Biofeedback, voluntary control, and human potential

This paper examines some of the philosophical and scientific relationships involving self-control, voluntary control, and psychophysiologic self-regulation. The role of biofeedback in mediating conscious and unconscious processes is explored. Demonstrations of superior voluntary control and its relationship to belief, confidence, and expectation are examined. Biofeedback demonstrates the potential of control to oneself, creating confidence in one's ability to establish enhanced and peak performance in athletics, education, and psychophysiologic therapy. Emphasis is placed on the power of images in all human functioning, and in enhancing human potential.     

Distinguishing Voluntarily Upregulation of Localized Central Alpha from Widespread Posterior Alpha

Applied Psychophysiology and Biofeedback - Neurofeedback (NF) training based on alpha upregulation has been widely used on patient and healthy populations. However, active voluntary modulation of...     

Biofeedback training and human functional state control

Biofeedback (BFB) training paradigm has outstanding place among various approaches to non-phrarmacological human functional state correction. Being an universal way for voluntary self-regulation of physiological functions, it is characterized by efficacy, accessibility and absence of side effects. However, the lack of fundamental knowledge about the BFB mechanisms leads to existence of numerous difficulties and problems that seriously limit the BFB possibilities. Most difficulties seem to concern the problem of adequate choice of BFB type or parameter being voluntary controlled via feedback signals. Some ways to solve this problem are drown on the base of general systems theory. It is shown that BFB procedures could be especially effective in conditions of close interaction between the BFB mechanisms and the central regulatory mechanisms. Such interaction could be reacheb by utilization of certain characteristics of brain electrical activity reflected in the electroencephalogram (EEG). The most perspective seems to be the utilization of discrete narrow band EEG spectral components, individual resonance EEG oscillators or some correlates of human EEG amplitude modulation processes.     

The Effect of Emotional Distance on Psychophysiologic Concordance and Perceived Empathy Between Patient and Interviewer

– This preliminary study investigated the effect of emotional distance on psychophysiologic concordance and perceived empathy in a clinical population. Participants included 20 adult outpatients from a mental health clinic that underwent a brief semi-structured interview with a trained psychiatrist in either an emotionally neutral or an emotionally distant condition. Simultaneous skin conductance (SC) levels of the patient and interviewer were recorded and used to calculate a measure of psychophysiologic concordance. Interviewer gaze was rated by an independent observer and used as a proxy indicator of emotional distance. Observer ratings of interviewer gaze, SC concordance, and patient ratings of perceived interviewer empathy were significantly lower in the emotionally distant condition compared with the emotionally neutral condition (p < 0.05). Results suggest that increased emotional distance is associated with decreased psychophysiologic concordance and reduced subjective ratings of perceived empathy. The observed differences in psychophysiologic concordance support the use of this measure as a potential marker of empathy in a clinical population in an interview setting.     

Efficacy of a Brief Biofeedback Intervention on Mood,Arousal, Mental Workload,Movement Time,and Biofeedback Device Preference

Applied Psychophysiology and Biofeedback - Biofeedback (BF) training has been utilized with performers for years. Previous literature highlights the effectiveness of multi-week intervention...     

Visceral orienting reflexes as significant components of psychophysiologic personality assessment

Activ. nerv. sup. (Praha) 28, 2, 1986. Utilizing a combination of idiographic and nomothetic research designs with repeated measures in several breeds of dogs, we discovered stable constitutional differences in psychophysiologic reactions to repeated exposure to psychologically stressful situations. Some dogs showed high psychophysiologic adaptation (HA dogs). Other dogs developed persistent psychophysiologic reactions to the psychologically aversive environment: tachycardia, polypnea, profuse salivation, high energy metabolism and muscle tension, and high urinary vasopressin and catecholamines (low adaptation or LA dogs). Retrospective analysis of the development and extinction of cardiac and respiratory orienting reflexes (OR) in these two types of dogs revealed that the LA dogs exhibit higher frequency and more intense, persistent and highly fluctuating (poorly modulated) cardiac and respiratory OR than the HA dogs, which show rapid OR habituation and good modulation. Insofar as one may extrapolate these data to human subjects, recording dynamics of development and habituation and degree of modulation of visceral OR may facilitate early detection of individuals at risk for cardiorespiratory and other psychovisceral disorders.     

