Effects of age on communication skill levels and prevalence of maladaptive behaviors in autistic and mentally retarded children

This study investigated the effect of age on communication and maladaptive behavior in autistic and mentally retarded children. Forty-seven autistic and 128 mentally retarded children in a special school served as subjects. The cross-sectional method was used to compare junior and senior groups, and ratings on communication skills and maladaptive behaviors were obtained from teachers. We found that the skills of comprehension and conversation in autistic children improved significantly with age, and speech improved somewhat. In spite of this improvement in communication skills, maladaptive behaviors in the autistic children other than hyperactivity did not change significantly with age. Withdrawal improved significantly with age in the mentally retarded children but not in the autistic children.This study was supported in part by special grants from the Japanese Ministry of Health and Welfare for Research on Children with Abnormal Behaviors.     

Comparison of cognitive deficits among autistic and retarded children on the Arthur Adaptation of the Leiter International Performance Scales

Seven autistic, 7 mentally retarded, and 11 normal children were matched for mental age according to the Arthur Adaptation of the Leiter International Performance Scale (AALIPS). On the basis of two constructs, concrete discrimination and formal discrimination, all of the tasks in the AALIPS were grouped into two indices and six scales. Group comparisons were made on the indices and the scales. The results showed that (a) the performance of the autistic children was better than that of the other two groups on concrete discrimination tasks, (b) the performance of the autistic children was poorer than that of the other two groups on formal discrimination tasks, and (c) the quality of the autistic children's performance decreased as task requirements for formal discrimination increased. This pattern was not observed among the mentally retarded or normal children. A further analysis for sex showed significant main effects for sex on the formal discrimination tasks. The application of these results to test interpretation and future research is discussed.This research was based on the author's doctoral dissertation. The author wishes to express his appreciation to Drs. G. Liddle, L. Green, and W. Stilwell of the University of Kentucky; R. Attwater of the Hazel Park School District; and N. F. Wright.     

Reward value of prosodic features of language for autistic,mentally retarded,and normal children

The present study pursued hypotheses relevant to prosodic abnormalities in the expressive language of autistic children. An operant paradigm was employed to measure the intrinsic reinforcing value of a verbally presented story for autistic, mentally retarded, and normal groups controlling for chronological age and performance mental age. Results suggested that both autistic and mentally retarded children could perceive prosodic cues, although only mentally retarded children are able to use them in their expressive language. It was also suggested that linguistic stimuli may have less intrinsic reinforcement value for autistic and mentally retarded children than for normal children. Implications for future research and treatment were discussed.     

Measuring musical responsiveness in autistic children: A comparative analysis of improvised musical tone sequences of autistic,normal, and mentally retarded individuals

This study provided a systematic analysis of improvised tone sequences of autistic children, as compared to musical improvisations by normal and mentally retarded control subjects. The data indicate that autistic children's tone patterns, analyzed and scored for rhythm, restriction, complexity, rule adherence, and originality, almost reached the scores of normal children. The highest individual total score in the study was achieved by an autistic child. Autistic children scored significantly higher than a control group of mentally retarded individuals. The autistic children's tone sequences showed high scores on the rhythm, restriction, and originality scales which support the notion of unusual musical responsiveness and abilities when compared to results in other performance and behavioral areas. In terms of complexity and rule adherence, autistic children's tone sequences resembled those of the mentally retarded by being rather short and repetitive.     

