Published Online: Aug 11 2017
DOI: 10.1002/wcs.1449
Videos of conspecifics elicited in viewer monkey's interactive social behaviors such as eye contact and the reciprocation of facial expressions. The viewer's behaviors were monitored by eye tracking and by electromyographical activity recorded from the facial muscles. The behaviors (e.g., facial expressions, gaze direction, etc.) of the monkeys shown in the videos were quantified by detailed ethograms. Under these naturalistic conditions, neural activity recorded from the amygdala showed new response properties. A subset of neurons responded to looking at the eyes and to eye contact while other neurons responded to the stretches and compressions of the facial skin during the production of facial expression. The latter observation led to the discovery of neurons in the amygdala that respond selectively to touch.