Role taking and social competence in autism and mental retardation

Recent data suggest that individuals with autism show deficits in social cognitive abilities when compared with nonautistic persons matched for mental age. These deficits have been proposed as a basis for the social interaction difficulties seen in autistic persons. In the present study, autistic youth were compared with a matched group of nonautistic mentally retarded youth on three role-taking tasks and three measures of social competence. Results indicated that the autistic group was relatively deficient on each of the social competence measures and on one of the role-taking measures. The role-taking measure on which the groups differed also correlated significantly with each of the social competence measures. Results were discussed in terms of the interplay between social cognitive abilities and social interaction.     

Patterns of emotional and behavioural disturbance associated with autistic traits in young people with severe intellectual disabilities and challenging behaviours

Emotional and behavioural disturbance was assessed in 82 individuals with severe intellectual disabilities and challenging behaviour using the Diagnostic Assessment for the Severely Handicapped-II (DASH-II). Levels of disturbance were compared firstly in individuals with and without features of autism as assessed by the DASH-II, and secondly in individuals with varying severities of autism. In both cases levels of ability and overall severity of behaviour disorder were comparable across groups. Individuals with autistic features were found to have significantly higher scores than nonautistic individuals on the DASH-II organic disorder, anxiety, mania, PDD/autism and stereotypies subscales. When participants with autistic features were separated into groups of severe and moderate autism and compared with nonautistic participants, significant effects of group were found for scores on the anxiety, mood, mania, PDD/autism, schizophrenia and stereotypies subscales. Scheffé tests were conducted to further evaluate between-group differences. Item analysis showed seven DASH-II items to have a 30% or more difference between levels of endorsement in autistic and nonautistic individuals, with six further items showing a 20% or greater difference in levels of endorsement. Findings are compared to those from previous research and implications for the conceptualisation of emotional and behavioural disorders in individuals with autism are discussed.     

Monoamine oxidase activity in blood platelets from autistic children

In order to evaluate the possible abnormality in monoamine oxidase (MAO) activity in early infantile autism, blood platelet samples were obtained from 20 autistic children, aged 2--12 years. MAO activity, measured fluorometrically using serotonin as substrate, was 5.24 +/- 1.65 (Mean +/- Standard Deviation) nM/MG protein/hour in these autistic children. This value was not significantly different from either that in 30 age-matched normal children or that in 39 nonautistic children with various psychiatric and neurological disorders, although autistic children had higher platelet serotonin concentration than these nonautistic individuals.     

An MRI study of the corpus callosum and cerebellum in mentally retarded autistic individuals

The areas of seven subregions of the corpus callosum and three subregions of the cerebellum were examined on midsagittal magnetic resonance imaging scans of 27 low-IQ autistic individuals and 17 nonautistic individuals of comparable mental age. Autistic individuals had a significantly smaller corpus callosum (most marked in the body). No significant between-group differences were found in cerebellum areas. Results demonstrate that abnormalities of the corpus callosum reported in high-functioning autistic individuals are also present in autistic individuals with mental retardation and extend previous reports showing no evidence for a selective hypoplasia of cerebellar lobules VI-VII.     

Monoamine Oxidase Activity in Blood-Platelets From Autistic Children

In order to evaluate the possible abnormality in monoamine oxidase (MAO) activity in early infantile autism, blood platelet samples were obtained from 20 autistic children, aged 2–12 years. MAO activity, measured fluorometrically using serotonin as substrate, was 5.24 ± 1.65 (Mean ± Standard Deviation) nM/mg protein/hour in these autistic children. This value was not significantly different from either that in 30 age-matched normal children or that in 39 nonautistic children with various psychiatric and neurological disorders, although autistic children had higher platelet serotonin concentrations than these nonautistic individuals.     

Autism diagnostic interview: A standardized investigator-based instrument

The development of a new standardized investigator-based interview for use in the differential diagnosis of pervasive developmental disorders is described, together with a diagnostic algorithm (using ICD-10 criteria) based on its use. Good interrater reliability for algorithm items was shown between four raters, two in Canada and two in the UK, who rated 32 videotaped interviews. The items also significantly discriminated between 16 autistic and 16 nonautistic mentally handicapped subjects. The algorithm based on ICD-10 identified all 16 autistic individuals and none of the 16 nonautistic subjects.     

Minor physical anomalies in young psychotic children

The authors examined three groups of children for minor physical anomalies: 52 autistic children, 34 nonautistic siblings of these patients, and 29 normal controls. The total number of anomalies and the weighted score were significantly higher in the autistic children. The formation of these anomalies in the first three months of fetal life may concur with the developmental deviation of the central nervous system in some of these individuals.     

