Contrast polarity and face recognition in the human fusiform gyrus

Functional imaging has revealed face-responsive visual areas in the human f usiform gyrus, but their role in recognizing familiar individuals remains c ontroversial. Face recognition is particularly impaired by reversing contra st polarity of the image, even though this preserves all edges and spatial frequencies. Here, combined influences of familiarity and priming on face p rocessing were examined as contrast polarity was manipulated. Our fMRI resu lts show that bilateral posterior areas in fusiform gyrus responded more st rongly for faces with positive than with negative contrast polarity. An ant erior, right-lateralized fusiform region is activated when a given face sti mulus becomes recognizable as a well-known individual.