Hemispheric asymmetries for whole-based and part-based face processing in the human fusiform gyrus

Behavioral studies indicate a right hemisphere advantage for processing a f ace as a whole and a left hemisphere superiority for processing based on fa ce features. The present PET study identifies the anatomical localization o f these effects in well-defined regions of the middle fusiform gyri of both hemispheres. The right middle fusiform gyrus, previously described as a fa ce-specific region, was found to be more activated when matching whole face s than face parts whereas this pattern of activity was reversed in the left homologous region. These lateralized differences appeared to be specific t o faces since control objects processed either as wholes or parts did not i nduce any change of activity within these regions. This double dissociation between two modes of face processing brings new evidence regarding the lat eralized localization of face individualization mechanisms in the human bra in.