INT’L. J. PSYCHIATRY IN MEDICINE, Vo1.6(1/2), 1975 BIOFEEDBACK AND SELF-CONTROL OF PHYSIOLOGICAL FUNCTIONS: CLINICAL APPLICATIONS’ Peter P. Hauri, Ph.D.’ Dartmouth Medical School, Hanover, New Hampshire ABSTRACT-The parameters amenable to biofeedback learning are mentioned, including brainwaves, muscle tension, temperature, the cardiovascular system, and others. A discussion follows of the clinical application of biofeedback in the treatment of such disorders as tension headaches, neuromuscular reeducation, epilepsy, “dysponesis,” cardiac arrhythmias, blood pressure and migraines. The usefulness of biofeedback has been demonstrated also in the field of psychotherapy for purposes of desensitization, treating anxious patients, encouraging specific personality changes, and indicating stress to patients. According to traditional view, some bodily functions can be controlled voluntarily (skeletal muscles, breathing, and so forth), while others are governed by homeostatic mechanisms not amenable to conscious control (blood pressure, body temperature, and so forth). The work reviewed in this paper will challenge some aspects of this view. It has, of course, been known for a long time that occasional, extraordinary people such as fakirs and yogi can manipulate certain autonomic functions. These demonstrations were rarely taken seriously, however, until Miller’s 1969 summary [ l ] on the learning of visceral and glandular responses. Miller seemed to show that under curare (to exclude skeletal responses) rats could be operantly conditioned (i.e., modified by positive or negative reinforcement) to control most “autonomic” functions. Not only could they learn how to increase or decrease heart rate, blood pressure, and intestinal contractions, but they even seemed capable of controlling such specific details as dilating blood vessels to the kidneys only or to one ear independently of the other. At about the same time as Miller summarized his work, the findings of Kamiya [2] on alpha conditioning caught popular fancy. Kamiya showed that humans can learn how to produce or inhibit occipital alpha waves when they are informed continuously about the state of their EEG. Trained subjects claimed This review was written with the help of U.S.P.H.S.Research Grant M H 24268. ’ Director, Dartmouth-Hitchcock Sleep Clinic; Associate Professor of Psychiatry, Dartmouth Medical School, Hanover, New Hampshire 03755. 255 0 1976,Baywood Publishing Co., Inc. doi: 10.2190/L766-9GFR-HXFD-WFFX http://baywood.com 256 I PeterP. Hauri that alpha waves were associated with pleasant feelings of relaxation, “letting go,” and a narrowing of perceptual awareness. Since meditators were known to produce copious amounts of alpha, the stage seemed set for learning “instantaneous Zen.” Miller’s work is now under criticism because investigators, including Miller himself, cannot replicate some of his earlier findings [3]. Similarly, it seems possible that the good feelings of early alpha subjects had more to do with their expectations than with the alpha state itself [4]. Although there may have been flaws in the early work of both Miller and Kamiya, their work popularized the biofeedback methodology now used so extensively. Biofeedback can be defined as the use of monitoring instruments to detect and amplify selected physiological processes in order to make previously unavailable physiological information accessible to the subject’s consciousness. Usually, the following steps are involved: 1) Measure a physiological parameter in a motivated subject. 2) Display (feed back) the measurement to the subject. 3) The subject learns (consciously or unconsciously) what behaviors change the display, usually by trial and error methods. 4) The subject is reinforced for changes in the correct direction, usually simply by seeing success. 5) Hopefully, the subject learns (consciously or unconsciously) what internal cues are associated with the reinforced changes. He then no longer needs the feedback display, but can control the physiological parameter directly. PARAMETERS AMENABLE TO BIOFEEDBACK LEARNING Currently, almost any month brings news of additional physiological parameters supposedly conditionable by biofeedback. The following list includes a few of current interest in work with humans. Brain waves It appears that almost any rhythm present in the conscious human EEG can be brought under voluntary control by biofeedback. Some examples are occipital alpha (8-12 cps), central and frontal “alpha” [5], theta (3-7 cps) [6], beta (18-25 cps, important in alertness) [7], 40 Hertz waves (apparently important in learning and problem solving) and the sensory motor rhythm (12-14 cps) [8]. Other researchers teach inhibition of certain frequencies (e.g., inhibition of alpha waves to improve attention) [9]. Furthermore, it seems possible to operantly change specific components of the evoked potential [ l o ] or to modify phase relationships between two EEG pickup points [ 111 . As better computer-assisted feedback equipment becomes available, it might be possible to train even more complex brain wave patterns, thereby selectively influencing more specific aspects of cognitive functioning. Biofeedback and Self-Control 1 251 Muscle Tension In most muscle tension work, the average electrical activity in a muscle (detected by relatively large surface electrodes) is measured and fed back. A different approach has been developed by Basmajian [12], who uses fine wire electrodes to record from a number of single motor units. Subjects apparently learn quite readily to fire these units in any prescribed sequence or pattern. Basmajian had hoped to connect these single motor unit discharges to servomotors in artificial limbs so that amputees might move such limbs by firing appropriate