How Executive Functions Correlate with Intelligence in Children and Adolescents in Autism Spectrum Disorders

ABSTACT Dysexecutive syndrome has been consistently reported in children and adolescents with autism spectrum disorders (ASD). Particularly, impairments have been documented in working memory, inhibition, and mental flexibility. However, the relationship between executive impairments and intellectual functioning is far from clear in this population. This study aimed to investigate how executive functions (EF) are associated with intelligence in ASD. Children and adolescents with ASD (N = 69) were compared to typically developing (TD) individuals (N = 68), matched in chronological age and sex. The Wechsler Intelligence Scales were used to assess participants’ intelligence quotient (estimated IQ). EF – working memory, shifting, and inhibition – were assessed using the Digit Span, Wisconsin Card Sorting Test and Stroop Test, respectively. TD individuals outperformed ASD in all cognitive assessment measures. Correlation analysis showed that while for the ASD group intelligence was associated with shifting abilities, in the TD group the association was observed for working memory measures. Linear regression analysis supported that the association between intelligence and EF domains differed between groups, particularly regarding shifting abilities (interaction term significant), whereas working memory showed a similar trend in both groups (difference in effect size is non-significant). Results suggest that specific executive function domains are associated with ASD intellectual functioning and differ from TD individuals, which may be related to adaptive behavior outcomes.