A comparative study of autistic subjects' performance at two levels of visual and cognitive perspective taking

This study extended previous investigations of autistic subjects' perspective-taking abilities through a within-subjects contrast between two levels each of both visual and cognitive problems with stringent controls against guessing. When compared with normal and mentally retarded subjects', the autistic group's performance supported Baron-Cohen's (1988) hypothesis of a selective deficit for cognitive perspective taking among autistic subjects. Both levels of visual perspective taking demonstrated virtually unimpaired performance for autistic subjects with no significant difference between them and control groups. On the cognitive perspective-taking tasks, however, the performance of the three groups was significantly different, with the vast majority of autistic subjects unable to do even the most basic level of this task. Possible explanations and educational implications were discussed.This article is based on a thesis by the first author prepared for the degree of Bachelor of Arts (Honours) in Psychology and conducted under the supervision of the second author. The authors thank the staff, parents, and children from the Association for Autistic Children of W.A. and from the Mildred Creak Centre for Autistic Children. In addition staff, parents, and students from several day care centers, schools, preschools, and special schools provided invaluable assistance.     

Adenosine Deaminase Activity Decreased in Autism

Six purine enzymes assayed in 18 autistic subjects were compared to enzyme activity levels in 19 normal, 17 mentally retarded, and 16 cerebral palsied control subjects. Adenosine deaminase demonstrated reduced activity in the autistic subjects when compared with the mean activity of normal, mentally retarded, and cerebral palsied subjects. Analysis of variance and covariance revealed a significance of difference at the 0.02 level. Further research is recommended.     

An advanced test of theory of mind: Understanding of story characters' thoughts and feelings by able autistic,mentally handicapped,and normal children and adults

Research has suggested that the core handicaps of autism result from a specific impairment in theory of mind (ToM). However, this account has been challenged by the finding that a minority of autistic subjects pass 1st- and even 2nd-order ToM tests while remaining socially handicapped. In the present study, able autistic subjects who failed ToM tasks, those who passed 1st-order, and those who passed 2nd-order tasks were tested with a battery of more naturalistic and complex stories. Autistic subjects were impaired at providing context-appropriate mental state explanations for the story characters' nonliteral utterances, compared to normal and mentally handicapped controls. Performance on the stories was closely related to performance on standard ToM tasks, but even those autistic subjects who passed all ToM tests showed impairments on the more naturalistic story materials relative to normal adult controls.This work was completed while the author held an MRC studentship, and was submitted in partial fulfillment of a Ph.D. degree, University of London. I am grateful to the teachers and pupils of the following schools, for their kind assistance: Broomhayes School, Heathlands School, Helen Allison School, Sybil Elgar School, Springhallow School, Ramsden School. I also thank Fran Siddons for her help in collecting the data, and Uta Frith and all my colleagues at the CDU for invaluable discussions.     

Autistic Children's Use of Semantic Common Sense and Theory of Mind: A Comparison with Typical and Mentally Retarded Children

To compare Japanese autistic children's use of semantic knowledge and theory of mind with mentally retarded and typically developing children's, they were tested on their comprehension of active and passive sentences and false belief understanding. Autistic children were sensitive to plausibility levels of semantic bias as were 4-year-olds with typical development when comprehending sentences, although impaired in belief understanding as compared with mentally retarded children and typically developing 5-year-olds. Children's sentence comprehension had no association with belief understanding. Results suggest that autistic children with certain verbal intelligence can utilize semantic common sense to comprehend sentences as can typically developing children and that the ability to comprehend sentences is relatively independent of theory of mind.     

Effects of age on adaptive behavior levels and academic skill levels in autistic and mentally retarded children

This study investigated the effect of age on adaptive behavior and academic skill in autistic and mentally retarded children. Subjects were 47 autistic and 128 mentally retarded children from a special school. Cross-sectional comparisons were made between junior and senior groups using ratings obtained from teachers on adaptive behaviors and academic skills. We found that the levels of toilet training, eating skills, participation in group activities, and self-control in the autistic children improved significantly with age. The skills of number concepts in the autistic children also improved with age. However, these adaptive and academic levels were in general significantly lower than those of the mentally retarded children. The levels of initiative did not improve significantly in either the autistic or the mentally retarded children, and they were significantly lower in the autistic children. The implications of these findings in the context of our previous study on the changes of communication and maladaptive behaviors with age in the autistic children are discussed. This study was supported in part by Foundations' Fund for Research in Psychiatry Grant No. 71-500 to the principal author.     

