Effects of covert sensitization on facial EMG: a pilot study.

Two subjects currently undergoing covert sensitization treatment were asked to imagine alternately the covert scene and a pleasant imagery scene while EMGs from the corrugator and forearm extensor muscle sites were continuously monitored. Visual inspection of the data suggests that corrugator EMG can reliably discriminate the covert-sensitization scene from the pleasant imagery and from resting baseline conditions. Facial EMG may have potential for objectively studying imagery and its role in covert sensitization and other imagery-based treatments.