Abstract
The ventral temporal cortex (VTC) in humans includes functionally defined regions that preferentially respond to objects, faces and places. Recent developmental studies suggest that the face selective region in the fusiform gyrus (‘fusiform face area’, FFA) undergoes a prolonged development involving substantial increases in its volume after age 7. However, the endpoint of this development is unknown. Here we used functional magnetic resonance imaging (fMRI) to examine the development of face-, object- and place-selective responses in the VTC of adolescents (12 – 16 year olds, n = 14) and adults (18 – 40 year olds, n = 11). Subjects underwent fMRI in a 3T scanner (3x3x3 mm voxels), while viewing images of faces, objects, scenes and scrambled images, presented in pseudo-random ordered blocks and performing a 1-back task. Outside the scanner subjects participated in a recognition memory task for faces, objects and places. We found that the volume of face-selective activations in the right fusiform gyrus (i.e. right FFA) and right inferior occipital gyrus was substantially larger in adults than in adolescents, and was postively correlated with age. This development was associated with higher response amplitudes and selectivity for faces in these face-selective regions and increased differentiation of the distributed response patterns to faces versus non-face stimuli across the VTC. Furthermore, right FFA size was correlated with face recognition memory, but not with recognition memory of objects or places. In contrast, the volume of object- and place-selective cortical regions or their response amplitudes did not change across the age-groups. Thus, we found a striking and prolonged development of face-selectivity across the VTC during adolescence. These findings have important implications for theories of VTC's development and its functional specialization.
NSF BCS-0617688 and NIH R21EY017741.