motor neurons. The idea, apparently feasible, is awaiting commercial development. Temperature Since human core temperature is 98"-99"F, the temperature on the body surface and in the extremities is controlled mainly by vasoconstriction, depending on such factors as secretion of adrenalin and noradrenalin, ANS activity, and so forth. Temperature in the extremities, therefore, relates to emotions and psychological arousal. Taub [13] found that twenty of twenty-five subjects could learn finger temperature control of 2-6°F in four sessions lasting fifteen minutes each. He was also able to train subjects to raise their temperature in one part of the hand but not another, or in one finger but not the adjacent one, a rather remarkable feat if it can be replicated. ardiovascular System Since the cardiovascular system pulsates, feedback for both heart rate and blood pressure is usually given on a beat by beat basis. For heart rate, the length of the last R-R interval is electronically compared with the patient's average. For blood pressure a pressure cuff is inflated to the subject's mean systolic (or diastolic) pressure, and reinforcement is given after each beat depending upon whether a Korotkoff sound is heard. Heart Rate. Many subjects can learn increases of fifteen beats per minute in one session [14]. In general, learning how to increase heart rate is akin to learning a motor skill, being highly dependent on motivation and detailed feedback information. Decreasing heart rate, however, does not seem to be a finely tuned, learnable skill [15]. Blood Pressure. Both increases and decreases of systolic blood pressure can apparently be learned rather quickly [16]. Goldstein et al. [17] showed in a three month study on baboons that prolonged training to increase diastolic blood pressure resulted in less sensitive baroreceptors. This suggests that prolonged biofeedback might chronically change the level at which certain homeostatic mechanisms operate. 258 / PeterP.Hauri Miscellaneous Parameters Besides the above, human biofeedback has been used to change the electrical reactivity of the skin [18], to dilate bronchial tubes [19], and to control stomach acidity [20], among others. It appears that a surprising number of physiological parameters can be brought under operant control once the technical problems of measuring these parameters in a patient have been solved. Many of the studies reported so far, however, are essentially case reports [21], suggestive of new research directions without carrying heavy scientific weight. Specifically, the mediating role of skeletal musculature in so-called ANS learning cannot be excluded in most human studies. THEORETICAL ISSUES CONCERNING BIOFEEDBACK Research on biofeedback raises a number of important theoretical issues concerning the nature of operant conditioning, homeostatic mechanisms, and the relationship between various physiological parameters. These questions have been discussed in detail elsewhere [22]. Since this review is mainly concerned with clinical applications, only two treatment-related issues will be briefly mentioned. General Relaxation Response Versus Learning Specific Physiological Parameters According to Benson et al. [23], humans are capable of a generalized, integrated relaxation response, apparently mediated by hypothalamic mechanisms. Whenever biofeedback is used clinically, it seems pertinent to ask whether the main goal in treatment is to teach the control of specific physiological parameters, or whether the idea is to induce Benson’s general relaxation response. Some researchers have commented that no matter whether low EMG, alpha production, or a decrease in blood pressure is the goal of biofeedback, subjects cannot learn successfully if they “try too hard.” Rather, successful subjects adopt a passive attitude, letting things happen rather than making them happen. This sounds quite similar to processes discussed in some Eastern philosophies. To the extent that biofeedback is focused on inducing Benson’s general relaxation response, it does apparently have a kinship to meditation, autogenic training, hypnosis and some religious experiences. Relaxation, however, is not the goal of all biofeedback. There are other areas (such as neuromuscular reeducation and the control of cardiac arrhythmias) where biofeedback is used in a much more active, arousing mode. Biofeedback and Self-Control I 259 What Is Learned? While some of the early animal studies suggest that physiological parameters can be directly controlled through operant conditioning, it seems doubtful that this is the major mode of action in most work with humans. Learning to control a certain physiological parameter often involves simply learning which cognitive state results in the desired physiological response (e.g., finding that imagining a peaceful scene warms the hands). Once the appropriate cognitive state is identified, the task becomes simply to remain in it for the desired period. While this use of biofeedback has little to do with ANS learning, it can have dramatic effects on a person’s well-being. For example, when a drastically over-worked and over-stimulated person is asked to sit down and practice increasing hand temperature twice a day for half an hour, major homeostatic adjustments can apparently flow simply from interrupting an overexcited, overstressed life style. In other cases, however, biofeedback teaches patients totally new states of existence. Many a patient is told by his physician to “go home and relax,” but unconsciously he progressively increases his muscular tension the harder he tries to relax. Using EMG biofeedback, such patients can discover a state entirely new to them-namely, true, deep muscle relaxation. Finally, there are patients who learn to control