Selective processing of social stimuli in the superficial amygdala

The human amygdala plays a pivotal role in the processing of socially significant information. Anatomical studies show that the human amygdala is not a single homogeneous structure but is composed of segregable subregions. These have recently been functionally delineated by using a combination of functional magnetic resonance imaging (fMRI) and cytoarchitectonically defined probabilistic maps. However, the response characteristics and individual contribution of these subregions to the processing of social‐emotional stimuli are little understood. Here, we used this novel technique to segregate intra‐amygdalar responses to facial expressions and nonsocial control stimuli. We localized facial expression‐evoked signal changes bilaterally in the superficial amygdala, which suggests that this subregion selectively extracts the social value of incoming sensory information. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.