Tower of Hanoi performance of retarded young adults and nonretarded children as a function of solution length and goal state

Three experiments were conducted with the Tower of Hanoi task to assess problem solving ability in 6-, 7-, 8-, and 10-year-old nonretarded children and mentally retarded young adults of varying maturational ages. In Experiment 1 we gradually reduced the number of moves required for solution until subjects could solve the 3-disk tower-ending problem. Although all groups experienced difficulty with the standard 7-move problem, all but the trainable retarded group readily solved the 6-move problem. The trainable group did not reach a comparable level of success until the 4-move problem. On the 7-move problem the retarded groups performed at the level of nonretarded groups that were maturationally $\text{1}\text{1}\text{2}$ to 3 years younger. An analysis of first moves indicated that subject groups differed in the strategies they used to solve the problems. In Experiment 2, practice effects were ruled out as a source of the superior performance on the 6- than on the 7-move problem. In Experiment 3, 7- and 10-year-old nonretarded children and mentally retarded young adults did not differ on 5-move problems in which configuration of the goal states was varied. A comparison of all 5-move problems judged to have the same depth of search requirements indicated that the tower-ending problems were significantly easier to solve than the partial-tower-ending problems, which in turn were easier than the flat-ending problems. A limited depth of search capacity sets boundaries on the use of sophisticated strategies and, to a large extent, accounts for the retarded groups' maturational lag.     

Mental retardation and perception of global motion

We have found that mildly mentally retarded adults are impaired in their perception of global stereoscopic forms (Fox & Oross, 1988) in ways that cannot be attributed to peripheral visual deficits or failures to comprehend. To assess the generality of that result, we measured the ability of mentally retarded adults to perceive kinematographic forms. Mentally retarded and nonretarded adults were presented with a two-choice, forced-choice detection task requiring the location of a target's spatial position. The discriminability of the forms was varied by systematic reductions in both element density and temporal correlation. We found that, relative to nonretarded adults, mentally retarded adults exhibited large qualitative deficits in their ability to discriminate these kinematographic forms when either density or correlation was reduced. After considering a number of alternative interpretations of these data based on factors such as peripheral visual impairment and a failure to attend, we could find none more compelling than a perceptual interpretation, which posits a deficit within the short-range motion system.     

Anderson's Overlap-Hypothesis and the Discontinuities of Growth

Role-taking ability and level of moral development were measured in three groups of boys and girls including 16 moderately retarded adolescents (mean chronological age 15; mean mental age 9), 16 nonretarded adolescents matched for chronological age, and 16 nonretarded children matched for mental age. The mentally retarded adolescents scored significantly lower on role-taking ability and moral development than the adolescents matched for chronological age. They did not differ from children of their same mental age in role-taking ability; and they tended to score lower in moral development. The results supplied qualified support for Kohlberg's theory of moral development.     

GENERALIZATION AND TRANSFER BETWEEN COMPREHENSION AND PRODUCTION: A COMPARISON OF RETARDED AND NONRETARDED PERSONS

The study compared the acquisition, generalization, transfer, and maintenance of language comprehension and production responses by persons at two IQ levels: mentally retarded (N = 10) and nonretarded (N = 10). The two levels of the IQ Level factor were combined factorially with two levels of a Training Condition factor: Comprehension-Production and Production Only. Participants in the former groups were trained sequentially to (a) comprehend coin labels by pointing, and then (b) produce verbally the correct coin label. Participants in the Production Only groups were trained on the latter response only. A three-factor mixed design with one repeated measure plus a multiple baseline across coin responses was employed. Results indicated that both mentally retarded and nonretarded subjects attained a high level of acquisition and maintained their performance on 1- and 4-week follow-up tests. No difference occurred between mentally retarded and nonretarded participants in magnitude of acquisition, but the mentally retarded groups took approximately three times as many trials to complete training. Data also suggested, contrary to past research, that generalization from comprehension to production was bidirectional, with no difference in magnitude between mentally retarded and nonretarded subjects. Transfer from comprehension to production occurred in both nonretarded and retarded subjects; comprehension training facilitated a savings of trials in production training. These results show that language differences between retarded and nonretarded persons are quantitative rather than qualitative as some past research may have suggested.     

