Approach-withdrawal and cerebral asymmetry: emotional expression and brain physiology

In this experiment, we combined the measurement of observable facial behavior with simultaneous measures of brain electrical activity to assess patterns of hemispheric activation in different regions during the experience of happiness and disgust. Disgust was found to be associated with right-sided activation in the frontal and anterior temporal regions compared with the happy condition. Happi-ness was accompanied by left-sided activation in the anterior temporal region compared with disgust. No differences in asymmetry were found between emotions in the central and parietal regions. When data aggregated across positive films were compared to aggregate negative film data, no reliable differences in brain activity were found. These findings illustrate the utility of using facial behavior to verify the presence of emotion, are consistent with the notion of emotion-specific physiological patterning, and underscore the importance of anterior cerebral asymmetries for emotions associated with approach and withdrawal. This and the accompanying report (Ekman, Davidson, & Friesen, 1990) represent the convergence of two independent yet overlapping lines of research. One is theory and evidence from Ekman's laboratory, which, from an evolutionary per-spective, takes the position that each emotion is characterized by unique patterns of expressive behavior and physiological ac-tivity (e.g., Ekman, 1977, 1984). The second is research from Davidson's laboratory on cerebral asymmetry and emotion, which indicates the differential involvement of the two cerebral hemispheres in the control of certain positive and negative emo-tions (e.g., Davidson, 1984a, 1984b, 1987; Davidson &Tomar-ken, 1989)