Biofeedback Procedures Research Articles

Behavioural Medicine: The Application of Behaviour Therapy to Physical Health

Three typical areas of application of behavioural medicine are described: biofeedback, relaxation training, and various cognitive behavioural procedures. It is argued that biofeedback has led to few useful clinical treatments but both relaxation and more complex procedures and methods of analysis can contribute to the prevention and treatment of disease. This is illustrated with examples from the literature on headache and the prevention and treatment of coronary heart disease and cancer.

The relationship between external anal and external urethral sphincter activity in continent women

AbstractThe relationship between the external anal sphincter and the periurethral sphincter muscles is an unresolved issue. Recordings of the external anal sphincter (EAS) are commonly used to indicate the responses of the urethral sphincter during urodynamic evaluations and in biofeedback procedures for the treatment of urinary incontinence. This study examined the validity of using anal sphincter training to teach control of the external urethral sphincter. Subjects were 5 continent women, aged 37–51 years, who reported being free of all urologic symptoms. Using visual biofeedback of anal sphincter pressure, subjects were trained to voluntarily contract the sphincter to four amplitudes: 5, 10, 15, and 20 mmHg (6.8, 13.6, 20.4, and 27.2 cmH2O). Then they were guided through a series of controlled anal sphincter contractions, while the response of the urethral sphincter was measured using surface electrodes embedded in a Foley catheter. At each of four bladder volumes, subjects performed 16 contractions (four contractions at each of the four amplitudes). The order of contractions was counterbalanced, using a Latin square design. The results show a strong, statistically significant, monotonic relationship between the magnitude of anal sphincter contraction (pressure) and the level of urethral sphincter electromyographic (EMG) activity. The results support the use of the external anal sphincter as an indicator of urethral sphincter activity for the purpose of conducting biofeedback in the treatment of urinary incontinence.

Biofeedback-produced hemispheric asymmetry of slow cortical potentials and its behavioural effects

Two studies served to examine behavioural effects of slow cortical potentials (SPs). SPs were manipulated by means of a biofeedback procedure. The ability of human subjects to alter SPs differentially between the two hemispheres - specifically over the lateral aspects of teh central sulcus - was tested by providing feedback ofthe SP difference betwrrn C3 and C4. In Expt. I, 21 of the 45 subjects produced hemispheric asymmetries of more than 2 μV between C3 and C4 on an average after 80 trials of analogue, continuous and immediate feedback. In Expt. II, SP changes were fed back digitally at the end of each trial. Within 120 trials, 20 of the 48 subjects reached the criterion of a minimum 2-μV difference in SPs between C3 and C4 on the average. Average differentiation remained significantly below the SP differentiations achieved for continuous feedback. Trials with feedback were followed by ‘task’ trials without feedback, during which subjects were still requested to produce SP changes but also had to complete a task: Either sensorimotor tasks (Expt. I) or forced choice handedness tasks (Expt. II) were presented to evaluate behavioural consequences of hemispheric SP differences. In subjects achieving the required SP differentiation it affected the behavioural output in agreement with the known functions of the respective cortical area.

Elimination of stuttering and maintenance of fluency by means of airflow, tension reduction, and discriminative stimulus control procedures

An intensive stuttering treatment program is described. Twenty-four adult stutterers were treated using graded airflow, tension/relaxation, and electromyographic (EMG) biofeedback procedures to produce fluent speech. A discriminative stimulus control procedure was used to facilitate the transfer and maintenance of fluency following treatment. All 24 subjects met the criterion of <-1% stuttered words by the end of treatment, and 17 clients (70%) maintained fluent speech in follow-up assessments conducted for from 1 to 42 months following treatment. The results are discussed in terms of the effectiveness of the treatment and maintenance procedures utilized.

The relationship of extraneous movements to lumbar paraspinal muscle activity: Implications for EMG biofeedback training applications to low back pain patients

Within recent years clinicians and researchers have applied paraspinal EMG biofeedback procedures during static and dynamic movement retraining of chronic low back pain patients. Most of these applications make use of surface electromyography, an approach complicated by the fact that the erector spinae muscles are deeply situated. This descriptive study reveals that extraneous movements, such as neck flexion and pelvic rotation, can elicit profound activity from percutaneously placed EMG electrodes while little change is seen at the skin surface. The implications of these observations for the use of EMG feedback to remediate low back pain are discussed.

