biofeedback and self-control of physiological functions

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.
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