Temporal Dynamics of the Neural Representation of Social Relationships

Abstract

Humans can rapidly encode information from faces to support social judgments and facilitate interactions with others. We can also recall complex knowledge about those individuals, such as their social relationships with others, but the timecourse of this process has not been examined in detail. This study addressed the temporal dynamics of emerging visual and social relationship information using electroencephalography (EEG) and representational similarity analysis (RSA). Participants became familiar with a 10-person social network, and were then shown faces of that networks members while EEG was recorded. To examine the temporal dynamics of the cognitive processes related to face perception, we compared the similarity structure of neural pattern responses to models of visual processing, face shape similarity, person identity, and social connectedness. We found that all types of information are associated with neural patterns after a face is seen. Visual and identity models became significant early after image onset, but only the identity model stayed associated with neural patterns until 400 ms. Models representing social connections were also present beginning around 200 ms, even in the absence of an explicit task to think about the friendships among the network members. A partial correlation showed that visual and social information contribute uniquely to person perception, although differences were found between models of social connection. This study highlights the speed and salience of social information relating to group dynamics that are present in the brain during person perception. Significance StatementWe live our lives in social groups where complex relationships form among and around us. It is likely that some of the information about social relationships that we observe is integral during person perception, to better help us interact in differing situations with a variety of people. However, when exactly this information becomes relevant has been unclear. In this study, we present evidence that information reflecting observed relationships among a social network is spontaneously represented in whole-brain patterns shortly following visual perception, and is uniquely present around 400 ms. These results are consistent with neuroimaging studies showing spontaneous spatial representation of social network characteristics, and contribute novel insights into the timing of these neural processes.