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Biofeedback Therapists

History

Biofeedback therapy has a relatively short history. The term itself did not come into widespread use until roughly 1969, when the results of four separate lines of research converged into a new approach to the treatment of a variety of medical and psychological conditions.

Until the early 1960s, psychologists generally accepted the premise that biological responses typically thought to be "involuntary," or under the control of the autonomic nervous system (such as heart rate, stomach acid secretion, blood pressure, or skin resistance), could not be modified or influenced using measurable instrumental means. Instead, this form of conditioned learning was thought possible only for responses that were under "voluntary" control, such as skeletal muscle responses. A definitive statement of this collective assumption appeared in a 1961 textbook, prompting a number of scientists to begin studies to refute it.

Four areas of study in particular yielded notable results. One approach employed a shock-avoidance paradigm in which subjects could avoid mild electrical shocks by making appropriate adjustments in heart rate. These studies demonstrated that statistically significant increases and decreases in heart rate could be obtained using instrument-based conditioning techniques. Other work achieved similar results using positive reinforcement paradigm rather than shock avoidance.

About the same time, several other researchers showed that galvanic skin response, the ability of the body to conduct minute amounts of naturally occurring electrical current across the skin, could also be controlled by individuals.

As these reports surfaced, critics began to appear. They pointed to the fact that some voluntary responses can elicit a response that appears to be autonomic or involuntary. For instance, changes in heart rate can be initiated by altering respiration patterns or tensing certain muscle groups—both responses under voluntary control. If changes in heart rate, an autonomically mediated response, were "caused" by changes in responses under voluntary control, critics argued, such a demonstration would not prove that heart rate itself could be changed by voluntary control.

A third line of research sought to address this concern, removing the effect of voluntary responses from the equation. Laboratory rats were injected with curare, a drug that paralyzes all skeletal muscles (including those that enable the animals to breathe). They then were maintained on artificial respiration, which kept them alive and exactly regulated their breathing. Finally, an electrode was implanted in the hypothalamus, the part of the brain that regulates body temperature, certain metabolic processes, and other involuntary activities, so the researchers could control its actions. With this preparation, scientists showed that several involuntary responses could be spontaneously conditioned—not only heart rate, but blood pressure and urine formation, among others. This demonstration of large-magnitude changes in the responses of the internal organs in animals encouraged researchers to speculate on the wide range of human psychosomatic disorders that might be treatable with biofeedback.

Eventually, a fourth avenue of research emerged in the field of electroencephalography (EEG), the study of electrical activity in the brain. Several scientists began to study whether subjects could "voluntarily" produce certain EEG patterns—particularly the alpha rhythm, a distinctive rhythm associated with deep relaxation. Because of the similarity in the subjective experience of a "high alpha state" with that reported for meditation, self-control of EEG patterns attracted much attention beyond the scientific community, helping the entire field to grow.