Superior temporal sulcus as the hub for distributed brain networks that support social perception

Over the last decade, there has been a significant surge of interest towards the neural underpinnings of social cognition, and indeed several candidate brain structures have been implicated based on the results of such studies. While the vast majority of these studies have utilized impoverished stimuli and task paradigms (e.g., contrasting two perceptual categories such as faces vs. bodies), there have been recently also studies that have utilized naturalistic stimuli such as movie clips to investigate the neural basis of social cognition.

In their recent study, Lahnakoski et al. (2012) presented, during 3-Telsa functional magnetic resonance imaging, healthy volunteers with a collection of short movie clips containing both social features (i.e., faces, human bodies, biological motion, goal-oriented actions, emotions, social interactions, pain, and speech) and non-social features (i.e., places, objects, rigid motion, people not engaged in social interaction, non-goal-oriented action, and non-human sounds). Brain activity patterns were then modeled based on the time course of occurrence of these social and non-social features.

Interestingly, the authors observed that the posterior superior temporal sulcus responded to all social features but not to any of the non-social features. Furthermore, there were four extended networks that participated in processing of specific social signals: 1) a fronto-temporal network responding to multiple social categories, 2) a fronto-parietal network preferentially activated by bodies, motion, and pain, 3) a temporal-lobe-amygdala network responding to faces, social interaction, and speech, and, finally, 4) a fronto-insular network that activated during perception of emotions, social interactions, and speech. Taken together, these results disclose the posterior superior temporal sulcus as a central hub for distributed brain networks that support social perception, and add to accumulating pool of evidence indicating that utilization of naturalistic stimuli in fMRI studies provides an effective tool for the study of the neural basis of social cognition.

Reference: Lahnakoski JM, Glerean E, Salmi J, Jääskeläinen IP, Sams M, Hari R, Nummenmaa L. Naturalistic fMRI mapping reveals superior temporal sulcus as the hub for distributed brain network for social perception. Frontiers in Human Neuroscience (2012) 6: 233. http://dx.doi.org/10.3389/fnhum.2012.00233