The aim of this paper is to review data from my laboratory, which were collected in an attempt to determine whether the facial EMG response is a general component of the emotional reaction. In a number of studies it was found that facial reactions: first, are spontaneously elicited and differ according to the kind of emotional stimuli to which subjects are exposed; second, are sensitive to learning; third, are consistent with how the subjects perceive the stimuli and their own specific emotions; fourth, are congruent with autonomic responses; fifth, are more pronounced for females than for males; and finally, differ among subjects with specific fears. These data converge to indicate that facial muscle activity is a general component of the emotional reaction and demonstrate that the facial EMG technique is a sensitive tool for measuring emotional reactions.
Ulf Dimberg (1990) studied this question.