Specific effects and biofeedback versus biofeedback-assisted self-regulation training

In any field, clear and logical conceptualizations are the basis of accurate models----correct research design----correct results----correct conclusions----advancement in the field. Faulty conceptualizations----faulty models----faulty research design----faulty results----faulty conclusions----confusion. In analyzing the conceptualizations of "biofeedback" as expressed by John Furedy (1987) in, "Specific versus Placebo Effects in Biofeedback Training: A Critical Lay Perspective," we focus on two issues: Does biofeedback have a treatment effect? Is biofeedback necessary for the training effect? In discussing issue (1) we describe the multiple meanings of "biofeedback" and raise the fundamental question: Is biofeedback a treatment? We argue that faulty conceptualizations of clinical biofeedback (1) assume that the treatment in clinical biofeedback is "biofeedback" with specific effects, (2) assume that the scientific basis of biofeedback is dependent upon demonstrations of these specific effects through double-blind design that distinguish "specific" from "placebo effects," and (3) trivialize clinical research by attempting to determine the usefulness of biofeedback information--usefulness that is already understood logically by professionals and consumers and demonstrated by clinical studies in the laboratory and in the clinic. We further argue that accurate conceptualizations of clinical biofeedback (1) identify self-regulation skills as the treatment with specific effects of physiological change and symptom reduction, and (2) describe the use of information from biofeedback instruments as scientific verification of self-regulation skills. Finally, the scientific basis of clinical biofeedback is based on (1) evidence from experimental and clinical control studies that have demonstrated the effectiveness of self-regulation skills for symptom alleviation, and (2) the use of biofeedback instruments to verify the acquisition of self-regulatory skills, thus fulfilling the scientific dictum of verifiability.     

Uncomfortable issues in radiation protection posed by low-dose radiobiology

This paper aims to stimulate discussion about the relevance for radiation protection of recent findings in low-dose radiobiology. Issues are raised which suggest that low-dose effects are much more complex than has been previously assumed. These include genomic instability, bystander effects, multiple stressor exposures and chronic exposures. To date, these have been accepted as being relevant issues, but there is no clear way to integrate knowledge about these effects into the existing radiation protection framework. A further issue which might actually lead to some fruitful approaches for human radiation protection is the need to develop a new framework for protecting non-human biota. The brainstorming that is being applied to develop effective and practical ways to protect ecosystems widens the debate from the narrow focus of human protection which is currently about protecting humans from radiation-induced cancers.     

Biofeedback Via Telehealth: A New Frontier for Applied Psychophysiology

Psychophysiological diagnostic and therapeutic methods, to include biofeedback, have been found to be empirically effective in the treatment of a variety of physical disorders. In many areas of the country, however, certified biofeedback practitioners are not well distributed, limiting patient access to this treatment modality. Psychologists at Tripler Army Medical Center have pioneered efforts to develop and provide these needed services via a telehealth venue. Such capability significantly improves access to care, particularly for patient's located at considerable distance from the provider. As the telecommunications infrastructure in rural and remote areas is often quite basic, such a system must be capable of operating within these limited parameters. The system developed by the authors provides real-time video and audio interactivity and allows the therapist to monitor and control biofeedback equipment located at the remote site. The authors discuss the clinical applications, the technology, and relevant practical and ethical issues.     

Specific effects and biofeedback versus biofeedback-assisted self-regulation training

In any field, clear and logical conceptualizations are the basis of accurate models → correct research design → correct results → correct conclusions → advancement in the field. Faulty conceptualizations → faulty models → faulty research design → faulty results → faulty conclusions → confusion. In analyzing the conceptualizations of “biofeedback” as expressed by John Furedy (1987) in, “Specific versus Placebo Effects in Biofeedback Training: A Critical Lay Perspective,” we focus on two issues: Does biofeedback have a treatment effect? Is biofeedback necessary for the training effect? In discussing issue (1) we describe the multiple meanings of “biofeedback” and raise the fundamental question: Is biofeedback a treatment? We argue that faulty conceptualizations of clinical biofeedback (1) assume that the treatment in clinical biofeedback is “biofeedback” with specific effects, (2) assume that the scientific basis of biofeedback is dependent upon demonstrations of these specific effects through double-blind designs that distinguish “specific” from “placebo effects,” and (3) trivialize clinical research by attempting to determine the usefulness of biofeedback information — usefulness that is already understood logically by professionals and consumers and demonstrated by clinical studies in the laboratory and in the clinic. We further argue that accurate conceptualizations of clinical biofeedback (1) identify self-regulation skills as the treatment with specific effects of physiological change and symptom reduction, and (2) describe the use of information from biofeedback instruments as scientific verification of self-regulation skills. Finally, the scientific basis of clinical biofeedback is based on (1) evidence from experimental and clinical control studies that have demonstrated the effectiveness of self-regulation skills for symptom alleviation, and (2) the use of biofeedback instruments to verify the acquisition of self-regulatory skills, thus fulfilling the scientific dictum of verifiability.     

