The fusiform face area responds equivalently to faces and abstract shapes in the left and central visual fields

Abstract

The fusiform face area (FFA) is widely believed to be specialized for processing faces. Although the FFA is most responsive to faces, this region also consistently responds to non-face items. This suggests that the FFA may be tuned to a feature that is shared by faces and non-face items. Based on the known left visual field face-processing bias along with evidence that the FFA responds to the visual feature of shape, we hypothesized that the FFA may be particularly tuned to shapes presented in the left visual field. We tested this hypothesis using functional magnetic resonance imaging (fMRI). In a face localizer run, participants viewed blocks of faces or objects. In a separate run, blocks of intact or scrambled abstract shapes were presented in the left, the central, or the right visual field. Within each of the eleven face-processing regions-of-interest (identified by contrasting faces and objects), the magnitude of activity associated with faces was compared to the magnitude of activity associated with intact shapes. Consistent with previous results, collapsing over shape visual field location, the magnitude of activity associated with faces was greater than the magnitude of activity associated with shapes in the FFA. However, separating by shape visual field location revealed an equivalent magnitude of activity associated with faces and shapes in the FFA when shapes were presented in the left and central visual fields. These findings indicate that the FFA, rather than being specialized for holistic face processing, mediates shape processing in the left and central visual fields.