The human amygdala and emotion

Findings from humans and animals suggest that the amygdala helps to guide behaviors and to process knowledge about stimuli and situations that are of special importance to the survival of an organism. The amygdala makes critical contributions to many cognitive processes, including memory, attention, and decision-making. Lesion and functional imaging studies in humans support a role for the amygdala in recognizing emotions in facial expressions, especially fear. Although it has been known from animal studies that the amygdala is important in the acquisition of nondeclarative forms of memory, such as conditioned responses, studies in humans show that the amygdala also modulates encoding of declarative knowledge about emotional material. Future studies will determine the amygdala's role in the conscious experience of emotion, a topic that is just beginning to be explored. Further advances are being made by high-resolution functional imaging, and by electrophysiological recordings from single neurons within the human amygdala.