BIOFEEDBACK: REVIEW, HISTORY, AND APPLICATION.

By: Donald E. O'Hair, Ph.D.

Doctor O'Hair is a clinical psychologist in private practice in San Diego, California for the past 22 years. In addition, he was the Clinical Director of the Centre for Clinical Research of San Diego for 20 years. The Centre conducted pharmaceutical clinical research in cardiovascular and psychiatric medicine. Doctor O'Hair also was the Research Coordinator for the Mercy Hospital Heart Institute in San Diego.

Doctor O'Hair is the Chairman of the Board of Directors for Discrete Data Systems, Inc., a manufacturing company of biofeedback instruments and computer-assisted biofeedback systems. He invented one of the first computer biofeedback systems used in the United States.  If you are interested in information about biofeedback instruments or resources for securing biofeedback instruments at low cost, contact Dr. O'Hair at his email address at: DoctorOHair@yahoo.com

ABSTRACT
The theories involved in psychophysiology and biofeedback date back to the early part of this century. The application of specific biofeedback techniques and procedures began only 25 years ago. The use of electromyograph (EMG) and peripheral skin temperature are the principle modalities used today in clinical practice. They are not only used as a monotherapy but also used in combination with individual psychotherapy, autogenic training and hypnosis. Biofeedback increases the treatment options available for the medical and psychological health care practitioners. There have been some new development in psychophysiology and biofeedback. There are two area, both with a history in biofeedback: EEG and EMG.

In the past 60 years psychophysiological research has examined the relationship between emotional states and physiological states (Rubinstein and Parloff, 1962). Within the past 28 years attempts have been made to affect these emotional states, as well as states of consciousness, through a process called biofeedback. As the name implies, biofeedback can be made explicit to the subject through the ordinary sensory channels (visual, auditory, tactile). The prefix "bio" from its Greek language origin, means "life." The word "feedback" means to return information to its origin. Biofeedback, therefore, is biological information which is returned to the source that created it so that source can understand and have control over it.

Pyschophysiological monitoring has been used for many decades determine physical and emotional states. For instance, the electrodermal or galvanic skin response has been used to detect emotional arousal. Today, EMG is used to monitor and to diagnosis lower back problems.

BIOFEEDBACK IN REVIEW
To insure its survival, the human organism maintains itself through homeostatic mechanisms. The major means utilized to maintain this balance is feedback control (Ashby, 1963). For example, the human being must have available to him information about his behavior in order to control and alter it. This information comes through one or more of the senses. The simple ability to reach out and touch an object with the hand is mediated by the visual experiences or feedback of the proximity of the hand to the object that is to be touched. This phenomenon or process is called a feedback loop (Gaarder, 1971).

This feedback loop plays an important role, for instance, in the understanding of cybernetics and electronics (Ashby, 1963). To illustrate, electrically negative feedback is defined as part of the output of a signal which is returned to the input in order to make the output more pure and linear. This same process takes places in the human organism which uses its sensory feedback to affect and perfect the precision of its behavior. A very simple form of this kind of feedback is provided when a human being views himself in the mirror in order to groom himself.

Biofeedback is the process in which a subject receives information about his biological state. Usually a subject is not aware of his physiological functions, especially those controlled by the autonomic nervous system, such as heart rate and peripheral vasoconstriction. Biofeedback creates an external loop by which a subject can monitor one or more of his physiological states. An early example of this kind of feedback was conducted by Margolin and Kubic (1944). They used a subject's amplified respiration and heart beat to induce a hypnotic state in the subject. The subject heard his own heart beat and breathing rate which aided in the hypnotic induction. Although the subjects were not instructed to alter these physiological functions, the feedback of their biological system was used to affect their conscious and emotional state.

The more recent use of biofeedback is partly related to the advent of the solid state electronic technology which allows miniature high performance amplifiers to be housed in small enclosures. The low cost of these components has made biofeedback equipment relatively inexpensive and readily available to both the researcher and the consumer (Schwitzgebel, 1975). A sophisticated circuit that amplifies only a few microvolts of biological activity can be constructed in only a few square centimeters of space at a very low cost (Silverman and Jenden, 1971).

