cf. Guttentag, 1989).

V.

PERSONS WITH MENTAL RETARDATION SOMETIMES TRANSFER STRATEGIES

Persons with mental retardation often fail to use strategies outside of the specific situation in which they were trained. This phenomenon, called welding (cf. Brown, 1978), is one of the principal reasons for teaching self-management processes to persons with mental retardation. Task-specific skills are useful in particular contexts, but self-management processes are presumably so general

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that the person need not discriminate the conditions of applicability (cf. Brown et af., 1979).

Ferretti (1989) reviewed a few studies that have reported evidence of strategy transfer by persons with mental retardation. One such study (Burger et al., 1981) suggests the conditions that may promote strategy transfer. Burger et af. (1981) contrasted the effectiveness of three approaches to teaching persons with mental retardation to transfer a verbal abstraction strategy. These approaches were distinguished by the degree of client involvement in the program and whether clients received self-management training in addition to task-specific training. In each case, clients received extensive practice on multiple exemplars of the training materials. In the specific strategy training condition, children were told to label each item in a triad and describe the attributes of the items that could be used to generate a verbal abstraction. In the combined self-management and specific strategy training condition, children were taught to use three self-interrogative verbalizations patterned after Meichenbaum ( 1977), in addition to receiving training on the verbal abstraction strategy. Finally, children in the modeling and self-management condition were given the same experience as the self-management group, except that their involvement was limited to observing the training of their self-management cohorts. Finally, control children were given uninstructed practice on the task. After training, all clients received a maintenance test on untrained exemplars of the training materials, a retention test on trained exemplars, and a transfer test involving verbal dyads that were auditorially presented. Burger rt al. (1981) found that children in the three instructed groups performed comparably to and better than the control group on the maintenance and transfer tests. Interestingly, specific strategy training was sufficient to secure strategy transfer in persons with mental retardation. This study shows that extended practice with multiple exemplars of the materials or task affects strategy transfer (cf. Ferretti, 1989; Stokes & Baer, 1977). In fact, behavioral researchers have established a technological armamentarium for promoting the transfer of skills (cf. Engelmann & Carnine, 1982; Fox, 1989; Horner, Dunlap, & Koegel, 1988; Stokes & Osnes, 1989), much of which involves extended training with multiple exemplars and very little of which involves the use of self-management training (cf. Baer, 1990). Anderson’s (1983; Singley & Anderson, 1989) ACT* theory of skill acquisition and transfer provides an interpretative context for the beneficial effects of multiple-exemplar training. In this theory, production systems are used as a formalism to model cognition. In essence, a production system consists of a set of condition-action rules, called productions. For example, the above-mentioned balance-scale strategy ( “ I f one side has more weights and the other side has its weights farther from the middle, then the side that has the big difference in weight or distance will go down”) describes a condition-action pairing that could be modeled as a production (cf. Klahr & Siegler, 1978). A production is

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fired, that is, an action is executed, when its condition matches the contents of working memory. In brief, skill acquisition and transfer occur in declarative and procedural stages. In the declarative stage, facts about the skill are interpreted by general problem solving productions, such as analogical procedures that map the components of the source problem onto the target problem. In the procedural stage, domain-specific productions that control cognition in specific situations are formed. According to the theory, skill acquisition and transfer always proceed from the declarative to the procedural stage. The transition from the declarative stage (using a set of analogical procedures to interpret factual information) to the procedural stage (forming domain-specific procedures) is accomplished by the process of knowledge compilation, during which sequences of general productions are collapsed into domain-specific productions. As a result of knowledge compilation, the capacity-intensive process of analogical mapping is bypassed. The theory's usefulness is illustrated by considering transfer data reported by Butterfield and Ferretti (1984'). In this study, children of average intelligence were taught procedures for solving inclined-plane problems. In the inclined plane, children saw two tracks down which steel balls could roll. Each track's angle of incline could be adjusted from 5" to 30" in 5" increments, and each ball's distance from the plane's vertex could be varied by placing it behind one of 6 Ushaped stops that were approximately 14 cm apart. A target box was placed below the plane's vertex. Each plane's angle and each ball's distance from the vertex could be adjusted so that the ball on one plane landed farther in the target box than the other ball, or so that both balls landed in same place. The child's task was to decide if one ball would land farther than the other ball or if they would land the same distance. Like the balance scale, children use at least five different strategies to solve the inclined-plane problem, and these strategies are also related to development and intelligence (cf. Ferretti & Butterfield, 1989; Ferretti et a l . , 1985). Moreover, the balance-scale and inclined-plane problems are psychologically isomorphic in the sense that both problems' computational strategies can be placed in one-to-one correspondence despite the fact that they have different surface features (cf. Butterfield & Ferretti, 1984; Ferretti & Butterfield, 1989). Children in this study were assigned to one of three groups that differed with respect to their instructional history prior to inclined-plane training. In the inclined-plane only group, children received no instruction prior to inclined-plane training. In the balance-scale and inclined-plane group, children received balance-scale instruction before receiving inclined-plane training. Finally, the memory and inclined-plane group received instruction on a memory problem like that described by Butterfield el al. (1973) before receiving inclined-plane training. The memory problem shared no isomorphic properties with the inclined plane. If prior strategy training on an isomorphic problem promotes transfer, then the

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balance-scale and inclined-plane group should have learned the inclined-plane strategy faster than either of the other groups. In fact, strategy instruction on isomorphic problems created a substantial instructional savings. Prior training on a problem isomorph was sufficient to produce strategy transfer. The data reported by Burger et al. (198 1) and Butterfield and Ferretti (1984) can be explained by ACT* in two ways. First, transfer will be seen to the degree to which two tasks share common productions. For example, the computational strategies taught by Butterfield and Ferretti (1984) were identical in the balancescale and inclined-plane conditions, so it is no surprise that transfer of training was observed (cf. Singley & Anderson, 1989). Second, analogical patternmatching mechanisms could have been used to map the common features of the source and target problems in either Burger et al. (1981) or Butterfield and Ferretti ( 1984), resulting in transfer of the procedural representations. Training with multiple exemplars makes it easier for the person to identify the characteristics of the task that are similar across situations. Once the common conditions and actions are identified, transfer will occur.

VI.

GENERAL CONCLUSIONS

We began this paper by describing three widely held beliefs about the problem solving of persons with mental retardation and then proceeded to critically analyze the efficacy of self-management training in promoting strategy transfer in persons with mental retardation. We showed that there are serious methodological, logical, and interpretative difficulties associated with many of these studies. In our judgment, the strongest conclusion we can draw from both the cognitive and behavioral training studies is that the literature is inconclusive about the self-management deficiency hypothesis’ usefulness in accounting for strategy transfer effects in persons with mental retardation. We then reviewed evidence about the determinants of strategy production and transfer in persons with mental retardation. Our analyses showed that persons with mental retardation can be productive when the interaction of the task environment and their processing capacities are taken into account. More specifically, persons with mental retardation can be productive when the task is not too difficult, when they understand the task requirements, and when they have the content knowledge required for successful task performance. Each of these factors is affected by constraints on working memory capacity and, in turn, affects the functional capacity available to these persons. Moreover, there is evidence that persons with mental retardation sometimes transfer strategies, especially when they receive training with multiple exemplars of the task or instructional materials. Cognitive interpretations of this fact emphasize the importance of analogical pattern-matching mechanisms in forming generalizable knowledge

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structures. It seems as if self-management training is not necessary to induce transfer in persons with mental retardation. We believe that limitations in the functional working memory capacity of persons with mental retardation should also be related to learning even though the empirical literature is somewhat unclear about this possibility (cf. Brown & Campione, 1984; Campione & Brown, 1987; Campione et a l . , 1982; Campione, Brown, Ferrara, Jones, & Steinberg, 1985). The inconsistent findings are especially surprising because intelligence tests were originally designed to identify children who were unable to profit from experience (Binet & Simon, 1914). Nevertheless, the early empirical evidence does not show intelligence-related differences in learning (cf. Campione & Brown, 1984, 1987; Campione et a l . , 1985; Ferrara, Brown, & Campione, 1986; Woodrow, 1917, 1946). Campione, Brown, and their colleagues (Campione & Brown, 1984, 1987; Campione et al., 1982, 1985; Ferrara et a l . , 1986) have analyzed the conditions responsible for the early failures to see a relationship between learning and intelligence. For example, Campione et d.(1985) taught children with mental retardation and MA-matched children of average ability to solve Raven-like matrix problems by administering a graded series of hints about a solution strategy. Children saw incomplete 3 X 3 matrices composed of figures that were related by simple rules. The child’s task was to uncover the rules that would enable her or him to chose a figure that completed the matrix. Correct responses during learning required the application of a single rule, and children with mental retardation learned as fast as children of average ability. After learning, children took an unaided maintenance test involving different exemplars of the same rules. Finally, children were given a series of transfer tests that required the simultaneous application of two previously learned rules. A graded series of hints was also given during the transfer tests. Children with mental retardation needed more hints to transfer than children of average ability and were less likely to maintain strategy use, especially when the item presentation format differed from original learning. So, children with mental retardation learned as quickly as children of average ability, but they were less likely to maintain the strategy and needed more help to transfer it to variants of the training task. More recently, Ferretti and Butterfield (1991) taught children with mental retardation, children of average ability, and intellectually gifted children to solve balance-scale problems using three developmentally graded strategies. The strategies differed in the number of dimensions that had to be simultaneously coordinated. The Rule I1 strategy required children to make balance-scale decisions by first considering the weight dimension and, if weight was uninformative, then considering the distance dimension. It is a lexicographic strategy (cf. Slovic, Fischoff, & Lichtenstein, 1977) that does not require the simultaneous coordination of multiple sources of information (cf. Case, 1985). In contrast, Rules 111 and IV required the simultaneous coordination of information about two dimen-

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sions to render a decision (Case, 1985; Ferretti & Butterfield, 1989). In Rule 111, children compared the relative differences along the weight and distance dimensions, and chose the side associated with the bigger differences. In Rule IV, children added the number of weight and distance units on each side of the scale, and chose the side with the greater value. According to Case (1985), both rules involve the use of an abstract dimension that requires the simultaneous coordination of both dimensions. Ferretti and Butterfield found that children did not differ in the amount of training to learn Rule 11, but that children with mental retardation required more training to learn rules 111 and IV than children of average ability or gifted children. The findings of Campione et af. (1985) and Ferretti and Butterfield (199 1) can be reconciled if we take into account the role of functional working memory limitations in learning. In Campione et al., children were required to learn a single rule to complete the Raven-like matrix. Under these conditions, children with mental retardation learned as quickly as children of average ability. In Ferretti and Butterfield, Rule I1 did not require the simultaneous coordination of dimensional information. Again, children with mental retardation learned as quickly as children of average ability or gifted children. In contrast, Rules 111 and IV required the coordination of information about two dimensions. Under these conditions, children with mental retardation learned more slowly than children of average ability or gifted children. Thus, it appears learning may be related to intelligence-related differences in functional working memory capacity. We previously showed that persons with mental retardation sometimes transfer knowledge and strategies when the training conditions make the conditions of applicability salient to the learner, for example, when the learner receives training across multiple exemplars. Nevertheless, the literature shows that persons with mental retardation generally do not spontaneously transfer strategies (cf. Blackman & Lin, 1984; Borkowski & Cavanaugh, 1979; Campione & Brown, 1984; Campione et a l . , 1982). Transfer difficulties should be expected if functional working memory capacity constrains problem solving (cf. Carr, 1984; Singley & Anderson, 1989). In most transfer situations, the performance conditions are not identical to those during original learning (Brown & Campione, 1978). Under these conditions, transfer requires that the person hold parts of the strategy and the critical conditions of the old situation in working memory while analogically comparing them to the new situation. Thus, transfer to unpracticed situations will place heavy demands on functional working memory capacity. We previously acknowledged that the use of strategies and the availability of knowledge are affected by constraints on working memory capacity and, in turn, affect the functional capacity of working memory. In other words, working memory capacity is a property of the information processing system that is determined by the effects of a number of factors. For example, a skilled reader may have more content knowledge than a poor reader, and his or her processes of

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encoding, lexical access, and semantic analysis may be more automatic, than those of a poor reader (cf. Just & Carpenter, 1987). Any of these factors could be responsible for differences in functional working memory capacity. Conversely, limitations on functional working memory capacity constrain the representation of to-be-understood information, and hinder the acquisition and compilation of knowledge important for comprehension. Knowledge, strategies, and working memory limitations may interact to determine individual or group performance differences in any situation. This suggests that there should be substantial performance variability from situation to situation, and much of the data reviewed in this paper is consistent with this expectation; however, as the performance of persons with mental retardation is impaired across a broad range of complicated information processing tasks, we believe that they experience much broader limitations in functional working memory capacity than persons without mental retardation (cf. Torgeson, Kistner, & Morgan, 1987). The question, then, is what is it about working memory processes that so severely constrains the functional capacity of persons with mental retardation'? One possibility is that the speed of information processing constrains the working memory capacity of persons with mental retardation. Persons with mental retardation are generally slower than persons of average ability in many information processing situations (cf. Brewer, 1987; Brewer & Smith, 1990; Cam, 1984; Maisto & Baumeister, 1984; Stanovich, 1978). We conceive of working memory as a dynamic system that depends upon the use of elementary information processes and strategies for the activation and maintenance of information. If the processes upon which these strategies depend operate slowly, then information will be lost from working memory before it can be used in many performance situations (cf. Anderson, 1983). This account is consistent with evidence from the general experimental and developmental literature that shows that the speed of information processing is related to functional memory capacity (e.g., Baddeley, 1986; Baddeley, Thomson, & Buchanan, 1975; Case, Kurland, & Goldberg, 1982; Chi, 1977). Perhaps, then, the slowness of information processing in persons with mental retardation limits the amount of information that can be kept active; that is, it constrains functional working memory capacity.

