Implicit learning in children and adolescents with and without autism spectrum disorders: Exploring the effects of individual differences

Implicit learning plays an important role in the acquisition of various skills that are often deficient in individuals with autism spectrum disorder (ASD). The present study examines the implicit learning ability of children and adolescents with ASD, by comparing it to that of a typical group of peers, using the Artificial Grammar Learning (AGL) task. In addition, this study investigates whether the above ability is associated with individual characteristics, namely intelligence quotient (IQ), ASD symptoms severity, and individual perception style (global/holistic or local/focused). The sample consisted of 20 individuals with mild to relatively severe ASD symptoms and 20 age- and gender-matched typically developing (TD) individuals. The unconscious (implicit) nature of learning was assessed via a subjective measure, the "no-loss gambling" method, which allows an unbiased evaluation of the confidence accompanying each judgement. The results provided evidence of implicit learning, which was preserved in the ASD group, although reduced relative to the typical group. Multiple linear regressions with interaction terms between group and participants' scores on the Wechsler Abbreviated Scale of Intelligence (WASI), the Childhood Autism Rating Scale (CARS), and performance on a Navon-type task examined whether the possible relationships between each of the above scores and AGL and implicit learning differ in the two groups. Implicit learning was not significantly associated with IQ, ASD symptoms severity, or individual perception style (except for perception style in terms of reaction times [RTs] for the TD group). These results confirm and extend earlier findings supporting the resilience of implicit learning to individual differences.