Today biofeedback training includes how to use biofeedback instruments not only for relaxation training, but also for treatment of hypertension (Benson, Shapiro, Tursky, and Schwartz, 1971), cardiac arrhythmias (Weiss and Engel, 1971), migraine headaches (Sargent, Green and Walters, 1972), Raynaud's syndrome (Surwit, 1973), tension headaches (Budzynski and Stoyva, 1969, 1970), test anxiety (Garrett and Silver, 1972), seizure activity (Sterman, 1973), stomach acidity (Gorman and Kamiya, 1972), incontinence, and elimination of subvocal reading (Hardych, Petrinovich, and Ellsworth,

THEORY BEHIND BIOFEEDBACK
There are many who choose to explain biofeedback exclusively with the principles of operant conditioning (Kimmel, 1967). For example, if the behavior of a rat in a laboratory maze is to be shaped into a particular pattern, any activity which approximates that desired behavior is rewarded or reinforced. This conditioning is a form of feedback; the desired behavior or response provides the organism with a reward. The parallel to biofeedback is obvious.

Miller (1969) has worked with the basic understanding of operant conditioning with animals, showing that physiological variables which once were thought to be involuntary, can, in fact, be controlled. For example, when an animal moves in the desired physiological direction, a reward is given; the animal is thereby given feedback on its behavior. Using this technique, Miller (1969) found that the peripheral vascular system of rats could be conditioned; they raised the temperature of their ears. Other studies using operant conditioning techniques have shown that it is possible to use biofeedback to gain control over the autonomic nervous system. This control has involved heart rate (Weiss and Engel, 1971) as well as blood pressure changes (Benson, Shapiro, Tursky and Schwartz, 1971).

It is difficult, however, to attribute the total process of biofeedback to the principles of operant conditioning. The feedback given in operant conditioning is in the form of a compelling reward or punishment to provide motivation for the desired behavior. With biofeedback the information is usually given to the subject in a visual or auditory form. There are clearly other motivations involved with human subjects who are using biofeedback. These motivations include the element of social reinforcement not found in the conditioning of animals in the laboratory. The subject may want to please the experimenter or therapist conducting the biofeedback training. Therefore, the subject's expectations of symbolic social reward are an important variable in biofeedback training, a factor not present in animal studies.

DEVELOPMENT OF BIOFEEDBACK
In the last 8 to 10 years in the United States the use of biofeedback has become commonplace in almost every practice of psychology, psychiatry and physical rehabilitation therapy. Along with the use of autogenic therapy and hypnosis, biofeedback has now become universally acclaimed as an important method of learning how to achieve a state of deep relaxation. However, this situation has not always been the case. The first attempts at using biofeedback for stress management date back to the early part of the 1960's. There were those from universities and clinics who were postulating that the EEG biofeedback could be beneficial to everyone. Studies were done with the Yogis from India to demonstrate that during meditation they produced large amounts of the alpha-brain rhythm on all of the major lobes of the brain.

Some clinicians maintained that all that was needed was to use our advanced electronic technology to teach people, through biofeedback, how to produce that same alpha-state so they could become "instant Yogis." In a sense, America could now accomplish in a few weeks or months of EEG biofeedback training, what it took the Yogis twenty years to accomplish. It was believed that EEG biofeedback of the alpha brain rhythm could allow every individual to reach a heightened state of consciousness. Of course, this dream did not come true.

In America the public image during this period of time thought of biofeedback as an experimental procedure used only by researchers. Biofeedback clearly was not accepted by a major segment of health-care professionals, including physicians, psychologists, psychiatrists and neurologists. Biofeedback remained on the outside of traditional medicine and psychology. This perception was to change by the end of the 1970's. The Biofeedback Society of American was formed in 1968 by a small group of dedicated professionals who believed that biofeedback could make a significant contribution to behavioral medicine. They organized their efforts and began to research further new modalities of biofeedback training. As is the case with many new ideas, there was a group of people who had a vision and a dedication to these ideas in spite of what others thought. Today, the persistence of those dedicated professionals has provided us with a powerful treatment modality.