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Simon. H. A,, & Hayes, J. R. (1976). Understanding complex task instructions. In D. Klahr (Ed.), Cognitiori and insfruction ( pp. 269-289). Hillsdale, N1: Erlbaum. Singley, M. K . , & Anderson, A. R. (1989). The transfer of cognitive skill. Cambridge, MA: Harvard University Press. Slovic, P., Fischoff, B.. & Lichtenstein, S. (1977). Behavioral decision theory. In M. R. Rosenzweig & L. W . Porter (Eds.). Annual review of psychology (Vol. 28. pp. 1-39). Palo Alto, CA: Annual Reviews. Sowers, J., Verdi, M.. Bourbeau, P., & Sheehan, M. (1985). Teaching job independence and flexibility to mentally retarded students through the use of a self-control package. Journal of Applied Behavior Anal.ysis, 18, 81-85. Spearman, C. E. (1923). The nature of intelligence and the principles of cognition. London: Macmillan. Spitz, H. H. (1966). The role of input organization in the learning and memory of mental retardates. In N. R. Ellis (Ed.), International review of research in mental retardation (Vol. 2, pp. 29-56). New York: Academic Press. Spitz, H. H. (1973). Consolidating facts into the schematized learning and memory system of educable retardates. In N. R. Ellis (Ed.), lnternational review of research in mental retardation (Vol. 6. pp. 149-168). New York: Academic Press. Spitz, H. H.. & Borys, S. V. (1977). Performance of retarded adolescents and nonretarded children on one- and two-bit logical problems. Journal ofExperimenfa1Child Psychology, 23,415-429. Spitz, H. H., & Borys, S. V. (1984). Depth of search: How far can the retarded search through an internally represented problem space? In P. H. Brooks, R. Sperber, & C. McCauley (Eds.), Learning and cognition in the mentally retarded (pp. 333-358). Hillsdale, NJ: Erlbaum. Spitz, H. H., & Webreck, C. A. (1972). Effects of spontaneous vs. externally-cued learning on the permanent storage of a schema by retardates. American Journal of Mental Deficiency, 77, 163168. Spitz, H. H.. Webster, N. A,, & Borys, S. V. (1982). Further studies of the Tower of Hanoi problem solving performance of retarded young adults and nonretarded children. Developmental Psychology, 18, 922-930. Stanovich, K. E. (1978). Information processing in mentally retarded individuals. In N. R. Ellis (Ed.), International review of research in mental retardation (Vol. 9, pp. 29-60). New York: Academic Press. Sternberg, R. J. (1981). Intelligence and nonentrenchment. Journal of Educational Psychology, 73, 1-16. Stokes, T. F., & Baer, D. M. (1977). An implicit technology of generalization. Journal of Applied Behavior Analysis, 10, 349-367. Stokes, T. F., & Osnes, P. G. (1989). An operant pursuit of generalization. Behavior Therapy, 20, 337-355. Thorndike, E. L., Bregman. E. 0.. Cobb, M. V., & Woodyard. E. (1926). The measurement of intelligence. New York: Teachers College Press. Torgeson, 1. K., Kistner, J. A., & Morgan, S. (1987). Component processes in working memory. In J. G. Borkowski & J. D. Day (Eds.), Cognition in special children: Comparative approaches to retardation, learning disabilities, and giftedness (pp. 49-85). Norwood, NJ: Ablex. Turnbull, H. R.. 111. (1988). Fifteen questions: Ethical inquiries in mental retardation. In J. Stark, F. Menolascino, M. Albarelli, & V. Gray (Eds.), Mental retardation and mental health: Classification, diagnosis. treatment, services ( pp. 368-377). New York: Springer-Verlag. Turnure, J. E., Buium, N., & Thurlow, M. L. (1976). The effectiveness of interrogatives for promoting verbal elaboration productivity in young children. Child Development, 47. 85 I 855. Wechsler, D. (1958). The measurement and appraisal of adult intelligence (4th ed.). Baltimore, MD. Williams & Wilkins.

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Wehman, P. (1975). Behavioral self-control with the mentally retarded. Journal of Applied Rehabilitation Counseling, 6 , 27-34. Wehman, P., Schutz, R . , Bates, P., Ilenzaglia, A,, & Karan, 0. (1978). Self-management programmes with mentally retarded workers: Implications for developing independent vocational behaviour. British Journal of Social Clinical Psychology, 1 7 , 57-64. Whitman, T. L. (1987). Self-instruction, individual differences, and mental retardation. American Journal of Mental Deficiency, 92, 213-223. Whitman, T. L. (1990). Self-regulation and mental retardation. American Journal on Mental Refardation, 94, 341- 362. Whitman, T. L., & Johnston, M. (1983). Teaching addition and subtraction with regrouping to educable mentally retarded children: A group self-instructional training program. Behavior Therapy, 14, 127-143. Wolf. M. M. (1978). Social validity: The case for subjective measurement or how applied behavior analysis is finding its heart. Journal of Applied Behavior Analysis, I I , 203-214. Woodrow, H. A. (1917). Practice and transference in normal and feebleminded children: I . Practice. Journal of Educational Psychology. 8 , 85-96. Woodrow, H. A. (1946). The ability to learn. Psychological Review. 53, 147-158.

Long-Term Memory and Mental Retardation JAMES E. TURNURE DEPARTMENT OF EDUCATIONAL PSYCHOLOGY UNIVERSITY OF MINNESOTA MINNEAPOLIS, MINNESOTA 55455

I.

INTRODUCTION

Ericsson and Chase (1982) begin their notable article, “Exceptional Memory,” by saying, “There are scientific records of memory feats that deviate so markedly from the normal that they are called exceptional and are assumed to reflect a memory system structurally different from that of most people” (p. 607). They are referring to extraordinary memory performances such as those reported for mnemonists (Hunt & Love, 1972; Luria, 1965/1968), but the same type of assertion can be made regarding exceptional instances or cases of memory loss or malfunction, as observed in individuals diagnosed as amnesic (cf. Squire & Butters, 1984). Such memory losses or deficits are often attributed to the mentally retarded (cf. Detterman, 1979; Frankenstein, 1970; Gallagher, 1984). Some of the research reviewed here investigated possible memory differences among nonretarded children of normal intelligence and two groups of exceptional children, identified as gifted and mentally retarded, whose exceptional deviations in intellectual functioning might suggest deviant memory functioning. The purpose of this article is to review research on long-term memory (LTM) so as to place findings and interpretations within the perspective of extraordinary memory phenomena, in the sense of Ericsson and Chase (1982). The outline of this article takes the general form of Belmont’s early authoritative and incisive review, contained in Volume 1 of this series (Belmont, 1966). Thus, there will be a section dealing with “the historical development of the problem of studying retention in fast and slow learners” (Belmont, 1966, p. 220), emphasizing more recent efforts to study semantic memory and other “ecologically valid” questions (Neisser, 1982). Instead of following Belmont INTERNATIONAL REVIEW OF RESEARCH IN MENTAL RETARDATION, Vol 17

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(1966) and discussing methodological issues pertaining to such research in a separate section, I interpolate methodological discussions as they pertain to newer issues, emphasizing analysis of contamination of material during the retention interval and the role of retrieval cues (Tulving, 1983) and other memory test issues (Roediger, 1990). Section 111 reviews basic and applied research providing information on the long-term retention capabilities of persons with mental retardation, and is followed by a final discussion in Section IV.

I I.

HISTORICAL BACKGROUND

The concept of memory has assumed paramount importance in psychological research and theory since 1960 (cf. Melton, 1963; Neisser & Winograd, 1988; Weinert & Perlmutter, 1988). with an attendant proliferation of empirical findings and theoretical models (Richardson-Klavehn & Bjork, 1988). The present article is devoted to long-term memory (LTM), with an emphasis on the role of retrieval cues in assessing the availability and accessibility (cf. Tulving & Pearlstone, 1966) of meaningful material originally learned by nonretarded, mentally retarded, and gifted groups of children. Until recently, relatively little experimental research had been conducted on LTM, although the general literature usually referred to a small number of classics, particularly Bartlett (1932; cf., also, Woodworth & Schlosberg, 1954). There has been a strong upsurge of interest lately (Bahrick & Karis, 1982; Morris, 1988; Neisser, 1982; Neisser & Winograd, 1988). Research with children was even more sparse. For instance, in an extensive research review of children’s memory development, Rohwer and Dempster (1977) sounded a plaintive note regarding retrieval from memory: In this problem area our ignorance is vast about the basic processes responsible for retrieval, about conditions that enhance retrieval. about developmental and individual differences in retrieval processes, and about conditions that might compensate for as yet unidentified improficiencies. A reduction in any or all of these unknowns would greatly increase the potential of research as a resource for education. ( p. 430)

There also has been a recent, but more limited, increase in interest in children’s recall over long intervals (cf. Weinert & Perlmutter, 1988). Research concerned with mental retardation has been even less frequent (Belmont, 1966; Detterman, 1979). Hence, again, there has been a recent rise in research, focused on a few specific topics (Ellis, Woodley-Zanthos, & Dulaney, 1989; McCartney, 1987). Possibly because of the paucity of reliable research findings, there seems to have been little shift in the divided opinions in the field regarding LTM in retarded individuals; with the pro or no- “storage”-deficiency group (cf. Bel-

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mont, 1978; Clarke & Clarke, 1974; Spitz, 1973) relying on Belmont’s 1966) review for support, and the con group (cf. Baroff, 1974; Frankenstein: 1970; Gallagher, 1984) relying on professional observation. The recent impetus for investigations of LTM with exceptional popu.itions emerges from both theoretical and practical considerations. Memory theorists have proposed that given “deep” meaningful processing (Craik, 1973) or other mechanisms of LTM activation (Atkinson & Shiffrin, 1968), task material learned should be stored and retained over long time intervals. In a practical vein, teachers are always interested in whether learning, however achieved, will be retained for significant periods. Given the important implications and sound justification and need for LTM research, it is striking that so little work has been attempted on this problem (Neisser, 1982). Major methodological difficulties have been impediments to work on LTM, and controversies over their solution have virtually forestalled research (cf. Bartlett, 1932; Belmont, 1966; Neisser, 1982). The fundamental requirements for research on LTM have been stated in several reviews that have emphasized conditions of original learning and tests of retrieval, particularly cued recall approaches. Rohwer and Dempster (1977) discussed several of the important requirements in doing comparative research on aspects of retrieval from longterm memory, notably the requirement that equivalent “degrees of storage” be achieved by comparison groups prior to retrieval test. They also noted the need for more comparisons between cued and free recall (see, also, Watkins & Gardiner, 1982). Bahrick (1 984) has recently emphasized that “dependable conclusions regarding the loss of memory content require accurate assessments of the level of original knowledge and of rehearsals during the retention interval” (p. 2). In other words, the crucial conditions necessary for unequivocal interpretations of subjects’ and groups’ performances in memory tests lie in (1) establishing the equivalence of “degrees of storage” or “state of memory” of experimental groups to be compared, (2) ensuring that these initial memory states are uncontaminated by interinterval reminders or rehearsals, and (3) arranging that retrieval cues are varied systematically. The first, the original learning equivalency issue, was the focus of Belmont’s (1966) review, and the criteria he established are still the major methodological criticisms brought to bear in reviews of long-term memory (Detterman, 1979; McCartney, 1987). Indeed, control over the conditions of encoding is critical to understanding most important theoretical questions of memory research, and Winograd (1988) identifies the particular, if partial, solution of this problem by Ebbinghaus as that pioneer’s most outstanding contribution to the scientific study of memory. Even Morris (1988), after one of the most devastating attacks on the “verbal learning” approach to memory research that followed from Ebbinghaus’ method since Neisser’s ( 1978) ecologically inspired diatribe, asserts that it is “necessary to make every effort possible to obtain similar degrees of control for

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the aspects of memory that we [naturalistic memory researchers] study” (p. 106), as did Ebbinghaus and his followers. The two major methodological impediments to the controlled study of longterm memory emphasized by Bahrick (1984), controlling original learning and controlling occurrences of rehearsal during the long interval or term before memory is tested, revolve around the necessity of allowing the human subject freedom of access to the multifarious stimulation of her or his everyday environment or natural ecology. Thus, research on ecologically valid materials may be seen to be more problematic than that on more esoteric laboratory materials. That is, if researchers simply took available materials from the everyday environment (such as stories, lessons, social or other cultural events) and assessed subjects’ knowledge, or taught the pertinent information at the time of the original learning test, this learning or knowledge acquisition experience would be only partially controlled. The subjects’ differential familiarity with the content, or aptitude for learning under the experimental conditions would vary, leading to compound problems in measurement and control whose solutions have been only partially successful (Bahrick, 1984; Banaji & Crowder, 1989; Brewer, 1988; McCauley, 1988). Such difficulties led to Ebbinghaus’ radical solution of eliminating meaningful content by using nonsense syllables as the learning material in his experiments. And it is this solution that has been rejected by contemporary ecologically oriented or natural memory researchers (Morris, 1988; Neisser, 1978). Despite much “ingenuity and inventiveness by the experimenters” (Morris, 1988, p. 102) involved in the ecological approach to the problem of control and measurement of original learning, no solution involving meaningful learning has matched the methodological rigor of Ebbinghaus’ solution of avoiding it (see, most recently, McCauley, 1988). Another truly remarkable aspect of Ebbinghaus’ solution of the original learning problem was that it simultaneously solved the second methodological problem of uncontrolled intertrial rehearsals. It seems very unlikely that nonsense syllables would be cued for rehearsal during a retention interval. In contrast, if meaningful material is selected from people’s environments to be used to establish an original learning baseline from which to measure the retention interval, then the everyday information will probably contain cues to stimulate additional processing of some of the information. Subjects are likely to reexperience and reactivate the learned memory materials, at various times and to varying degrees, contaminating the temporal interval of the memory to be tested in uncontrollable and often unknowable ways, unless, perhaps, the materials to be learned, although meaningful in themselves and to-be-learned by common techniques, are so obscure or unusually formatted as to be unlikely candidates for any intertrial activation. Thus far, 1 have attempted to establish the methodological impediments to conducting experiments on “pure” long-term memory. I can summarize a con-

