Social processing by the primate medial frontal cortex.

The primate medial frontal cortex is comprised of several brain regions that are consistently implicated in regulating complex social behaviors. The medial frontal cortex is also critically involved in many non-social behaviors, such as those involved in reward, affective, and decision-making processes, broadly implicating the fundamental role of the medial frontal cortex in internally guided cognition. An essential question therefore is what unique contributions, if any, does the medial frontal cortex make to social behaviors? In this chapter, we outline several neural algorithms necessary for mediating adaptive social interactions and discuss selected evidence from behavioral neurophysiology experiments supporting the role of the medial frontal cortex in implementing these algorithms. By doing so, we primarily focus on research in nonhuman primates and examine several key attributes of the medial frontal cortex. Specifically, we review neuronal substrates in the medial frontal cortex uniquely suitable for enabling social monitoring, observational and vicarious learning, as well as predicting the behaviors of social partners. Moreover, by utilizing the three levels of organization in information processing systems proposed by Marr (1982) and recently adapted by Lockwood, Apps, and Chang (2020) for social information processing, we survey selected social functions of the medial frontal cortex through the lens of socially relevant algorithms and implementations. Overall, this chapter provides a broad overview of the behavioral neurophysiology literature endorsing the importance of socially relevant neural algorithms implemented by the primate medial frontal cortex for regulating social interactions.