Double dissociation of dynamic and static face perception provides causal evidence for a third visual pathway.

Abstract

The two-pathway ventral ("what") and dorsal ("where") model of visual perception has dominated neuroscience for over 30 years. In this framework, face perception, crucial for social interactions, is linked to the ventral pathway, which processes static features. However, dynamic facial expressions activate the superior temporal sulcus, outside both established pathways. An alternative model recently proposed a third visual pathway dedicated to dynamic facial expressions. Using neuroimaging and behavioral testing in 108 patients with focal brain lesions, we provide causal evidence of a double dissociation between static and dynamic face perception. Our findings show direct causal evidence for the putative third visual pathway that bypasses the occipital and fusiform face areas.