The role of EMG awareness in EMG biofeedback learning

Underlying most research on biofeedback learning is a theoretical model of the processes involved. The current study tested a prediction from the Awareness Model: High initial EMG awareness should facilitate response control during EMG biofeedback training. Seventy-two undergraduates were assessed for forehead EMG awareness by asking them to produce target responses from 1.0 to 5.0 microV every 15 s for 16 trials. Based on this assessment, two groups (high and low awareness) were trained for 64 trials to produce these target levels with either EMG biofeedback, practice (no feedback), or noncontingent EMG feedback. A transfer task was identical to the initial assessment. During training, the biofeedback group deviated less from target than the practice and noncontingent groups. The biofeedback group was the only group to improve from initial EMG awareness activity. During transfer, only the low awareness biofeedback group remained below initial EMG awareness level. These findings can be interpreted in terms of the Two-Process Model.     

EMG biofeedback training versus systematic desensitization for test anxiety reduction.

Investigated EMG biofeedback training as a method to reduce test anxiety among 40 university students. A procedure combining EMG biofeedback training with systematic desensitization (SD) was compared to an automated SD program not using EMG feedback. The study also evaluated the effectiveness of EMG feedback relaxation training without SD. Ss were randomly assigned to 1 of 4 groups: (a) EMG biofeedback training with SD, (b) EMG biofeedback relaxation training, (c) automated SD, and (d) no-treatment control. At the end of the program, all participants were administered the Suinn Test Anxiety Behavior Scale, Sarason's Test Anxiety Scale, and an anagrams test, given under threat conditions. Results suggest that EMG biofeedback training is a useful technique for reducing test anxiety, but not necessarily more effective than SD. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

EMG biofeedback training of Type A and Type B behavior pattern subjects.

Assessed the relative efficacy of EMG biofeedback training to reduce tension levels in Ss characterized either by the presence of the coronary-prone behavior pattern (Type A) or by its absence (Type B). 55 college students, classified as Type A or B on the basis of Jenkins Activity Survey (Form T) scores, were randomly assigned to either a biofeedback or a control group. Ss met for 6 training sessions, then returned for a 7th session to perform without biofeedback a series of easy (4-digit recall) and difficult (7-digit recall) tasks. Biofeedback Ss attained a greater degree of relaxation during training than did control Ss, regardless of A/B status. Also, biofeedback Ss maintained greater relaxation during task performance than did control Ss. Across groups, Type A's performed significantly better than Type B's on difficult tasks, and although Type A biofeedback Ss had EMG levels as high as Type B controls for the actual duration of performance tasks, they maintained significantly lower EMG levels than either group prior to, between, and after performance tasks. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential shaping of EEG theta rhythms

Heart rate, EEG, frontal EMG, and forearm EMG were recorded in 20 subjects for 3 baseline, 8 feedback, and 2 postbaseline sessions in order to compare two biofeedback methods of teaching subjects to increase theta EEG activity. Subjects were divided into high- and low-EMG groups. Five high-EMG subjects, and 5 low-EMG subjects then received 8 sessions of strictly theta feedback. The remaining 10 subjects, 5 from the high-EMG group, and 5 from the low-EMG group, received a "graduated" training which involved shaping the target response. This procedure consisted of 4 initial sessions of EMG feedback, followed by a second phase consisting of 4 sessions of theta feedback. Results showed a clear relationship between subjects' baseline frontal EMG levels and the effect of the training methods. Although subjects with high-EMG baseline increased their theta output only with the two-phase training, subjects with low-EMG baseline levels performed better when given theta feedback only. This result shows not only that amounts of theta can be reliably increased, but that training techniques should be adapted to the physiological characteristics of the individual--in this case, baseline levels of frontal EMG levels.     

Biofeedback training in treatment of childhood constipation: a randomised controlled study