Psychometric assessment of first-degree relatives of 62 autistic probands in Utah

The Wechsler Intelligence Scales, Wide Range Achievement Test, and the Shipley-Hartford Test were administered to 122 parents and 153 siblings of 62 autistic probands in Utah. Scores were distributed as expected within the published normative ranges for each scale. Parents' scores correlated with those of their nonautistic children, but neither parents' nor siblings' scores correlated with the IQ level of the autistic probands. These results do not confirm prior reports from England and the United States of a high rate of cognitive and learning problems in the siblings of autistic individuals, nor the aggregation of such problems in the siblings of probands with high or low levels of cognitive function.     

An evaluation of the autism behavior checklist

The Autism Behavior Checklist (ABC), an assessment instrument for autistic individuals, was evaluated in a group of 157 subjects, 94 clinically autistic and 63 nonautistic. The two groups differed significantly in ratings of pathology. Both false positive and false negative diagnostic classifications were made when the results of the checklist were compared with clinical diagnosis. Effects of developmental level and age were observed. The ABC appears to have merit as a screening instrument, though results of the checklist alone cannot be taken as establishing a diagnosis of autism. Important issues of reliability and validity remain to be addressed.     

Brief report: Differences in sex ratios in autism as a function of measured intelligence

Results from analyses of sex ratios as a function of IQ are presented for 623 autistic children (487 males, 136 females) and 506 nonautistic, communication-handicapped and behavior-disordered children (374 males, 132 females). Proportionately more autistic females were found to have IQs of 34 or below than above 34. However, a linear trend of an increasing number of males with increasing intelligence was found only for nonautistic subjects. The relevance of these findings to genetic factors and the heterogeneity of autism is discussed.     

Comparisons between autistic and nonautistic children on the Test for Auditory Comprehension of Language

Expressive language differences between autistic and nonautistic populations have been a topic of research in the past decade, yet little information is available in regard to the receptive language performances based on standardized tests. Questions as to the existence of sex differences in language have also been raised. The study examines the performance of 19 matched pairs of autistic and nonautistic children on the Test for Auditory Comprehension of Language. As well, the data were analyzed according to sex for each group. The results indicated that there were no significant differences between groups or between the sexes in either group. Questions for further research are raised.     

Social class distribution of fathers of children enrolled in the Iowa Autism program

The social class distribution of fathers with autistic children attending a locally well-known and state-supported modern autism program was examined and was compared to the social class distributions observed in a nonautistic, mentally retarded population, in children with other psychiatric disorders, and in the general population from which the present autistic sample was drawn. No significant differences were found among the groups. The findings supported the view that if studies are not biased by certain selection factors outside the autistic child's clinical picture and diagnosis, and if services become better known and readily available, then no differences in social class distribution between autistic and nonautistic groups occur. The results suggest that social class is not an important factor in the origin of autistic syndrome.     

Developmental changes in brain serotonin synthesis capacity in autistic and nonautistic children

Serotonin content, serotonin uptake sites, and serotonin receptor binding measured in animal studies are all higher in the developing brain, compared with adult values, and decline before puberty. Furthermore, a disruption of synaptic connectivity in sensory cortical regions can result from experimental increase or decrease of brain serotonin before puberty. The purpose of the present study was to determine whether brain serotonin synthesis capacity is higher in children than in adults and whether there are differences in serotonin synthesis capacity between autistic and nonautistic children. Serotonin synthesis capacity was measured in autistic and nonautistic children at different ages, using alpha[11C]methyl-L-tryptophan and positron emission tomography. Global brain values for serotonin synthesis capacity (K complex) were obtained for autistic children (n = 30), their nonautistic siblings (n = 8), and epileptic children without autism (n = 16). K-complex values were plotted according to age and fitted to linear and five-parameter functions, to determine developmental changes and differences in serotonin synthesis between groups. For nonautistic children, serotonin synthesis capacity was more than 200% of adult values until the age of 5 years and then declined toward adult values. Serotonin synthesis capacity values declined at an earlier age in girls than in boys. In autistic children, serotonin synthesis capacity increased gradually between the ages of 2 years and 15 years to values 1.5 times adult normal values and showed no sex difference. Significant differences were detected between the autistic and epileptic groups and between the autistic and sibling groups for the change with age in the serotonin synthesis capacity. These data suggest that humans undergo a period of high brain serotonin synthesis capacity during childhood, and that this developmental process is disrupted in autistic children.     

A comparison of obstetrical records of autistic and nonautistic referrals for psychoeducational evaluations

Heretofore most studies dealing with the association between perinatal complications and autism have used a normal comparison group. In this study obstetrical records of 59 autistic children were compared to those of 28 nonautistic children whose intelligence has a similar range and distribution as the autistic sample. Using an optimality score to reflect number of obstetrical complications, we found that the nonautistic controls experienced less optimal conditions than the autistic sample. Abnormal presentation at birth is the only factor that occurred more frequently for the autistic sample than control sample.We are grateful to our friends and colleagues, Sam Odom and Arthur Koch, for assistance with the statistical treatment of the data. We also acknowlege the support of Henry Schroeder, Director of the Institute for the Study of Developmental Disabilities.     

