Background: Recent studies have suggested that the social and cognitive impairments in autism are associated with neural processing deficits in specific brain regions. However, these studies have primarily focused on neural systems responsible for face processing and social behaviors. Although repetitive, stereotyped behaviors are a hallmark of autism, little is known about the neural mechanisms underlying these behaviors in the disorder.
Methods: We used functional magnetic resonance imaging (fMRI) to investigate the neural correlates of shifts in behavioral response and cognitive set in 18 individuals with high-functioning autism and 15 neurotypical control participants. Participants performed a target detection task specifically designed to distinguish shifts in response from shifts in cognitive set.
Results: Individuals with autism showed lower accuracy on response shifting trials, independent of whether those trials also required a shift in cognitive set. Compared with control subjects, participants with autism showed reduced activation in frontal, striatal, and parietal regions during these trials. In addition, within the autism group, the severity of restricted, repetitive behaviors was negatively correlated with activation in anterior cingulate and posterior parietal regions.
Conclusions: These results suggest that executive deficits and, by extension, repetitive behaviors associated with autism might reflect a core dysfunction within the brain's executive circuitry.