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ceptualization of the nature of “pure” memory research (Tulving, 1983) in the following model: Learn

Time Interval

Retrieve

Descriptively, T I ,or Time 1, refers to the moment when a stimulus or nominal event is experienced by an individual in a recordable way, that is, is learned. It is important to establish that it is the effective stimulus, not the nominal one, that is the substance of any memory to be studied (cf. Tulving, 1983, p. 284), and that it is the experience as recorded by the individual, even in an idiosyncratic manner, that is the essence of the memory. Controlling or measuring precisely the establishment of what any one person registered about TI in a verifiable way is the problem of original learning. The interval is the time period that ensues between the moment of record and the subsequent reactivation of its reregistration or expression, tacit or overt, in a cognitive processing system or behavioral activity. A necessary distinction must be made here to isolate LTM from short-term or working memory (STM). Belmont (1966) initially pointed to the often vague and arbitrary nature of the distinction between STM and LTM. Temporally, there appears to be an empirical basis for identifying any test time after 20 sec as implicating the establishment of a LTM record (cf. Hussy & von Eye, 1988), although such a brief period seems less than compelling as a basis for investigating the durability of a mental event. Further, it is hard to imagine how conditions might change sufficiently in any 20sec interval to avoid the claim that simple repetition rather than long-term remembering was involved. From one perspective, short-term memory tests are primarily investigations of what subjects have actually learned in the course of their immediately prior experiences. Therefore, for experimental clarity and to relate to practical and naturalistic circumstances, I used an extended retest interval criterion of from an hour or beyond (up to 50 years or more; cf. Bahrick, 1984) as a basis for including studies for review or reference. The concern expressed here for interinterval contamination appears unusual in the literature, with the exception of Bahrick’s discussion. The problem is likely to become more salient as LTM research addresses more ecologically representative and more applied issues, such as retention of school learning over the summer (Carter, 1984; Hoepfner, 1980; Turnure & Engen-Wedin, 1985). It is important to realize that this matter is not as readily overcome as some would imply. For instance, Neisser (1991) lauds Bahrick’s (1984) studies of LTM for Spanish learned in school up to 50 years past, for controlling important variables, including retention interval rehearsals, by applying covariance techniques; however, Neisser does not acknowledge that Bahrick did not, and presumably could not, verify subjects’ reports of such rehearsals in the way he did for reports of the

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number of courses taken, grades achieved, and time elapsed since the last Spanish course taken (the latter being of questionable reliability). Such assessments and corrections must be subject to much more scrutiny and research, as other assessments of LTM for real-life events have been shown to have variable and potentially distorting degrees of error (Radke-Yarrow, Campbell, & Burton, 1970). The third major facet of LTM, the T , matter of retrieval of original learning, was given its contemporary emphasis by Tulving and Pearlstone (1966). Retrieval has been presented as a principle by Tulving (1983), who describes it as the dependency of remembering on “the conditions prevailing at the time of its attempted recollection, particularly that component of the conditions that we refer to as retrieval information” ( p. 4), as well as the nature of the original event and its encoding. Tulving’s views are emphasized here because the positions established in Tulving and Pearlstone ( 1966) inspired the bulk of my research on LTM and its implications for mental retardation. As previously indicated, manipulation of retrieval cues has been seen as of both theoretical and practical importance.

Ill. LONG-TERM RETENTION WITH EXCEPTIONAL SUBJECTS Despite the increase in the acknowledgment of long-term retention as a matter of fundamental, theoretical, and practical importance, LTM research with subjects identified as mentally retarded is a virtual terra incognita. Since Belmont’s (1966) review, apparently only seven studies can be identified: four are published studies (Ellis et uf., 1989; McCartney, 1987; Scott, 1971; Stinnett & Prehni, 1970), and three are unpublished works by my colleagues and me, to be reviewed in this article (Turnure, 1986; Turnure & Engen-Wedin, 1985; Turnure, Thurlow, & Buium, 1977). The seven studies can be partially aligned according to a recent distinction emerging in the general memory literature between explicit and implicit memory. Explicit memory refers to intentional and conscious recollections of past learning and experiences, and includes most traditional studies of recall and recognition. Implicit memory is unintentional and unconscious, but is evident in much behavior, such as perceptual learning and motor skills, which are acquired automatically, often in studies of priming and transfer. Unfortunately, this emerging theoretical formulation is presently at a stage of almost bewildering empirical and conceptual complexity (cf. Richardson-Klavehn & Bjork, 1988) and increasing controversy (see, for instance, Bower, 1990; Roediger, 1990). Still, it appears that the analytical approach to memory tasks inspired by this conceptualization provides an important complement to other possible organizations of the extant LTM literature, such as episodic versus semantic memory

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(Brown, 1975; Tulving, 1983), procedural versus propositional memory (see Tulving, 1983), and the traditional rote versus meaningful. In the absence of any concensus on the theoretical nature of LTM, reference will be made to a variety of these distinctions as seems necessary. The following review generally moves from more basic processes, such as sensorimotor and perceptual learning, to higher-order ones (e.g., semantic). Where possible, studies are ordered from implicit to explicit types of memory phenomena. Because of the increasing complexity of the processes presumably employed, as well as the increasing probability of controversy, description and discussion expand likewise.

A.

Studies Involving Basic Processes

Scott (1971) studied the acquisition of a motor skill, balancing on a stabilometer. His subjects were 36 children, identified as educable mentally retarded, with IQs ranging from 52 to 79, and chronological ages (CAs) of 10 to 13: years. They were matched with nonhandicapped children of the same CAs. The children learned to balance themselves on a small, elevated platform. Subjects performed on fixed numbers of trials, either 16 or 24, scored in blocks of 4, and so the design can be classified as reflecting equal opportunity to learn (Belmont, 1966). After original learning, children were retested 28 days later, allowing for a first trial block retention score and a relearning score. Scott ( 197 1 ) reports that the rates of original learning for nonhandicapped children and those with handicaps were the same, but that the level of performance of the nonhandicapped was higher, as is often the case in such comparative studies utilizing the equal opportunity methodology. This lack of equivalency on original learning raises questions regarding Scott’s report of equivalent forgetting for both types of subjects over the 4-week interval, as well as his report of a faster relearning rate for the nonhandicapped children. Nevertheless, Scott also reported that the distribution of individual performances of the children with mild retardation fell within the range of performances of the normal children. On balance, Scott’s (197 I ) study provides some support for the conclusion that there is no difference in retention of this motor skill, at least, for groups with and without mental retardation, indicating that some procedural memories are not deficient in individuals with such handicaps. Skilled performances are classified as tests of implicit memory (Schacter, 1987), and retention of such skills is commonplace, not only among the general population (Annett, 1979) but even among the amnesic group (cf. Corkin, 1968). The following three studies pertain to the rather basic processes of automatic memory, recognition, and rote learning. Ellis and his colleagues (Ellis, Palmer, & Reeves, 1980; Ellis et ul., 1989) have recently demonstrated equivalent shortterm memory performance by individuals with mental retardation and nonhandicapped children and college students on such automatic processes (Hasher &

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Zachs, 1984) as frequency of occurrence and spatial location. In their study of spatial location, Ellis et al. (1989) included a 3-month, long-term follow-up test on a picture relocation task with subjects who had Down syndrome and college students. The study included both free recall and picture relocation scores. The subjects with Down syndrome showed no decline in recall (although recall was very low overall, around 15%, compared with 35% for college students) and a slight improvement in picture relocation, from 67 to 75%. In this study, the recall task is clearly one of explicit and rote memory, and so might be evidence of conscious or intentional recollection, which is generally considered a difficult and troublesome form of memory. Although sketchy, details on the procedures of this aspect of the experiment indicate that subjects reviewed the materials at 3 months, prior to the recall task. Thus, this might be classified as a relearning task, and hence a test of implicit memory. Unfortunately, the learning phase of the experiment did not include a criterion, and the original and follow-up scores correlated only .35,indicating that the levels of performance may reflect not LTM, but the successive residuals of two functionally independent learning trials. This finding, then, appears to have little to say regarding LTM. The memory-for-location data also appear to be a direct or explicit test of memory, and as such are interesting because they are the result of automatic and not conscious processing. Because they are explicit tests, performance should be sensitive to individual differences such as handicaps related to intelligence or developmental level (Roediger, 1990). It thus appears that some explicit tasks can tap unconscious learning i n a wide array of subjects, and in a number of important or even fundamental processing systems, such as keeping track of frequency, spatial location and temporal order. Again, although the compelling data derive from only short-term tasks, the persistence of the ability in subjects with Down syndrome demonstrates the durability of a functional skill, somewhat analogous to motor learning, especially because it can be “fine-tuned” with repeated experience. The existence of normal LTM in subjects with mental retardation, for information acquired in a basic perceptual processing task, was recently demonstrated in an experiment by McCartney ( 1987). This experiment was designed specifically to investigate the question of whether a LTM deficiency existed in 16-year-old individuals with mild mental rctardation, as compared with peers without this disability. McCartney (1987) designed his study to meet the methodological requirements identified by Belmont ( I966), regarding equating original learning and avoiding floor and ceiling effects. McCartney also chose a task with some degree of ecological validity, a face-recognition task, utilizing photographs of human faces selected from popular magazines. Subjects initially viewed individual pictures and, subsequently, I day, I week, and 6 months later, were required to choose previously seen faces from pairings with new photos from the original large pool of pictures. An additional variable was number of exposures:

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30 of the 105 target faces were shown once; 30 were shown twice; 30 were shown three times; and 15 distinctive photos, usually of familiar faces, were shown five times, with these latter photos used for training and validating purposes. Routine methodological and procedural matters appear to have been dealt with properly. The use of popular magazines does, however, raise the question of intertrial interval contamination: Was such material seen later either as a general cue to study photographs of people, with at least implicit reference or activation of some or all aspects of the experimental sessions, or as more specific cues activating retrieval of some number of actual stimuli. There is no indication of any effort to monitor this potential problem (see Bahrick, 1984). Although there is no evidence of systematic bias in the results of this study, clearly the possibility of such distortions, or alternative explanations for various patterns of outcomes, can be imagined. Also, as has been traditional practice, there was no attempt to vary retrieval cues. The recognition task, as employed, was an explicit test; alternatives could have involved degraded photos (see Lorsbach & Woman, 1988, for an interesting example of contrasting implicit and explicit tests of picture memory with learning-disabled subjects). The most pertinent result of this focused and well-done study was that no difference in LTM was obtained for the two groups of adolescents. McCartney (1987) noted that all of the functions observed that were free of ceiling effects were basically parallel, “suggesting that long-term retention is quite stable regardless of intelligence or acquisition level” (p. 46). McCartney concludes that, coupled with the Klausmeier, Feldhusen, and Check (1959) study, mentioned earlier, and the Scott (1971) study, “the majority of the evidence to this point supports the conclusion that there is not a deficit in the long-term memory of retarded persons” (p. 3 17). The results of Stinnett and Prehrn (1970), however, are not completely consistent with McCartney’s conclusion. In this study, the sample of children with mild mental retardation (average IQ of 69) were about 15 years old, community based, and in special classes. The nonretarded children were approximately I year younger. Stinnett and Prehm (1970) carried out a rather sophisticated and complex methodological study focusing on recommended methods for equating original learning. On the basis of Belmont’s (1966) review, Stinnett and Prehm contrasted the standard measure of equal amount learned, which ignores time or trials to criterion, with Gillette’s method of adjusted learning, in which items to be learned are removed from tasks when responded to correctly. This method was designed to control for overlearning of early-learned material: All subjects make the same number of correct responses and learning is usually more efficient. They also devised an alternative to Gillette’s method, called a modified method of adjusted learning, which could be applied with a stricter criterion than a single correct response (e.g., three consecutive correct responses per item). Subjects learned a very difficult paired-associate task, involving six stick-