BACKGROUND: Because abnormal defaecation dynamics, which can be modified by biofeedback, are considered to be the underlying problem in constipation, biofeedback training may be a useful treatment for constipation. This treatment has mainly been studied in uncontrolled trials. We evaluated defaecation dynamics and clinical outcome in chronically constipated children in a randomised study comparing conventional treatment and conventional treatment with biofeedback training. METHODS: Patients, 5 to 16 years old, were referred to the Academic Medical Center in Amsterdam by general practitioners, school doctors, paediatricians, and psychiatrists. They had to fulfil at least two of four criteria for paediatric constipation and were included if they had been treated medically for at least one month before randomisation. Patients had a medical history, abdominal and rectal examination, and anorectal manometry at the start and end of the 6-week intervention period. The conventional group received laxative treatment with additional dietary advice, toilet training, and maintenance of a diary of bowel habits. The biofeedback group received the same conventional treatment and additionally five biofeedback training sessions. During the first 3 weeks, patients visited the outpatient clinic weekly; two subsequent visits were twice monthly. FINDINGS: 94 patients were randomised to conventional treatment (CT) and 98 to conventional treatment with additional biofeedback training (CT+BF). Normal defaecation dynamics increased in the CT group from 41% to 52% (not significant) and in the CT+BF group from 38% to 86% (p = 0.001). At 6 weeks, more patients in the CT+BF group showed normal defaecation dynamics, compared to the CT group (p < 0.001). This result was unaltered by controlling for baseline status in a logistic regression model. At 1 year, successful treatment (defaecation frequency > or = 3/week, soiling and/or encopresis < 2/month, and no laxatives) was accomplished in 59% of the CT and 50% of the CT+BF group (p = 0.24). The results were maintained after 1 1/2 years follow-up. No association was found between achievement of normal defaecation dynamics and clinical outcome. INTERPRETATION: Additional biofeedback training compared to conventional therapy did not result in higher success rates in chronically constipated children. Furthermore, achievement of normal defaecation dynamics was not associated with success: abnormal defaecation dynamics seem not to play a crucial role in the pathogenesis of childhood constipation. Intensive conventional laxative treatment should remain the first choice in chronically constipated children.     

Biofeedback as therapy: Some theoretical and practical issues.

Gives examples of the use of biofeedback in individual therapy from basic research on self-regulation of blood pressure and heart rate and from clinical research on essential hypertension and Raynaud's disease. Patient motivation is a critical variable, since its absence may hamper long-term success in therapy, as indicated by case histories. The use of cognitive and somatic mediators as an aid to self-regulation, both with and without feedback, is illustrated. It is concluded that biofeedback, in conjunction with other medical and psychological techniques, may prove effective for a selected group of motivated patients having acute rather than chronic organ damage. A combined behavioral-biological model, emphasizing (a) the natural relations between responses; (b) the exact manner in which the feedback and reward is given; and (c) biological, cognitive, and environmental constraints, is offered as a potential means of predicting whether biofeedback training will be clinically significant for a given patient. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Area and volume conservation among the elderly: Assessment and training.

Conducted 2 studies to examine whether the elderly maintain the competence to adequately solve problems of logical thinking. In the 1st study the performance of 60 noninstitutionalized middle-class elderly females was assessed on area and volume conservation tasks. On overall performance only 33.3% of the Ss were classified as conservers. In the 2nd study a training paradigm was used to determine whether simple verbal feedback activated the strategies required for adequate performance on conservation tasks. 22 Ss who failed at least 2 conservation tasks in the assessment study were administered a 20-trial training procedure. Half of these Ss received simple verbal feedback following each response, while half received no feedback. Results on an immediate posttest indicated that the feedback group performed significantly better than the control group on the near transfer posttest task and on the majority of far transfer tasks. The results are discussed in terms of a distinction between competence and performance. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lactate formation from [U-13C]aspartate in cultured astrocytes: compartmentation of pyruvate metabolism

Sixteen subjects naive to biofeedback learned lateralised interhemispheric control of slow cortical potentials (SCPs) across electrode sites F3-F4 during three sessions of visual electroencephalograph (EEG) biofeedback. Subjects were required to generate slow negativity shifts either towards the left or the right hemisphere in sixty pseudorandomly ordered trials per session. Group 1 (n = 8) were told to use emotional strategies in the task (positive emotions for left hemisphere activation, negative emotion for right hemisphere activation), group 2 received no guidance. Both groups received feedback in the form of an on-screen rocket-ship, initially centrally placed, which rose to indicate an increase in left hemisphere negativity (relative to the right hemisphere) and fell to indicate an increase in right hemisphere negativity (relative to the left hemisphere). A 2 x 3 x 3 x 2 ANOVA (group x session x block x trial) showed no performance differences between the strategy and no strategy groups. Both groups learned to produce correct direction shifts in the final third of each session during both trial types (P < 0.001). The no strategy group showed a particularly strong within session learning effect (P < 0.0037) with poor performance in the early part of the sessions, and strong shifts at the end. Subjects high on withdrawal showed stronger rightward shifts in keeping with right hemisphere involvement in behavioural withdrawal. This is the first demonstration of self regulation of interhemispheric frontal asymmetry.     

