Biofeedback is a technique of mind/body medicine in which sensitive instruments attached to the body produce visual or auditory signals representing changes in physiological functioning. The signals enable the person to learn to consciously regulate physical processes such as heart rate and blood pressure.
During the 1960s, scientists made great headway in the development of sensitive instruments that could be attached to the body and measure changes in physiological functioning. Some of these scientists were working with laboratory animals, studying ways of regulating – or teaching the animals to regulate – physical functions. Other researchers were interested in whether humans might be able to use information, or "feedback," from such devices to intentionally regulate what are normally considered automatic functions. They soon found that people could, with the help of instantaneous feedback, learn to alter their blood pressure, heart rate, body temperature, muscle tension and other bodily states.
The human capacity for "self-regulation" was dramatized in studies of several Indian mystics who could seemingly violate the laws of biology. In a series of experiments at the Menninger Foundation in Topeka, Kansas, under the direction of Elmer and Alyce Green, an Indian yoga master named Swami Rama demonstrated his ability to alter his blood pressure, heart rate, and body temperature at will. Indeed, the yoga master was able to vary the temperature and blood pressure in different limbs simultaneously(1).
The term "biofeedback" was coined in 1969 with the formation of the Biofeedback Research Society, now known as the Association for Applied Psychophysiology and Biofeedback (AAPB). Since the 1960s and 1970s, biofeedback has been steadily growing in acceptance as a method for teaching people voluntary control over bodily states. The earliest documented clinical applications were in treating symptoms of migraine, tension headache, torticollis, hypertension, Raynaud’s phenomenon and disease, muscular dysfunction of cerebral palsy, neuromuscular disorders, and epilepsy.
Types of Biofeedback
The most commonly used form is electromyographic (EMG) biofeedback. An EMG sensor is attached to the skin and signals the amount of electrical activity related to muscle tension in the area of the sensor. This is very useful in helping people learn to relax muscles, for they have direct feedback — which may be visual readouts, lights, beeps or tones — as to the degree of tension. This approach is often used for the regulation and management of tension headaches and chronic pain conditions.
Other kinds of biofeedback include:
thermal, which senses the temperature of the skin as an indication of blood flow and relaxation
electrodermal (EDR), measuring subtle changes in amounts of perspiration
electroencephalogram (EEG), measuring brain wave activity
finger pulse, for measuring heart rate and force, which is useful for anxiety or cardiovascular conditions
breathing patterns — monitoring the rate, volume, rhythm, and location (belly or chest) of each breath
Biofeedback relies upon the "wiring" of the mind/body relationship. The nervous system runs throughout the body, carrying signals to all its tissues and organs. It is through this network that a person is able to exercise voluntary control or self-regulation of bodily processes. An important focus of biofeedback theory and research are two physiological reactions that take place as a result of mental experiences: the stress response and the relaxation response.
The Stress Response. The stress response is a set of changes in the body that occur when an individual experiences what they perceive to be a challenging or threatening situation. Commonly called the "fight or flight" reaction, the stress response includes increases in blood pressure, respiratory and heart rates, oxygen consumption (burning of fuel), blood flow to skeletal muscles and away from the extremities, perspiration, and muscle tension, and decreases in immune functioning.
The Relaxation Response. The relaxation response includes changes in the body that are just the opposite, or a mirror image, of the stress response(2,3). Breathing and heart rates slow, blood pressure decreases, and muscle tension lessens. The relaxation response has been demonstrated to have important benefits for symptom reduction and healing in a wide range of illnesses(4). At the heart of biofeedback therapy is practice in eliciting the relaxation response, making this a powerful form of treatment for many stress-related conditions.
Unlike some other forms of mind/body medicine, the precise instrumentation used in biofeedback lends itself well to research studies, of which there are now a great number. For example, in a study of 44 college students with chronic tension headaches, 52 percent of those using biofeedback techniques had at least a 50 percent reduction in headache activity(5). A controlled study of patients with irritable bowel syndrome found that biofeedback training brought a significant reduction in symptoms, a change that was still present six months later(6). Another controlled study found a 41 percent reduction in migraine headaches in patients using a thermal biofeedback procedure at home(7).
What Are the Potential Uses of Biofeedback?
Any bodily process that can be measured with instrumentation in "real time" – on a moment to moment basis – can potentially be controlled or influenced through the help of these techniques. Biofeedback has many applications, including those disorders that benefit from stress reduction and relaxation training. Specific conditions for which biofeedback is used include:
Teeth grinding and clenching (bruxism)
TMJ (temporomandibular joint disorder)
Raynaud's phenomenon or disease (cold extremities)
Muscle disorders (including helping people learn to re-use limbs that have been traumatized)
Who Practices Biofeedback and What is Their Training?