Vividness of Imagery and Locus of Control as Predictors of Normotensives' Ability to Learn Downward Control of Blood Pressure

Two ‘individual’ variables (level of imagery, locus of control) were investigated for their effects upon subjects' ability to learn and generalise downward control of blood pressure via biofeedback procedures. Also investigated was the effect of visual numerical feedback versus no-feedback combined with instructions. Subjects were volunteers with normal blood pressure who were randomly assigned to feedback of systolic blood pressure, feedback of diastolic blood pressure or no-feedback under an interrupted time-series design which consisted of an adaptation period, baseline, training, rest, and post-test (generalisation of task without feedback). Results indicated that neither of the two ‘individual’ variables was associated with any significant reductions of blood pressure within either the training or generalisation periods. Feedback was negatively associated with training effects. Findings are discussed in terms of the ease of comprehension of numerical feedback of a fluctuating variable, with suggestions for future research using fine-grained and stable measures of cardiac performance.

Cardiovascular responses to mental arithmetic and handgrip during different conditions of postural change.

ABSTRACTTwenty healthy male subjects, aged 18–29 yrs, were studied during three sequences of four different postural trials‐sitting, sitting to standing, standing, and standing to sitting. The first sequence was a baseline, without other stimulation. In the remaining two, subjects performed a mental arithmetic task and an isometric handgrip task during each trial (counterbalanced). Systolic blood pressure, diastolic blood pressure, heart rate, and skin conductance were recorded during the trials. The physiological responses to the two tasks were shown to vary as a function of the specific postural trial. Systolic and diastolic blood pressure were generally more sensitive to these effects than heart rate or skin conductance. The two tasks facilitated increases in blood pressure during the sitting to standing trials, especially during the standing phase. The increases in blood pressure were comparable to those reported previously for voluntary control and biofeedback procedures. Mental and physical strategies are effective in increasing blood pressure during postural change and may be useful in the management of orthostatic hypotension.

The effect of changes in facial muscle tension on respiratory resistance

The relationship between changes in facial electromyographic (EMG) levels and respiratory resistance was examined. Thirty adult males were assigned equally to 1 of 3 groups; a facial muscle tension increase group (EMG increase), a facial tension decrease group (EMG decrease), and a noncontingent group (EMG noncontingent). Biofeedback procedures, based on EMG recordings made form electrodes positioned over the frontalis muscles, were used to effect muscle tension changes. Individuals in the EMG increase group exhibited increases in facial tension, but individuals in the EMG decrease group failed to show muscle tension changes. Respiratory resistance increased in individuals in the EMG increase group but did not change in individuals in the EMG decrease group. Like the EMG decrease group subjects, EMG noncontingent group subjects changed neither in facial tension nor in respiratory resistance. The results provided some support for a hypothesis linking facial muscle tension and respiratory resistance.

Intensive Stuttering Therapy in a Public School Setting

Two intensive stuttering treatment programs, which were implemented in a public school setting, are described. In the initial program, six students were treated using graded airflow, tension/relaxation, and EMG biofeedback procedures to reduce stuttering frequency. A discriminative stimulus (S D ) control procedure was to be used to facilitate the maintenance of fluency following treatment, but due to time constraints only one student completed the S D program. All six students met the criterion of ⩽1% stuttered words by the end of the treatment, but only the one student who completed the maintenance procedure continued to meet the fluency criterion of ⩽1% stuttered words at follow up, 7 months later. In the second treatment program, nine students were treated using procedures only slightly modified from the first program. The modified procedures allowed all students to complete all aspects of the treatment program, including the discriminative stimulus (S D ) control procedure. All nine students in the second program met the criterion of ⩽1% stuttered words by the end of treatment and six of the nine continued to meet the criterion of ⩽1% stuttered words in follow up assessment 6 to 7 months post treatment. The procedures and results are discussed in terms of the relevance of intensive behavioral programming of stuttering therapy in the public schools.

Temperature-biofeedback treatment of migraine headache. Specific effects and the effects of "generalization training".

Digital skin temperature biofeedback was used in the treatment of migraine headache. The value of a "generalization-training" procedure as well as the relationship between temperature control and clinical effects were studied. In all, 24 migraine sufferers were randomly assigned to either "standard" or a "generalization-training" biofeedback procedure and were given eight treatment sessions. Headache activity was measured before, during, and after treatment; and digital skin temperature was continuously measured during training sessions. From the results the following tentative conclusions were drawn: (1) Those who acquire temperature control show greater decrease in headache, (2) pretreatment baseline finger temperatures might predict if temperature control will be achieved, and (3) "generalization-training" methods do not seem to result in a greater degree of temperature control.

