Lynn Waterhouse

Plasma oxytocin levels in autistic children.

BACKGROUND Social impairments are central to the syndrome of autism. The neuropeptide oxytocin (OT) has been implicated in the regulation of social behavior in animals but has not yet been examined in autistic subjects. METHODS To determine whether autistic children have abnormalities in OT, midday plasma samples from 29 autistic and 30 age-matched normal children, all prepubertal, were analyzed by radioimmunoassay for levels of OT. RESULTS Despite individual variability and overlapping group distributions, the autistic group had significantly lower plasma OT levels than the normal group. OT increased with age in the normal but not the autistic children. Elevated OT was associated with higher scores on social and developmental measures for the normal children, but was associated with lower scores for the autistic children. These relationships were strongest in a subset of autistic children identified as aloof. CONCLUSIONS Although making inferences to central OT functioning from peripheral measurement is difficult, the data suggest that OT abnormalities may exist in autism, and that more direct investigation of central nervous system OT function is warranted.

Oxytocin and autistic disorder: alterations in peptide forms

BACKGROUND Oxytocin (OT) is synthesized as a prohormone that is sequentially processed to peptides. These peptides are the bioactive amidated form (OT) and the C-terminal extended peptides, OT-Gly, OT-Gly-Lys and OT-Gly-Lys-Arg, which are designated together as OT-X. As an extension of our previous study finding decreased plasma OT in autism, studies were conducted to determine whether there were changes in OT peptide forms in autistic children. METHODS Twenty eight male subjects (97 +/- 20 months; range, 70-139 months), diagnosed with DSM-IV autistic disorder through observation and semi-structured interview, were compared with 31 age-matched nonpsychiatric control subjects (106 +/- 22 months; range, 74-140 months). Using OT antisera with different specificity for the peptide forms, we measured plasma OT and OT-X in each group. RESULTS T tests showed that there was a decrease in plasma OT (t = 4.4, p <.0001), an increase in OT-X (t = 2.3, p <.03) and an increase in the ratio of OT-X/OT (t = 4.5, p <.0001) in the autistic sample, compared with control subjects. CONCLUSIONS The results suggest that children with autistic disorder show alterations in the endocrine OT system. Deficits in OT peptide processing in children with autism may be important in the development of this syndrome.

Executive Functioning in High-functioning Children with Autism

Executive functioning was investigated in 34 children (24 boys and 10 girls) with developmental language disorder (DLD) and 21 children (18 boys and 3 girls) with high-functioning autistic disorder (HAD) matched on Full Scale IQ, Nonverbal IQ, age (mean age 9 year, 1 month), and SES. The DLD group had a Verbal IQ that was 10 points higher than the HAD group. These children were given the Wisconsin Card Sorting Test (WCST), the Mazes subtest from the WISC-R, the Underlining test, and the Rapid Automatized Naming test. In addition, these children were given the Vineland Scales of Adaptive Functioning and the Wing Diagnostic Symptom Checklist in order to assess severity of autistic symptomatology. Results indicated that the only significant difference between the two groups on the cognitive tasks was perseverative errors on the WCST; there was no significant difference on total number of categories achieved or total number of errors on the WCST or on the other executive function measures. There was also significant overlap in the scores between the two groups and the difference in perseverative errors was no longer significant when Verbal IQ was partialled out. Executive functioning was strongly related to all IQ variables in the DLD group and particularly related to Verbal IQ in the HAD group. Although there was a relationship in the HAD group between executive functioning and adaptive functioning, as well as between executive functioning and autistic symptomatology, these relationships were generally no longer significant in the HAD group after the variance due to Verbal IQ was accounted for. The results are interpreted to indicate that although impaired executive functioning is a commonly associated feature of autism, it is not universal in autism and is unlikely to cause autistic behaviors or deficits in adaptive function.

Multiple Intelligences, the Mozart Effect, and Emotional Intelligence: A Critical Review.

This article reviews evidence for multiple intelligences theory, the Mozart effect theory, and emotional intelligence theory and argues that despite their wide currency in education these theories lack adequate empirical support and should not be the basis for educational practice. Each theory is compared to theory counterparts in cognitive psychology and cognitive neuroscience that have better empirical support. The article considers possible reasons for the appeal of these 3 theories and concludes with a brief rationale for examining theories of cognition in the light of cognitive neuroscience research findings.

Affect comprehension in children with pervasive developmental disorders.