Biofeedback is used by practitioners from a variety of health professions including physicians, psychologists, clinical social workers, counselors, nurses, and others. There is no licensing in biofeedback; most practitioners work under the license of their profession.
In the United States, the only certifying body is the Biofeedback Certification Institute of America (BCIA), which publishes an annual register of certified practitioners. Certification requires at least a bachelor’s degree in a health discipline, 200 hours of training and clinical supervision in biofeedback methods, and written and practical exams using instrumentation. Practitioners need not be licensed in a health discipline in order to be certified by BCIA.
Is Biofeedback Safe?
Biofeedback therapy is non-invasive. It does not involve drugs or treating the body with any other outside materials or substances. Any changes that occur in the body are governed by the mental intention of the patient. Thus there are no strict contraindications or risks, although caution should be taken as discussed below.
The deep relaxation arising from certain biofeedback methods may accentuate the depression of the central nervous system induced by pharmaceutical drugs, such as those used in the treatment of anxiety or muscle tension. If the person becomes particularly successful in reducing or controlling their symptoms with biofeedback, medication levels may need to be adjusted.
It is also possible that deep relaxation may allow emotions that had not been previously recognized to come to one’s awareness. In these cases, it is helpful to have a good rapport and trusting relationship with the practitioner for discussion of such feelings, which may vary in intensity.
Finally, it has been suggested that biofeedback is contraindicated in people with certain psychiatric disorders, but there is no research showing ill effects(8).
What to Expect in a Practitioner’s Office
The first step in working with a biofeedback practitioner is the assessment. The practitioner will take a history of the client’s illness or condition and its symptoms, and arrive at a diagnosis. The diagnosis may be of a physical or psychological condition, or both. An important part of the assessment is an appraisal of the client’s lifestyle and behaviors that may affect his or her overall health, and a determination of how these factors might influence symptoms. Recommendations for behavior and lifestyle change are often made to support treatment goals.
After the assessment, a course of treatment is chosen. Treatment sessions may last 30 to 90 minutes. The person is usually seated in a comfortable chair or is lying down on a treatment table. The practitioner places small sensors, which are connected via wires to the feedback equipment, in contact with the person’s skin. The sensors may be in the form of a finger ring or small electrodes attached with tape to the body, where they monitor changes in temperature, electrical energy released by the muscles (muscle tension), or moisture from perspiration. All these sensing devices send electrical impulses to the feedback equipment, which may display the results graphically on a meter or computer screen, or with colored or flashing lights. Auditory feedback may also be given in the form of sounds and tones.
The practitioner may use hypnosis, guided imagery, breathing exercises, meditations or progressive muscle relaxation exercises in conjunction with the biofeedback to help the person achieve the desired state.
The client quickly discovers that the displays, lights or tones vary in response to his or her mental states and mental intention. With instruction and encouragement from the practitioner, the person learns to manipulate the lights or tones, and move them in the desired direction by consciously relaxing selected muscles and achieving certain states of mind and body.
With practice, it becomes progressively easier to attain the desired state so that it can be reached without the help of the equipment. To reinforce what is being learned, exercises to be done outside the treatment session, either with or without equipment, are frequently part of a biofeedback program.
William Collinge, Ph.D., M.P.H.
1. Green E, Green A. Beyond Biofeedback. New York: Dell, 1977
Green E, Green A. General and specific applications of thermal biofeedback. In J.V. Basmajian (ed.), Biofeedback–Principles and Practice for Clinicians. New York: Williams and Wilkins, 1989
2. Benson H, Beary J, Carol M. The relaxation response. Psychiatry, 37:37-46, 1974
3. Benson H. The Relaxation Response, New York: Avon Books, 1975, and Beyond the Relaxation Response, New York: Berkley Books, 1985
4. Mandle CL, Jacobs SC, Arcari PM, Domar AD. The efficacy of relaxation response interventions with adult patients: a review of the literature. J Cardiovasc Nurs, 10(3):4-26 1996
5. Rokicki LA, Holroyd KA, France CR et al. Change mechanisms associated with combined relaxation/EMG biofeedback training for chronic tension headache. Applied Psychophysiology and Biofeedback, Vol 22(1): 21-41 1997
6. Blanchard E, Schwartz S, Suls J et al. Two controlled evaluations of multicomponent psychological treatment of irritable bowel syndrome. Behavior Research and Therapy, 30:175-89 1992
7. Holroyd K, Holm J, Hursey K et al. Recurrent vascular headache: home-based behavioral treatment versus abortive pharmacological treatment. Journal of Consulting and Clinical Psychology, 56:218-23 1988
8. Schwartz M, ed. Biofeedback: A Practitioner’s Guide, 2nd edition. New York: Guilford Press, 1995