Abstract
Facial expressions are powerful signals that communicate information about our emotional states to other people. Additionally, behavioral evidence suggests that body language also conveys emotional signals, yet we do not fully understand how the brain responds to body expressions. In the macaque brain there is a discrete network of patches in inferior temporal (IT) cortex that are selectively activated by bodies (Premereur, et al., 2016, Curr Biol. 26(24): 3269-79). Our aim in this study was to determine whether these cortical body-selective patches respond more to fearful bodies in comparison to neutral bodies. We used whole-brain functional imaging to first localize the body-selective patches in two subjects (Macaca mulatta). Then, while the same subjects were awake in the scanner, we presented them with images of bodies that were classified as either fearful or neutral. We also manipulated the orientation of the stimuli (upright vs. inverted) and the species of the stimuli (macaque bodies vs. human bodies). In both subjects we found that the body-selective patches were more activated by fearful bodies than neutral bodies, regardless of species. Further, while stimulus orientation modulated the response to fearful human bodies, it did not affect the response to fearful macaque bodies. These results distinguish the body-selective patches from the adjacent face-selective patches, where activity was influenced more by orientation and less by emotional valence. The observed differences between these two category-selective networks shed light on the functional architecture of IT cortex and its relationship with the amygdala.