Detection of noncontingent feedback in EMG biofeedback

Noncontingent feedback is frequently used as a placebo control procedure in biofeedback research. Researchers, however, have criticized this procedure for lacking credibility because of easy detection. The present study examined detection of false feedback in biofeedback with EMG. Contingent feedback (CF), truly random false feedback (FF), and controlled false feedback (CFF) groups were compared for changes in EMG levels, report of inaccurate feedback, and report of learning muscle activity reduction. The results indicated that FF procedures are easily detected; therefore, differences found between the FF and CF groups may be influenced by extraneous variables. The CFF group did not detect false feedback, but subjects reported some suspicions in later trials. With more trials, CFF may have also been detected. These results indicate a need for more attention to appropriate placebo control procedures in evaluating the parameters and efficacy of biofeedback.     

Detection of noncontingent feedback in EMG biofeedback

Noncontingent feedback is frequently used as a placebo control procedure in biofeedback research. Researchers, however, have criticized this procedure for lacking credibility because of easy detection. The present study examined detection of false feedback in biofeedback with EMG. Contingent feedback (CF), truly random false feedback (FF), and controlled false feedback (CFF) groups were compared for changes in EMG levels, report of inaccurate feedback, and report of learning muscle activity reduction. The results indicated that FF procedures are easily detected; therefore, difference found between the FF and CF groups may be influenced by extraneous variables. The CFF group did not detect false feedback, but subjects reported some suspicions in later trials. With more trials, CFF may have also been detected. These results indicate a need for more attention to appropriate placebo control procedures in evaluating the parameters and efficacy of biofeedback.     

Controlled group designs in biofeedback research: Ask, “what does the control group control for?”

The extant literature on the specific role of biofeedback in promoting skeletal muscular relaxation is reviewed and found deficient with respect to the use of properly controlled group outcome research. The review emphasizes the failure of commonly used control procedures to adequately control a number of potentially confounding variables. Strengths and weaknesses of three types of controlled group design (attention placebo, pseudofeedback, and altered contingency) are discussed with respect to their relative usefulness in controlling certain nonspecific or placebo effects in biofeedback research. Many published biofeedback studies failed to measure the credibility of control procedures or the subject's ability to discriminate different feedback contingencies. The studies reviewed suggest that the various control procedures used are not inert and are not equivalent with respect to their effects on control group behavior. The suggestion is made that the controlled group outcome design be accepted as the minimum requirement for testing the specific effects of biofeedback, and possible methods for improving control procedures are discussed.     

Heart rate and blood pressure biofeedback

The experimental literature on the use of biofeedback with heart rate and blood pressure, published since 1972, was reviewed and summarized along several dimensions: magnitude of change, effects of extended training, type of feedback, temporal feedback factors, motivational factors, instructional effects, individual differences, and the mediation/specificity issue. The research on biofeedback and heart rate was found to be fairly well developed. Research on biofeedback and blood pressure, however, was found to be much less advanced. Moreover, most of the studies were done with hypertensive subjects.     

