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Beyond Biofeedback – Drs Elmer and Alyce Green

The heart is a group of muscles. To a large extent it, like the muscle in blood vessel walls, is under autonomic (involuntary) nervous control. A number of variables combine to regulate heart behavior, including genetic and conditioned factors (the autonomic habits that the body has learned). Psychophysiological inputs such as fear and joy, and physiological factors, such as whether one is resting, jogging, whatever, also determine heart behavior at any given moment. Considering the great number and variety of determinants, and the complexities of their moment-to-moment interactions, it is easy to see why autonomic regulators evolved for control of the heart and circulatory system. Be that as it may, the point here is that because certain aspects of the heart's ongoing activity are readily perceived with the aid of biomedical instruments, it is possible to feed back to a person information about the behavior of the heart and thereby provide an opportunity to learn conscious control.

An early study investigated heart-rate stabilization (Hnatiow and Lang, 1965). The subjects were forty, normal, healthy, male university students. Twenty of them (the experimental group) were asked to keep the heart rate as steady as possible during the experiment. They were instructed to watch the heart-rate display (synchronized with the output of a cardiotachometer) and told that keeping the pointer in the center of the display would help them in their task. The remaining twenty subjects (the control group) were instructed to keep their body processes at a steady level and to track the pointer visually. Pointer movements were not synchronized with the subject's heart rate but merely simulated cardiac change. The findings indicated that subjects who are given meaningful information can significantly reduce normal heart-rate variability.

The most comprehensive clinical research in the area of heart-rate control is that of Bernard Engel and his associates. An early study (1971) described work with patients suffering from premature ventricular contraction (PVC), which can be thought of as erratic heart rhythm. Eight patients took part in the study, and each was told the nature of the experiment in detail. They were informed as to the response being monitored and allowed to inspect their own records throughout the experiment. Visual feedback was provided by three lights: a green light to signal the patient to speed the heart, a red light signaling to slow down the heart, and a yellow light that stayed on whenever the heart rate was correct. Most of the patients participated in ten sessions, with about thirty-four minutes of each session devoted to each of four conditions:

(1) heart-rate speeding,
 (2) heart-rate slowing,
(3) alternate speeding and slowing, and
(4) control of heart-rate variability.

In addition, the patient was provided with information about the occurrence of each premature contraction.

All of the patients learned some degree of heart-rate control. Four were able to reduce the frequency of PVCs significantly and to maintain control without additional training during a three- to twenty-one-month follow-up. A fifth patient learned to recognize PVCs through "internal awareness" and to control them through resting. Three subjects did not learn PVC control in the forty sessions.

In another study (1975) Engel demonstrated that if the EKG (electrocardiographic) signal is displayed on an oscilloscope so that the flub-dup action of each heartbeat is displayed as a visible spike-and- hump pattern (familiar to anyone who follows the medical dramas of TV), then it is possible to learn to control sections of the heartbeat. The salient features of the EKG signal are called the R wave and the T wave. Generally speaking, the R wave is taller than the T wave, but with certain heart peculiarities the R wave is too short, or sometimes is upside down relative to the T wave. Engel showed that simply by watching the oscilloscope and willing a change, subjects can learn to increase the height of the R wave.

This demonstration ranks along with Basmajian's single-motor-unit research as revolutionary, to say the least. It is theory-busting. If individual bits of heart behavior can be self-regulated through the feedback of information, what does this imply for the control of other organs in the body?