PT - JOURNAL ARTICLE AU - Aidan Makwana AU - Georg Grön AU - Ernst Fehr AU - Todd A. Hare TI - A neural mechanism of strategic social choice under sanction induced norm compliance AID - 10.1523/ENEURO.0066-14.2015 DP - 2015 Jun 16 TA - eneuro PG - ENEURO.0066-14.2015 4099 - http://www.eneuro.org/content/early/2015/06/16/ENEURO.0066-14.2015.short 4100 - http://www.eneuro.org/content/early/2015/06/16/ENEURO.0066-14.2015.full AB - In recent years, much has been learned about the representation of subjective value in simple, non-strategic choices. However, a large fraction of our daily decisions are embedded in social interactions in which value guided decisions require balancing benefits for self against consequences imposed by others in response to our choices. Yet, despite their ubiquity, much less is known about how value computation takes place in strategic social contexts that include the possibility of retribution for norm violations. Here, we used functional magnetic resonance imaging (fMRI) to show that when human subjects face such a context connectivity increases between the temporoparietal junction (TPJ), implicated in the representation of other peoples’ thoughts and intentions, and regions of ventromedial prefrontal cortex (vmPFC) that are associated with value computation. In contrast, we find no increase in connectivity between these regions in social non-strategic cases where decision-makers are immune from retributive monetary punishments from a human partner. Moreover, there was also no increase in TPJ-vmPFC connectivity when the potential punishment was carried out by a computer programmed to punish fairness norm violations in the same manner as a human would. Thus, TPJ-vmPFC connectivity is not simply a function of the social or norm enforcing nature of the decision, but rather occurs specifically in situations where subjects make decisions in a social context and strategically consider putative consequences imposed by others.Significance Statement: A large fraction of our decisions are embedded in social contexts that require balancing benefits for self against the positive or negative reactions of others in response to our choices. Yet, how the brain computes the value for different courses of action in such choices is unknown. We examined the neurobiological mechanisms underlying strategic social choices in the context of potential retributive punishment. Our findings indicate that there are specific increases in the functional interactions between brain regions previously associated with mentalizing about others’ beliefs and key nodes of the brain’s value computation system during choices in which it is necessary to balance direct personal gains against the likelihood of subsequent norm enforcing punishment by other people.