Localized EEG alpha feedback training: a possible technique for mapping subjective,conscious, and behavioral experiences

Subjects who received EEG alpha feedback recorded from two homologous scalp areas (central-temporal) were trained to have ON-OFF control over the left and right sides. The partial success in demonstrating localized control suggests that subjects may be trained for very specific control. Localized training may be used to partition the subjective, conscious and behavioral experiences associated with selected EEG patterns and to develop an independent subjective physiological language. Applications to medicine and altered states of consciousness are discussed.Presented in part at the Biofeedback Research Society Meeting, St. Louis, Mo. (1971).     

The “How and Why” of Group Biofeedback for Chronic Disease Management

Biofeedback has been shown to have some level of efficacy for the treatment of a number of chronic medical conditions; however, individualized biofeedback treatment is not always feasible. While group- based interventions are growing in practice due to numerous advantages, the dearth of research examining the efficacy of Group Biofeedback (GBF) suggests that this treatment modality may not be commonly utilized. Thus, the current paper highlights some advantages and constructively addresses potential challenges of utilizing GBF. Obstacles specific to GBF include equipment for participants, need for support staffing, and billing. However, the potential benefits are numerous, and pertain to cost-effectiveness, improved patient access, and additive benefits specific to group-based treatment. We offer a six-session GBF protocol to be used to guide future clinical work in this area. We hope that through the ideas and protocol presented in this paper, biofeedback practitioners will be more inclined to implement GBF.     

Voluntary control of sexual responding in men and women: Implications for the etiology and treatment of sexual dysfunctions

Recent psychophysiological investigations have shown that biofeedback and operant conditioning procedures are associated with changes in genital vasomotor activity in men and women. Although the exact role played by biofeedback or operant contingencies in the establishment of genital vasomotor control has not been conclusively established, some degree of voluntary control has been reliably demonstrated over a response that is traditionally viewed as an involuntary component of the human sexual response cycle. The present article critically reviews the experimental literature pertinent to the issue of voluntary self-control of sexual responding and makes recommendations concerning future research. The implications of this literature for traditional etiological theories and treatment approaches for sexual dysfunctions are discussed. The potential of biofeedback and operant techniques for shaping genital responses, increasing discriminability, enhancing body awareness, and facilitating cognitive labeling of genital sensations are discussed as they relate to the stated goals of sex therapy.     

The ontogeny of voluntary control of activity and its cerebral mechanisms

Literature data on the ontogeny of voluntary control of activity are reviewed. The relationship of the development of different components of voluntary activity control with the functional maturation of the brain, mainly the frontal lobes, which are traditionally regarded as the main cerebral substrate of the programming, regulation, and control of human activity at different stages of development, is considered.     

M wave potentiation during and after muscle activity

The M wave (muscle compound action potential) has been shown to enlarge between successive 3-s voluntary contractions of the human thenar and extensor digitorum brevis (EDB) muscles. The changes, which affected both the amplitude and the area of the M wave, were more obvious in the thenar than in the EDB muscles. In the thenar muscles the mean amplitude was already significantly enlarged after the first voluntary contraction and close to the maximal value by the third (mean maximal increase 23.6 +/- 12.6% of control). The increase in mean M wave area was more gradual, reaching a maximum of 29.3 +/- 14.1% at 100 s. After the voluntary thenar contractions ceased, the amplitude of the M wave subsided more rapidly than the area and had regained the control value within 50 s. The magnitude and time course of the increase in EDB M wave area (maximum change 25.9 +/- 15.2%) were similar to those of the thenar muscles; however, the subsequent decline was slower. The amplitude of the EDB M wave showed the least change, and the maximum increase (11.4 +/- 9.6%) occurred early in the postcontraction period. In both muscles the changes in M wave amplitude and area were significantly different from the control values.     

