Distributed representation of facial expression in the superior temporal sulcus: An fMRI study

According to our model of the human neural system for face perception (Haxby et al., TICS, 2000) the face-responsive region in the fusiform gyrus is more involved in the representation of invariant aspects of a face and the recognition of identity whereas the superior temporal sulcus is more involved in the representation of changeable aspects of faces such as eye gaze and expression. To test this model we employed functional magnetic resonance imaging (fMRI; 3T GE) to determine patterns of neural response to face expressions in these two regions. Five healthy individuals performed a one back repetition detection task while looking at faces with different expressions (happy, angry, disgusted, fearful, neutral) and nonsense patterns. Face-responsive voxels were identified in anatomically-defined fusiform and superior temporal sulcal cortex. Expression-related patterns of response in these regions were analyzed using the split-half correlation method (Haxby et al. Science, 2001). Patterns of response that distinguished among expressions were found in the superior temporal sulcus but not in the fusiform gyrus. These results provide further support for the hypothesis that face-responsive cortex in the superior temporal sulcus plays a stronger role than does fusiform cortex in the representation of face expression.