Abstract
Multiple brain areas are recruited during the perception of faces. However, the structural connections between the many functional areas that form the cortical network for face perception remain largely unknown. Here we use fMRI in conjunction with diffusion weighted imaging and deterministic fiber-tracking to investigate white matter connectivity between these functionally-defined visual areas. Face selective regions were identified using standard functional localizer scans contrasting faces to objects. The core set of regions of interest identified by this localizer included: the FFA (fusiform face area), the STS (superior temporal sulcus), aIT (anterior temporal lobe) and multiple OFA (occipital face area) regions. Subjects also participated in a diffusion spectrum imaging scan using a 257 direction sequence collected with a 32-channel head-coil, reconstructed using a generalized q-imaging method (Yeh, Wedeen, & Tseng, 2010). The functional regions of interest were then used as seeds for deterministic fiber-tracking to map the white matter connections between these visual areas. Connectivity was found between all of the OFA regions, FFA and aIT. Intriguingly, very little connectivity was identified between STS and other face selective regions, calling into question the role of the STS in static face processing. Finally, the multiple OFA regions identified with the functional localizer all showed connectivity to FFA, suggesting these neuranatomically distinct posterior regions are subserving different functional roles within the face perception network. Our results provide a more complete map of the structural connectivity between functional areas of the face processing network and inform future studies of the specific functional roles of these brain regions.
Perceptual Expertise Network (#15573-S6), a collaborative award from James S. McDonnell Foundation, by the Temporal Dynamics of Learning Center at UCSD (NSF Science of Learning Center SBE-0542013), by an NIH EUREKA Award (#1R01MH084195-01) to MJT, by the PA Department of Health, Commonwealth Universal Research Enhancement (C.U.R.E.) program, Formula Award Number 4100050890, 2010.