Frontalis EMG Biofeedback Research Articles

EMG biofeedback training, transfer of training, and coping with stress

In phase one, 56 subjects either did (biofeedback training) or did not (no biofeedback training) receive frontal EMG biofeedback training, and either were (stress) or were not (no stress) threatened with electric shocks during the training periods. Results indicated that the threat of shock was effective in increasing arousal (as measured by self-report and multiple physiological indices), and that the biofeedback training provided under both stressful and non-stressful conditions was effective in reducing frontal EMG levels and the extent to which subjects worried about the shock, but was not effective in reducing physiological arousal, self-report of arousal, or the perceived painfulness of the shock. In phase two, the subjects from phase one were exposed to another threat of shock situation, but no additional biofeedback was provided. Fourteen additional subjects were not threatened with electric shock and served as a control group. Results indicated that the threat of shock was again effective in increasing arousal, and that subjects who had previously received biofeedback training under either stressful or non-stressful conditions were able to reduce their levels of frontal EMG and self-report of arousal, but not their levels of physiological arousal. The results provide evidence that EMG biofeedback training can reduce EMG levels under stressful as well as non-stressful conditions, and that this effect will transfer to a stressful non-training situation. However, the fact that the EMG reductions were generally not accompanied by reductions in arousal suggests that EMG biofeedback may have limited effectiveness as a general procedure for coping with stress.

Evaluation of biofeedback in the treatment of borderline essential hypertension.

Direct biofeedback of blood pressure was compared with frontal EMG biofeedback and with self-instructed relaxation for the treatment of essential hypertension in a controlled group outcome study. Patients were followed up for four months after the end of treatment. Generalization of treatment effects was assessed through pre- and posttreatment measurements of blood pressure under clinical conditions in a physician's office. There were no significant reductions in diastolic blood pressure. The systolic blood pressure (SBP) of the patients receiving blood pressure biofeedback decreased 8.1 mm mercury (p = 0.07) and the SBP of the patients in the relaxation condition decreased 9.5 mm mercury (p = 0.05). In the generalization measures, there were significant reductions in SBP for the relaxation group. The results are discussed in terms of the general lack of replicability within the area of biofeedback treatment of hypertension.

An evaluation of frontal EMG as an index of general arousal

Two experiments were conducted to investigate the sensitivity of frontal EMG to increased arousal. In Experiment 1 subjects who were aroused by a physical threat (electric shock) showed changes in skin temperature and self-report of arousal, but did not show changes in frontal EMG. In Experiment 2 subjects who were aroused by an evaluative threat (poor performance on an important intelligence test) showed changes in skin temperature, pulse rate, finger pulse volume, and self-report of arousal, but again failed to show changes in frontal EMG. The finding that frontal EMG was not sensitive to increases in arousal is inconsistent with what has generally been assumed and suggests that frontal EMG biofeedback training may not be effective for teaching persons to reduce high levels of arousal.

Frontalis EMG feedback training: An electronic panacea?

Studies dealing with the application of frontalis EMG feedback to the treatment of a variety of disorders are reveiwed. Successful applications of frontalis EMG feedback training have been reported in the treatment of muscle contraction headaches, asthma, essential hypertension, insomnia, chronic anxiety, phobias, and cerebral palsy. While available evidence does suggest that frontalis EMG feedback training may be helpful in the treatment of these disorders, these effects are equivalent but not superior to those that can be obtained using more conventional and less costly treatment techniques such as relaxation training. In addition, there appears to be a lack of clear rationale for the use of frontalis as a training site in treatment of these disorders. It is concluded that claims made about the clinical advantages of frontalis EMG biofeedback as compared to other methods of relaxation are not scientifically justified.

Finger pulse amplitude and frontalis EMG biofeedback effects of single- and two-system training

The relationship between finger pulse amplitude (PA) and frontalis EMG was studied first by looking at general physiological changes accompanying successful bidirectional PA control. Seven successful subjects were then asked to produce two patterns of PA and EMG (PAincEMGdec and PAdecEMGdec) while receiving both PA and frontalis EMG biofeedback. Results indicate subjects can easily produce the differentiation pattern of PAdecEMGdec but cannot produce the integration pattern of PAincEMGdec. These rather paradoxical results may indicate subjects were using an "attentional" rather than "arousal" strategy for controlling PA and have implications for the use of peripheral vasomotor training as a general relaxation technique.

Frontal EMG-biofeedback training of athetoid cerebral palsy patients

Six athetoid cerebral palsy patients participated in the following: speech and motor prebiofeedback training evaluation; frontal EMG biofeedback training, 6 wk; speech and motor postbiofeedback training evaluation. Frontal pretraining levels for the subjects averaged 28.9 muV p-p. Subjects' feedback consisted of an auditory signal (clicks) varying proportionately with frontal EMG activity. A visual meter display of the integrated EMG was also provided. Self-regulation of frontal EMG was evident for all subjects within session 1. Throughout all sessions, EMG levels of 2-4 mu V were often attained. Trend analysis of EMG acquisition curves showed significant reduction in frontal tension across sessions for all but one subject. Frontal posttraining levels averaged 13.0 muV p-p. Parents or subjects, or both, reported subtle improvements in various speech and motor functions, a finding confirmed by objective postbiofeedback training evaluation. Only the 2 most severely impaired subjects, JA and DS, failed to improve significantly on the speech measures. All subjects improved significantly on those measures that tapped fine and gross motor skills. Collectively, these results indicate that EMG biofeedback training shows promise as an additional treatment modality in the habilitation of cerebral palsy patients.

Biofeedback-assisted cue-controlled relaxation for the treatment of flight phobias

Three Ss exhibiting an extreme fear of flying were successfully treated using EMG biofeedback-assisted cue-controlled relaxation in conjunction with systematic desensitization. The procedure involved (1) training Ss in deep muscle relaxation using frontalis EMG biofeedback, and (2) pairing a self-generated cue word—“Relax”—with low levels of frontalis EMG. The cue-controlled relaxation resulted in deeper levels of relaxation than non-cue assisted relaxation, and appears to afford a useful treatment modality for a range of disorders. Cognitive vs conditioning explanations were discussed.