FRONTOPOLAR MECHANISMS FOR DRIVING SOCIAL AND ECONOMIC DECISIONS IN PRIMATE GROUPS

Primate group behavior allows individuals to build affiliations and benefit from the reciprocation with others but also poses the unique challenge of tracking others’ behavior across multiple distinct interactions. These interactions can often also be highly dynamical and change rapidly based on the reputation or wealth distribution of others. The single-cellular mechanisms that precisely underlie these decisions or that drive the social-economic behavior of groups, however, remain poorly understood. Here, we obtained multiple-neuronal recordings from the dorsomedial prefrontal cortex (dmPFC) and frontopolar (FP) cortex of Rhesus macaques as they performed a structured reciprocity-based social task. In this task three individuals interacted with each other over multiple rounds by offering each other reward and which could allow us to dissociate computations associated with interactive behavior, social preference, and group dynamics. Behaviorally, we find that the monkeys demonstrated a strategic preference for other individuals and favored rewarding those who reciprocated. The rate at which individuals reciprocated within and across sessions was reflected in distinct levels of reputation. At the single-cellular level, we have previously shown that different subpopulations of dmPFC neurons tracked the identity of the current actor and reward recipient. Here, we show that the activity of a subpopulation of FP neurons correlated with the current actor’s own reputation for reciprocity. These findings reveal neurons in the primate prefrontal cortex that encode information about specific individuals within social groups and which could help optimize economic benefit during interactive group dynamics.