Due to the efforts of the Association for Psychophysiology and Biofeedback and others over time, there have been major changes in the use of biofeedback, in its acceptance by health care professionals, in the modalities used, in the type of presentation of the displayed biofeedback, in the electronic circuitry utilized, and in the actual treatment procedures used. Furthermore, there has been a large group of psychologists, psychiatrists and university professors who have continued to use biofeedback in their clinics and have discovered new forms of biofeedback.

ELECTROMYOGRAPH BIOFEEDBACK
As a result of the failure of EEG biofeedback to promote stress reduction in the first years of the 1970's, researchers and psychologists began to examine and use electromyographic (EMG) biofeedback. With the EMG the patient could perceive a direct connection or relationship between what he experienced and what the biofeedback displayed back to him. For instance, with the electrodes connected to the forehead frontalis muscles, the patient could clench his teeth or raise his eyebrows and watch the biofeedback signal reflect his increased muscular activity. Biofeedback from the central nervous system, that is the muscles of the body, was much more immediate and understandable to the patient than the vague EEG brain wave activity. Clinical application of EMG biofeedback has grown in popularity among health care professionals and has begun to be used for other than relaxation training. For instance, it has become an effective treatment for muscle contraction headaches, post-stroke muscle rehabilitation and reeducation, childhood hyperkinesias, fecal incontinence, and asthma (Olton and Noonberg, 1980).

It was clear that EMG biofeedback provided to a subject substantial physiological information regarding the activity of the central nervous system. However, there was a need to monitor the autonomic nervous system. Traditionally, the galvanic skin response (GSR) or electrodermal response (EDR) had been used to monitor the sympathetic part of the autonomic nervous system. The problem with the GSR is that it is subject to many artifacts. For example, if the subject takes a deep breath or tightens a muscle group, the electrical resistance of the skin decreases, causing a rapid change in the biofeedback signal.

It has been found that the measurement of peripheral skin temperature could provide a more reliable measure of sympathetic-autonomic nervous system activity. The changes take place more slowly than those of the GSR, and the changes are not subject to the annoying artifacts of the GSR.

TEMPERATURE BIOFEEDBACK
In 1939 Mittelmann and Wolff (1939) showed that experimentally induced affective disturbances were accompanied by a fall in finger temperature. This result is understandable because the sympathetic nervous system outflow constricts peripheral blood vessels. Four years after the first experiment, they conducted another study in which they recorded finger tip temperature changes during psychoanalytic interviews. They measured the minute to minute changes in finger temperature during the interviews. They discovered vasoconstriction in the fingers during increased conflict. Vasodilatation was correlated with uninhibited action and increased emotional security. They found that temperature changes were correlated with the degree of emotional stress, whether this stress was conscious or below conscious awareness. They suggest that, as a subject tried to compensate for his emotional feeling by denying them, there was an accompanying fall in finger temperature.

Mittelmann and Wolff (1943) defined emotional stress as anxiety, anger, embarrassment, humiliation, joy with anxiety, depression with hostility, guilt, fear of abandonment, and conflict over the use of the hands for aggressive and sexual purposes. They claimed that, when the subjects experienced or verbalized any of the above conflicts and stress during the interview, the finger temperature would fall. If the subject denied such stress but exhibited some bodily indication that the stress affected him, there was also a fall in finger temperature. The latter lowering of peripheral finger temperature appeared to be greatest when the subject was not aware of his emotional conflict.

One of the interesting findings of this research of Mittelmann and Wolff (1943) is that emotionally objectified anxiety did not lower finger temperature. If a subject could provide himself with an emotional security and a sense of self esteem, that is, to believe that he was relaxed, his finger temperature would remain at a high level rather than fall, as it would during perceived anxiety. Merely shutting out his emotional stress was not sufficient to prevent the fall of finger temperature; an active belief that he felt relaxed, with an accompanying sense of well-being, did prevent the fall of finger temperature.

