Facial expressions of emotion as conditioned stimuli for human autonomic responses.

This investigation tested the hypothesis that congruity of a facial affective expression with an aversive outcome as compared to incongruity of an expression and outcome would result in superior differential conditioning of an autonomic response (skin conductance) to the facial expression. Using a differential conditioning paradigm with slides of fear faces and happy faces as CS+ and CS- or CS- AND CS+, resepctively, the resultant findings are consistent with predictions. Both magnitude and rate of acquisition of the differential conditioned response were greater when a fear expression was reinforced by shock than when a happy expression was reinforced by shock.