The Ability to Encode Facial and Emotional Expressions by Educable Mentally Retarded and Nonretarded Children

The object of the present study was to investigate whether 20 educable mentally retarded (EMR) children matched for verbal mental age on the Peabody Picture Vocabulary Test (PPVT; Dunn, 1965) with 20 nonretarded (NR) controls were adept in identifying emotional facial expressions and producing the equivalent word adjectives. I also reassessed the relationship between the phase of identifying facial expressions (i.e., happy, sad, angry, and scared) and the phase of producing emotional word adjectives, consisting of 16 emotional linguistic constructions (4 short stories for each of the adjectives) between higher in verbal ability educable mentally retarded (HEMR) children and higher in verbal ability nonretarded controls (HNRC) and between low in verbal ability educable mentally retarded (LEMR) children and low in verbal ability nonretarded controls (LNRC). There were no significant differences between EMR and NR children in general, despite the fact that EMR children had deficits in receptive linguistic competence.     

The ability to encode facial and emotional expressions by educable mentally retarded and nonretarded children.

The object of the present study was to investigate whether 20 educable mentally retarded (EMR) children matched for verbal mental age on the Peabody Picture Vocabulary Test (PPVT; Dunn, 1965) with 20 nonretarded (NR) controls were adept in identifying emotional facial expressions and producing the equivalent word adjectives. I also reassessed the relationship between the phase of identifying facial expressions (i.e., happy, sad, angry, and scared) and the phase of producing emotional word adjectives, consisting of 16 emotional linguistic constructions (4 short stories for each of the adjectives) between higher in verbal ability educable mentally retarded (HEMR) children and higher in verbal ability nonretarded controls (HNRC) and between low in verbal ability educable mentally retarded (LEMR) children and low in verbal ability nonretarded controls (LNRC). There were no significant differences between EMR and NR children in general, despite the fact that EMR children had deficits in receptive linguistic competence.     

Forgetting in retarded and nonretarded persons under conditions of minimal strategy use

Short-term memory processes of mentally retarded (mild, moderate, and severe) and nonretarded persons were compared in a delayed matching-to-sample task that minimized the use of verbal rehearsal. In addition to trials with delays up to 20 s, the inclusion of trials on which the sample and comparison stimuli occurred simultaneously made it possible to isolate memory and discriminability. Forgetting was most pronounced between the simultaneous and 0-s conditions, and nonretarded subjects forgot less than retarded subjects between these conditions. There were no group differences beyond the 0-s delay. Ease of strategy use failed to account for individual differences, and reported strategy use was not related systematically to performance. These findings are incompatible with the hypothesis that normal-retarded differences occur only on tasks involving effortful cognitive strategies. Differences between nonretarded and retarded groups in this study may be due to a failure in automatic encoding processes in retarded persons.     

Automatic and conscious processing in retarded and nonretarded adolescents

Educable mentally retarded and nonretarded adolescents participated in incidental learning tasks that emphasized the utilization of processes that were consciously controlled but not deliberately aimed at memory (Experiment 1). Retarded individuals' performance on a standard recognition test was equivalent to that of nonretarded subjects following phonetic encoding and nonstrategic encoding, but was deficient following semantic encoding. Retarded subjects also demonstrated a lower level of performance on a rhyme recognition task. In Experiment 2, retarded subjects provided a pattern of responding identical to that of nonretarded subjects on a picture-word interference task designed to assess automatic processing. The two groups produced equivalent levels of semantic activation. It was argued that the results of the two experiments indicate deficient semantic processing on the part of retarded individuals relative to that of nonretarded individuals that cannot be accommodated by a structural-deficiency model, a developmental-lag model, or a hypothesis that predicts intelligence-related differences only when the task involves the use of deliberate mnemonic strategies.     

Behavioral expectations of retarded and nonretarded children

Two experiments were conducted to examine the effect of the mental retardation (MR) label on impression formation among retarded and nonretarded children and adolescents. The first experiment, conducted with nonretarded children in a mainstreamed school, indicated that they have pessimistic expectations of retarded children with regard to cognitive and ability-related behaviorsand, to a lesser extent, social behaviors (i.e., getting married). However, their reactions were not as pessimistic nor as “patronizing” as were those demonstrated by college students in previous research. In the second experiment, mentally retarded adolescents indicated that they also have negative behavioral expectations of retarded children, however, their self expectations were negative only for social behaviors. The results suggest that, among retarded persons, the expectations associated with the MR label are negative for social behavior, but apparently less pessimistic for cognitive and ability related tasks.     