Brainstem auditory evoked response and subcortical abnormalities in autism

Previous studies of the neurobiology of autism that have used the brainstem auditory evoked response have given contradictory results. The authors of this study considered two supplementary aspects; they added an ipsilateral masking procedure, and they compared the results for every subject to the values (corrected for age and sex) of a large number of normal children. Twenty autistic (according to DSM-III-R criteria) and 13 mentally retarded (nonverbal IQ less than 75) subjects were assessed. Eighty percent of the autistic subjects had abnormal interpeak latencies, compared to 15% of the mentally retarded subjects. The I-V and III-V prolonged interpeak latency values were seen only in the autistic subjects. The ipsilateral masking procedure doubled the rate of detection of higher-brainstem abnormalities in the autistic children.     

Vigilance performance of mildly mentally retarded adults

Mildly mentally retarded adults were compared on both an auditory and a visual vigilance task with subjects having greater than average intelligence. Contrary to results reported by Semmel (1965) using a visual task, no difference was found in the rate of decline of performance between the two groups in either of the two tasks, although overall performance of the above-average group was superior to that of the retarded group. The results offered no support for the hypothesis that mentally retarded persons suffer from a more rapid decay in arousal under conditions of reduced sensory variation. Nor did they support a suggestion that in this particular situation retarded subjects would demonstrate more inattention than would nonretarded subjects.     

Phonological investigation of verbal autistic and mentally retarded subjects

A review of the pertinent literature indicates that autistic children are likely to show normal but delayed development of speech sounds. In contrast, atypical phonological development is suggested by experiments demonstrating that autistic subjects are deficient in their ability to extract the components of structured auditory input. A systematic investigation of the speech sound systems of verbal autistic and mentally retarded children reveals a delay in phoneme acquisition, as well as a relative uniformity of error types in both groups. The autistic subjects, however, differ significantly from the mentally retarded in the phonemic substitutions which they make. Autistic subjects are also characterized by a high correlation between frequency of phonological errors and level of overall language development. The findings are interpreted as supporting the hypothesis that the autistic group shows a more global delay in language development.This investigation was supported by Grant MA-5525, Medical Research Council, Ottawa, Ontario, Canada. It was supported previously for a period of three months by the Ontario Ministry of Health, Project No. PR 474C. Subjects were provided by the Ontario Society for Autistic Children, the Thistletown Regional Centre, Rexdale, Ontario, and the Hamilton Public School System. Gail Martin assisted in the coordination of this study. Informed consent was obtained from the parents of the children following explanation of the procedures used in our work.     

The effects of stimulus-fading on acquisition of a visual position discrimination in autistic,retarded, and normal children

Trial-and-error training on a visual position-discrimination task was given to 8 autistic children, 8 retarded children, and 8 children of approximately normal intelligence. Subjects sat before an apparatus containing 3 translucent response panels (left, right, and center). A correct response was to press whichever outside panel was closer to a small black square projected to the right or left of center on the center panel (criterion discrimination). Apart from 3 additional normal-IQ subjects who learned the criterion discrimination (and who were excluded from the experiment proper), performance remained at a chance level for all 3 groups. The remaning 24 children received a 60-trial stimulus-fading program designed to teach the discrimination. Normal-IQ subjects performed best on the program, followed by retarded and autistic subjects. Statistical analysis revealed that the autistic and retarded groups did not differ in performance and that the normal-IQ subjects performed reliably better than the autistic subjects. All 3 groups improved markedly on the criterion-discrimination task as a result of the stimulus-fading program. The significance of this observation and its implications for teaching autistic children are discussed.This research was supported by a grant from The Ruth Schwartz Foundation to the second author. It is based on an Honours thesis submitted by the first author to the Psychology Department of University of Toronto in 1973.The authors would like to express their appreciation to the following persons whose assistance aided in the research: Mr. F. J. Reynolds, Assistant Superintendent, Metropolitan Toronto School Board; Mrs. Jean Bruce, Principal of Beverley School; the following teachers at Beverley School: Mrs. Barr, Mrs. Butcher, Mrs. Lambkin, Miss Lawson, Mrs. Rider, and Miss Sharp; Mr. N. Onyschuk, Principal of Harold Lawson School; Gillian Cunningham, Harold Lawson School; and the following persons from the Clarke Institute of Psychiatry: Mary Lou Anderson, Bonnie Corbeil, Susan Curnoe, Lorna Greer, Judith Mack, Sharon Mooney, John Muravsky, Karen Phillips, Teryl Portigal, James De Roy, Lise Somjen, and Trudie Taman.     