Production and reversal of DOCA-salt hypertension in baboons.

We describe for the first time a non-human primate model of mineralocorticoid-salt hypertension. Baboons instrumented for chronic, direct measurement of arterial pressure, underwent sodium chloride loading (8.6 or 17.1 mEq/kg/day) by different routes for several weeks and deoxycorticosterone acetate (DOCA) 5 mg/2 days i.m., in addition to sodium chloride, for periods lasting up to several months. Salt loading alone at 8.6 mEq/kg/day had no chronic effect on mean arterial pressure (MAP). Salt loading at both doses in combination with DOCA produced increases in MAP within a few days which became progressively larger over weeks to months. DOCA-salt hypertension was associated with hyporeninemia and mild hypokalemia, without consistent changes in heart rate or plasma catecholamines. A biofeedback procedure applied to three animals failed to reduce tonic blood pressure. In two of these animals, administration of clonidine or atenolol also had no antihypertensive effect, whereas a diuretic combination (hydrochlorothiazide and triamterene) rapidly abolished the hypertension. The absence of amelioration of the hypertension by a central sympatholytic agent or a beta-adrenoceptor blocker, coupled with the absence of increased plasma catecholamines, suggests that increased sympathetic activity may not contribute to the hypertension in contrast with findings in lower animals but consistent with clinical reports.

Alpha Enhancement: A Comparison Study of Biofeedback, Open Focus Training, and Control Procedures

Alpha wave production has been related to affective and physiological arousal states since Berger's (1929) initial research. More recently, the possibility of subjects' control of alpha production has been investigated via the innovation of biofeedback procedures. Research conducted by Kamiya in the 1960s and others led to the early conclusion that alpha-wave production could be controlled and that such control could facilitate enhancement of a person's state of physical and psychological well-being. Subsequent research data have questioned these conclusions. The present study focused upon alpha-wave production with or without a procedure for relaxation called "open-focus training." Twenty subjects were divided into four equal groups and seen for three 20-min. sessions. Results suggested a deterioration of alpha production with all groups combined, no significant differences between the biofeedback and no biofeedback control groups (without "open-focus training"), and greater decrease in alpha production during each session in the "open-focus" groups (with or without biofeedback). These unusual results and their implications are discussed.

Use of EMG biofeedback procedures with learning disabled children in a clinical and an educational setting.

This report presents two related investigations of the effects of biofeedback relaxation training upon academic attainment of learning disabled boys. The first study was conducted in a university clinical center where LD experimental boys showed significant improvement over controls on measures of reading, spelling, verbal IQ, eye-hand coordination, auditory memory, and handwriting legibility. Behavioral self-control and self-concept also improved significantly. The second study tested the applicability of the same biofeedback relaxation procedures in the public schools by teachers of LD boys. The experimental boys improved significantly over the controls on measures of reading, spelling, eye-hand coordination and handwriting. Precautions and need for further research are discussed.

Biofeedback training: offerings, plans, and some attitudes in graduate schools and internships.

Graduate schools and APA-approved internships in North America were surveyed to determine the type and extent of biofeedback training, additional biofeedback training planned, requirements considered to be a minimum necessary before beginning clinical practice of biofeedback, when biofeedback is considered an appropriate application, and whether biofeedback is considered a "passing fad" in clinical practice. Questionnaires were returned by 56% of the graduate schools and 54% of the internships, and revealed training in 58% and 67% respectively. Training in biofeedback procedures appears to be growing, and most graduate schools and internships think that biofeedback is not a passing fad in clinical practice. Training emphases vary considerably across graduate schools and internships, with some schools and internships excluding theory and/or practice and/or research from their instruction. The results are discussed in relation to the question of determining which procedures to include in future instruction.

EMG—Induced Muscle Relaxation as a Treatment for Learning Disability: Efficacy yet to be Proven

Biofeedback procedures for stress reduction have been widely used in a variety of settings. While there are many reports of the successful application of EMG procedures for general tension-reduction with adults and children, little has been done concerning these procedures with children who suffer from a specific learning disability. The present paper reviews the use of EMG biofeedback with learning-disabled children and, after examining those studies performed to date concludes that the supportive conclusions drawn by previous authors can be criticised on methodological grounds, and that the issue of indirect treatment of learning disability via EMG biofeedback is open to discussion. Directions for future research are described.

