Abstract
Non-human primate neuroanatomical studies have identified a cortical pathway from the superior temporal sulcus (STS) projecting into dorsal sub-regions of the amygdala, but whether this same pathway exists in humans is unknown. Here, we addressed this question by combining thetaburst transcranial magnetic stimulation (TBS) with functional magnetic resonance imaging (fMRI) to test the prediction that the STS and amygdala are functionally connected during face perception. Human participants (N=17) were scanned, over two sessions, while viewing 3-second video clips of moving faces, bodies and objects. During these sessions, TBS was delivered over the face-selective right posterior STS (rpSTS) or over the vertex control site. A region-of-interest analysis revealed results consistent with our hypothesis. Namely, TBS delivered over the rpSTS reduced the neural response to faces (but not to bodies or objects) in the rpSTS, right anterior STS (raSTS) and right amygdala, compared to TBS delivered over the vertex. By contrast, TBS delivered over the rpSTS did not significantly reduce the neural response to faces in the right fusiform face area (rFFA) or right occipital face area (rOFA). This pattern of results is consistent with the existence of a cortico-amygdala pathway in humans for processing face information projecting from the rpSTS, via the raSTS, into the amygdala. This conclusion is consistent with non-human primate neuroanatomy and with existing face perception models. References Pitcher, D., Japee, S., Rauth, L., & Ungerleider, L. G. (In Press). The superior temporal sulcus is causally connected to the amygdala: A combined TBS-fMRI study. Journal of Neuroscience.
Meeting abstract presented at VSS 2017