Efficient serum-free retroviral gene transfer into primitive human hematopoietic progenitor cells by a defined, high-titer, nonconcentrated vector-containing medium

BACKGROUND: Home training in self-lowering of blood pressure using continuous blood pressure feedback has not previously been reported. Enhancement of laboratory-learned skills was hypothesized on the basis of outcomes from other intellectual, emotional and physical endeavours. OBJECTIVE: To examine the supplementary effect of home blood pressure biofeedback training. DESIGN: Thirty unmedicated, mild hypertensives participated in a randomized, double-blinded, modified contingency placebo-controlled study. METHOD: After suitable screening and baseline blood pressure measurements subjects undertook eight laboratory biofeedback sessions and then 12 home training sessions over 4 weeks using continuous finger blood pressure monitoring. RESULTS: In the laboratory those being administered active therapy (n=16) lowered systolic pressures by 5 +/- 5.4 mmHg compared with a lowering of 4 +/- 4.2 mmHg with placebo (NS). During the fourth week at home lowering for the active group (11 +/- 8 mmHg) was greater than that with placebo (4 +/- 6.2 mmHg, P=0.017). Arm-cuff blood pressures were not statistically different for groups and with time but that of the active group was lower by 9 +/- 15.4/7 +/- 10.2 mmHg, which is a clinically relevant change, after home biofeedback. CONCLUSIONS: The efficacy of self-lowering of systolic blood pressure in mild hypertensives by continuous feedback was enhanced by 6 mmHg with 4 weeks of practice at home. Standard arm-cuff blood pressure was reduced by a clinically relevant amount. The home environment proved cost effective for this 'high-tech' approach.     

Change mechanisms in EMG biofeedback training: Cognitive changes underlying improvements in tension headache.

43 college students suffering from recurrent tension headache were randomly assigned to 1 of 4 EMG biofeedback training conditions. Although all Ss were led to believe they were learning to decrease frontal EMG activity, actual feedback was contingent on decreased EMG activity for half of the Ss and increased EMG activity for the other half. Within these 2 groups, Ss also viewed bogus video displays designed to convince them they were achieving large (high success) or small (moderate success) reductions in EMG activity. Results show that regardless of actual changes in EMG activity, Ss receiving high-success feedback had substantially greater improvement in headache activity (53%) than Ss receiving moderate success feedback (26%). Performance feedback was also related to score changes in locus of control and self-efficacy measures administered pre- and posttreatment. Changes in these 2 cognitive variables during biofeedback training were correlated with reductions in headache activity following treatment, while changes in EMG activity exhibited during training were uncorrelated with outcome. (54 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of active training upon conjunctive concept attainment in children.

Examined the performance of 48 3rd graders given no feedback as to the correctness of their hypotheses, on color-, number-, and size-dominant conjunctive concept problems. Each of 3 active training groups solved a training problem involving 1 stimulus dimension. A control group received only verbal instructions. Results of repeated-measures analyses of variance for both behavioral and verbal attainment indicate that (a) fewer trials to solution were required by active training groups (p     

Homeostatic reconditioning in stress-related disorders: A preliminary study of migraine headaches.

18 19–55 yr old migraine headache patients were assigned to a group that learned (1) to raise finger temperature, via visual biofeedback, after neutral imaginal experiences or (2) to raise finger temperature after stressful imaginal experiences. At the completion of training, Ss participated in an outcome session without feedback. Laboratory training, combined with home practice using the same respective imaginal experiences, resulted in Ss' being able, with on-task concentration, to raise finger temperature without feedback and also resulted in significant clinical reductions in headache activity. Improvement was more marked at 4-wk follow-up. Ss trained in vascular recovery after stress showed more improvement than did other Ss. Overall, the Ss who showed the most reliable vascular recovery conditioning effects were those whose migraine prodromal symptomatology was not an accurate predictor of headache or absence of headache. The significance of what is called homeostatic reconditioning, after stress, in stress-related disorders, rather than the "aspirin" approach of many biofeedback treatments, is discussed. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Therapeutic effectiveness of voluntary heart rate control in reducing anxiety.