The implications from the above-cited research for biofeedback are important. First, there is a clear link between emotional tension and finger temperature. Second, there is a correlation between the degree of the fall in finger temperature and the intensity of the subject's anxiety. Third, the extent to which a subject is aware or unaware of an emotional conflict or sense of tension will not prevent the lowering of the finger temperature. This result suggests that skin temperature could be considered a more "objective" index of a subject's level of stress or anxiety although his subjective sense of the emotional feelings may not reflect this anxiety. Fourth, a subject can, through belief in his sense of well-being, security, or superiority, override his tension. If the subject can relax and objectify his emotional reactions, he can maintain his finger temperature at a high level. This latter finding suggests that subjects can have some voluntary control over their peripheral skin temperature by way of their mental state. It is also an important consideration in understanding biofeedback of finger temperature.

Another investigation of the clinical use of finger temperature biofeedback was undertaken by Sargent, Green, and Walters (1972). They treated subjects with migraine headaches using autogenic techniques (Schultz and Luthe, 1969). In addition, they used finger temperature biofeedback to assist the patients in gaining control of their vascular migraine headaches by warming their hands. It has been found that 85% of patients who suffer from migraines also routinely display cool hands (25øC to 30øC). They found that there was a significant correlation with increases in finger temperature and reduction in migraine headaches.

Temperature biofeedback, therefore, can be useful for confirming and demonstrating deep relaxation. For instance, with the use of autogenic training techniques the patient hears the words "my hands are warmer, my hands are heavier." With the use of accompanying temperature biofeedback the effects of that relaxation process can be demonstrated by showing that the hands are indeed warmer when the subject does, in fact, relax. In this manner, temperature biofeedback is used as a monitor to the sympathetic part of the autonomic nervous system. Conversely, when the subject stops the relaxation process, the hand temperature begins to decrease and become cooler.

In addition, temperature biofeedback is a convenient, non-invasive measure of hypnotic induction. As a skilled hypnotherapist, this author routinely uses temperature biofeedback, in addition to non-verbal cues, as an indication of what phases and words best promote a deepened trance for the patient. The actual audio feedback is sometimes incorporated into the induction process. The appearance of a rapid cooling of the hand temperature can be indicative of emotionally laden feelings beginning to be experienced by the patient, and it can also mean that the patient is bringing himself back to conscious awareness.

SUMMARY
The principles of biofeedback date back more than a half century. The actual practice of biofeedback itself has developed in few short years. It developed from a curiosity to a well-established treatment procedure for a variety of medical problems. It started primarily with the use of EEG biofeedback to teach persons to relax. By 1975, clinicians were using at least bimodal biofeedback in which the EMG monitored the activity of the central nervous system, and the peripheral hand temperature measured the activity of the autonomic nervous system. Biofeedback is a powerful therapeutic tool which teaches persons to take responsibility to learn self-regulation of themselves and their bodies.

BIBLIOGRAPHY

Ashby, W. R. An Introduction to Cybernetic. New York: John Wiley & Sons, Inc., 1963.

Benson, H., Shapiro, D., Tursky, B, & Schwartz, G. E. Decreased Systolic Blood Pressure Through Operant Conditioning Techniques in Patients with Essential Hypertension. Science, 1971, 217.

Bernstein, D. A. and Borkovec, T. D. Progressive Relaxation Training: A Manual for the Helping Professionals. Chicago: Research Press, 1973.

Blanchard, E. B., & Young, L. D. Clinical Applications of Biofeedback Training. Archives of General Psychiatry, 1974,30, 573-589.

Brown, B. B. Stress and the Art of Biofeedback. New York: Harper and Row, 1977.

Budzynski, T & Stoyva, J. An Instrument for Producing Deep Muscle Relaxation by Means of Analog Information Feedback. Journal of Applied Behavioral Analysis, 1969, 2, 231-237.

Diamond, S., et.al. The Value of Biofeedback in the Treatment of Chronic Headaches: A Five Year Retrospective Study. Headache, 1979, 19, 90-96.

Fisher-Williams, M., Nigl, A. J. & Sovine, D. L. A Textbook of Biological Feedback. New York: Human Sciences Press, 1981.

Fuller, G. D. Biofeedback: Methods and Procedures in Clinical Practice. San Francisco: Biofeedback Press, 1977.

Gaarder, K. Control of States of Consciousness: II. Attainment through External Feedback Augmenting Control of psychophysiological Variables. Archives of General Psychiatry, 1971, 25, 436-441.

