Domain Specificity in Visual Cortex

We investigated the prevalence and specificity of category-selective regions in human visual cortex. In the broadest survey to date of category selectivity in visual cortex, 12 participants were scanned with functional magnetic resonance imaging while viewing scenes and 19 different object categories in a blocked-design experiment. As expected, we found selectivity for faces in the fusiform face area (FFA), for scenes in the parahippocampal place area (PPA), and for bodies in the extrastriate body area (EBA). In addition, we describe 3 main new findings. First, evidence for the selectivity of the FFA, PPA, and EBA was strengthened by the finding that each area responded significantly more strongly to its preferred category than to the next most effective of the remaining 19 stimulus categories tested. Second, a region in the middle temporal gyrus that has been reported to respond significantly more strongly to tools than to animals did not respond significantly more strongly to tools than to other nontool categories (such as fruits and vegetables), casting doubt on the characterization of this region as tool selective. Finally, we did not find any new regions in the occipitotemporal pathway that were strongly selective for other categories. Taken together, these results demonstrate both the strong selectivity of a small number of regions and the scarcity of such regions in visual cortex.