Objectives: We used a game playing paradigm adapted from social cognitive neuroscience to increase our understanding of the cognitive and neural mechanisms underlying these deficits. The paradigm permits assessment of social and nonsocial factors within the same game to evaluate the influence of peer exchanges on neural and behavioral responses.
Methods: We collected behavioral data and functional MRI (fMRI) images from male children 8-to-12 years with either high functioning autism (15) or typical development (17). A modified Prisoner’s Dilemma game was employed that required the participant to cooperate or compete with both a putative human and a computer partner with the potential to earn money. Based on previous studies, we hypothesized that boys with autism would cooperate more than neurotypical boys and show a pattern of activation that was similar regardless of whether they were playing with a human or computer partner. We further speculated that children with autism would show reduced activation of limbic striatal regions often recruited during affective and reward learning.
Results: Behaviorally, the children with autism cooperated more than the neurotypical children who engaged in more competitive play. The autism group endorsed more negative emotional responses, especially to partner defection. Based on both response strategy and partner type differential recruitment of social evaluation and reward brain regions were revealed between the groups. The autism group demonstrated less brain activation overall in response to human partners whereas the neurotypical group recruited many prototypical affective learning brain regions. Strikingly the children with autism showed more robust activation of socioemotional brain regions, such as the amygdala and cingulate, to nonsocial stimuli than to the social stimuli and differential caudate response to negative social interactions.
Conclusions: Our results show that children with autism cooperate more, and this is associated with decreased activity in brain circuitry supporting competitive play and a reduced response in the caudate to partner defection. The increased activity to a computer rather than a child partner supports a fundamental disturbance of social engagement and affective learning in children with autism. Atypical recruitment of limbic and reward systems during reciprocated and unreciprocated play suggests a failure to provide appropriate social relevance and reward value in autism.