Performance on the dimensional change card sort and backward digit span by young children with autism without intellectual disability.

The early development of executive function (EF) and its relation to autism symptom expression is of considerable theoretical interest, particularly in children without general cognitive delay. Executive function was tested in 23 children with autism spectrum disorders (ASD) without intellectual disability and 20 age- and IQ-matched typically developing children. Even though performance was equivalent between the two groups on tests of general intelligence, flexibility in card sorting was lower for children with ASD. Verbal working memory during the backward digit span did not differ between groups. Among children with ASD, poorer performance on card sorting distinguished a subgroup with worse social-communication functioning above and beyond IQ. Controlling for IQ social and repetitive symptoms of ASD did not differ based on card sorting ability.