The neural basis of perceiving emotional bodily expressions in monkeys

Higher animals invest considerable time and brain resources in monitoring each others' body language. A network of dedicated brain structures is presumably involved in social perception. We hypothesized that functional magnetic resonance imaging may reveal portions of inferior temporal cortex participating in processing social signals. We used contrast agent-enhanced awake monkey functional magnetic resonance imaging to test whether subdivisions of inferior temporal cortex are sensitive to emotional body displays of conspecifics, and whether the degree of activation reflects the social intention expressed. We show that portions of superior temporal sulcus play a central role in processing body images of conspecifics and that these areas are preferentially sensitive to threat signals indicating that threat may be the most salient social signal.