Neuronal basis of group cooperation and social ties in monkeys and humans

The negative impact on society's mental health by social distancing during the current COVID-19 pandemic highlights the importance of social interactions in maintaining a healthy life. Reputation, cooperation, and an individual's social ties play a crucial role in social interactions. My proposal will examine the interdependence and neural correlates of these psychological processes. I hypothesize that a social tie's strength influences cooperative behavior; similarly, cooperative behavior fosters social ties. Further, I hypothesize that the interplay of neuronal activity in the dorsomedial prefrontal cortex (dmPFC) and insular cortex underpins these processes. My recent studies of human and non-human primate dmPFC showed its involvement in encoding social processes. Yet, its role in cooperation and social tie formation is unclear. To test these hypotheses, we will first characterize the neuronal representations underlying group cooperation. Second, we will identify the neuronal mechanisms underlying fundamental behavioral processes in forming and maintaining social ties during naturalistic interactions in monkeys. Third, we will compare in a new world monkey and humans the association between group cooperation and social ties? formation and maintenance. This new line of investigation will shed light on how elementary social computations during group interactions such as social dilemmas are computed at the single-neuronal and population levels within the primate brain. Overall, this proposal will allow us to study social interactions in a way that has never been done before and will lay the foundation of future work in my independent laboratory. By using an innovative approach, this project aims to identify the brain's mechanisms underlying the formation of non-kin and non-reproductive alliances. The information gleaned from this work will lay the groundwork for a comprehensive behavioral and neuronal mechanistic understanding of social ties.