Effects of instructed imagery on temperature on hands.

Abstract

There is, at present, controversy over whether voluntarg control of manual temperature can be attained by way of biofeedback ( 5 ) . Difficulty in obtaining control of manual temperarure with biofeedback seems paradoxical in light of the extensive literature indicating that such control can be attained by Pavlovian conditioning ( 2 ) , induction of attitudes related to such diseases as urticaria and Raynaud's disease ( I ) , and hypnosis ( 3 ) . It is important to submit research using methods other than biofeedback to careful scrutiny. The present study focussed on the effectiveness of instructed imagery in producing thermal control. Sixteen college-student volunteers served as subjects. Baseline thermal measures were taken for each of 15 min. Both hands warmed for 13 subjects during baseline, both cooled for one subject and the temperature of hands changed in opposite directions lor the remaining two subjects (binomial f l < .03). Mean change for right and left hands was identical at 5.6 F. Next, these subjects were randomly assigned to two equal groups, in one of which they were instructed to imagine their hands in very warm water and in the other they were to imagine their hands in ice cold water. Manual temperatures were taken each minute from 0 to 15. The mean of the temperature of baseline and for Min. 0 was compared with each of the last 10 readings. If at least 9 of the 10 (binomial p < .03) readings differed in the appropriate direction from that mean, a subject was cons~dered to have achieved the desired change. All 10 subjects with the image related to cooling cooled reliably on at least one hand, and six of them did so on both hands. Mean peak change for this group was -1.91 F. Five of the subjects with the image related to warmth showed reliable warming of at least one hand, but only one of them did so for both hands. Indeed, four of them exhibited reliable cooling of at least one hand. Mean peak increase for this group was 0.66 F. These findings indicate the control of temperature of the hands can be achieved through merely giving instructions to produce relevant images, without hypnosis, conditioning, or feedback. Sokolov ( 4 ) has pointed out that drops in the temperature of the hands are a component of orientation responses. It is possible that the tendency for cooling to occur even with imagery related to warmth was due to competition between this component and a tendency for shifts in temperarure to occur in correspondence with the quality of the image. Better control might be achieved if this orientational component could be minimized, perhaps through long practice on a given image. It is possible that some of the difficulties encountered in obtaining warming by way of biofeedback are due to the inherent requirement that attention be directed toward the stimulus providing feedback which creates orientational responses sometimes competitive with the target behavior. REFERENCES 1. GOTTLIBB, A,, GLESER, G., & GO~~SCHALK, L. Verbal and physiological responses to hypnotic suggestion of attitudes. Psychosomatic Medicine, 1967, 29, 172-J83. 2. GOTTSCHALK, L. A study of conditioned vasomotor response in ten human subjects. Psychosomatic Medicine, 1946, 8, 16-27. 3. MASLACH, C., ~ ~ A R S H A L L , G., & ZIMBARDO, P. Hypnotic control of peripheral skin temperature. Psychophysiology, 1972, 9, 600-605. 4. SOKOLOV, Y. Percefition and the conditioned reflex. New York: Macmillan, 1963. 5. TAUB, E. Some methodological issues in the training of self-regulation of skin temperature. Proceedings of the Biofeedback Re~earch Society, Sixth Annual Meeting, Monterey, California, 1975. Accepted November 12, 1975.