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figure stimuli and six consonant-vowel-consonant trigram response terms, to a general criterion of three correct responses to each of the pairs: In the standard condition, three perfect trials of 100% recall were required, or three correct responses per item in any trial in the Gillette method, with three consecutively correct in the modified Gillette procedure. Subsequent to reaching criterion, each study participant was: ( I ) tested immediately, with a trial that presented all six stimuli for response without feedback; (2) tested 24 hours later for recall, and the measure was the number of response items correctly anticipated on the first relearning trial. Following this trial, subjects were brought to the same criterion under the method they had been assigned, producing a relearning score. The most pertinent results of this complicated study were that ( I ) different learning conditions had obvious effects on trials to criterion and immediate recall, and (2) these outcomes make LTM measures difficult to interpret. Regarding original learning, the nonhandicapped group performed substantially better than the handicapped, and the methods of adjusted learning improved performance significantly and were equally effective for both groups, resulting in no Subject x Method interaction. This interaction was, however, significant on immediate recall: nonhandicapped groups performed slightly and significantly poorer on the modified method and substantially and significantly poorer on Gillette’s method, and handicapped groups performed substantially poorer on both methods of adjusted learning. Thus, it is not at all clear that the basic requirement of achieving equal learning or “degrees of storage” was met in any of the conditions. After 24 hours, it appears that the recall test on the first relearning trial, which is an explicit test of memory, produces evidence of weaker recall by the subjects with retardation; but the relearning data, which reflect an implicit test, clearly show similarity of functions, implying no deficiency in long-term retention for this sort of material. Stinnett and Prehm (1970) concluded that their results demonstrated the difficulty of ensuring equivalent original learning states in comparative memory studies, and that the observation of a retention deficit in people with retardation is method dependent. Their position remains pertinent and valid. Summarizing over the studies reviewed, which investigated LTM in very basic and fundamental processing systems, it seems fair to paraphrase and extend the assessment of Ellis ef a l . (1989, p. 526) regarding automatic encoding and retention of frequency, location, and sequencing information: All of these areas of learning and retention are important aspects of adaptive behavior, and it is encouraging to find them appearing intact in so many persons with mental retardation. This conclusion is, of course, somewhat premature and certainly overgeneralized. The extant data are too sparse for conclusive statements, and, given the heterogeneity of the population identified with mental retardation, the relative homogeneity of the groups in the Klausmeier et al. study (84- to 104-

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year-old, community-based, special-class youths with mild retardation), the Scott study (10- to 13&year-old, community-based youths in public schools), and McCartney’s and Stinnett and Prehm’s studies (15- to 16-year-old, communitybased, special-class youths with mild retardation) put firm constraints on population generalization. Furthermore, the nature of memory is understood to be far too complex, presently, for such generalizations over that complete domain based on the limited sample of tasks found in these studies. Finally, all of the studies, although generally meritorious and fairly convincing, are open to some questions and qualifications.

B.

Studies Involving Semantic Processing

Studies of semantic processing extend coverage of the tasks, content, and, according to some theoretical analyses, memory or processing systems involved in LTM capabilities. The studies reviewed constitute a program of research carried out by my colleagues and me, designed to extend studies of the effects of cognitive strategy training on learning and short-term memory for meaningful verbal material to investigations of retention after significant periods of time. Our resolution of the problem of original learning, which is the initial hurdle to conducting LTM research, relied on prior research demonstrating that a pairedassociate task using a questioning format can induce extensive and equivalent learning among groups of children with wide individual differences (Buium & Turnure, 1977; Kestner & Borkowski, 1979; Turnure, Buium, & Thurlow, 1976). When the pairs were presented once by an experimenter who asks questions that the child is instructed to answer, both children of average IQ and those of low IQ master 70 to 90% of a paired-associate list containing as many as 24 pairs. The experimenter displayed pictures of the stimulus (e.g., nurse) and response (e.g., window) items as each question was posed, (i.e., asking a question such as Why is the nurse breaking the window‘?).The child then answered the question (e.g., There is ~ f j r eand the nurse must escape). Initially, the tests were short-term, standard cued-recall, retention tests that were administered within minutes of initial learning. Apparently, the dramatic improvement in learning on the shortterm retention test over traditional paired-associate learning of the labels alone (10-40% correct for even shorter lists; Thurlow & Turnure, 1972) and on list learning based on the repetition of items embedded in single sentences (cf. Jensen & Rohwer, 1963) reflects the greater depth of processing promoted by the question-answer techniques (Turnure et ol., 1976) for all groups of children. Memory theorists have suggested that with “deeper” processing, paired associates should be stored and retained over long intervals as well (c.f. Atkinson & Shiffrin, 1968; Craik, 1973; Morris, 1988). More specifically, the equivalent learning demonstrated under the questioning technique conditions, which were themselves instances of equal opportunity conditions (c.f. Belmont, 1966;

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Gillette, 1936), generates the plausible inference that the learning demonstrated could translate into equivalent degrees of storage or states of memory, particularly because the processing required of the subjects (e.g., comprehending the questions and producing sensible answers) is identical. Therefore, the primary requirement for a study of long-term retention across groups apparently was now available. The issue of how to control intertrial reminders and rehearsals was a focus of the experiments. In essence, the potential for control came ensconced in the selection of method, based as it was on the paired-associate structure of the memory test. We tacitly relied on the operation of task-test context effects to minimize reactivation of most of the materials in the subject’s everyday environments, especially as all of the pairs of common and familiar stimulus items were unlikely combinations (e.g., sock-tire, doll-pie) because of the randomization of item pairing. If this sort of learning is isolatable, then the second of the fundamental conditions for the controlled study of pure memory seemed to be available (cf. Bahrick, 1984; Bartlett, 1932, pp. 2-7, 10-13). A rather unnoticed value of elaborated learning is that several types of potential retrieval cues are available, including verbal, visual, textual, and content contextual cues. Depending on how the original elaborative experience was structured, a wide range of cues can be manipulated. Furthermore, by retaining each subject’s specific answers, the cues can closely approximate the subject’s idiosyncratic mental processing. Furthermore, the interrogative technique of inducing verbal elaboration (Buium & Turnure, 1977; Turnure er al., 1976) is based on adaptations of natural language usage (cf. Chuckovsky, 1968; Rosen & Rosen, 1973). Question answering itself is a prevalent form of human discourse (Andre, 1987; Turnure, 1985; Turnure er al., 1976), so at least some degree of ecological and naturalistic validity (Neisser, 1978) can be claimed for the technique. In this section, I summarize a series of three studies of long-term retention with three major independent variables: ability level of the subjects, retest intervals, and numbers or types of cues used to facilitate the retrieval of word pairs stored in long-term memory (Tulving & Watkins, 1973). Early on, we (Buium & Turnure, 1976; Turnure & Buium, 1975) adapted a model of information acquisition and reproduction from the “contextualist” position articulated by Jenkins ( 1974), which clearly expresses a specific relationship between learning and memory. An obvious derivation of this model leads to the hypothesis that, if task materials and instructions are arranged to ensure effective, meaningful subject involvement in them, (1) equivalent initial learning should obtain, and (2) LTM tests should reveal equivalent retention. That is, irrespective of their IQs, subjects should show equal long-term retention if they have experienced equally effective, meaningful initial learning, unless they have a substantial LTM defect, as do amnesic patients (Squire & Butters, 1984). The goal of the three studies reviewed here was to investigate cued retrieval

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from long-term memory of paired associates learned 10-30 days earlier in three populations of children equated for mental age-EMR, nonretarded, and gifted. The initial learning experience in all studies consisted of answering questions about word/picture pairs without being told to intentionally remember the pairs; this was followed immediately by a short-term paired-associate test. Varied within and across experiments were (1) the length of time before long-term recall was tested (Study I), and (2) the type of retrieval cue used (all experiments). The conditions of initial storage (prior learning context) included a rich, focal, verbal and visual context for the word pair (Tulving, 1983) that helped establish a “link” between stimulus and response words in several contexts. The visual context consisted of a line drawing of the stimulus word and a line drawing of the response word. The verbal context consisted of the stimulus and response labels, plus a why question about the two that linked them into a kind of “script”-an implicit, meaningful event-as well as a response provided by the subject that was usually in the form of a causal answer to the question. The item pairs to be remembered by the subjects are both verbally and visually encoded during the training session. As the experimenter holds up a pair of pictures, one in each hand, he or she asks the subject a question about the pictured items in which the item presented on the subject’s left is encoded as the noun subject of the question (and is the “stimulus” item), and the item on the subject’s right is encoded as the noun direct object of the question (the “response” item). Everything experienced during the acquisition or training session that preceded the long-term retrieval session by 10 to 30 days provides a prior learning context, features of which may be used as retrieval cues. In general, the prior learning context may be partitioned into four classes of potential contextual features or cues, ranging from features that directly encode the target items to be recovered to peripheral or “accidental” features of the learning setting (Tulving, 1983). The focal objects, the paired associates themselves, as pictured in line drawings and verbalized as noun components of the questions asked, might be said to constitute the first-order visual and verbal context. The question asked about the item pair constitutes a second-order verbal context for the paired associates. There was no comparable second-order visual context (e.g., a picture illustrating the interaction constituted in the question). Third-order features of the visual and verbal context might be said to include graphic elements of the illustrations and syntactic or stylistic aspects of the questions asked. Finally, we might consider other “accidental” (from our perspective) environmental setting features as a residual category of fourth-order contextual aspects of the task. In the experiments reviewed here, situational effects, including third- and fourth-order contextual features, were held relatively constant from storage to retrieval, which should facilitate recall. All children were tested at retrieval by the same tester, in the same room, using identical materials and equipment. The first- and second-order contextual features may be partitioned into con-

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tinua of gradually more inclusive visual and verbal cues, so that prompts would range from free recall (no visual or verbal cues presented) to complete repetition or relearning (both stimulus and response pictures presented visually and both the question and subject's answer to it, including both the stimulus and response names, presented verbally). In general, retrieval cues tested consisted of the arrangement of elements selected from the visual and verbal parameters of the task. The first-order visual stimulus continuum consists of showing stimulus-response picture pairs during initial learning, and showing only the stimulus picture during a short-term retrieval test. Visual features that could be used to reestablish the visual context were ( 1 ) no visual context, ( 2 ) stimulus picture only, ( 3 ) response picture only, and (4) both stimulus and response pictures. The first-order verbal continuum consists of the stimulus and response words, and parallels the visual continuum: ( 1 ) neither the stimulus nor the response label, ( 2 ) the stimulus label only, (3) the response label only, or (4) both the stimulus and the response labels. MIN INT

--. -I

MAXv

"1-

D.--*,

Gifted EMR Gifted EMR Gifted EMR

18

16

5u

14-

CL

0

u

-

12

-

a Y

2z

10-

86A-

2-

FIG. I. Mean number correct as a function of retention interval and prmipt condition lor gifted and EMR subjects. Key t o prompt conditions: MIN. minimal; INT. intcrnlediate: MAXv, niaximal visual.

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The second-order verbal continuum consists of the enveloping experimenterprovided questions and the subject-provided answers, which were hypothesized above to account for the high rate of “incidental” learning of paired associates. This may be partitioned into ( I ) no question or answer, (2) question only, (3) answer only, or (4) both question and answer. The first study we conducted (Turnure et ul., 1977) included 90 gifted children, whose mean IQ was 140 and mean CA was almost 8 years (estimated mental age = I35 months), and 90 educable mentally retarded children, whose mean IQ was 72 and mean CA was about 1 I years (estimated mental age = 84 months). All subjects initially performed in a “why”-type question-answer procedure. The data in Fig. I reflect, first, the mean number correct on acquisition (immediate retention interval) of 20 paired associates, which was 75% overall performance by the EMR (M = 15.08, SD = 2.54) and 85% for the gifted (M = 16.76; SD = 2.06). (Note that these SDs indicate ceiling effects were absent.) The other data points reflect mean performances on three retrieval tasks by independent groups of 10 subjects each, who were not informed that they were to be retested and who were seen 10,20, or 30 days after acquisition. On the second day, subjects received one of three types of prompt trial and then a standard paired-associate test. The minimal prompt (Min) consisted of the 20 stimulus items from acquisition, whose labels they repeated. In the maximal visual prompt (Maxv), the stimulus-response picture pairs were shown and subjects repeated their labels, but nothing was said about the original verbal elaboration content. In the intermediate condition (Int), the stimulus item was shown and the subject repeated a paraphrase or derivation of the original verbal elaboration that never mentioned the response term, for instance: Original question

Why is the dog barking at the fight?

Original answer

Because the light’s too bright and he doesn’t like it.

Retrieval prompt

The dog is barking at it because it’s too brighr and he doesn’t like it.

The minimal prompt condition results show that both gifted and retarded children were increasingly unable to retrieve response items as a function of the intervals, generating classic forgetting curves on this explicit memory test. It is clear that the memories of gifted children are not impervious to time. The maximal visual prompt condition, which would be considered an implicit memory test, shows that this visual reminder not only improves performance, but generates perfect retrieval and further learning. Note that this is true for both gifted and retarded children. It may seem surprising that the retarded children’s memories are so good, but this finding is further supporting evidence that, whatever memory problems people with retardation have, storage per se is not

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among them (cf. Belmont, 1966). The intermediate condition showed that this version of reinstating the original verbal context only had a marginal or transitory facilitative effect on the retarded children’s response in retrieval, but the gifted children apparently could utilize this information, and produced significantly more responses after 20 and 30 days. These data show that (1) given minimal retrieval cues, over time, both gifted or retarded children became increasingly unable to respond with previously learned responses, an increasingly reliable and general finding in any population (cf. Loftus, 1982); (2) certain “reminders” can reinstate levels of learning very efficiently; (3) some curing conditions appear to produce population differences. The data from the minimal prompt condition, especially from the gifted group, also may be taken to imply that intertrial rehearsal contamination did not occur. These results, especially the last finding, were further investigated in Studies 2 and 3 (Turnure & Gudeman, 1984), which were very similar to the first. Gifted, average, and mentally retarded children of similar levels of achievement were presented the same question-answer task as the prior subjects without intentional memory instruction, and all subjects were retested 21 days later, under one of nine experimental cuing conditions (three in Study 2, six in Study 3; there were also several control groups). The cuing conditions ranged from such minimal cues as free recall, to just mentioning the stimulus items (i.e., the subjects of the original questions) or showing the stimulus picture (Study 2), through such partial context reinstatements as repeating the question-answer context with or without mentioning the response items (i.e., objects of the original questions), with the higher degrees of verbal context crossed with presenting the stimulus picture, but never the response pictures (Study 3). These conditions were considered, empirically, parametric variations of the verbal and visual information involved during original learning (Tulving & Watkins, 1973), and also reasonable simulations of retrieval conditions in school and other social circumstances. Study 2 compared the efficacy of free recall and “minimum” prompts in cuing the retrieval of verbal material learned by the interrogative technique. The prompts used consisted of those termed,first-order prompts alone, the stimulus or response labels or pictures. The retrieval conditions, then, were free recall, stimulus picture only, or verbal stimulus label only. Presenting graphic elements, pictorial or written, is a common cuing technique in paired-associate learning, but providing only a verbal utterance appears unusual, as is inclusion of a free recall test for paired-associate measurement (cf. Horowitz & Prytulak, 1969). Immediately after the retention test, all subjects reviewed each picture pair for 10 sec, and then were retested with the standard stimulus cue procedure, as a form of relearning, comparable to the maximal visual prompt treatment in Study 1. A 21 -day test-retest interval was used in all conditions; assignment to conditions of subjects within populations and general assignment to testing days were randomized.

