Mixed Multi-Level Visual, Reward, and Motor Signals in Dorsomedial Frontal Cortex Area F7 during Active Naturalistic Video Exploration

Abstract

In the primate brain the frontal lobes support complex functions, including social cognition. Understanding the functional organization of these regions requires an approach for rich functional characterization. Here we used a novel paradigm, the visual exploration of dynamic social and non-social video scenes, to characterize diverse functions in area F7 of dorsomedial premotor cortex in the macaque monkey (Macaca mulatta) previously suggested to be involved in the representation of social interactions. We found that neural populations within this area carry information about both visual events in the videos, like head turning, and higher-level social categories, like grooming. In addition to signaling visual events, the population also encoded the delivery of juice reward. Our novel free viewing paradigm and naturalistic stimuli elicited active visual exploration, and we found that a large fraction of F7 neurons responded to the subjects own saccadic eye movements. Information from these three different domains were not separated across distinct neural sub-populations, but distributed, such that many neurons carried sensory, reward, and motor information in a mixed format. Thus we uncover a hitherto unappreciated diversity of functions in region F7 within dorsomedial frontal cortex.