Two neural pathways of face processing: A critical evaluation of current models

The neural basis of face processing has been extensively studied in the past two decades. The current dominant neural model proposed by Haxby et al. (2000); Gobbini and Haxby (2007) suggests a division of labor between the fusiform face area (FFA), which processes invariant facial aspects, such as identity, and the posterior superior temporal sulcus (pSTS), which processes changeable facial aspects, such as expression. An extension to this model for the processing of dynamic faces proposed by O'Toole et al. (2002) highlights the role of the pSTS in the processing of identity from dynamic familiar faces. To evaluate these models, we reviewed recent neuroimaging studies that examined the processing of identity and expression with static and dynamic faces. Based on accumulated data we propose an updated model, emphasizing the dissociation between form and motion as the primary functional division between a ventral stream that goes through the FFA and a dorsal stream that goes through the STS, respectively. We also encourage future studies to expand their research to the processing of dynamic faces.