Demonstrates the therapeutic effectiveness of heart rate control training in the treatment of a phobia. The S was a male college student who experienced a high degree of anxiety in association with receiving injections. S received 14 1-hr sessions of biofeedback training over the course of 2 mo and was encouraged to practice heart rate control between sessions. A time-series analysis of pretreatment and posttreatment assessment indicated significant fear reduction due to the biofeedback intervention. Results serve to further illustrate that learned control of heart rate deceleration is an effective self-control skill for coping with anxiety. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biofeedback as a placebo: Anxiety reduction facilitated by training in either suppression or enhancement of alpha brainwaves.

Assessed the differential effects (on experiential reports of anxiety) of actual performance and perceived success at an EEG biofeedback task. 10 college students who were high in trait anxiety (MMPI, State-Trait Anxiety Inventory) underwent training in either the suppression of enhancement of EEG alpha activity with the expectation that success at their biofeedback task would result in reductions of chronic anxiety levels. Both groups experienced significant reductions in both trait and state anxiety. Anxiety reductions were highly correlated with the trainees' ratings of perceived success at the feedback task but were unrelated to either the direction or magnitude of the changes in their alpha activity. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of respiratory sinus arrhythmia biofeedback versus passive biofeedback control.

The objective of this study was to examine the acute effects of a portable respiratory sinus arrhythmia (RSA) biofeedback device as compared to passive biofeedback control on state anxiety, heart rate (HR), and Stroop task (Congedo, 2003) performance during repeated administration of the Stroop task cognitive stressor in a single brief session. Participants were individuals reporting stress levels at least 1 SD above the mean on the Perceived Stress Scale (Cohen, Kamarck, & Mermelstein, 1983). The RSA group had significantly reduced HR compared to the control group at postintervention and Stressor 2. Both groups significantly improved Stroop scores. Together, these preliminary results suggest that brief relaxation training can reduce state anxiety but that RSA biofeedback appears to have added benefits in reducing state anxiety and HR stress reactivity compared to passive relaxation techniques. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Credibility and desirability of positive and negative structured feedback in groups.

Examined 3 different sequences of positive and negative feedback delivered in T groups to 46 undergraduates. The believability and desirability of the feedback, as rated by the Ss who received the feedback, were the main areas of interest. Positive feedback was more desirable and tended to be more believable than negative feedback. Overall, the sequence of negative feedback delivered first, followed by later positive feedback, was more effective than positive feedback followed by negative feedback. A 3rd group, which received a mixture of positive and negative feedback, rated the T group lowest as a learning experience. No significant differences in cohesion resulted from the different feedback conditions. Some implications of these findings for training laboratories and group psychotherapy are discussed. (20 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Alcoholism, alpha production, and biofeedback.

Obtained EEGs of 20 alcoholics and 20 nonalcoholics (mean ages, 44 and 45 yrs, respectively) during a 20-min baseline period. Alcoholics produced less alpha (8-13 CPS) than nonalcoholics, a finding that supports previous speculations that alcoholics have a higher level of arousal. Biofeedback training designed to increase alpha production and thereby reduce arousal was given during 3 subsequent daily sessions of 20 min each. In one condition Ss were given accurate biofeedback, whereas in the other they were given random (noncontingent) feedback. Accurate biofeedback did not result in greater increases in alpha than did random biofeedback. This finding is discussed in terms of the problem of generalizing from the younger, more sophisticated, and better motivated populations on which the biofeedback techniques were developed to the clinical populations to which the biofeedback techniques are applied to treatment. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biofeedback and electrodermal self-regulation in psychopathy.

Examined the degree to which psychopaths can learn to modify their spontaneous skin resistance responses (SSRRs) using intructions and biofeedback. Ten clinically defined psychopaths and 12 control Ss were tested, using a within-S design. Ss were required to increase and decrease the frequency of SSRRs, first without feedback, then with biofeedback training, and finally without feedback. During prefeedback with instructions alone, control Ss were able to raise SSRRs relative to resting baselines, but psychopaths showed no SSRR control. After 16 min of biofeedback training, both groups were able to raise and lower their SSRRs to a comparable degree. The results for heart rate, measured at the same time, presented the opposite pattern; during prefeedback with instructions alone, both groups produced comparable increases in heart rate, but in postfeedback the controls maintained heart rate whereas the psychopaths did not. Data suggest that psychopaths are as capable of learning to voluntarily regulate electrodermal activity as are controls, but they still differ in autonomic patterning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)