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 h ad 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 Functi oning and the Wing Diagnostic Symptom Checklist in order to assess severity of autistic symptomatology. Results indicated that the only significant di fference between the two groups on the cognitive tasks was perseverative er rors on the WCST; there was no significant difference on total number of ca tegories achieved or total number of errors on the WCST or on the other exe cutive function measures. There was also significant overlap in the scores between the two groups and the difference in perseverative errors was no lo nger significant when Verbal IQ was partialled out. Executive functioning w as strongly related to all IQ variables in the DLD group and particularly r elated to Verbal IQ in the HAD group. Although there was a relationship in the HAD group between executive functioning and adaptive functioning, as we ll as between executive functioning and autistic symptomatology, these rela tionships were generally no longer significant in the HAD group after the v ariance due to Verbal IQ was accounted for. The results are interpreted to indicate that although impaired executive functioning is a commonly associa ted feature of autism, it is not universal in autism and is unlikely to cau se autistic behaviors or deficits in adaptive function.