The effects of visual feedback on hemispheric alpha asymmetries and reported processing strategies: A single-subject experimental design

A double reversal single-subject experimental design was used to study the effects of visual feedback on the hemispheric alpha asymmetries of a male subject during a linguistic task. Results indicated that the subject demonstrated flexibility in hemispheric alpha and corresponding processing strategies employed when an alpha biofeedback procedure was used. These results provide further support for the notion that right and left hemispheric activation is associated with different, yet compatible, cognitive strategies and that both can be manipulated under conditions of feedback.

A components analysis of biofeedback in the treatment of fecal incontinence.

Fecal incontinence is a socially disabling symptom for which rectosphincteric biofeedback has been reported to be dramatically effective. The most commonly employed biofeedback procedure incorporates three separate and potentially effective components: exercise of the external sphincter muscle, training in discrimination of rectal sensations, and training synchrony of the internal and external sphincter responses. This paper reports the results of single case experiments employed with eight incontinent patients to examine the contributions of each of these components. All eight patients improved, but only one required the biofeedback procedure as it was originally described. Three responded to sensory discrimination training, one to exercise training, and one to the training of synchronous sphincteric responses; three recovered independently of the effects of biofeedback. Despite the achievement of continence, the rectosphincteric reflexes following treatment continued to be abnormal in every case. These findings suggest that the character of the external sphincter response to rectal distension is an unreliable index of sphincter function and that exercise and sensory discrimination training procedures are effective for some cases of fecal incontinence.

Operant control of EEG and event-related and slow brain potentials.

Research on operant control of brain potentials is reviewed. From single-unit firing and spontaneous EEG activity to event-related potentials such as sensory and pain evoked potentials, and slow potential shifts, most of the aspects of electrical brain activity have been investigated. Results produced by conditioning of spontaneous EEG oscillations (alpha and theta) dampened the early enthusiasm: e.g., no increase above baseline levels could be achieved and no reliable behavioral effects became manifest. Evidence accumulates, however, that operant conditioning of the sensorimotor rhythm (12-15 Hz) may lead to successful self-regulation and that epileptic patients may profit from the training. First steps in the conditioning of brainstem, as well as pain evoked potentials suggest that self-regulation of EPs can be achieved by adequate biofeedback procedures. If some of the observed behavioral effects prove to be stable, the therapeutic usefulness seems to be within reach. A comparable progress has been achieved for the operant control of slow potentials (DC-shifts across seconds). Biofeedback procedures have been used successfully as a scientific tool to achieve systematic variations on a psychological level and to record psychological covariations. This method may provide insights into the behavioral meaning of electrical brain activity.

Hemispheric alpha asymmetries during an electromyographic biofeedback procedure for stuttering: A single-subject experimental design

A single-subject “double-reversal” experimental design was used to investigate the use of electromyographic (EMG) biofeedback on the dysfluent behaviors of a right-handed male stutterer. A systematic decrease in EMG amplitude accompanied a progressive approximation of increased verbal complexity resulting in increased fluent behavior. Electroencephalographic (EEG) alpha data (8–12 Hz) gathered during baseline and pre- and post- treatment sessions appeared to co-vary with changes in fluency with right hemispheric suppression associated with greater dysfluencies and left hemispheric alpha suppression with decreased dysfluencies. The results are discussed relative to stutterer's adoption of differing behavioral production strategies for fluent speech that are associated with hemispheric information processing strategies.

Biofeedback: A possible substitute for smoking, experiment I.

Biofeedback techniques were utilized in this study to identify those physiological variables which possibly contribute to maintenance of cigarette smoking and to investigate the hypothesis that smoking frequency would decrease when individuals were trained via biofeedback procedures to increase 8–12 Hz occipital EEG activity as a substitute for smoking. Results of the study indicate that of the six smokers physiologically monitored, the following physiological changes occured while actually smoking one cigarette: four smokers increased the percent of time they were producing 4–8 cycle per second (Hz) brain waves; five smokers increased their heart rate (beats per minute); all six smokers decreased their 8–12 Hz activity. Immediately after the smoking of one cigarette, six of the smokers demonstrated an increase in their heart rate and four of the smokers demonstrated a decrease in their skin temperature. There did not appear to be any specific consistent brain wave change across the subjects. Two smokers, who were able to continue producing high levels of 8–12 Hz activity without use of the biofeedback equipment, were able to quit completely at the end of an eight-month follow- up period.