The Third Visual Pathway for Social Perception

TL;DR

This paper proposes a third visual pathway in primates dedicated to processing dynamic social cues, integrating anatomical and neuroimaging evidence to expand understanding of social perception mechanisms.

Contribution

It introduces a novel third visual pathway from V1 to STS, specialized for social cue processing, beyond the traditional ventral and dorsal streams.

Findings

Identification of a third pathway from V1 to STS.

Specialization in processing facial expressions, gaze, and body movements.

Supports social perception by interpreting actions and intentions.

Abstract

Influential models of primate visual cortex describe two functionally distinct pathways: a ventral pathway for object recognition and the dorsal pathway for spatial and action processing. However, recent human and non-human primate research suggests the existence of a third visual pathway projecting from early visual cortex through the motion-selective area V5/MT into the superior temporal sulcus (STS). Here we integrate anatomical, neuroimaging, and neuropsychological evidence demonstrating that this pathway specializes in processing dynamic social cues such as facial expressions, eye gaze, and body movements. This third pathway supports social perception by computing the actions and intentions of other people. These findings enhance our understanding of visual cortical organization and highlight the STS's critical role in social cognition, suggesting that visual processing encompasses a dedicated neural circuit for interpreting socially relevant motion and behavior.