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Although IQ scores were not available, the children considered handicapped were in special classes, and the “gifted” children were in special enrichment programs. The children with mental handicaps (whom we considered to have mild mental retardation) had CAs averaging 1 I .8 years, and the “gifted” children had a mean CAs of 7.9 years; the average children’s mean CA was 8.7. On initial acquisition with the interrogative technique the “gifted” group averaged 17.4 correct; the average students, 17.2; and the students with handicaps, 15.2. The average sample showed some evidence of a ceiling in their data, as two subjects scored 100% correct, and one prompt group formed had a SD of 1.27, notably less than the 1.5 criterion proposed by Belmont (1966). This qualification did not appear to bear heavily on the findings, however. The results are presented in Fig. 2, which shows similar retention and “relearning” functions for all groups, across conditions, with the children identified as handi-

20-

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. Normal

,” Gifted EMR

-

-

1211-

10

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21-

Immediate

Delayed recall 1 Retention interval

Delayed recall 2

FIG. 2 . Mean acquisition, prompted retention, and final retention scores by ability group.

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capped showing slightly poorer performance, which was statistically significant in an analysis of covariance. The final retention test showed that all groups recovered to their initial acquisition levels, as would be expected based on the results of the maximal visual prompt condition of Study 1 . No Ability Level x Condition interaction was found in any analysis. Again, overall these data indicate a problem of accessibility, but not availability, for this array of children, and also show an apparent greater susceptibility of children with mental handicaps to drastic reductions in structured prompts or contextual cues. Study 3 followed the pattern of Study 2 . Subjects learned the 20-pair list of pictures in the interrogative technique and were retested 3 weeks later. At retest, cues selected from the visual dimension varied from nil, that is, no picture in half the visual contexts, to moderate, that is, presentation of stimulus items only. The verbal parameter was varied from utterances of the names of the original pairings; through utterance, via paraphrase, of the original elaborative context incorporating the stimulus name; to utterance of the complete elaboration contexts including both stimulus and response item names. Crossing these factors produced six conditions for contrast. The fact that both stimulus and response terms were to be uttered at the time of retrieval raised the possibility that test-related responses could be acquired at the time of retrieval; therefore, independent groups of children were run in similar fashion to provide estimates of base learning rates for such exposure. Although IQ scores were not available, all pupils in the group with handicaps were performing at least two grade levels below average for their CAs (M = 1 I .98 years) in both reading and math; and the gifted students (CA M = 7.45) were performing 2 or more years above grade level in reading and math. The average students were performing within 1 year of grade level (CA M = 9.71 years). The results on acquisition showed slight evidence of a ceiling on acquisition, but no population difference (EMR M = 16.83, SD = 2.30; average M = 16.99, SD = 1.79; gifted M = 16.89, SD = 2.07). One of the recall conditions for the gifted and the average subjects showed a slight ceiling compression. The mean numbers of correct scores on retention tests of all groups in the six conditions of Study 3 are displayed to the right in Fig. 3 , with the results from Study 2 on the left, for comparative purposes. The two most pertinent general outcomes observable in Study 3 were that ( 1 ) the EMR had a significantly lower retention score than the other two groups, and ( 2 ) the relationships of all of the data points within subject categories is the same, indicating that all groups were affected similarly by the cuing variables. This conclusion is supported by the lack of an Ability Group X Condition interaction, independent of the slight ceiling in one prompt condition. The results showed that high rates of recall (90%or better) were not achieved by children in the EMR sample unless they received both a picture prompt and a verbal prompt that included both the stimulus word and the

21 1

LONG-TERM MEMORY A N D MENTAL RETARDATION

response word. The average children recalled 90% or more of the items they had learned if cues included both stimulus and response terms, regardless of picture availability. The gifted children recalled 90% or more in four of the six conditions if they received a picture prompt in ( I ) any of the verbal conditions and (2) the question-answer with both terms, but no picture. The inverse relation between degree of context provided and ability level is obvious, but caution must be exercised in drawing conclusions from these observations. First, the relative lack of strength of the other two conditions in enhancing recall for the gifted sample in Study 3 cannot be ignored, nor can the drop in recall of the gifted subjects of Study 2 . Second, the generally good recall of the retarded children cannot be ignored, particularly because the relative ordering of condition outcomes over Studies 2 and 3 is almost identical, in most respects, to that in both of the other populations. Third, in all conditions there is overlap across populations, and wide individual differences as well, as was noted in most of the studies of more basic processes reviewed earlier. These data show that all three populations have similar response functions. although the mentally retarded lag in relation to the other groups to a statistically significant degree. 20 18

-

16 -

p 8f 5

14: 12:

13

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' 5

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4

6:

; ; I

4 -

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2 -

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-

-

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S-R, Q-A;

Q-A;

NOPC SWd, S-R, S P c NoPc

Study3 Verbal/visual conditions

d

Average Gifted

S-R, SPC

0-A;

S-R, Pc

L

FIG. 3 . Studies Z and 3: prompted retention group means by ability group and prompt condition. Key to prompt conditions: S Wd. stimulus word; No Pc, no stimulus picture; No Vb, no verbal; S Pc. stimulus picture: Q - A . question-answer: S-R. stimulus-response.

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The overall recall function appears to be determined by specific organizations of cue elements. Obviously, based on the findings for the minimal cue conditions of Study 2, without extensive context cuing, well-learned, meaningful material cannot be retrieved even by good students on an unexpected “pop quiz” basis after 2 or 3 weeks. This indicates that gifted children do not have exceptional memories in the sense of Ericsson and Chase (1982). And, conversely, given the same circumstances but providing sufficient context, mentally retarded children may be shown to reactivate or access learned information rather well, indicating that memory in this population is not exceptional either.

IV.

CONCLUSIONS

This review of LTM research has demonstrated a continuum of memory performances that follows much the same form across different types of tests and cuing conditions for EMR, nonhandicapped average, and gifted children. Thus, evidence is accumulating that the LTM capacity of young mildly handicapped individuals is intact and functions within normal ranges on an array of tasks. Of course, the data base in this area is still quite sparse, and the available evidence is not completely consistent. In particular, the slightly but significantly poorer performance of the EMR subject samples in several of the studies reviewed might be interpreted to support the position that their memories are distinctly and qualitatively deficient (cf. Detterman, 1979). Conversely, the similarity of the patterns of results across populations in most of the studies clearly implies only a quantitative deviation from normal performance, or, as Belmont (1978) put it, “Retarded people’s memory deficiencies are very much like normal children’s deficiencies” (p. 179), that is, normal. In effect, the long-term memory functions described here are quite consonant with field research involving a broad cross section of normal adults. Loftus ( 1982) summarized studies showing numerous instances of forgetting of meaningful information, taking the general form of Ebbinghaus’ forgetting curves, which would hardly imply that their memories are defective: The same logic would presumably hold for persons with mental retardation. Furthermore, it is worth emphasizing once more the wide individual differences found in all groups and the overlap among them. ‘There are no instances of subjects showing consistently low profiles of performance irrespective of cue condition, as would be expected of memory-defective clinical populations such as amnesiacs, Alzheimer’s syndrome patients, and those with other memory disorders. Thus, mildly retarded individuals appear to have both implicit and explicit memory systems that have sufficient capacity or potential for retaining quite extensive amounts of learned information and skills.

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There remains a great need for investigations involving more tasks, including studies of autobiographical memory, in people with retardation. Furthermore, as theoretical issues involving LTM emerge, more attention will need to be given to developing more control and more precise measures of original learning, retrieval conditions, and interval contamination than has been possible in the studies reviewed. For instance, none of the studies reviewed, even that by Klausmeier et al. (1959), successfully equated original learning in all respects, in that some aspect of the methods had to be adjusted to bring the performances and, presumably, the processing of the EMR subjects into the proximity of their nonhandicapped comparison groups. The results reported in this review appear to have both theoretical and applied, particularly educational, implications for individuals with mild mental retardation. The methods and findings described should contribute to reducing the “unknowns” decried by Rohwer and Dempster (1977), cited earlier. Everyday and, in particular, school activities seem seldom to involve the radical reduction of prior context and cues, as in free and standard cued recall research, nor their complete reinstatements, as in recognition. Rather, it is information on the effects of reinstating “middling” amounts and kinds of prior experience that is most pertinent to, at least, applied work. Reports of the lack of communication and ineffectiveness of instruction in classrooms (cf. Goodlad, 1984), for instance, suggest that teachers may be erroneously assuming that much recall occurs on the basis of a brief reminder of prior lessons. A major implication of this research is that the structure of retrieval conditions may be as important as how the original learning conditions were structured, and as complicated as trying to ensure equivalent original learning (see Stinnett & Prehm, 1970). Extensions of this research may have implications for diagnostic practices with individuals who are more severely retarded, for whom no LTM data appear to be available. Certainly memory assessment batteries could be expanded to include tests of implicit and explicit memory and of meaningful verbal material, which, in the case of the question-asking technique emphasized in the latter part of the review, produces very natural “semantic processing” and overt responding, all within the controlled confines of the paired-associate task. The growing appreciation of the extent of individual differences and the varieties of diagnostic subgroups among the mentally retarded population clearly indicates the need for more intense and subtle analyses of psychological processes, including studies of apparent neuropsychological concomitants among the severely retarded, even though the vast majority of the retarded, it must be emphasized, appear to have no known neurological involvements (cf. MacMillan, 1982; Zigler, 1967). ACKNOWLEDGMENTS

I thank Lori Mack and Jane Schleisman for secretarial and bibliographic assistance.

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James E . Turnitrr REFERENCES

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Index

A

AAMR. see American Association on Mental Retardation Abnornial development. Soviet assessment and, 130 Abstraction problem solving and, 164 Soviet assessment and, 125 Accuracy. problem solving and, 162 Achievement adaptive behavic!rs and, 44 long-term memory and, 208 Soviet assessment and. 125. 138, 145 Acoustic propertier. language development and. 77 perception, 57-59. 62 production, 66-67, 69. 75-76 Activity. Soviet assessment and, 123-124 ACT* theory. problem solving and, 177, 179 Adaptation, problem solving and, 153- 154. 156. 159 Adaptive behaviors. 1-3, 47-48 life-span development. 19 characteristics of individuals. 41 -42 design issues, 20-23 Down syndrome persons. 36-39 empirical studies, 23-35, 39-40 moderating factors, 40-41, 46-47 residential cnvironment. 42-46 semilongitudinal designs, 21-23 traditional designs, 20-21 structure, 4-5. 16-19 empirical approaches, 7- 16 rational approaches, 5-7 verbal communication and, 91, 93, 108 Adaptive Behavior Scale, life-span development and, 2, 29 structure, 5 , 8-9, 15-17

Adult-infant interaction, language development and, 77-80 Age adaptive behaviors and, I , 3 life-span development. 19-21, 24-40 moderating factors, 47 structure, 16-17 language development and, 77-78, 80-81 perception, 61-62 production, 69-73 long-term memory and, 199, 205, 207, 209-210 mental. see Mental age problem solving and, 161-163, 174, 176. I80 Soviet assessment and, 136-137 verbal communication and conversational repair, 107 managing speech acts, 100, 102-103 research, 94, 97-98 topic organization, 105 Age at death, adaptive behaviors and, 38 Aggressive behavior adaptation, 7, I I language development and, 82 Alzheimer's disease, adaptive behaviors and, 36 American Association of Mental Deficiency, adaptive behaviors and, 27 American Association on Mental Retardation (AAMR) adaptive behaviors and, 1-2, 5 . 9. 29 verbal communication and, 9 I Amnesia, long-term memory and, 199, 204. 212 Analogical mapping, problem solving and, 178-179 Anticipation. problem solving and, 161I62 219

