The third visual pathway in cognition and disease

Abstract:  The third visual pathway describes the anatomical connectivity that projects from primary visual cortex, via the motion-selective area V5/MT and into the superior temporal sulcus (STS). Converging evidence demonstrates that this pathway is specialized for social perception, principally the visual perception of moving faces and bodies. Neuroimaging studies report that brain areas in the third pathway exhibit impaired neural responses in individuals with a range of clinical disorders and mental illnesses including autism, schizophrenia, ADHD, hallucinations, and depression. While these disorders exhibit a broad range of symptoms, there are common underlying cognitive mechanisms that can account for the impaired processing reported in the brain areas in the visual third pathway. Most notably an impairment in predicting the social behaviour of others based on dynamic social cues. These impairments manifest in different aetiologies across a range of clinical disorders and can impair the predictive mechanisms that underpin social cognition.