Functional organization of social perception in the human brain
Humans can readily perceive a multitude of features from social interactions, but the phenomenological and neural basis of social perception has yet to be solved. Short film clips with rich social content were shown to 97 healthy participants while their haemodynamic brain activity was measured with fMRI. The stimulus clips were annotated for 112 social features yielding the initial stimulus model. Cluster analysis revealed that 13 dimensions were sufficient for describing the social perceptual space. Univariate GLM using these dimensions as predictors was used to map regional neural response profiles to different social features. Multivariate pattern analysis was then utilized to establish the regional specificity of the responses. The results revealed a posterior-anterior gradient in the processing of social information in the brain. Occipital and temporal regions responded to most social dimensions and the classifier revealed that these responses were dimension specific; in contrast Heschl gyri and parietal areas were also broadly tuned to different social signals yet the responses were domain-general and did not differentiate between dimensions. Altogether these results highlight the distributed nature of social processing in the brain as well as the specific contributions of feature-specific versus domain-general social perceptual processes.