Abstract
Developmental prosopagnosia (DP) refers to a lifelong face recognition deficit that cannot be attributed to acquired brain damage despite intact general cognitive abilities and sensory functions. Among the network of brain regions mediating face processing, the right fusiform face area (FFA) has been associated with face configuration representation. Paradoxically, DP individuals exhibit normal fMRI response amplitude profile in the right FFA, showing higher activation for faces than objects from other categories. This puzzling finding and other evidence have led to the conclusion that the right FFA appears to be intact in DP individuals but that connections among face processing regions are impaired. Using fMRI and multi-voxel pattern analysis (MVPA), here we report that DP individuals exhibited abnormal neural response patterns to faces in the right FFA. Specifically, the right FFA showed no discrimination between intact faces and faces in which parts were rearranged in a scrambled configuration (scrambled faces). This deficit was limited to the right FFA, as normal neural pattern discrimination for intact and scrambled faces was found in the right occipital face area and the lateral occipital object-processing region. DP individuals also exhibited normal face response amplitude profile and largely intact pattern discrimination to different face parts in the right FFA. Thus, in DP individuals, despite right FFA's preference to face stimuli and its ability to form unique representations for different face parts, face parts do not seem to be properly combined to give rise to the intact face gestalt to allow the formation of unique representations for intact and scrambled faces. To our knowledge, this is the first direct neural evidence showing that, in DP individuals, face configuration representation is impaired in the right FFA. We argue that such impairment may play a central role in behavioral deficits observed in DP individuals.
Meeting abstract presented at VSS 2014