Selective activation of neuromuscular compartments within the human trapezius muscle

Task-dependent differences in relative activity between “functional” subdivisions within human muscles are well documented. Contrary, independent voluntary control of anatomical subdivisions, termed neuromuscular compartments is not observed in human muscles. Therefore, the main aim of this study was to investigate whether subdivisions within the human trapezius can be independently activated by voluntary command using biofeedback guidance. Bipolar electromyographical electrodes were situated on four subdivisions of the trapezius muscle. The threshold for “active” and “rest” for each subdivision was set to >12% and <1.5% of the maximal electromyographical amplitude recorded during a maximal voluntary contraction. After 1 h with biofeedback from each of the four trapezius subdivisions, 11 of 15 subjects learned selective activation of at least one of the four anatomical subdivisions of the trapezius muscle. All subjects managed to voluntarily activate the lower subdivisions independently from the upper subdivisions. Half of the subjects succeeded to voluntarily activate both upper subdivisions independently from the two lower subdivisions. These findings show that anatomical subdivisions of the human trapezius muscle can be independently activated by voluntary command, indicating neuromuscular compartmentalization of the trapezius muscle. The independent activation of the upper and lower subdivisions of the trapezius is in accordance with the selective innervation by the fine cranial and main branch of the accessory nerve to the upper and lower subdivisions. These findings provide new insight into motor control characteristics, learning possibilities, and function of the clinically relevant human trapezius muscle.     

Contralateral effects of unilateral resistance training: a meta-analysis.

It is often claimed that strength training of one limb increases the strength of the contralateral limb, but this has not been demonstrated consistently, particularly in well-controlled studies. The aim was to quantitatively combine the results of other studies on the effects of unilateral training on contralateral strength in humans to provide an answer to this physiological question. We analyzed all randomized controlled studies of voluntary unilateral resistance training that used training intensities of at least 50% of maximal voluntary strength for a minimum of 2 wk. Studies were identified by computerized and hand searches of the literature. Data on changes in strength of contralateral and control limbs were extracted and statistically pooled in a meta-analysis. This approach allows conclusions to be based on a statistically meaningful sample size, which might be difficult to achieve in other ways. Seventeen studies met the inclusion criteria, and 13 provided enough data for statistical pooling. The contralateral effects of strength training reported in individual studies varied from -2.7 to 21.6% of initial strength. The pooled estimate of the effect of unilateral resistance training on the maximal voluntary strength of the contralateral limb was 7.8% (95% confidence interval: 4.1-11.6%). This was 35.1% (95% confidence interval: 20.9-49.3%) of the effect on the trained limb. Pooling of all available data shows that unilateral strength training produces modest increases in contralateral strength.     

Biofeedback treatments of generalized anxiety disorder: Preliminary results

Forty-five individuals with generalized anxiety (38 with GAD as defined by DSM-III) were randomized to 4 treatment conditions or a waiting list control. Patients received 8 sessions of either frontal EMG biofeedback, biofeedback to increase EEG alpha, biofeedback to decrease EEG alpha, or a pseudomeditation control condition. All treated subjects showed significant reductions in STAI-Trait Anxiety and psychophysiologic symptoms on the Psychosomatic Symptom Checklist. Only alpha-increase biofeedback subjects showed significant reductions in heart rate reactivity to stressors at a separate psychophysiological testing session. Decreased self-report of anxiety was maintained at 6 weeks posttreatment.     

The Raynaud's Treatment Study: Biofeedback Protocols and Acquisition of Temperature Biofeedback Skills

The Raynaud's Treatment Study (RTS) compared temperature biofeedback training and a behavioral control procedure (frontalis EMG biofeedback) with nifedipine-XL and a medication placebo for treatment of primary Raynaud's phenomenon (RP) in a large (N = 313) multicenter trial. The present study describes the RTS biofeedback protocols and presents data on the acquisition of digital skin temperature and frontalis EMG responses in the RTS. The findings point to substantial problems with acquisition of physiological self-regulation skills in the RTS. Only 34.6% of the Temperature Biofeedback group (N = 81) and 55.4% of the EMG Biofeedback group (N = 74) successfully learned the desired physiological response. In contrast, 67.4% of a Normal Temperature Biofeedback group (N = 46) learned hand warming. Multivariate analysis found that coping strategies, anxiety, gender, and clinic site predicted acquisition of hand-warming skills whereas variables related to RP disease severity did not. Physiological data showed vasoconstriction in response to the onset of biofeedback and also found that performance in the initial sessions was critical for successful acquisition. These findings indicate that attention to the emotional and cognitive aspects of biofeedback training, and a degree of success in the initial biofeedback sessions, are important for acquisition.     

