Facial electromyographic responses to vocal affect expressions.

In this study we investigated facial electromyographic (EMG) responses to vocal affect expressions. We also measured emotion-related action tendencies by requesting the subjects to indicate their tendency to approach or withdraw from the person uttering the stimulus word. In addition, emotional contagion (EC) was measured with a questionnaire-based scale. The results showed that hearing the expression of anger increased EMG activity in the subjects' brow region more than hearing contentment. In contrast, the expression of contentment activated the periocular muscle region more than anger. The expressions of anger elicited behavioral withdrawal responses, whereas the neutral expressions and contentment evoked approach responses. Subjects scoring low and high on EC exhibited different patterns of EMG responses. The results support the view that negative and positive affects are contagious from hearing human vocal affect expressions.