The Efficacy of Behavioral Treatments for Hypertension

Evidence is reviewed for the efficacy of behavioral treatments for hypertension. The format chosen here is a review of reviews given that numerous consensus committee reports and quantitative reviews on the topic have been published. Extensive evidence from over 100 randomized controlled trials indicates that behavioral treatments reduce blood pressure (BP) to a modest degree, and this change is greater than what is seen in wait-list or other inactive controls. Effect sizes are quite variable. The observed BP reductions are much greater when BP levels were high at pre-test, and behavioral studies tend to underestimate possible benefits because of floor effects in their protocols. Blood pressure measured in the office may be confounded with measurement habituation. Multi-component, individualized psychological treatments lead to greater BP changes than do single-component treatments. Among biofeedback treatments, thermal feedback and electrodermal activity feedback fare better than EMG or direct BP feedback, which tend to produce null effects. There continues to be a scarcity of strong protocols that properly control for floor effects and potential measurement confounds.     

Blood volume pulse biofeedback in the treatment of migraine headache: A controlled evaluation

In order to evaluate the specific effects of blood volume pulse (BVP) biofeedback in the treatment of migraine headaches, 21 female migraine patients were randomly assigned to one of three experimental conditions: temporal artery constriction feedback, temporal artery dilation feedback, or waiting list. Biofeedback training consisted of 15 sessions over an 8-week period. All patients completed 5 weeks of daily self-monitoring of headache activity and medication before and after treatment. Results showed that constriction and dilation biofeedback were equally effective in controlling migraines and produced greater benefits than the waiting-list condition. No significant relationships were found between therapeutic gains and BVP self-regulation skills. However, further analyses revealed that changes in headache activity and medication were associated with changes in vasomotor variability. The current rationale for the use of BVP biofeedback in the treatment of migraine is questioned and a new one is proposed.     

Conditions for effective allosteric feedforward and feedback in metabolic pathways

Whether an allosteric feedback or feedforward modifier actually has an effect on the steady-state properties of a metabolic pathway depends not only on the allosteric modifier effect itself, but also on the control properties of the affected allosteric enzyme in the pathway of which it is part. Different modification mechanisms are analysed: mixed inhibition, allosteric inhibition and activation of the reversible Monod-Wyman-Changeux and reversible Hill models. In conclusion, it is shown that, whereas a modifier effect on substrate and product binding (specific effects) can be an effective negative feedback mechanism, it is much less effective as a positive feedforward mechanism. The prediction is that catalytic effects that change the apparent limiting velocity would be more effective in feedforward activation.     

Expectancies of reinforcement control in biofeedback and cognitive performance

This study investigated the effects of expectancies concerning the controllability of outcomes in a biofeedback task. Forty-eight college undergraduates were subjects. Frontal (forehead) electromyographic (EMG) responses were measured during baseline (no treatment), pretreatment, and test sessions. During pretreatment, subjects were assigned to one of three groups. Using a fictitious blood vessel control task, the success group received false feedback and instructions that conveyed that outcomes had been successfully controlled. The failure group received feedback and instructions that conveyed that outcomes had not been controlled. A control group was given no specific task. During the subsequent test stage, all subjects were asked to reduce frontal muscle tension levels through relaxation while assisted with true EMG feedback. Relative to the success and control groups, EMG levels of the failure group reflected more rapid acquisition of frontal muscle relaxation. However, performance on a cognitive task was not affected by the pretreatment. It was concluded that expectancies generated during the false feedback pretreatment were related to later biofeedback performance. The results were discussed in terms of concepts of locus of control and theories of learned helplessness and reactance.A version of this paper was presented at the annual meeting of the Biofeedback Society of America, San Diego, 1979.     

Effects of alternative control procedures for electromyographic biofeedback relaxation training

Twenty-four college students participated in a single session of electromyographic (EMG) biofeedback in a comparison of three experimental control procedures commonly employed in biofeedback relaxation training research. One group received contingent EMG biofeedback from the forehead area, and each subject in this group served as his or her own control. Subjects in a second group received noncontingent EMG feedback from a tape recorder but were instructed to use the feedback signal to relax their forehead muscles (single blind). Subjects in a third group received the same auditory feedback as those in the second group but were not told the purpose or source of the feedback stimulus (yoked control). The contingent feedback group showed significantly less EMG activity when compared to the other two groups. However, this group did not exhibit significant EMG level decrements from the beginning to end of the session. This seemingly contradictory finding may have been due to statistically capitalizing on the artifactually high EMG level of the experimental and control groups, although the single-blind and yoked-control groups showed nonsignificant increases across the session. The single-blind group's data had a variance several times larger than the other two groups' variance. Findings are discussed with respect to a probing hypothesis as opposed to the previously offered frustration hypothesis. Of the three control procedures, the data suggest the yoked control as the procedure of choice for EMG biofeedback relaxation research.The authors would like to thank David Kazar and Claudia Coleman for their technical assistance with this article.     

