Biofeedback for the treatment of fecal incontinence

Biofeedback therapy has been proposed as a treatment for fecal incontinence with good, short-term results. PURPOSE: This study was designed to assess long-term clinical results of biofeedback therapy compared with medical therapy alone and to assess manometric results in patients treated with biofeedback. METHODS: Two groups of incontinent patients were studied. Group 1 consisted of 16 patients (3 males and 13 females; mean age, 59.9 years). Etiologies treated by biofeedback included descending perineum syndrome (7), postfistula or hemorroidectomy (4), and miscellaneous (5). Group 2 consisted of eight patients (two males, six females; mean age, 62.2 years). Etiologies treated with medical treatment alone (including enema and antidiarrheal therapy) included descending perineum syndrome (3), postfistula or hemorroidectomy (2), and miscellaneous (3). The incontinence score was initially 17.81±3.27 (standard deviation) in Group 1 and 17.0±2.77 in Group 2. Resting pressure of the upper and lower anal sphincter, maximum squeezing pressure, and duration of contraction were not initially different in Groups 1 and 2 but were significantly lower than in the control group of patients without incontinence (n=12; 8 males, 4 females; mean age, 66.4 years) (P<0.05). Follow-up duration was 30 months, with intermediate clinical score at 6 months for Group 1. RESULTS: After biofeedback therapy, the incontinence score at 30 months was lower in Group 1 (14.43±6.35 vs.17.81 ±3.27;P<0.035) and unchanged in Group 2 (18.0±2.72 vs.17.0±2.77). However, in Group 1 the score at 6 months was much lower than at 30 months (6.31±7.81 vs.14.43±6.35;P<0.001). Only the amplitude of voluntary contraction and upper anal pressure (51.1 (range, 27–90) vs 36.7 (range, 20–80) mmHg) were significantly increased (81.5 (range, 55–120) vs.62.1 (range, 30–90) mmHg;P<0.05). CONCLUSION: Biofeedback improved continence at 6 months and at 30 months. However, the score at 6 months was much better, suggesting that the initial good results may deteriorate over a long time. These data suggest that it could be useful to reinitiate biofeedback therapy in some patients.     

Vergence can be controlled by audio feedback,and induces downward ocular deviation

We measured horizontal and vertical eye positions, using binocular search coils, in three humans. Subjects could maintain vergence by means of audio biofeedback. Feedback consisted of a pair of audio tones, one variable and one fixed at a reference frequency. The variable tone was controlled by instantaneous vergence and provided immediate feedback on the vergence state. The reference frequency, which they attempted to match, was set to correspond to a target distance of either 0.34 m or 0.14 m. Subjects could maintain vergence consistently, even while undergoing lateral motions at 0.5 Hz and 0.2 g peak acceleration in darkness. There was also a consistent tendency for the eyes to deviate downward during near vergence. The results may be useful in experiments in which one wishes to control vergence without providing a visual reference which might inhibit conjugate eye movements.     

Heart Rate Perception and Heart Rate Control

Twenty-one subjects look the Autonomic Perception Questionnaire (APQ) and later were given another test of ability to perceive heart activity. The second test involved subjects' tracking of their own heart rates (HR). They were then tested for ability to increase and decrease HR from their resting baseline levels. No significant relationships were found between HR control and APQ score. HR decrease success seemed to depend mainly on respiration differences between rest and decrease periods. The subjects who achieved high scores on the heart tracking test increased HR significantly better than did low scorers. This heart perception vs HR increase relationship did not depend upon respiration rate, respiration amplitude, or baseline HR differences between high and low scorers on the tracking test. A low correlation between APQ and tracking score seemed to indicate that the two perception tests measured different attributes of the subjects.     

Operant Conditioning of Heart Rate: Somatic Correlates

The relationships between heart rate (HR) and several parameters of somatic activity were evaluated in human subjects when shuck avoidance was made contingent on either increases or decreases in HR. In order to depict any influence of the contingency specific 10 HR, somatic activity was controlled to varying degrees by instructions and the use of non-contingent control groups. When increases in HR were reinforced, the contingency we found to influence somatic activity but an effect specific to HR was also observed. When decreases in HR were reinforced, there was no evidence that HR were influenced independently of somatic activity. The result are discussed with respect to several current issues.     

Postural destabilization induced by trunk extensor muscles fatigue is suppressed by use of a plantar pressure-based electro-tactile biofeedback

Separate studies have reported that postural control during quiet standing could be (1) impaired with muscle fatigue localized at the lower back, and (2) improved through the use of plantar pressure-based electro-tactile biofeedback, under normal neuromuscular state. The aim of this experiment was to investigate whether this biofeedback could reduce postural destabilization induced by trunk extensor muscles. Ten healthy adults were asked to stand as immobile as possible in four experimental conditions: (1) no fatigue/no biofeedback, (2) no fatigue/biofeedback, (3) fatigue/no biofeedback and (4) fatigue/biofeedback. Muscular fatigue was achieved by performing trunk repetitive extensions until maximal exhaustion. The underlying principle of the biofeedback consisted of providing supplementary information related to foot sole pressure distribution through electro-tactile stimulation of the tongue. Centre of foot pressure (CoP) displacements were recorded using a force platform. Results showed (1) increased CoP displacements along the antero-posterior axis in the fatigue than no fatigue condition in the absence of biofeedback and (2) no significant difference between the no fatigue and fatigue conditions in the presence of biofeedback. This suggests that subjects were able to efficiently integrate an artificial plantar pressure information delivered through electro-tactile stimulation of the tongue that allowed them to suppress the destabilizing effect induced by trunk extensor muscles fatigue.     