Emotion-related and abstract concepts in autistic people: Evidence from the British Picture Vocabulary Scale

Autistic and nonautistic retarded adolescents and young adults, individually matched for chronological age and performance on the British Picture Vocabulary Scale (BPVS; Dunn, Dunn, & Whetton, 1982), were compared on those items of the BPVS that independent raters judged (a) emotion-related and (b) highly abstract. Compared to control subjects, autistic individuals scored lower on emotion-related vis-à-vis emotion-unrelated items, an effect that could not be attributed to the social content of the items. However, autistic and nonautistic subjects achieved similar scores when responding to highly abstract vis-à-vis concrete words of the BPVS. The findings suggest that autistic individuals have specific impairments in grasping emotion-related concepts. They also suggest the need for further study of autistic and nonautistic retarded subjects' difficulties in abstracting. The results have a bearing on the interpretation of the BPVS and on the use of this test as a matching procedure.This study was funded by a Project Grant from the Medical Research Council, whilst Dr. Hobson was an MRC Senior Fellow. We thank Janet Ouston for her major part in the original BPVS testing of subjects, Beate Hermelin for her persistent encouragement and lively criticism, and Cathy Lord for her most helpful suggestions. We are very grateful to the individuals who took part in the study, and to the staff who so kindly helped us at the Helen Allison School and Tivoli House, Gravesend, and the Cherry Orchard Centre, Croydon.     

Single-photon emission computed tomography of the brain in autism: effect of the developmental level

Brain single-photon emission computed tomography was performed in 22 autistic and 10 nonautistic disabled patients. The regional cerebral blood flow in both laterotemporal and dorso-medio-lateral frontal areas decreased significantly in the autistic group compared with in nonautistic group. In the autistic group, the regional cerebral blood flow was significantly higher in the right temporal and right parietal lobes than that in the left ones. Inversely, the regional cerebral blood flow in the frontal and occipital lobes was significantly higher on the left side than on the right side. In the nonautistic group, except for in the dorso-medio-lateral frontal lobes (left > right), there was no difference in the regional cerebral blood flow in either cerebrum or cerebellum. A positive correlationship between regional cerebral flow and development quotient (intelligence quotient) was observed in the left laterotemporal and both dorso-medio-lateral frontal areas, and a negative one was observed in the cerebellar vermis area. These results suggest that the regional cerebral blood flow decrease in the temporal and frontal areas relates to not only the brain mechanism of autism reported previously but also intelligence levels.     

A comparative study of attachment behavior in young children with autism or other psychiatric disorders

The present study examined attachment behavior in children with autism and children with other developmental or psychiatric disorders. The groups were matched on chronological and mental age, IQ, and socioeconomic status. When a modified Strange Situation paradigm was used, no group differences were found in proximity seeking, contact maintenance, proximity avoidance, or contact resistance; the groups also did not differ in their overall security ratings. Attachment security was related to several developmental variables in the autistic group but not in the nonautistic comparison group. This suggests that attachment formation may involve different processes in autistic children than in nonautistic children of equivalent intellectual level.     

Minerals in the hair and nutrient intake of autistic children

The concentrations of calcium, magnesium, zinc, copper, lead, and cadmium were determined in scalp hair samples from a group of 12 autistic children and a group of 12 nonautistic control children. The only statistically significant difference between median concentrations of minerals in the hair from the two groups was a 62% decrease in the concentration of cadmium in the hair of autistic children. This decrease was probably not physiologically significant. The nutrient intake of autistic children as a group was found to be adequate and typical of well-fed American children. It was concluded that the children in neither the autistic nor the nonautistic control group showed evidence of toxicity or deficiency of the minerals or nutrients studied, but because of food idiosyncracies nutrient intake should be monitored.     

Hello and Goodbye: A Study of Social Engagement in Autism

We videotaped 24 children, adolescents, and young adults with autism, individually matched for chronological age and verbal mental age with 24 nonautistic persons with mental retardation, for their spontaneous and prompted greetings and farewells towards an unfamiliar adult. Compared with control subjects, those with autism were less likely to offer spontaneous verbal and nonverbal gestures of greeting and farewell, and were less likely to establish eye contact even when they were offered a greeting. There were also fewer autistic subjects who smiled, or who waved goodbye. Results corresponded with raters' subjective judgments of participants' interpersonal engagement with the stranger. One interpretation of the findings is that they reflect a relative lack of intersubjective engagement by autistic individuals.     

Social attachments in autistic children

Social responses of young autistic children to separation from and reunion with their caregivers did not differ from the social responses to similar situations of young mentally retarded nonautistic children. Most autistic children directed more social behaviors to their caregivers than to strangers and increased their preferential behavior after separation. Individual differences in social responses were not associated with the level of representational skills shown by the autistic children.