INDEX

Attention language development and, 61 Soviet assessment and, 128, 142 Auditory events, language development and, 62, 64-66, 80 Auditory sensitivity, language development and, 56-57, 59 Auditory signals. language development and, 63 Automaticity, problem solving and, 158 Automatic memory, exceptional subjects and, I99 Automatic processing, problem solving and, 157 B Babbling, language development and, 67-68, 70, 80-81 Babbling drift, language development and, 6768 Balance-scale task. problem solving and, 175, 177- 180 Behavior problem solving and, 156-157, 160 Soviet assessment and. 122 Behavioral Development Survey, adaptive behaviors and, 29 Behavioral functioning, Soviet assessment and, 1 I8 Behavioral training studies. problem solving and, 165-170, 179 Biological processes language development and, 60 Soviet assessment and. 126 Brain, Soviet assessment and, 122, 125 C Canonical syllable stage, language development and, 69, 81 Capacity language development and, 74, 81 problem solving and, 157, 178-179 Central nervous system, Soviet assessment and, 125, 136 Chunking language development and, 64 problem solving and, 157-158

Classification, Soviet assessment and, I36 Client Development Evaluation Report, adaptive behaviors and, 10, 18. 29, 36, 45 Clinical assessment in Soviet Union, 117, 146 recent literature, 131, 133-134, 143 survey framework, I25 Cognition, problem solving and, 153 self-management. 159- 160, 169 strategy transfer, 177- 178 Cognitive competence, adaptive behaviors and. 3 life-span development, 27, 30-32, 34 moderating factors, 43, 45 structure, 12-16 Cognitive factors, language development and, 61 Cognitive functioning adaptive behaviors and, 6, 26 Soviet assessment and, 119, 134. 136 Cognitive processes. Soviet assessment and, 122-125, 127 Cognitive skills adaptive behaviors and, 25, 27, 37-39 Soviet assessment and, 135 verbal communication and, 97, 99, 104, 108, 110-111 Cognitive strategy training, long-term memory and, 203 Cognitive training problem solving and, 161-165, 170, 179 Soviet assessment and, 118 Cohort effects. adaptive behaviors and. 21-23, 30, 33 College students, long-term memory and, 199200 Communication skills, adaptive behaviors and, 6, 27 Communicative environment, language development and, 79 Community self-sufficiency, adaptive behaviors and, 10, 24-25 Community settings, adaptive behaviors and. 26, 29. 37, 42. 44 Comprehension, language development and, 60,71, 73. 74 Condition-action rules. problem solving and, I77 Congenital factors, adaptive behaviors and, 24 Consciousness, Soviet assessment and, 122 Constraints

22 1

INDEX

adaptive behaviors and, 24 on problem solving, see Problem solving Content knowledge, problem solving and, 172-173, 179, 181 Context adaptive behaviors and, 3, 47 language development and, 65 long-term memory and, 204-206, 208, 2 10-213 problem solving and. 153, 176 verbal communication and, 99- 100, 102104 Continuity, Soviet assessment and, 133 Controlled processing, problem solving and, 157, 175 Conversation, verbal communication and, 92, I 08 managing speech acts. 103 research, 93, 95, 97-98 topic organization, 104- 105 Conversational repair, verbal communication and, 93, 105-108 Correction probe. Soviet assessment and. 137 Crying, language development and, 74-76 Cues language development and, 58 long-term memory and, 194, 212-213 exceptional subjects, 201 history, 194-196, 198 semantic processes, 203-206, 208, 210212 problem solving and, 167-168, 172 Cultural deprivation, Soviet assessment and, 126 Culture language development and, 63-65 Soviet assessment and, 124, 126, 146

D Daily living skills, adaptive behaviors and, 27, 37-38 Deaf babbling myth, language development and, 68 Deafness, language development and, 56, 82 Decay, language development and, 61 Declarative stage. problem solving and. I78 Defectology, Soviet assessment and, 125, 128129, 136, 141, 143

Definition of mental retardation, adaptive behaviors and, 4 Degrees of storage, long-term memory and, 195, 202 Demographics, adaptive behaviors and, 24 Destructive behavior, adaptive behaviors and, 7 Development problem solving and, 175, 178, 180, 182 Soviet assessment and, 124- 126, 130 Developmental delays, verbal communication and, 103, 108, I l l Diagnosis, Soviet assessment and, 130 Dialectical materialism, Soviet assessment and, 122 Differential diagnosis, Soviet assessment and, 130 Discontinuity myth, language development and, 67 Domain-specific products, problem solving and, 178 Domestic activities, adaptive behaviors and, 6 Down syndrome adaptive behaviors and, 27-28, 36-41 language development and, see Language development long-term memory and, 200 verbal communication and, 94, 98. I10 conversational repair, 106 managing speech acts, 100, 103 Dynamic assessment, in Soviet Union, 126 Dynamic clinical assessment, in Soviet Union, 131, 133-134

E Early intervention programs, language development and, 66 Education, adaptive behaviors and, 22 Elaboration, problem solving and, 176 Electrophysiological evaluation, Soviet assessment and, 128 EMR adaptive behaviors and, 44 long-term memory and, 205, 207, 210, 2 12-2 I3 Encoding long-term memory and, 198, 202, 205 problem solving and, I82

222

INDEX

Environment, verbal communication and, 92 Episodic memory, exceptional subjects and, I98 Ethnicity, adaptive behaviors and, 41 Etiology adaptive behaviors and, 24, 41. 47 Soviet assessment and, 136 verbal communication and, I10 Exceptional subjects, long-term memory and. 193, 198-203 semantic processes, 203-212 Expansion stage. language development and, 69 Experience. language development and, 65. 80 Explicit memory. exceptional subjects and. 200-201, 207, 212-213 Explicit requests. verbal communication and. 107 Expressive vocals. Soviet assessment and. 137 External consequences, problem solving and, I70 External contingencies, problem solving and, I68

F Fac i I i tat ion language development and, 60-61 long-term memory and. 208 Factor analysis adaptive behaviors and. 4, 7 , 9. 14-19 Soviet assessment and, 135 Family. adaptive behaviors and, 44 Feedback language development and, 57 long-term memory and, 202 problem solving and, 156. 163, 167 Soviet assessment and. 137 Fine motor skills, adaptive behaviors and, I I Forgetting long-term memory and, 199, 207, 212 problem solving and, 172 Free recall, exceptional subjects and, 200. 206, 208, 213 Functional autonomy, adaptive behaviors and, I5

G

Gender, adaptive behaviors and, 41 Generalization

problem solving and, 167. 179 Soviet assessment and, 125, 136, 138 Genetic evaluations. Soviet assessment and. I36 Gestures. language development and, 62-63 Gifted children long-term memory and. 193 history. 194 semantic processes. 205, 207-210. 212 problem solving and, 180- I8 I Gist recall, problem solving and. 162 Goal definition, problem solving and, 161 Goal-directed behavior. problem solving and, 156- 157 Goals. problem solving and. 161. 165-166 Gross motor skills adaptive behaviors and, I I , 27. 38 language development and. 72 Guessing, Soviet assessment and. 137

H Habituation, language development and, 58. 66 Hearing. language development and, 56-57, 59 Hearing loss, language development and, 57. 72. 79 Hierarchical structure of abilities, adaptive behaviors and, 4. 18 Human labor, Soviet assessment and. 122 Hypotonia, language development and. 68. 7.5

I Imitation, language development and, 79-80 Impcrative expression. language development and, 62 Implicit memory, exceptional subjects and, 198-199, 201, 212-213 Implicit verbal requests, verbal communication and, 107 Inclined-plane training, problem solving and, 178-179 Independence, adaptive behaviors and, 6 , 18, 39 Independent living skills, adaptive behaviors and life-span development. 25. 27-28, 32, 37. 39

223

INDEX

structure, 1 I - 14 Infants. language development and crying, 74-76 interaction with adults, 77-80 vocalization, 56. 66-70 Information processing problem solving and. 154-158. 169. 181I82 verbal communication and. 95. 98 lnfraphonological approach. language develop ment and. 67. 69 Institutionalization adaptive behaviors and life-span development, 25-26, 28-29. 36-37 moderating factors. 42-43 verbal communication and, 95 Instruction. problem solving and, 159- 160 Integration principle, Soviet assessment and. 133 Integrative stage, language development and, 70 Intellective function, adaptive behaviors and. 3 Intellectual ability, adaptive behaviors and, 7. 16 Intellectual insufficiency. Soviet assessment and. 134-135 Intelligence adaptive behaviors and, 1. 4-5 definition of, 4 long-term memory and, 200 naive theory of. 153 problem solving and, 153-155. 181-182 self-management. 162 strategy production, 172- 175 strategy transfer, 178 Intelligence tests adaptive behaviors and. 3-4 Soviet assessment and. 123 verbal communication and. 91 Interference. problem solving and. 172 Interpersonal adjustment. adaptive behaviors and, 15. 33 Interpersonal behavior, structure, 6 Intertrial rehearsals, long-term memory and, I96 Intervention, Soviet assessment and, 117-1 18 Intonation, language development and, 77 lntrapersonal adjustment. adaptive behaviors and, 15 IQ adaptive behaviors and. 22. 25. 27

long-term memory and. 199. 201 semantic processes. 203-204, 207, 209210 verbal communication and, 96. 107 Isomorphic problems, problem solving and. 178-179

K Knowledge, theory of, Soviet assessment and, 123

L Labels long-term memory and, 203, 205-208 problem solving and, 161 Language adaptive behaviors and. 5 . 16, 27, 38 problem solving and, 169, 171 Soviet assessment and, 123, 139, 146 verbal communication and, 9 1-92 Language development, Down syndrome and, 55-56, 80-82 adult-infant interaction, 77-80 motherese, 76 perception auditory sensitivity, 56-57 capacity for speech, 57-59 from ear and eye, 62-63 linguistic specialization, 60-62 music, 63-66 production, 66 infant cry, 74-76 infant vocal development. 66-68 maturation. 68-74 Language therapy, verbal communication and, 91 Leading activity, Soviet assessment and, I23 Learning. long-term memory and exceptional subjects, 198-200 history, 196-198 semantic processes, 204 Learning capacity, language development and, 74, 81 Learning disability, Soviet assessment and. 136. 138, 140-142. 145 Learning potential, Soviet assessment and, 132, 138-140. 144-145

224

INDEX

Life-span development, adaptive behaviors and, see Adaptive behaviors Linguistic skills. adaptive behaviors and. 28 Linguistic specialization, language development and, 59-62 Long-term memory, 193-194. 212-213 exceptional subjects, 198- 199 basic processes. 199-203 semantic processes, 203-212 history, 194-198 problem solving and, 157-158

M Maintenance language development and, 60 problem solving and, 182 self-management. 161-164, 168 strategy transfer, 177 Maladaptive behavior, 47-48 life-span development and. 29 moderating factors, 40, 42, 44-45, 47 structure, 5 . 7, 1 1 , 14-15. 18-19 Managing speech acts, verbal communication and, 93, 99-104 Marginal babbles, language development and, 69 Maturation language development and, 68 Soviet assessment and, 127 Maturational theory of speech perception, language development and, 60 Maturity demands, adaptive behaviors and, 45-46 Mean length of utterance in morphemes (MLU) language development and, 73-74 verbal communication and, 100, 103, 111

Memory, see also Explicit memory; lniplicit memory; Long-term memory; Shortterm memory; Working memory language development and, 61 problem solving and, 154-155, 181-182 information processing, 157-158 self-management, 163, 170- 171 strategy production, 171-175 strategy transfer, 178 Soviet assessment and, 125-126, 128, 136. 140, 142

verbal communication and, 98 Mental age language development and, 72-74, 81 long-term memory and, 205, 207 problem solving and, 161-162, 180 verbal communication and, 108 conversational repair, 106 managing speech acts, 101. 103 research, 94, 98-99 Metaphonological approach. language development and, 67 Methodology, Soviet assessment and, 132 Methodology myth, language development and, 66 Mild mental retardation adaptive behaviors and, 25, 30-32. 45-46 long-term memory and, 199-201, 209 problem solving and, 162, 165-166, 169 verbal communication and, see Verbal communication Minnesota Developmental Programming System, adaptive behaviors and, 14, 2627. 37-38 MLU. see Mean length of utterance in morphemes Moderate mental retardation adaptive behaviors and, 32, 45-46 problem solving and, 166, 169. 171 verbal communication and. see Verbal communication Monitoring, problem solving and, 166- 169 Morphemes language development and, 71, 73-74, 80 verbal communication and, 100, 103, I I I Mother-child interactions, language development and, 78, 81-82 Motherese, language development and, 76 Motivation adaptive behaviors and, 25 verbal communication and, 101 Motor development adaptive behaviors and, 10-13, 28, 45 language development and, 7 1 Motor skills adaptive behaviors and life-span development, 27, 29, 36-40 moderating factors, 27, 29, 36-40 structure, 6, 1 1 , 14 long-term memory and, 198- I99 Soviet assessment and, 134 Motor stimulus, language development and, 62

225

INDEX

Multifactorial studies. adaptive behaviors and, 9-16 theories. 7. 23, 47 Music perception, language development and, 56. 58. 63-66. 77. 80

N Negative reinforcers, language development and. 75 Neonatal Behavioral Assessment Scale, language development and, 76 Nervous system, Soviet assessment and, 122. 124-125, 128 Neurological evaluation in Soviet Union. 125, 128. 133-135 Neurological involvement. long-term memory and, 213 Neurophysiological evaluation in Soviet Union. 125, 134 Nonintellective factors, adaptive behaviors and. 3 Nonsense syllables. long-term memory and. 196 Nonverbal cognition, language development and, 71-74, 81-82 Nonverbal requests, verbal communication and. 107 0

