Facial and emotional reactions to Duchenne and non-Duchenne smiles.

The purpose of the study was to investigate facial and emotional reactions while viewing two different types of smiles and the relation of emotional empathy to these reactions. Facial EMG was recorded from the orbicularis oculi and zygomaticus major muscle regions while subjects individually watched two blocks of stimuli. One block included posed facial expressions of the Duchenne smile (a felt smile) and a neutral face, the other block included expressions of another type of smile called non-Duchenne smile (an unfelt smile) and a neutral face. Emotional experiences were asked after each stimulus block. Finally, a measure of empathy was given. Facial EMG reactions differentiated between the neutral face and the Duchenne smile but not between the neutral face and the non-Duchenne smile. The Duchenne smile block induced experience of pleasure for the subjects who saw it as the first stimulus block. Empathy was correlated to the rated experiences of pleasure and interest after the Duchenne smile block.