Affect comprehension was studied in children with pervasive developmental disorders (PDD) and normal children matched for mental age. Three matching tasks were used: matching objects (a nonsocial control task), matching faces, and matching affects. The three tasks were developed to be of equal difficulty for normal children. Children were also tested for comprehension and expression of affect terms. The PDD children were impaired on affect matching relative to the normal controls. The PDD children were impaired on face and affect matching relative to their own performance on object matching, whereas the normal children were not. Within the PDD sample, object matching was correlated with mental age measures but not with measures of social behavior and play, but face and affect matching were significantly correlated with mental age as well as social behavior and play. Individual PDD children who showed relative deficits on face or affect matching tended to be more socially impaired than PDD children whose face and affect matching was consonant with their mental age. Results are discussed in terms of possible etiologies of the social deficit in PDD children, and the importance of subtypes within this population.

Subgroups of Children With Autism by Cluster Analysis: A Longitudinal Examination

OBJECTIVES A hierarchical cluster analysis was conducted using a sample of 138 school-age children with autism. The objective was to examine (1) the characteristics of resulting subgroups, (2) the relationship of these subgroups to subgroups of the same children determined at preschool age, and (3) preschool variables that best predicted school-age functioning. METHOD Ninety-five cases were analyzed. RESULTS Findings support the presence of 2 subgroups marked by different levels of social, language, and nonverbal ability, with the higher group showing essentially normal cognitive and behavioral scores. The relationship of high- and low-functioning subgroup membership to levels of functioning at preschool age was highly significant. CONCLUSIONS School-age functioning was strongly predicted by preschool cognitive functioning but was not strongly predicted by preschool social abnormality or severity of autistic symptoms. The differential outcome of the 2 groups shows that high IQ is necessary but not sufficient for optimal outcome in the presence of severe language impairment.

Sustained attention in children with autism

Although many children with early infantile autism cannot maintain attention to externally imposed tasks, they may continue a repetitive behavior of their own choosing for long periods of time. This study examined the performance of autistic and mental age matched normal children on a Continuous Performance Test of sustained attention. Results suggest that autistic childrens difficulties in sustaining attention on imposed tasks may be attributable partly to a developmental delay and partly to the motivational contingencies of task rather than to a primary impairment in the ability to sustain attention.

The responses of autistic children to the distress of others

The behavior of preschool children from five groups (developmental language disordered, high-functioning autistic, low-functioning autistic, mentally retarded, and normally developing) were coded in three situations: presentation of a nonsocial orienting stimulus (an unfamiliar noise) and two social situations involving simulated distress on the part of an adult with whom they were playing. Cognitive level was correlated with level of responsiveness to stimuli only for the two retarded groups (mentally retarded and low-functioning autistic). Girls showed more prosocial behavior than boys in both social situations, independent of diagnosis. The language-disordered children showed only mild and subtle social deficits. The low-functioning autistic children showed pronounced deficits in responding in all situations. The mentally retarded and high-functioning autistic children showed good awareness of all situations, but were moderately impaired in their ability to respond prosocially; they rarely initiated prosocial behavior, but did respond to specific prompts. The behavioral feature that marked both autistic groups, in contrast to all other groups, was a lack of social referencing; they did not tend to look toward an adult in the presence of an ambiguous and unfamiliar stimulus. Results are discussed in terms of variability between and among high- and low-functioning autistic children, and implications for the core deficits in autism.

Diagnosis and classification in autism.

This study compared four systems for the diagnosis of autism (DSM-III, DSM-III-R, DSM-IV, and ICD-10) with two empirically derived taxa of autism, and with three social subgroups of autism (Aloof, Passive, and Active-but-Odd) in 194 preschool children with salient social impairment. There were significant behavior and IQ differences between autistic and other-PDD groups for all four diagnostic systems, and a significant association was found (a) for Taxon B, diagnoses of autism, and the Aloof subgroup, and (b) for Taxon A, other-PDD, and the Active-but-Odd subgroup. Findings offer support for two major overlapping continua within idiopathic Pervasive Developmental Disorder.

Delayed match-to-sample performance in autistic children

The involvement of temporal lobe structures in autism has found support in several animal and human studies. The delayed match‐ and nonmatch‐to‐sample paradigms are two tasks that are sensitive to temporal lobe and frontal lobe development and damage and may be useful in the study of autism. High and low‐functioning autistic disordered (HAD, LAD) subjects and developmental language‐disordered (DLD) and mentally retarded (MR) control subjects were tested on a two stimuli matching paradigm. Both trial‐unique and repeated‐stimuli procedures were used. All subjects performed equally well with both procedures. Performances of HAD subjects and controls of similar nonverbal intelligence (DLD subjects) were not significantly different. The LAD group performed at chance levels and scored significantly lower than all other groups, but covarying for nonverbal intelligence eliminated all significant group differences. These results indicate successful performance on a visual recognition memory task by HAD subjects. T...