Person- and place-selective neural substrates for entity-specific semantic access

Abstract

Object-category has a pronounced effect on the representation of objects in higher level visual cortex. However, the influence of category on semantic/conceptual processes is less well characterized. In the present study, we conduct 2 fMRI experiments to investigate the semantic processing of information specific to individual people and places (entities). First, during picture presentation, we determined which brain regions show category-selective increases during access to entity-specific semantic information (i.e., nationality) in comparison to general-category discrimination (person vs. place). In the second experiment, we presented either words or pictures to assess the independence of entity-specific category-selective semantic representations from the processes used to access those representations. Convergent results from these 2 experiments show that brain regions exhibiting a category-selective increase during entity-specific semantic access are the same as those that show a supramodal (word/picture) category-selective response during the same task. These responses were different from classical "perceptual" category-selective responses and were evident in the medial precuneus for people and in the retrosplenial complex as well as anterior/superior sections of the transverse occipital sulcus and parahippocampal gyrus for places. These results reveal the pervasive influence of object-category in cortical organization, which extends to aspects of semantic knowledge arbitrarily related to physical/perceptual properties.

Keywords: concepts; domain; face; semantic; unique entities.