Occupational activities, adaptive behaviors and, 6 Oligophrenia. Soviet assessment and. 125, 142 Ontogenetic evaluation. Soviet assessment and, I35 Organizational strategies, problem solving and, I76 P Pain, response to, language development and, 75-76 Paired-associate tasks language development and, 62 long-term memory and, 201. 203-205, 207, 213 Parental achievement. adaptive behaviors and, 44

Parenting adaptive behaviors and, 44-46 language development and, 74-75 Pattern recognition skills, problem solving and. 158, 174, 179 Peer interactions, verbal communication and, 93-94, 100, 107 Perception, see ulso Speech perception problem solving and, 154 Soviet assessment and, 122, 128, 134 Perceptual abilities, language development and. 55 Perceptual learning long-term memory and, 198-199 theory of speech perception, 60 Performance, problem solving and, 182 self-management, 160, 165-166, 168, 170171 strategy production, 17I - I72 Perinatal factors, adaptive behaviors and, 24 Personal characteristics, adaptive behaviors and, 41-42, 46-47 Personal independence, adaptive behaviors and. 8, 18, 39 Personality, Soviet assessment and, I35 Personal maladaption life-span development, 33-35 structure, 7-8, 11-13, 15. 18 Personal self-sufficiency, adaptive behaviors and, 24-25, 44 Phonation stage, language development and. 69 Phonetics, language development and, 67, 72, 77 Phonetic segments, language development and, 77 Phonological processes, language development and, 70-7 1 , 76 Phrasing. language development and, 77 Physical development adaptive behaviors and, 6 Soviet assessment and, 134 Picture pairs, long-term memory and. 205-206 Picture prompts, long-term memory and, 21 1 Politeness, verbal communication and, 102 Pragmatic knowledge Soviet assessment and, 126 verbal communication and, 93-97, 104, 108-111 Prediction, Soviet assessment and, I37 Pregnancy, Soviet assessment and, 134

INDEX

Prenatal period adaptive behaviors and. 24 Soviet assessment and. 136 Preschool Attainment Record, adaptive behaviors and, 16 Primary Mental Abilities, adaptive behaviors and. 7 Priming. long-term memory and. 198 Primitive articulation. language development and, 69 Problem solving. 153- 156. 179- 182 information processing, 156- 158 self-management, 158- 159. 170-171 behavioral training. 165-170 cognitive training, 161- 165 instructional studies. 159- 160 strategy production, 175- 176 empirical evidence. 171-173 working memory. 173-175 strategy transfer. 176- I79 Procedural memory. exceptional subjects and. I99 Procedural stage. problem solving and. 178 Production systems, problem solving and. 177- I78 Productive abilities, language development and. 55 Prcifound mental retardation, adaptive behaviors and. I I , 30-33. 46 Prompting long-term memory and. 207-21 I problem solving and. 162, 165. 16X, 170171 Propositional memory. exceptional subjects and, 199 Prototypical syllables. language development and, 69 Psychoeducational assessment in Soviet Union. I18 recent literature. 13 1-136 survey framework, 125, 127 Psychological assessment in Soviet Union, 119, 144-146 recent literature. 131-139. 141-142 survey framework, 125, I28 Psychological processes, long-term memory and, 213 Psychology of cognition, problem solving and, I54 Psychometry problem solving and, 154

Soviet assessment and. 118, 146 recent literature, 131. 135, 140, 142. 144 Psychomotor factors. adaptive behaviors and. 14. 16 Psychopathological assessment, in Soviet Union. 133. 136

Q Qualitative assessment in Soviet Union, 120, 146 recent literature. 132 survey framework. 126- I28 Quantitative assessment in Soviet Union. 132. 144. 146 Quasiresonant sounds. language development and. 69 R Raven-like matrix problems, problem solving and, 180-181 Reactivity. problem solving and. 167- 168 Reading comprehension. problem solving and, 162. 164-165, 174 Reading skills, adaptive behaviors and. 38 Recall exceptional subjects and. 195. 198. 200. 213 semantic processes. 205-206. 210-212 problem solving and. 161-164. 172. 174 Soviet assessment and. 140 Receptive language. verbal communication and, 103 Receptive vocals, Soviet assessment and, I37 Recognition, long-term memory and, 198199. 201 Reference, language development and, 74 Referential task. verbal communication and, I06 Referents, establishment of. verbal communication and, 92-93, 95-99. 108 Rehearsal long-term memory and. 195-197. 204, 208 problem solving and self-management. 161- 164 strategy production, 172. 175- 176 Reinforcers language development and. 64,75 problem solving and. 167- 168

227

INDEX

Relearnins. long-term memory and, 199, 202. 206, 209 Repetition long-term memory and. 206 verbal communication and. 107 Residential environment. adaptive behaviors and. 24. 37. 41-46 Response. long-term memory and. 205-208, 2l0-2l I Responsibility. adaptive behaviors and. 6. 10. 15. I X . 2s Retention. long-term memory and, 199. 202204,209-210 Retention interval. exceptional subjects and. 194-197 Retrieval exceptional subjects and, 194. 201. 213 history, 194. I98 semantic processes. 204-208. 210. 212 problem solving and. 173 Rote learnins. long-term memory and. 199 Rote memory. exceptional subjects and. 200 Rules. problem solving and. 173- 175. 1801x1

S Scales of Independent Development, adaptive behaviors and. 8-9. 17 Scientific Research Institute of Defectology of the Academy of Pedagogic Science. 12s Scripts. long-term memory and. 205 Secondary task performance. problem solving and. 176 Second language learning, Soviet assessment and. 139 Self-care skills. adaptive behaviors and, 27. 38-39 Self-control. Soviet assessment and, 134 Self-esteem. adaptive behaviors and, 44 Self-help skills. adaptive behaviors and, 6 Self-instruction. problem solving and. 162, 164. 166-167. 169. 171 Self-management processes. problem solving and. 156. 158-159. 170-171, 179-180 behavioral training, 165- 170 cognitive training, 161-165 instruction. 159- I60 strategy production, I7 I

Self-regulation, Soviet assessment and, 138 Self-sufficiency. adaptive behaviors and, 10. 24-25? 44 Self-testing, problem solving and, 162. 170 Semantic memory. exceptional subjects and. 193, 198 Semantic processes language development and, 56, 74. 76. 81 long-term memory and, 198, 203-213 problem solving and. 182 Soviet assessment and, 137 verbal Communication and. 104. I 1 I Sensorimotor learning language development and, 73. 79 long-term memory and, 199 Serial recall, problem solving and. 162 Series-completion problems, problem solving and. 173-174 Sex. adaptive behaviors and, 37 Short-term memory exceptional subjects and, 197. 199. 203. 205-206 Soviet assessment and, 140 Single-factor hypothesis, adaptive behaviors and, 8 Situational demands, Soviet assessment and, 138 Social acceptability. verbal communication and, 102 Social adjustment. adaptive behaviors and. 44 Social behavior. adaptive behaviors and, 14 Social competence, adaptive behaviors and, 11-13, 15, 32, 34 Social context, Soviet assessment and, 122 Social interaction adaptive behaviors and, 9 Soviet assessment and. 126 verbal communication and, 91 Socialization adaptive behaviors and, 6, 9. 16 Soviet assessment and, 126 Social maladaption life-span development, 32-35 moderating factors. 44 structure. 7-8, 11-IS, 18 Social skills. adaptive behaviors and. 39-40, 43 Somatic evaluation, Soviet assessment and, 133-134 Soviet assessment, 117-1 19. 144-146 previous reviews, 120-121

228 recent literature, I28 analytic strategy, 131-132 clinical assessment, 133- 136 learning potential, 138- 140 procedures, 129- I3 I psychoeducational assessment, 136- 138 results, 132-133 sample, 128-131, 129 standardized data, 140-144 research literature, 119-120 survey framework, I2 I philosophical concepts, 122- I26 qualitative approaches, 126-128 Spatial location, long-term memory and, 200 Spatial organization, Soviet assessment and. 136- I37 Special education Soviet assessment and. 117-1 19, 144, 146 recent literature. 129-130, 133, 139 survey framework. I2 I - I26 verbal communication and, 91 Speech innate capacity for, 57-59 Soviet assessment and, 136 verbal communication and, 93, 99- 104 Speech acts, verbal communication and, 93, 99- I04 Speech contrasts, language development and, 59-60 Speech development, 56-57 Speech perception, language development and, 56, 80 auditory sensitivity, 56-57 ear and cye, 62-63 innate capacity, 57-59 linguistic specialization, 60-62 music, 63-66 perceptual learning theory. 60 universal theory, 60 Speech production, language development and auditory sensitivity, 56-57 capacity, 57-59 ear and eye, 62-63 experience, 68-74 infant cry, 74-76 infant vocalization, 66-68 music perception, 63-66 Speech reception, language development and, 60 Speech therapy, verbal communication and, 91 Standardized assessment data in Soviet Union, 132, 140-144

INDEX

Stanford-Binet, Soviet assessment and, 142I43 State of memory, exceptional subjects and. 195, 204 Stimulus language development and, 62, 64-65. 80 long-term memory and exceptional subjects, 202 history, 197 semantic processes, 203-208, 210-21 I verbal communication and, 95-96 Storage degrees of, 195, 202 exceptional subjects and, 194- 195, 204205. 207 Strategy production, problem solving and, 153-156. 175-176, 180-181 empirical evidence, 17 I - 173 information processing, 158 self-management, 158- 159, 161- 162, 165 working memory, 173- 175 Strategy selection, problem solving and. 157, 161, 166 Strategy transfer, problem solving and, 153, 155-156, 179. 181 self-management, 159. 162 strategy production, 176 Syllable production. language development and. 80 perception. 56-57 production, 68-72 Synonyms, Soviet assessment and, 137 Syntactic development, language development and, 56. 71-74. 76. 81 Syntax language development and, 68 Soviet assessment and. 137 verbal communication and, 104. I I I

T Taking turns at talking, verbal communication and. 92-95, 104, 108 Target behavior, problem solving and, 167169 Task difficulty, problem solving and, 172-173 Task performance, problem solving and, 160. 162, 164, 166. 168, 180 Task-specific strategies, problem solving and self-management. 159, 166, 170

INDEX

strategy production. 176 strategy transfer, I77 Temporal perception, language development and. 64 Testing technology. Soviet assessment and. I18 Theory of fluid and crystallized intelligence, adaptive behaviors and, 7 TMR. adaptive behaviors and, 44 Topic organization. verbal communication and, 93. 104-105 Training adaptive behaviors and, 22 problem solving and. 165-168, 171 Training tasks, problem solving and, 153, 162 Transfer, see also Strategy transfer long-term memory and. 198 Twin pairs. Soviet assessment and, 135 Two-factor solution. adaptive behaviors and, 8 Two-factory theory, adaptive behaviors and, 7

U Unifactor studies, adaptive behaviors and, 89, 18, 47 Universal theory of speech perception, language development and, 60

Verbal learning, long-term memory and, 195, 206-207, 210-21 I Verbal processes, Soviet assessment and, 142 Verbal skills, adaptive behaviors and, 43 Vision, Soviet assessment and, 134 Visual context, long-term memory and, 205206, 210 Visual processes language development and, 62-64, 81 long-term memory and, 207 Soviet assessment and, 142 Visual reinforcers, language development and, 81

Vocabulary language development and, 73-74, 78-79, 81

Soviet assessment and, 128. 137 Vocal clashing, language development and, 77-19 Vocalization, language development and, 78, 82 linguistic specialization, 66-71 perception, 62 Vocational skills. adaptive behaviors and, 6, 14. 18

Vocational training, Soviet assessment and, 125. 128 W

V Verbal abstraction strategy. problem solving and, 177 Verbal communication. 91-92, 108- I I I nature of, 92-93 research. 93 conversational repair, 105- 108 establishing referents. 95-99 managing speech acts, 99- 104 taking turns at talking, 93-95 topic organization. 104- 105 Verbal context, long-term memory and, 205. 208 Verbal development, Soviet assessment and. 137 Verbalization long-term memory and, 205 problem solving and. 166. 177 Soviet assessment and. 118. 139

Wechsler Intelligence Scale for Children, Soviet assessment and, 135, 141-142 Welding, problem solving and, 176 Word pairs. long-term memory and, 204-205 Working memory exceptional subjects and, 197 problem solving and, 155, 179- 18 I information processing, 157- 158 self-management, 169- 171 strategy production, 171-175 strategy transfer, 178 Writing skills, adaptive behaviors and, 36. 38 L

Zone of potential development, Soviet assessment and, 127 Zone of proximal development, Soviet assessment and, 120, 127, 132-134. 139, 14.5

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Contents of Previous Volumes

Volume 1

A Functional Analysis of Retarded Development SIDNEY W. BlJOU Classical Conditioning and Discrimination Learning Research with the Mentally Retarded LEONARD E. ROSS The Structure of Intellect in the Mental Retardate HARVEY F. DINGMAN AND C . EDWARD MEYERS Research on Personality Structure in the Retardate EDWARD ZIGLER Experience and the Development of Adaptive Behavior H. CARL HAYWOOD AND JACK T. TAPP ,4 Research Program on the Psychological Effects of Brain Lesions in Human Beings

RALPH M. REITAN

Learning and Memory of Mental Retardates HERMAN H. SPlTZ Autonomic Nervous System Functions and Behavior: A Review of Experimental Studies with Mental Defectives RATHE KARRER Learning and Transfer of Mediating Responses in Discriminative Learning BRYAN E. SHEPP AND FRANK D. TURRISI A Review of Research on Learning Sets and Transfer of Training in Mental Defectives MELVIN E. KAUFMAN A N D HERBERT J. PREHM Programming Perception and Learning for Retarded Children MURRAY SIDMAN AND LAWRENCE T STODDARD Programming Instruction Techniques for the Mentally Retarded FRANCES M . GREENE