Cortical potentials associated with vocalization in the rhesus monkey.

Cortical potentials associated with vocalization have been investigated in two rhesus monkeys. In both animals a slow negative potential shift beginning approximately 1 sec prior to the onset of vocalization has been observed in transcortical recordings from precentral areas. It is suggested that this slow potential change might be the phylogenetic antecedent of the voluntary control of speech in humans.     

Applied psychophysiology and biofeedback of event-related potentials (brain waves): historical perspective, review, future directions

This paper reviews the efforts of workers in the 1960s-1980s to demonstrate voluntary control of exogenously evoked (event-related) potentials in visual, somatic sensory, and auditory systems in rats, cats, and humans. The first part of the paper reviews the conceptual foundation and development of the work--it actually arose from traditional sensory coding and neural correlates of behavior studies. The second part summarizes recent applications of the method in the area of pain control. In reviewing these matters, the major effort is directed at revealing how the ideas unfolded in very human, day-to-day, anecdotal terms. There is not much of an attempt to formally review the literature, which is cited for consultation elsewhere. In the same spirit, many possible future experiments are suggested by way of elucidating the key remaining questions in the area.     

Motor unit recruitment strategy of knee antagonist muscles in a step-wise, increasing isometric contraction

The purpose of this study was to determine if differences exist between the control strategies of two antagonist thigh muscles during knee flexion and extension muscular coactivation. Surface myoelectric signal (MES) of the quadriceps (rectus femoris) and the hamstrings (semitendinosus) were obtained from both muscles while performing step-wise increasing contractions during flexion and extension with the knee at 1.57 rad of flexion (90 degrees). The median frequency of the power density spectrum, which is related to the average muscle fiber action potential conduction velocity and therefore to motor unit recruitment, was calculated from each MES. The results suggest that, in all the subjects tested, when the muscle acts as antagonist most motor units are recruited up to 50% of the maximal voluntary force, whereas when the muscle acts as antagonist motor units are recruited up to 40% of the maximal voluntary force. The force range past 40–50% of the maximal force is also characterized by differences between the agonist/antagonist.     

Voluntary heart rate deceleration: A critical evaluation

This experiment was designed as a test of the view that the human heart rate (HR) deceleration response can be brought under voluntary control, when some form of exteroceptive feedback is available. Sixteen female volunteers were randomly assigned to two groups. The first group received instructions to decrease their HR plus a continuous negative (failure) binary feedback, while the second group received only the instructions. Each subject was given four sessions of HR deceleration training. Two identical tests were presented, one before and the other after the series of training sessions. These tests were divided into two parts. In the first part, subjects attempted to decrease their HR while undergoing an ischemic arm pain stress. In the second part, subjects performed a 40-trial HR discrimination task. The results indicate that all subjects decrease HR during both rest and voluntary control periods within each training session, but there are no significant group differences, no improvement in HR deceleration control over the four training sessions, and no difference in performance between rest and voluntary control periods. Similarly HR, blood pressure (BP), and the HR×BP product levels during the ischemic stress condition and the HR discrimination performance do not show group differences. It is suggested that the HR deceleration response may not meet the criteria generally applied to the definition of a voluntary response.     

Selective attention increases choice certainty in human decision making

Choice certainty is a probabilistic estimate of past performance and expected outcome. In perceptual decisions the degree of confidence correlates closely with choice accuracy and reaction times, suggesting an intimate relationship to objective performance. Here we show that spatial and feature-based attention increase human subjects' certainty more than accuracy in visual motion discrimination tasks. Our findings demonstrate for the first time a dissociation of choice accuracy and certainty with a significantly stronger influence of voluntary top-down attention on subjective performance measures than on objective performance. These results reveal a so far unknown mechanism of the selection process implemented by attention and suggest a unique biological valence of choice certainty beyond a faithful reflection of the decision process.