certain biofeedback parameters (e.g., the sensory motor rhythm [S]) without much cognitive insight. If this learning can be made to generalize outside the laboratory, there is little reason why it should be less effective than the cognitively mediated learning. Whether or not to combine “cognitive strategies” with biofeedback is an unsettled issue. Occasionally, cognitive training seems useful [24] while in other cases it seems to interfere with the learning process [25]. SOME DISORDERS CURRENTLY TREATED WITH BIOFEEDBACK Tension Headaches In a carefully controlled study, Budzynski et al. [26] demonstrated that a combination of frontalis EMG feedback and home relaxation exercises is quite effective in curing many tension headaches. This approach is rapidly becoming the treatment of choice for tension headaches in many laboratories throughout the country. Budzynski et al. heavily stress the need for daily home practice in addition to the laboratory sessions, and one might speculate that at least part of the lasting improvement in many headache patients relates directly to a subtle change in their life style. They sit down at least once a day for half an hour, something many of them had not done before. They also develop a feeling of mastery over their affliction, which replaces the feeling of utter helplessness. In 260 / Peter P. Hauri this way, more is changed than the frontalis muscle alone. Nobody has yet demonstrated that EMG training alone (without home practice) is effective in tension headaches. Neuromuscular Re-education Among the oldest and probably most promising uses of biofeedback is the area of neuromuscular re-education [27, 281. In short, it often appears superficially that a certain muscle is completely paralyzed, when a sensitive EMG recording still reveals minimal voluntary control. Using the EMG as a powerful motivator, patients are taught to extend this voluntary influence gradually, until actual muscle twitches, and later coordinated muscle movements become possible. The neural mechanisms involved in neuromuscular re-education are still poorly understood, but there is little question about the therapeutic effectiveness of EMG biofeedback in many of these cases. Similarly, EMG feedback can also be used to inhibit unwanted muscle movement. The most dramatic example of this is probably the very efficient suppression of subvocal speech during reading, as demonstrated by Hardyck [29] and many others. Epilepsy It appears that training the sensory motor rhythm (SMR) [8] has dramatic, beneficial effects on some forms of epilepsy. Although the number of epileptics so treated is still small, the effect seems reliable: three scientists working independently have reported similar, successful results in studies involving either long baselines or “blind” pseudo-feedback [30, 31, 321. Comment: Work with tension headaches, neuromuscular re-education, and the sensory motor rhythm in epilepsy establishes the clinical usefulness of biofeedback in these disorders on a relatively sound and scientific basis. Typically, the patients studied had a long-standing and carefully monitored disability that changed dramatically when biofeedback was introduced. Clinical applications discussed in the remaining part of this article are somewhat less solidly established, either because careful, long-term baselines were not taken or because the results are open to alternate interpretations (no control groups). “Dysponesis ” Since 1952, well before the current biofeedback movement, Whatmore [33] used EMG feedback methods to re-educate “dysponetic” patients. According to Whatmore, dysponesis means “misdirected energy,” i.e., patients react to various stimuli with specific, maladaptive muscle tensing. This interferes with normal functioning and results in symptoms such as anxiety, digestive disturbances, depression, head and backaches. Learning to give up dysponetic behavior through Biofeedback and Self-control / 261 multiple EMG feedback is said to be difficult (100-500 feedback sessions are often required), but Dr. Whatmore can point to an impressive success rate in large and very long follow-up studies (6-21 years). Unfortunately, minimal control data are presented from patients who had “dysponesis” but were treated without EMG feedback, and it is difficult to separate the effects of EMG feedback from the effects of long-term interactions with a very dedicated and enthusiastic physician. Chrdiac Arrhythmias In a careful and creative research program started in the early 1960’s, Engel and co-workers have had surprising success in modifying a wide range of cardiac arrhythmias. Basically, the patient’s heart rate is fed back to him through a display of lights. He then learns both to increase and decrease his heart rate, thereby alternatively aggravating and alleviating his particular problem. In one study, for example, five of eight patients with premature ventricular contractions (PVC’s) learned to markedly decrease these PVC’s by making their heart beat slowly and regularly. In another study, six patients with chronic atrial fibrillation (stable on digitalis) all learned some degree of heart rate control, and a patient with the Wolff-ParkinsonWhite (WW) syndrome learned to voluntarily use either the normal conduction pathway through the AV node and bundle, or to use the abnormal WPW pathway [34]. Not only do Engel’s studies offer hope that some cardiac problems will soon come under routine biofeedback treatment, they also result in a wealth of theoretical information concerning the modification of cardiac events. A particularly interesting case for biofeedback researchers is a 52-year-old female patient with PVC’s (and five previous MI’S). Early in training, this woman paradoxically “thought about relaxing” when she was