Long-Tern1 Memory in Mental Retardation JOHN M . BELMONT

Some Aspects of the Research on Mental Retardation in Norway WAR A R N U O T BJORGEN

The Behavior of Moderately and Severely Retarded Persons JOSEPH E. SPRADLIN AND FREDERIC L GIRARDEAU

Research on Mental Deficiency During the Last Decade in France R. LAFON A N D J. CHABANIER

Author Index-Subject Index

Psychotherapeutic Procedures with the Retarded MANNY STERNLIGHT

Volume 2

Author Index-Subject Index

A Theoretical Analysis and Its Application to Training the Mentally Retarded M.RAY DENNY

Volume 3

Incentive Motivation in the Mental Retardate PAUL S. SIEGEL

The Role of Input Organization in the 23 I

232 Development of Lateral and Choice-Sequence Preferences IRMA R. GERJUOY AND JOHN J. WINTERS, IR. Studies in the Experimental Development of Left-Right Concepts in Retarded Children Using Fading Techniques SIDNEY W. BIJOU Verbal Learning and Memory Research with Retardates: An Attempt to Assess Developmental Trends L. R . GOULET Research and Theory in Short-Term Memory KEITH C. SCOTT AND MARCIA STRONG SCOTT Reaction Time and Mental Retardation ALFRED A. BAUMEISTER AND GEORGE KELLAS Mental Retardation in India: A Review of Care, Training, Research, and Rehabilitation Programs J. P. DAS Educational Research in Mental Retardation SAMUEL L. GUSKIN AND HOWARD H. SPICKER

CONTENTS OF PREVIOUS VOLUMES Mental Retardation in Animals GILBERT W. MEIER Audiologic Aspects of Mental Retardation LYLE L. LLOYD Author Index-Subject Index

Volume 5 Medical-Behavioral Research in Retardation JOHN M. BELMONT Recognition Memory: A Research Stratcgy and a Summary of Initial Findings KEITH G . SCOTT Operant Procedures with the Retardate: An Overview of Laboratory Research PAUL WEISBERG Methodology of Psychopharmacological Studies with the Retarded ROBERT L. SPRAGUE AND JOHN S . WERRY Process Variables in the Paired-Associate Learning of Retardates ALFRED A . BAUMEISTER AND GEORGE KELLAS

Author Index-Subject Index

Sequential Dot Presentation Measures of Stimulus Trace in Retardates and Normals EDWARD A. HOLDEN, JR.

Volume 4

Cultural-Familial Retardation FREDERIC L. GIRARDEAU

Memory Processes in Retardates and Normals NORMAN R. ELLIS A Theory of Primary and Secondary Familial Mental Retardation ARTHUR R. JENSEN

German Theory and Research on Mental Retardation: Emphasis on Structure LQTHAR R. SCHMIDT AND PAUL B. BALTES Author Index-Subject Index

Inhibition Deficits in Retardate Learning and Attention LAIRD W. HEAL AND JOHN T. JOHNSON, JR.

Volume 6

Growth and Decline of Rctardate Intelligence MARY ANN FISHER AND DAVID ZEAMAN

Cultural Deprivation and Cognitive Competence J. P. DAS

The Measurements of Intelligence A. R . SILVERSTEIN

Stereotyped Acts ALFRED A. BAUMEISTER AND REX FOREHAND

Social Psychology and Mental Retardation WARNER WILSON

Research on the Vocational Habilitation of the

233

CONTENTS OF PREVIOUS VOLUMES Retarded: The Present, the Future MARC W. GOLD Consolidating Facts into the Schematized Learning and Memory System of Educable Retardates HERMAN H. SPIT% An Attention-Retention Theory of Retardate Discrimination Learning MARY ANN FISHER AND DAVID ZEAMAN Studying the Relationship of Task Performance to the Variables of Chronological Age, Mental Age, and IQ WILLIAM E. KAPPAUF Author Index-Subject Index

The Role of the Social Agent in Language Acquisition: Implications for Language Intervention GERALD J. MAHONEY AND PAMELA B. SEELY Cognitive Theory and Mental Development EARL C. BUTTERFIELD AND DONALD J. DICKERSON A Decade of Experimental Research in Mental Retardation in India ARUN K. SEN The Conditioning of Skeletal and Autonomic Responses: Normal-Retardate Stimulus Trace Differences SUSAN M. ROSS AND LEONARD E. ROSS Malnutrition and Cognitive Functioning J. P. DAS AND EMMA PIVATO

Volume 7

Mediational Processes in the Retarded JOHN G. BORKOWSKI AND PATRICIA B. WANSCHURA The Role of Strategic Behavior in Retardate Memory ANN L. BROWN Conservation Research with the Mentally Retarded KERI M. WILTON AND FREDERIC J. BOERSMA Placement of the Retarded in the Community: Prognosis and Outcome RONALD B. McCARVER AND ELLIS M. CRAIG Phybical and Motor Development of Retarded Persons ROBERT H. BRUININKS Subject Index Volume 8

Research on Eficacy of Special Education for the Mentally Retarded MELVINE E. KAUFMAN AND PAUL A. ALBERT0 Subject Index

Volume 9 The Processing of Information from ShortTerm Visual Store: Developmental and Intellectual Differences LEONARD E. ROSS AND THOMAS B. WARD Information Processing in Mentally Retarded Individuals KEITH E. STANOVICH Mediational Processes in the Retarded: Implications for Teaching Reading CLESSEN J. MARTIN Psychophysiology in Mental Retardation J. CLAUSEN

Self-Injurious Behavior ALFRED A . BAUMEISTER AND JOHN PAUL ROLLINGS

Theoretical and Empirical Strategies for the Study of the Labeling of Mentally Retarded Persons SAMUEL L. GUSKIN

Toward a Relative Psychology of Mental Retardation with Special Emphasis on Evolution HERMAN H. SPlTZ

The Biological Basis of an Ethic for Mental Retardation ROBERT L. ISAACSON AND CAROL VAN HARTESVELDT

234 Public Residential Services for the Mentally Retarded R. C . SCHEERENBERGER Research on Community Residential Alternatives for the Mentally Retarded LAIRD W. HEAL, CAROL K. SIGELMAN, AND HARVEY N. SWITZKY Mainstreaming Mentally Retarded Children: A Review of Research LOUISE CORMAN A N D JAY GOTTLIEB Savants: Mentally Retarded Individuals with Special Skills A. LEWIS HILL Subject Index

Volume 10

The Visual Scanning and Fixation Behavior of the Retarded LEONARD E. ROSS AND SUSAN h4. ROSS Visual Pattern Detection and Recognition Memory in Children with Profound Mental Retardation PATRICIA ANN SHEPHERD AND JOSEPH F. FAGAN 111 Studies of Mild Mental Retardation and Timed Performance T. NETTLEBECK AND N. BREWER Motor Function in Down’s Syndrome FERIHA ANWAR Rumination NIRBHAY N. SlNGH Subject Index

Volume 11

Cognitive Development of the LearningDisabled Child JOHN W. HAGEN, CRAIG R. BARCLAY, AND BETTINA SCHWETHELM Individual Differences in Short-Term Memory RONALD L. COHEN Inhibition and Individual Differences in Inhibitory Processes in Retarded Children PETER L. C. EVANS

CONTENTS OF PREVIOUS VOLUMES Stereotyped Mannerisms in Mentally Retarded Persons: Animal Models and Theoretical Analyses MARK H. LEWIS A N D ALFRED A. BAUMEISTER A n Investigation of Automated Methods for Teaching Severely Retarded Individuals LAWRENCE T. STODDARD Social Reinforcement of the Work Behavior of Retarded and Nonretarded Persons LEONIA K. WATERS Social Competence and Interpersonal Relations between Retarded and Nonretarded Children ANGELA R . TAYLOR The Functional Analysis of Imitation WILLIAM R . McCULLER AND CHARLES L. SALZBERG Index

Volume 12

An Overview of the Social Policy of Deinstitutionalization BARRY WILLER A N D JAMES I NTAG LI ATA Community Attitudes toward Community Placement of Mentally Retarded Persons CYNTHIA OKOLO AND SAMUEL GUSKIN Family Attitudes toward Deinstitutionalization AYSHA LATIB, JAMES CONROY. AND CARLA M . HESS Community Placement and Adjustment of Deinstitutionalized Clients: Issues and Findings ELLIS M . CRAIG AND RONALD B. McCARVER Issues in Adjustment of Mentally Retarded Individuals to Residential Relocation TAMAR HELLER Salient Dimensions of Home Environment Relevant to Child Development KAZUO NIHIRA, IRIS TAN MINK, AND C. EDWARD MEYERS

235

CONTENTS O F PREVIOUS VOLUMES

Current Trends and Changes in Institutions for the Mentally Retarded R. K . EYMAN. S . A. BORTHWICK, AND G. TARJAN Methodological Considerations in Research on Residential Alternatives for Developmentally Disahled Persona LAIRD W. HEAL AND GLENN T. FUJIURA A Systems Theory Approach to Deinstitutionalization Policies and Research ANGELA A. NOVAK AND TERRY R BERKELEY Autonomy and Adaptability in Work Behavior of Retarded Clients JOHN L. GIFFORD, FRANK R. KUSCH, JAMES E. MARTIN, AND DAVID M. WHITE Index

Volume 13 Sustained Attention in the Mentally Retarded: The Vigilance Paradigm JOEL B. WARM AND DANIEL B. BERCH Coniniunication and Cues in the Functional Cognition uf the Mentally Retarded JAMES E. TURNURE Mcrairicinor~.An Aspect of Metacognition in the Mentnlly Retarded ELAINE M. JUSTICE

Proactive Inhibition in Retarded Persons: Some Clues to Short-Term Memory Processing JOHN 1. WINTERS, JR. A Triarchic Theory of Mental Retardation ROBERT J. STERNBERG AND LOUISE C. SPEAR Index

Volume 14 Intrinsic Motivation and Behavior Effectiveness in Retarded Persons H . C A R L HAYWOOD AND HARVEY N. S W ITZKY The Rehearsal Deficit Hypothesis NORMAN W. BRAY AND LISA A TURNER Molar Variability and the Mentally Retarded STUART A. SMITH AND PAUL S . SIEGEL Computer-Assistcd Instruction for the Mentally Retarded FRANCES A. CONNERS, DAVID R. CARUSO, AND DOUGLAS K. DETTERMAN Procedures and Parameters of Errorless Discrimination Training with Developmentally Impaired Individuals GlULlO E. LANClONl AND PAUL M. SMEETS Reading Acquisition and Remediation in the Mentally Retarded NIRBHAY N. SINGH AND JUDY SINGH

Inspection Time and Mild Mental Retardation T. NETTELBECK

Families with a Mentally Retarded Child BERNARD FARBER AND LOUIS ROWITZ

Mild Mental Retardation and Memory Scanning C. J PHII.I.IPS AND T. NETTELBECK

Social Competence and Employment of Retarded Persons CHARLES L. SALZBERG, MARILYN LIKINS, E. KATHRYN McCONAUGHY. AND BENJAMIN LlGNUGARlSiKRAFT

Cognitive Determin;ints ot Reading in Mcnt;illy Rctarded Individuals KEITH E. STANOVICH Coniprchen\ion and Mental Retardation LINDA HICKSON BILSKY Semantic Procchring. Semantic Memory, and Recall LARAINE MASTERS GLIDDEN

Toward a Taxonomy of Honie Environments SHARON LANDESMAN Behavioral Treatment of the Sexually Deviant Behavior of Mentally Rerarded Individuals R. M . FOXX, R. G. BITTLE. D. R. BECHTEL, AND J. R. LIVESAY

236 Behavioral Approaches to Toilet Training for Retarded Persons S. BETTISON Index

CONTENTS OF PREVIOUS VOLUMES Physical Fitness of Mentally Retarded Individuals E. KATHRYN McCONAUGHY AND CHARLES L. SALZBERG Index

Volume 15 Mental Retardation as a Thinking Disorder: The Rationalist Alternative to Empiricism HERMAN H. SPITZ Developmental Impact of Nutrition on Pregnancy, Infancy, and Childhood: Public Health Issues in the United States ERNEST0 POLLITT The Cognitive Approach to Motivation in Retarded Individuals SHULAMITH KREITLER AND HANS KREITLER Mental Retardation, Analogical Reasoning, and the Componential Method J. McCONAGHY Application of Self-control Strategies to Facilitate Independence in Vocational and Instructional Settings JAMES E. MARTIN, DONALD L. BURGER, SUSAN ELIAS-BURGER, AND DENNIS E. MITHAUG Family Stress Associated with a Developmentally Handicapped Child PATRICIA M. MINNES

Volume 16 Methodological Issues in Specifying Neurotoxic Risk Factors for Developmental Delay: Lead and Cadmium as Prototypes STEPHEN R. SCHROEDER The Role of Methylmercury Toxicity in Mental Retardation GARY J. MYERS AND DAVID 0. MARSH Attentional Resource Allocation and Mental Retardation EDWARD C . MERRILL Individual Differences in Cognitive and Social Problem-Solving Skills as a Function of Intelligence ELIZABETH J. SHORT AND STEVEN W EVANS Social Intelligence, Social Competence, and Interpersonal Competence JANE L. MATHIAS Conceptual Relationships between Family Research and Mental Retardation ZOLINDA STONEMAN Index