Objectives: The purpose of the proposed study was to extend this line of research to investigate frontostriatal functioning in response to nonsocial stimuli presented in a cognitive control context.
Methods: Participants with and without autism completed an oddball target-detection task. On half the runs, targets were neutral faces taken from the Nimstim set of face stimuli. On half the runs, targets were so-called “High Autism Interest” (HAI) stimuli, derived from a passive-viewing eye-tracking study of children with autism (Sasson, et al. 2008). To date, we have assessed 16 typically developing individuals [mean age= 24.10 ± 3.58] and 5 individuals with Autism [mean age= 23.45 ± 4.83]. Primary analyses will contrast response to “HAI targets” and “Face targets.”
Results: Data collection is ongoing; however, analysis on our current sample reveal two important findings. First, replicating our previous findings, the ASD group demonstrated relatively greater dorsal anterior cingulate activation in response to face targets. However, the opposite pattern was observed in response to HAI targets: the ASD group displayed relatively decreased dorsal anterior cingulate activation in response to HAI targets.
Conclusions: Research has demonstrated that autism is characterized by aberrant functioning of frontostriatal brain systems during tasks requiring cognitive control. The overarching goal of our research is to examine frontostriatal functioning in autism when task stimuli are relevant to core symptoms. We have previously reported that ASD is characterized by dorsal anterior cingulate (dACC) hyperactivation during a cognitive control task that used social stimuli (Dichter et al, 2009). We interpreted this pattern to reflect the greater cognitive “effort” required to response to social targets in autism. dACC hyperactivation to face targets may represent a compensatory mechanism that is engaged to respond appropriately to social stimuli during a cognitive control task. We have extended this line of research to assess cognitive control of stimuli relevant to repetitive behaviors in autism, namely nonsocial stimuli that elicit greater visual attention in children with ASDs. In contrast to the pattern of brain activation observed in response to social targets, nonsocial targets prompted the opposite pattern of findings in the dACC: the ASD group demonstrated less dACC than their neurotypical counterparts. This finding suggests that cognitive control abilities in ASD may be superior to neurotypical individuals in the presence of certain nonsocial stimuli. These findings indicate that functioning of neurobiological mediators of cognitive control in autism is dependent on the types of stimuli processed: relevant brain systems may function more poorly in social contexts and less poorly in nonsocial contexts. Relations between fMRI activation patterns and core autism symptoms will be assessed, and implication for the executive function theory of autism will be discussed.