Biofeedback-assisted sexual arousal in females a comparison of visual and auditory modalities

This study was undertaken to investigate the effects of instructional set and biofeedback modality upon the ability of 23 females to achieve control over sexual arousal. Two levels of instructional set (increase, decrease) were completely crossed with three feedback modalities (audio, visual, no feedback). Changes in vaginal blood volume (VBV) and vaginal pulse amplitude (VPA) were monitored by a vaginal plethysmograph and reduced on line by a microcomputer. During feedback trials, all subjects received audio- or visual feedback of the VBV response. Subjects participated in two sessions, each consisting of six 3-minute trials, one in each instruction/feedback combination. Order of trials was counterbalanced. Subjective levels of arousal, VBV, and VPA were significantly higher under increase instructions. Also, a significant feedback effect was noted in the subjective measure and the VBV measure, favoring visual feedback for overall control of sexual arousal. However, the feedback effect accounted for a small portion of the variance, and it was concluded that performance was not appreciably superior with or without feedback. Thus practical considerations may determine the feedback modality to be used for vaginal vasocongestion in future research. Higher positive correlations of subjective ratings with vaginal blood volume occurred during feedback trials, which suggests that biofeedback may be helpful in discrimination training to facilitate awareness of the feelings associated with different arousal levels and correct labeling of increased vasocongestion as sexual. Further research is necessary to see if sexually dysfunctional women can benefit from a biofeedback component in a comprehensive therapy program and to determine the effect of many training sessions on discrimination and self-control of arousal.     

Biofeedback-assisted sexual arousal in females: a comparison of visual and auditory modalities

This study was undertaken to investigate the effects of instructional set and biofeedback modality upon the ability of 23 females to achieve control over sexual arousal. Two levels of instructional set (increase, decrease) were completely crossed with three feedback modalities (audio, visual, no feedback). Changes in vaginal blood volume (VBV) and vaginal pulse amplitude (VPA) were monitored by a vaginal plethysmograph and reduced on line by a microcomputer. During feedback trials, all subjects received audio- or visual feedback of the VBV response. Subjects participated in two sessions, each consisting of six 3-minute trials, one in each instruction/feedback combination. Order of trials was counterbalanced. Subjective levels of arousal, VBV, and VPA were significantly higher under increase instructions. Also, a significant feedback effect was noted in the subjective measure and the VBV measure, favoring visual feedback for overall control of sexual arousal. However, the feedback effect accounted for a small portion of the variance, and it was concluded that performance was not appreciably superior with or without feedback. Thus practical considerations may determine the feedback modality to be used for vaginal vasocongestion in future research. Higher positive correlations of subjective ratings with vaginal blood volume occurred during feedback trials, which suggests that biofeedback may be helpful in discrimination training to facilitate awareness of the feelings associated with different arousal levels and correct labeling of increased vasocongestion as sexual. Further research is necessary to see if sexually dysfunctional women can benefit from a biofeedback component in a comprehensive therapy program and to determine the effect of many training sessions on discrimination and self-control of arousal.     

脑电生物反馈系统的研制和脑电α成分反馈的研究

本文介绍了我们研制的微机化脑电反馈系统.并报告了我们所进行的正常人脑电α成分生物反馈训练实验,证明了脑电生物反馈提升α成分比例的可行性.本文还论讨了国际上现行关于脑电α成分生物反馈研究中存在的问题,提出了有效的解决方法.     

