Clarifying the neural circuit mechanisms of spontaneous social behavior in macaques

Research using nonhuman primates has investigated how the brain processes and represents a wide range of socially relevant information, such as others’ faces, actions and rewards. While our understanding has expanded considerably in recent years, much of the research has been conducted under highly controlled task conditions, leaving the neural underpinnings of naturally occurring social behaviors largely unexplored. In this Perspective, we first highlight recent efforts utilizing freely behaving primates to overcome these challenges. We then detail our own experiments, demonstrating how the combined use of behavioral analysis and neural manipulation techniques in freely moving macaques enabled us to identify a specific neural circuit critical for the spontaneous expression of mounting behavior. These strategies offer novel opportunities to validate and extend established knowledge concerning the neural basis of social behavior in experimental settings that more closely resemble those occurring in a real world.