Developmental auditory agnosia in the severely retarded: A further investigation

The hypotheses were investigated that (a) ability to recognize the auditory perceptual stimuli for familiar events is a developmental correlate to language acquisition and (b) the low functioning mentally handicapped suffer from auditory agnosia and are impaired in this ability. The subjects were 42 nonretarded children of ages 3 through 6 and 53 severely and moderately retarded, noninstitutionalized students. The retarded subjects were matched by mental age to the chronological age of the nonretarded children. The stimuli were 49 environmental sounds; the task consisted of sound-and-picture matching-to-sample. Group membership and developmental age were the factors in an analysis of variance design. The results revealed a strong effect of developmental age (p <. 0001). The effect of group was not significant, indicating that auditory agnosia may not be common among the lower functioning retarded. The assumption that agnosia may be a major factor underlying the language disability of the severely retarded was reexamined. It was suggested that the severely retarded achieve the requisite perceptual-semantic knowledge base for language too late, after the critical age for spontaneous and efficient language learning has passed.     

Influence of item identification on the memory performance of mentally retarded and nonretarded adults

The role of item identification in the memory performance of mentally retarded and nonretarded adults was examined by varying the identification and memory parameters of a sequential same-different task. In Study 1, retarded subjects' identification ability was demonstrated to be less efficient than nonretarded subjects' ability. In Study 2, target duration and interstimulus interval were varied. Memory performance differed between groups, and the memory deficit for retarded subjects was demonstrated to be independent of their identification deficit. The target durations in Study 2 were relatively brief, and in Study 3, the target duration was increased to insure that all subjects could identify the target. Mentally retarded subjects were demonstrated to have a memory deficit. The results were discussed in terms of possible sources of the memory deficit.     

Social problem solving and mother-child interactions of educable mentally retarded children

Mothers of retarded children and nonretarded children were observed and videotaped as they interacted with their own child in a seminaturalistic situation, requiring teaching, cooperation, and free play. The child's social problem-solving abilities were assessed independently. The Vineland scale was employed to provide some convergent evidence of social problem-solving as a component of social competence. Twelve educable mentally retarded and 19 nonretarded 10-year-old children and their mothers comprised the sample. For the mentally retarded group, it was found that the higher maternal directiveness, the lower the child's social problem-solving skills. Mothers who often gave the child opportunity for decision-making and social influence had children with higher problem-solving skills. The retarded children produced significantly fewer different strategies for solving social problems, but gave a wider range of strategies than has been found in previous research. There was some support that social problem-solving skills are related to social maturity.     

Fonctions exécutives,vieillissement cognitif et variations stratégiques

Aging is characterized by a decrease of cognitive performance in most of cognitive domains. One of the most fundamental issues is then to know what are the underlying mechanisms of these age-related changes in human cognition. Recent research suggests that in addition to speed of processing and working memory capacities, age-related impairment in executive functioning plays an important role in the cognitive decline associated to aging. Above and beyond performance, current research shows that the mediating role of executive function in age-related changes in cognitive performance occurs via changes in strategies variations (i.e., repertoire, distribution, execution, and selection of the strategies used to accomplish a cognitive task). In this article, we illustrate both strategic variations and underlying executive control mechanisms in two important cognitive domains : episodic memory and problem solving.     

Conceptual organization and memory in nonretarded, mildly retarded, and moderately retarded adults

Moderately retarded, mildly retarded, and nonretarded adults learned a list of 12 items from three categories to a criterion of 75% correct recall in a free-recall learning paradigm. Retention was measured 1 week later. The moderately retarded took more trials and had lower retention and clustering scores than the others. The mildly retarded took more trials and had lower retention than the nonretarded. The results violate Murdock's total time hypothesis (Cooper & Pantle, 1967) but support Mandler's (1967) contention that learning is enhanced by the mental capacity for organization.     

