Abstract
Behavioral and electrophysiological studies in humans suggest that face processing begins in early development and undergoes a slow maturation during childhood. Little is known about the underlying neural systems or the role of experience in this maturation process. In adults, a specialized region in the FFA responds preferentially to faces compared to other objects. Some studies have suggested a role for “expertise” in FFA's responsiveness to faces. Thus, one possibility is that less face recognition expertise in children (compared to adults) is associated with less face selectivity in children's fusiform gyrus. Here we used functional magnetic resonance imaging (fMRI) to examine FFA's maturation during childhood. Fifteen adults and 21 children (ages 7 – 16) underwent fMRI in a 3 T scanner, while viewing 10 epochs of each of 5 image categories presented in pseudo-random blocks. Image categories included: faces (male faces with neutral facial expressions), novel objects (abstract sculptures), places (indoor and outdoor scenes) and textures. Data were analyzed in SPM2. For each subject, regions of interest were defined as contiguous voxels in the fusiform gyrus that were selectively activated for faces or objects. We found fewer face selective voxels (faces > abstract objects, p textures, p < 0.001) were similar in children and adults (right fusiform gyrus in children: 45.5± 16.6 voxels, in adults: 28.3 ± 9.8 voxels, p < 0.46; left FFA in children: 37.3 ± 13.1, in adults: 34.3 ± 10.1 voxels, p < 0.85). These findings provide evidence for maturation of FFA during childhood perhaps due to accumulated exposure to human faces.
Supported by 1R21MH66747 & 5R21DA15893