Functional magnetic resonance imaging of human visual cortex during face matching: a comparison with positron emission tomography.

Cortical areas associated with the perception of faces were identified using functional magnetic resonance imaging (fMRI). T2*-weighted gradient echo, echo-planar MR images were obtained using a modified 1.5-T GE Signa MRI. In all nine subjects studied, performance of a face-matching task was associated with a region of significantly increased MR signal in the ventral occipitotemporal cortex, extending from the inferior occipital sulcus to the lateral occipitotemporal sulcus and fusiform gyrus. Smaller and more variable signal increases were found in dorsolateral occipitoparietal cortex near the intraparietal sulcus. Signal decreases were found in the angular gyrus and posterior cingulate cortex. Single-subject fMRI analyses revealed discrete areas of activation with well-defined borders. Group analyses of spatially smoothed fMRI data produced results that replicated most aspects of previous studies of face processing using positron emission tomography (PET). These results show that PET and fMRI identify functional areas with similar anatomical locations. In addition, fMRI reveals interindividual variation in the anatomical location of higher-level processing areas with greater anatomical precision.