Facial reactions to different emotionally relevant stimuli

Facial EMG activity was measured from the Corrugator supercilii and the Zygomatic major muscle regions while 48 subjects were exposed to pictures of angry and happy facial expressions, snakes and flowers as well as low and high preference nature scenes. The valency perspective predicted that facial reactions should be related to the intensity of the positive and the negative valency of stimuli. The mimicking behavior approach predicted that facial reactions should only be reflected as a mimicking response to the facial stimuli, whereas the evolutionary:biological perspective predicted that the most clearcut positive and negative facial reactions should be evoked by facial stimuli and by snakes. In support of the latter perspective, the present results showed that angry faces and snakes evoked the most distinct Corrugator supercilii muscle response, whereas happy faces evoked the largest Zygomatic major muscle response.