Comprehension of concrete and abstract words in autistic children

This study employed the Stroop paradigm to examine comprehension of single words in autistic children. The words of interest varied along a concrete-abstract dimension. In the Stroop paradigm, subjects are asked to name the color of ink in which color words are printed. Comprehension is indexed by the degree to which the automatic processing of words interferes with the colornaming task. For both concrete and abstract words, autistic children showed the same degree of interference as readingmatched controls. The findings corroborate and extend previous work suggesting that autistic children understand, and by implication, can mentally represent, at least some word meanings.This research was supported by grants from the Hospital for Sick Children Foundation, Toronto, Ontario, NSERC of Canada and Dalhousie RDFS. We thank the children and parents who made this research possible, and the anonymous reviewers for their thoughtful comments.     

Excessive water drinking behavior in autism

The aim of this study was to determine the incidence of polydipsia in 49 autistic children, and also the influence of psychotropic drugs and residential factors on water drinking behavior, as compared with in 89 mentally retarded children, in schools for mentally handicapped children in Fukui prefecture. Questionnaires were used to detect polydipsia and to assess the severity of the water drinking behavior in the autistic children and mentally retarded children. The incidence of polydipsia in the autistic children tended to be higher (P = 0.074) than that in the retarded children. The severity of water drinking behavior was significantly higher in autism (P = 0.022) than in mental retardation. The majority of the autistic children with polydipsia had been taking no psychotropic drugs. The incidence of polydipsia showed no significant difference between two residential situations, i.e. 'not at home' and 'at home'. The present study suggests that polydipsia or excessive water drinking behavior occurs more often in autism than in mental retardation, possibly due to some intrinsic factor in autism itself.     

Spontaneous rehearsal by mildly mentally retarded children and adolescents

The use of a rehearsal strategy by 10-, 12-, and 14-year-old mildly mentally retarded children and adolescents was investigated using a self-paced recall readiness task. This task, in contrast to those typically used to study rehearsal by retarded individuals, allowed subjects to study items in any order as many times as desired. Each age group used rehearsal, as indicated by increasing study time patterns and the number of repetitions per item. We suggest that previous studies have failed to detect rehearsal by retarded persons because the tasks used have constrained the range of possible types of study behavior. The implication of this finding for rehearsal deficit theories was discussed.     

A comparison of personality variables in autistic and mentally retarded children

Personality characteristics of 35 severely mentally retarded children, including 11 with Down's Syndrome, and 32 autistic children evaluated on the basis of the Behavior Rating Instrument for Autistic Children are compared and discussed. The children, 48 boys and 19 girls, ranged in age from 4 to 12 years. Rating on five scales pertaining to nature and degree of relationship to an adult as a person, communication, vocalization and expressive speech, drive for mastery, and psychosexual development, all described in some detail, indicated that the severely retarded group scored significantly higher in each area. Also higher for that group were the correlations between various scales. It is suggested that severely retarded children, particularly those with Down's Syndrome, are less disturbed, and better integrated than autistic and that fragmentation, compartmentalization and lack of generalization between key areas of function are specific factors in the autistic process.This study was supported in part by National Institute of Mental Health Grant MH-00982.