Garrett, B. L. & Silver, M. P. The Use of EMG and Alpha Biofeedback to Relieve Test Anxiety in College Students. Read before the American Psychological Association meeting, Washington, D.C., 1972.

Gorman, P. J. & Kamiya, J. Operant Conditioning of Stomach Acid pH. Read before the Biofeedback Research Society Meeting, Boston 1972.

Hiebert, A. & Fitzsimmons, G. A. A Comparison of EMG Feedback and Alternative Anxiety Treatment Programs. Biofeedback and Self Regulation, 1981, 6, 4, 501-516.

Hutchison, M. Megabrain. New York: Ballantine Books (Random House, Inc.), 1986.

Hardych, D. C., Petrinovich, L. F., & Ellsworth, D. W. Feedback of Speech Muscle Activity During Silent Reading: Two Comments. Science, 1967, 157, 581.

Jones, G. E. & Evans, P. A. Effectiveness of Frontalis Feedback Training in Producing General Body Relaxation. Biological Psychology, 1981, 12, 313-320.

Kimmel, H. D. Instrumental Conditioning of Autonomically Mediated Behavior. Psychological Bulletin, 1967, 67, 337-345.

Margolin, S. & Kubic, L. S. An Apparatus for the Use of Breath Sounds as a Hypnogogic Stimulus. American Journal of Psychiatry, 1944, 100, 610.

Miller, N. E. Learning of Visceral and Glandular Responses. Science, 1969, 63, 434-445.

Mittelmann, B. & Wolff, H. G. Affective States and Skin Temperature: Experimental Study of Subjects with "Cold Hands" and Raynaud's Syndrome. Psychosomatic Medicine, 1939, 1, 271-292.

O'Hair, D. E. The Relationship of Skin Temperature Feedback and the Reduction of Tension. Unpublished doctoral dissertation, California School of Professional Psychology, San Diego, California, 1976.

Olton, D. S. & Noonberg, A. R. Biofeedback: Clinical Applications in Behavioral Medicine. Englewood Cliffs, New Jersey: Prentice-Hall, 1980.

Peper, E. Ancoli, S. & Quinn, M. (Eds.) Mind/Body Integration, New York: Plenum Press, 1979.

Rubinstein, E. & Parloff, M. (Eds.) Research in Psychotherapy, Vol. I. Washington, D.C.: American Psychological Association, 1962.

Sargent, J. D., Green, E. E. & Walters, E. D. The Use of Autogenic Feedback Training in a Pilot Study of Migraine and Tension Headaches. Headache, 1972, 12, 120-125.

Schultz, J. H. and Luthe, W. Autogenic Therapy. Vol. 1, Autogenic Methods. New York: Grune and Stratton, 1969.

Schwartz, B. E., Shapiro, D. & Tursky, B. Self-control of Patterns of Human Diastolic Blood Pressure and Heart Rate Through Feedback and Reward. Psychophysiology, 1972, 9, 270.

Schwitzgebel, R. L. & Rugh, J. D. Of Bread, Circuses and Alpha Machines. American Psychologist, 1975, 30, 364-369.

Shirley, M. C., Burish, T. G. & Rowe, C. Effectiveness of Multiple-site EMG Biofeedback in the Reduction of Arousal. Biofeedback and Self-Regulation, 1982, 7, 2, 167-184.

Silverman, R. W. & Jenden, D. J. A Novel High-Performance Preamplifier for Biological Applications. IEEE Transactions on Bio-Medical Engineering, 1971, 18, 420.

Sterman, M. B. & Friar, L. Suppression of Seizures in an Epileptic Following Sensorimotor EEG Feedback Training. Electro-encephalography and Clinical Neurophysiology. 1972, 33, 89-95.

Surwit, R. S. Biofeedback: A Possible Treatment for Raynaud's Disease. In L. Birk (Ed.), Biofeedback: Behavioral Medicine. New York: Grune & Stratton, 1973.

Weiss, T., & Engel, B. T. Operant Conditioning of Heart Rate in Patients with Premature Ventricular Contractions. Psychosomatic Medicine 1971, 33, 301-321.

Yates, A. J. Biofeedback and the Modification of Behavior. New York: Plenum Press, 1980.