actually accelerating her heart rate (thereby increasing PVC’s). Conversely, she felt her heart was beating “dysrhythmically” when it was actually beating slowly and regularly. The implications of this case are obvious: occasionally, patients might produce pathology simply because they “mislabel” the states and feel “abnormal” when things function well. Blood Bessure Two training strategies have been established: direct beat-by-beat feedback of blood pressure [16, 35, 361 or decrease of blood pressure via general relaxation [37,38]. Both methods seem effective in decreasing hypertension, although the mechanisms by which the decrease is achieved still await clarification [21]. Specifically, patients seem to enroll in such studies when blood pressure is high, and the mere fact that they are now actively “doing something about their hypertension” might relieve much anxiety and in itself lower blood pressure. 262 1 Peter P. Hauri Migraines Migraine patients often have cold hands, 65-75°F. Although the precise mechanisms for this hand-cooling are still debated, it appears that teaching migraine patients to warm their hands reduces both the frequency and severity of migraines [24]. While this work is well publicized in the lay press and now involves literally thousands of patients, the evidence for this treatment of migraine is still largely anecdotal. Controlled studies are totally missing. Besides the syndromes discussed above, biofeedback has been used for the treatment of asthma (by teaching how to dilate bronchial tubes) [19], for the treatment of Raynaud’s disease [39], for insomnia [6, 401, and many other ailments. Obviously, the limits of this new treatment approach have not yet been delineated. Comment: Syndromes yielding to biofeedback are often refractory to treatment by orthodox medical approaches. This might well be because these syndromes could be caused by faulty learning or faulty motivation, two areas where traditional drug therapy is particularly inappropriate. BIOFEEDBACK AND PSYCHOTHERAPY Systematic Desensitization. The usefulness of biofeedback for behavior therapy is obvious, because deep levels of relaxation can apparently be achieved quickly and the therapist has an objective indicator of the patient’s state while presenting the anxiety provoking hierarchy. Anxiety. Raskin [41] and Garrett and Silver [42] report only moderate success treating clinically anxious patients with EMG feedback. Le Boeuf [43], however, suggests that the treatment of anxiety might have to be individualized according to an individual’s response pattern: i.e., EMG feedback for anxiety manifesting itself in muscular symptoms, heart rate feedback for patients who express their anxiety in that modality, and so forth. Specific Personality changes. Almost incidentally it was found that mastery of one’s physiological responses often results in significant psychological changes. For example, Fehmi [44] found that middle management executives who were given twenty sessions of alpha feedback became less field dependent and perceived themselves as calmer, less depressed, more able to concentrate, and more self-initiating, while executives who received “bogus” feedback did not change in this way. Should these personality changes be replicable and stable, feedback therapy might prove effective in changing specific undesirable psychological dimensions (such as too much field dependency). Biofeedback as Stress Indicators. Many patients, especially those suffering from psychosomatic diseases, seem to have difficulties recognizing when they are under stress. Biofeedback might be helpful liere. Rugh and Solberg [45] developed pocket-sized EMG equipment which provides audio-signals the moment a patient clenches h s jaw (bruxism). Fifteen bruxists carried these devices Biofeedback and Self-Control I 263 during their daily routine. In this way, they became aware of the conditions triggering their bruxism. Ten of the patients were then able to use these new insights to significantly decrease teeth clenching. Hopefully, similar devices can be developed to signal danger points in other diseases (e.g., hands cooling below a certain point in migraine). Thus the triggering situation could be discovered and analyzed, and symptoms averted or controlled before doing excessive damage. CONCLUDING REMARKS Obviously, biofeedback is here to stay; it has proven its worth in some bothersome, chronic diseases such as tension headaches, certain types of neuromuscular paralysis, and so forth. This drugfree approach to medical problems and the superficial similarity of biofeedback relaxation training with some Eastern philosophies, however, has attracted a large number of antimedical, antiscientific practitioners into this area. Therapeutic claims often overstate beyond belief the small kernels of sound, scientific evidence found in laboratories and clinical research. Clinicians will do well to keep a keen, but very critical eye on future developments, guarding both against excessive gullibility as well as against wholesale rejection of the field (where excellent scientific work currently mingles with obvious quackery). In terms of general medical practice, biofeedback stresses a point often overlooked: since some pathophysiological changes can apparently be brought on by faulty learning and conditioning, they might be corrected most efficiently by relearning and reconditioning. To be effective in this relearning process, the patient apparently should be an active participant, curing himself with the help of teaching aides such as biofeedback equipment, rather than relying passively on the physician’s skill and prescription. REFERENCES 1. Miller NE: Learning of visceral and glandular responses. 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