Controlling posture using a plantar pressure-based,tongue-placed tactile biofeedback system

The present paper introduces an original biofeedback system for improving human balance control, whose underlying principle consists in providing additional sensory information related to foot sole pressure distribution to the user through a tongue-placed tactile output device. To assess the effect of this biofeedback system on postural control during quiet standing, ten young healthy adults were asked to stand as immobile as possible with their eyes closed in two conditions of No-biofeedback and Biofeedback. Centre of foot pressure (CoP) displacements were recorded using a force platform. Results showed reduced CoP displacements in the Biofeedback relative to the No-biofeedback condition. The present findings evidenced the ability of the central nervous system to efficiently integrate an artificial plantar-based, tongue-placed tactile biofeedback for controlling control posture during quiet standing.     

The Effects of Feedback Sensory Modality, Feedback Information Content, and Sex on Short-Term Biofeedback Training of Three Responses

In three factorial experiments, auditory vs visual vs tactile feedback, analog feedback vs analog feedback which was anchored, and sex, were varied to assess the effects of these variables on performance in short-term biofeedback training of heart rate reduction, hand temperature increase, and forehead muscle tension reduction. A total of 108 subjects served in the study. Moderate but reliable changes were found during the course of the training session for all three physiological responses. The ability to reduce heart rate in a single training session did not appear to be a function of any of the variables manipulated in this study, but rather could be attributed to adaptation. In both muscle tension and temperature training, however, there were significant interactions between sex and sensory modality of the feedback stimulus and, in the case of muscle tension training, between information content of the feedback signal and sex. The overall pattern of results indicated that performance during biofeedback training is a complicated function of sex and the type of signal used to provide feedback, and that this function is not constant across physiological response systems.     

How a plantar pressure-based,tongue-placed tactile biofeedback modifies postural control mechanisms during quiet standing

The purpose of the present study was to determine the effects of a plantar pressure-based, tongue-placed tactile biofeedback on postural control mechanisms during quiet standing. To this aim, 16 young healthy adults were asked to stand as immobile as possible with their eyes closed in two conditions of No-biofeedback and Biofeedback. Centre of foot pressure (CoP) displacements, recorded using a force platform, were used to compute the horizontal displacements of the vertical projection of the centre of gravity (CoG _v ) and those of the difference between the CoP and the vertical projection of the CoG (CoP-CoG _v ). Analysis of the CoP-CoG _v displacements showed larger root mean square (RMS) and mean power frequencies (MPF) in the Biofeedback than in the No-biofeedback condition. Stabilogram-diffusion analysis further showed a concomitant increased spatial and reduced temporal transition point co-ordinates at which the corrective processes were initiated and an increased persistent behaviour of the CoP-CoG _v displacements over the short-term region. Analysis of the CoG _v displacements showed decreased RMS and increased MPF in the Biofeedback relative to the No-biofeedback condition. Stabilogram-diffusion analysis further indicated that these effects mainly stem from reduced spatio-temporal transition point co-ordinates at which the corrective process involving CoG _v displacements is initiated and an increased anti-persistent behaviour of the CoG _v displacements over the long-term region. Altogether, the present findings suggest that the main way the plantar pressure-based, tongue-placed tactile biofeedback improves postural control during quiet standing is via both a reduction of the correction thresholds and an increased efficiency of the corrective mechanism involving the CoG _v displacements.     

Technological adjuncts to enhance current psychotherapy practices: a review

Although there are several of reviews of technology in psychology, none to date has focused on technological adjuncts for improving traditional face to face therapy. However, examination of response, adherence, and dropout rates suggests there is considerable scope for improving traditional face to face services. The purpose of this paper was to examine technological adjuncts used to enhance psychotherapy practice. This review focused only on those technologies designed to supplement or enhance traditional therapy methods. Adjuncts designed to reduce direct therapist contact or change the medium of communication were not included. Adjuncts reviewed were mobile phones, personal digital assistants, biofeedback and virtual reality. Limitations in the current literature and directions for future research were identified and discussed. This review provides a comprehensive examination of the way in which adjunctive technologies may be incorporated into face to face therapy.     

Individual Differences in Ability to Control Heart Rate: Personality, Strategy, Physiological, and Other Variables

Three experiments (total N = 102) are reported which examined the relationship between individual differences in ability to control heart rate (HR) with feedback and differences in self-reported cognitive strategies, personality variables (locus of control, state and trait anxiety), physiological variables (respiration, somatic activity, basal HR and HR variability, and initial ability to control HR without feedback), and several auxiliary variables (e.g., weight, smoking, gender, exercise, and meditation). Two sets of analyses were performed. In the first set, differences in cognitive strategies and physiological concomitants between HR decrease and HR increase were studied revealing disparate patterns of cognitive strategies and physiological concomitants for the two directions of HR control. In the second set, the group of cognitive, strategy, personality, physiological, and auxiliary variables was searched to determine if any variables were related to individual differences in ability to decrease or increase HR. Cognitive strategies, personality, and auxiliary variables were generally unrelated to ability to control HR in either direction. Use of two cognitive strategies was found to be associated with lack of ability to increase HR, and non-smokers were better able to decrease HR. Strong relationships were found for somatic activity and ability to control HR without feedback, both of which successfully predicted differences in ability to decrease and increase HR with feedback. Implications of these findings for past and future studies of voluntary control of HR are discussed.