The effect of stress imagery on arousal and its implications for biofeedback of the frontalis muscles.

The purpose of this study was to determine whether the frontal muscles of the forehead during the imagination of an individualized stress situation reflect general arousal. Physiological arousal and subjective feelings of tension were measured during a stress and a relaxing imaginative situation, utilizing a counterbalanced design. Frontalis EMG during stress imagination was raised and was paralleled by more reported tension, elevated skin conductance, and trends toward increments in heart rate and respiration rate. The raised frontalis EMG can be seen as a consequence of the greater effort spent in the stress imaginative situation than in the relaxing one. This experiment supports an important assumption of the clinical application of frontalis EMG biofeedback to stress-related disorders. Other assumptions still remain to be examined.