Prefrontal control of actions in freely moving macaques
Our natural behavioral repertoires include complex coordinated actions of characteristic types. To better understand the organization of action and its neural underpinnings, we examined behavior and neural activity in rhesus macaques performing a freely moving foraging task in an open environment. We developed a novel analysis pipeline that can identify meaningful units of behavior, corresponding to recognizable actions such as sitting, walking, jumping, and climbing. On the basis of action transition probabilities, we found that behavior was organized in a modular and hierarchical fashion. We found that, after regressing out many potential confounders, actions are associated with specific patterns of firing in each of six prefrontal brain regions and that, overall, representation of actions is progressively stronger in more dorsal and more caudal prefrontal regions. Conversely, we found that switching between actions resulted in changed firing rates, with more rostral and more ventral regions showing stronger effects. Together, these results establish a link between control of action state and neuronal activity in prefrontal regions in the primate brain.