Control in memory for movement cues by mentally retarded children

The study was designed to determine the desirability of providing external prompts (1) to use a mnemonic to enhance accuracy of recall and (2) to use response 'priming' in memory for spatial location by mentally retarded persons. Two groups of 40 mentally retarded boys and girls and two groups of 40 MA-matched nonretarded children were compared for accuracy in the recall of movement on an arm-positioning task. No differences were found between mentally retarded subjects and MA-matched subjects treated under the same conditions. However, all groups were unable to make spontaneous control adjustments to accommodate the covert manipulations made just prior to recall. By providing response primes, appropriate performance adjustments were made by all groups, resulting in a significant improvement in accuracy of recall. These findings serve to reaffirm earlier reports showing remarkable similarity between the mentally retarded and MA-matched nonretarded subjects.     

Mnemonic strategy instruction in coding, processing, and recall of movement-related cues by mentally retarded children

The purpose of study was to examine the differential coding and processing characteristics of two movement cue types in the investigation of the short-term memory of mentally retarded and nonretarded children. The central focus of the study was to determine the effects of formal instruction in the use of a mnemonic versus no instruction with both types of cues in a memory for movement paradigm. The investigation was conducted across two experiments. The main conclusion drawn from Exp. 1 was that movement 'location' cues were coded, processed, and retained by both the mentally retarded and the nonretarded children, but only the former required instruction in the use of a mnemonic to achieve accurate recall. Exp. 2 was fundamentally a replication of Exp. 1 with the exception that movement 'extent' cues were maintained reliable. The results were similar but not exactly the same as those of Exp. 1. Only the mentally retarded children given mnemonic instruction appeared to code, process, and retain movement 'extent' cues over time. The net result of the two experiments was that formal instruction in the use of a mnemonic was of benefit to the mentally retarded subjects and was not necessary for nonretarded subjects to achieve the same level of movement accuracy.     

Conceptual Organization and Memory in Nonretarded,Mildly Retarded,and Moderately Retarded Adults

Moderately retarded, mildly retarded, and nonretarded adults learned a list of 12 items from three categories to a criterion of 75% correct recall in a freerecall learning paradigm. Retention was measured 1 week later. The moderately retarded took more trials and had lower retention and clustering scores than the others. The mildly retarded took more trials and had lower retention than the nonretarded. The results violate Murdock's total time hypothesis (Cooper & Pantle, 1967) but support Mandler's (1967) contention that learning is enhanced by the mental capacity for organization.     

Memory in educable mentally retarded adults: Deficit in subject or experimenter?

Educable mentally retarded (EMR) and nonretarded adults free recalled lists of (a) words, (b) minitasks performed by the subjects (SPTs), (c) minitasks performed by the experimenter (EPTs), or (d) task instructions. The EMR subjects were significantly inferior to the nonretarded subjects in the immediate recall of words, EPTs and instructions, but not in the immediate recall of SPTs. This proficiency of the EMR subjects in SPT recall was attributed to the nonstrategic nature of this test. The EMR subjects were, however, inferior to the nonretarded subjects in a final free recall (recall of all lists) of all four types of item.     

Penser autrement les difficultés scolaires : les apports du Rorschach en système intégré

This study examines school under-achievement from the perspective of clinical psychology. We compare 2 groups of children in the 3^rd grade (mean age 9) based on their results on a national test of French language and Mathematics. We present the Rorschach results of 7 high performers compared to 7 low performers, all of whom have IQ scores (K. ABC) that are in the average range (90 - 109). The Rorschach data (Comprehensive System) demonstrate no differences between these groups of children concerning affective functioning and stress tolerance. However, the quantitative and qualitative results are notably different concerning attitudes relative to complex situations, in the area of critical self-perception and conflict-resolution strategies.     

Le rôle de la mémoire de travail dans la production écrite de textes

Integration of capacity (Just and Carpenter, 1992) and componentiel (Baddeley, 1986) conceptions of working memory in models of text composition (Hayes, 1996 ; Kellogg, 1996 ; McCutchen, 1996) has allowed studying several facets of the role of working memory in writing acquisition and in expert management of the writing processes. This article presents these two conceptions and examines their respective contribution in the field of writing research from two perspectives: The demands of the writing processes (in terms of processing and transient storage) and the influence of working memory capacity on the control of production. The conclusion underlines the importance of investigating the on-line management of text production, the role of the visuo-spatial sketchpad, and to link strategies for allocating the working memory resources with text quality.