Salience-based information integration: An overarching function of the “social brain”?

Behavior in social contexts is routinely accompanied by neural activity in a brain network comprising the bilateral temporoparietal junction (TPJ), dorsomedial and dorsolateral prefrontal cortex (dmPFC and dlPFC), and precuneus. This network – often referred to as the “social brain network” (SBN) – is thought to have evolved in response to the information processing demands of life in social groups. However, its precise functional contributions to behavior are unclear, since many of its areas are also activated in non-social contexts requiring, for example, attentional orienting or context updating. Here we argue that these results may reflect a basic neural mechanism implemented by areas in this network that is commonly required in both social and non-social contexts: Integrating multiple sensory and memory inputs into salient configurations, such as social constellations or perceptual Gestalts. We tested this hypothesis using a numeracy paradigm that orthogonally varied the salience of sensory target configurations and the required motor responses. Even in this non-social task, several regions of the SBN (TPJ, dmPFC, and precuneus) showed higher activity when the goal required the brain to attend to more versus less salient perceptual configurations. This activation pattern was specific to configuration salience and did not reflect general task demand or switching to new contexts. Taken together, these results suggest that the integration of information into salient configurations may be a key function of SBN regions, thus offering a new perspective on the widespread recruitment of these areas across social and non-social contexts.