Matthew Rushworth, Dept. of Experimental Psychology & Welcome Centre for Integrative Neuroimaging (WIN) at FMRIB, University of Oxford, UK | Comparing the impact of the social environment in macaques and humans

Abstract

The social environment in which we live impacts both on our brains and on our behaviour. I will review studies examining the impact that the social environment has on brain structure and function in macaques over the longer term and on humans over the very short term. For example, although people estimate their abilities on the basis of their own performance in a rational manner, their estimates of themselves are partly merged with the performance of others. Reciprocally, their ability estimates for others also reflect their own, as well as others’ performances. We refer to this as self-other-mergence.

We found that it operated in a context-dependent manner: interacting with high or low performers respectively enhanced and diminished a person’s own ability estimates in cooperative contexts but the opposite occurred in competitive contexts. Self-other-mergence not only influenced subjective evaluations, it also affected how people subsequently objectively adjusted their performance. Perigenual anterior cingulate cortex tracked people’s own performance. Dorsomedial frontal area 9 tracked other individuals' performances but also integrated contextual and self-related information. Self-other-mergence increased with the strength of self and other representations in area 9 suggesting it carries interdependent representations of self and other.