Systematic Review of Biofeedback Interventions for Addressing Anxiety and Depression in Children and Adolescents with Long-Term Physical Conditions

Children and adolescents with long-term physical conditions are at increased risk of psychological problems, particularly anxiety and depression, and they have limited access to evidence-based treatment for these issues. Biofeedback interventions may be useful for treating symptoms of both psychological and physical conditions. A systematic review of studies of biofeedback interventions that addressed anxiety or depression in this population was undertaken via MEDLINE, EMBASE, PsycINFO, CINAHL and the Cochrane Central Register of Controlled Trials databases. Primary outcomes included changes in anxiety and depression symptoms and ‘caseness’. Secondary outcomes included changes in symptoms of the associated physical condition and acceptability of the biofeedback intervention. Of 1876 identified citations, 9 studies (4 RCTs, 5 non-RCTs; of which all measured changes in anxiety and 3 of which measured changes in depression) were included in the final analysis and involved participants aged 8–25 years with a range of long-term physical conditions. Due to the heterogeneity of study design and reporting, risk of bias was judged as unclear for all studies and meta-analysis of findings was not undertaken. Within the identified sample, multiple modalities of biofeedback including heart rate variability (HRV), biofeedback assisted relaxation therapy and electroencephalography were found to be effective in reducing symptoms of anxiety. HRV was also found to be effective in reducing symptoms of depression in two studies. A range of modalities was effective in improving symptoms of long-term physical conditions. Two studies that assessed acceptability provided generally positive feedback. There is currently limited evidence to support the use of biofeedback interventions for addressing anxiety and depression in children and adolescents with long-term physical conditions. Although promising, further research using more stringent methodology and reporting is required before biofeedback interventions can be recommended for clinical use instead or in addition to existing evidence-based modalities of treatment.     

The effects of EMG feedback training during problem solving: a case study.

The present case study investigated the effects of competing task demands on biofeedback training to reduce frontalis muscle tension. Baseline levels of frontalis muscle tension were recorded for relaxation and problem solving. The subject was trained to decrease muscle tension with biofeedback for the problem-solving task alone. The results indicated that EMG training during problem-solving was successfully accomplished. Frontalis muscle tension during relaxation baseline did not change as a result of reductions in muscle tension during problem-solving feedback training. This suggests that the decrease of muscle tension cannot be attributed to reductions in overall muscle tension levels. Instead, training was specific to the problem-solving feedback phases. Additionally, it was found that accuracy in problem-solving did not decline as a result of simultaneous feedback training. Thus EMG biofeedback training can be accomplished and exercised without disruption of ongoing mental activity.     

Stress management techniques: Are they all equivalent,or do they have specific effects?

This article evaluates the hypothesis that various stress management techniques have specific effects. Studies comparing various techniques are reviewed, as well as previous literature reviews evaluating the effects of individual techniques. There is evidence that cognitively oriented methods have specific cognitive effects, that specific autonomic effects result from autonomically oriented methods, and that specific muscular effects are produced by muscularly oriented methods. Muscle relaxation and/or EMG biofeedback have greater muscular effects and smaller autonomic effects than finger temperature biofeedback and/or autogenic training. EMG biofeedback produces greater effects on particular muscular groups than progressive relaxation, and thermal biofeedback has greater finger temperature effects than autogenic training. Disorders with a predominant muscular component (e.g., tension headaches) are treated more effectively by muscularly oriented methods, while disorders in which autonomic dysfunction predominates (e.g., hypertension, migraine headaches) are more effectively treated by techniques with a strong autonomic component. Anxiety and phobias tend to be most effectively treated by methods with both strong cognitive and behavioral components.This work was supported by grants Nos. HL-34336 and HL-44097 from the Heart, Lung, and Blood Institute of the National Institutes of Health. Material in this article has been condensed and updated from three chapters in Lehrer, P. M., and Woolfolk, R. L. (1993).Principles and practice of stress management, Vol. 2, New York: Guilford Press.     

The effects of EMG feedback training during problem solving

The present case study investigated the effects of competing task demands on biofeedback training to reduce frontalis muscle tension. Baseline levels of frontalis muscle tension were recorded for relaxation and problem solving. The subject was trained to decrease muscle tension with biofeedback for the problem-solving task alone. The results indicated that EMG training during problem solving was successfully accomplished. Frontalis muscle tension during relaxation baseline did not change as a result of reductions in muscle tension during problem-solving feedback training. This suggests that the decrease of muscle tension cannot be attributed to reductions in overall muscle tension levels. Instead, training was specific to the problem-solving feedback phases. Additionally, it was found that accuracy in problem-solving did not decline as a result of simultaneous feedback training. Thus EMG biofeedback training can be accomplished and exercised without disruption of ongoing mental activity.