Auditory Biofeedback Training Research Articles

Assessment of the Acute Effects of Wearable Sensor Derived Auditory Biofeedback on Gross Lumbar Proprioception

Lower back disorders (LBDs) affect a large proportion of the population, and treatment for LBDs have been shifting toward individualized, patient-centered approaches. LBDs are typically associated with poor proprioception. Therefore, there has been a recent uptake in the utilization of wearable sensors that can administer biofeedback in various industrial, clinical, and performance-based settings to improve lumbar proprioception. The aim of this study was to investigate whether wearable sensor-derived acute auditory biofeedback can be used to improve measures of gross lumbar proprioception. To assess this, healthy participants completed an active target repositioning protocol, followed by a training period where lumbar-spine posture referenced auditory feedback was provided for select targets. Target re-matching abilities were captured before and after acute auditory biofeedback training to extract measures related to accuracy and precision across spine flexion targets (i.e., 20%, 40%, 60%, 80% maximum). Results suggest a heterogenous response to proprioceptive training whereby certain individuals and spine flexion targets experienced positive effects (i.e., improved accuracy and precision). Specifically, results suggest that mid-range flexion targets (i.e., 40-60% maximum flexion) benefited most from the acute auditory feedback training. Further, individuals with poorer repositioning abilities in the pre-training assessment showed the greatest improvements from the auditory feedback training.

Within-session and between-session effects of auditory biofeedback training on center of pressure location during gait in patients with chronic ankle instability

ObjectivesTo establish preliminary gait training dosage parameters for patients with chronic ankle instability (CAI) by determining the within-session and between-session effects of auditory biofeedback training on center of pressure (COP) location during gait. DesignObservational Longitudinal. SettingLaboratory. Participants19 participants with CAI, 8 participants who did not receive auditory biofeedback (NoFeedback group) and 11 participants who did receive auditory biofeedback (AuditoryFeedback group) over an 8-session 2-week intervention. Main outcome measuresCOP location was measured at the start and at each 5-min interval during treadmill walking across all eight 30-min training sessions. ResultsThe AuditoryFeedback group had significant within-session lateral-to-medial shifts in COP location during only session-1 at the 15-min (45% of stance; peak mean difference = 4.6 mm), 20-min (35% and 45%; 4.2 mm), and 30-min time intervals (35% and 45%; 4.1 mm). Furthermore, the AuditoryFeedback group had significant between-session lateral-to-medial shifts in COP location at session-5 (35–55% of stance; 4.2 mm), session-7 (35%–95%; 6.7 mm), and session-8 (35%–95%; 7.7 mm). The NoFeedback group had no significant changes in COP location within-sessions or between-sessions. ConclusionsParticipants with CAI who received auditory biofeedback during gait needed an average of 15-min during session-1 to meaningfully shift their COP location medially and 4-sessions before retaining the adapted gait pattern.

Motor learning on postural control using auditory biofeedback training

Motor disorders are characterised by damage to the central nervous system, which subsequently affects muscles, motor skills and brain function. People with motor disorders can suffer injury as a result of falls and recovery from falls can be challenging. Augmented biofeedback modalities is an important tool used in physical therapy, providing individuals with biofeedback that helps guide them through the therapy. Biofeedback modalities have been designed for most of our senses, including auditory, visual and haptic and advances in technology have meant that biofeedback therapy can make use of wearable technology and future advances are expected to further assist. Therefore, it will be key to determine which biofeedback method works best for different training exercises and conditions in order to maximise the benefits of technological advances. Dr Naoya Hasegawa and Professor Tadayoshi Asaka are investigating which biofeedback method works best for different therapies. Their goal is to understand the characteristics of sensory modalities used for biofeedback training in order to help physical therapists determine appropriate approaches for different individuals. The researchers are currently investigating postural control with a view to defining the characteristics of postural control during walking and standing and developing new methods to enhance or improve it. This work involves the use of force plates, 3D motion analysis systems and electromyograms.

Changing accommodation behaviour during multifocal soft contact lens wear using auditory biofeedback training

Biofeedback training has been used to access autonomically-controlled body functions through visual or acoustic signals to manage conditions like anxiety and hyperactivity. Here we examined the use of auditory biofeedback to improve accommodative responses to near visual stimuli in patients wearing single vision (SV) and multifocal soft contact lenses (MFCL). MFCLs are one evidence-based treatment shown to be effective in slowing myopia progression in children. However, previous research found that the positive addition relaxed accommodation at near, possibly reducing the therapeutic benefit. Accommodation accuracy was examined in 18 emmetropes and 19 myopes while wearing SVCLs and MFCLs (centre-distance). Short periods of auditory biofeedback training to improve the response (reduce the lag of accommodation) was performed and accommodation re-assessed while patients wore the SVCLs and MFCLs. Significantly larger accommodative lags were measured with MFCLs compared to SV. Biofeedback training effectively reduced the lag by ≥0.3D in individuals of both groups with SVCL and MFCL wear. The training was more effective in myopes wearing their habitual SVCLs. This study shows that accommodation can be changed with short biofeedback training independent of the refractive state. With this proof-of-concept, we hypothesize that biofeedback training in myopic children wearing MFCLs might improve the treatment effectiveness.

Learning effects of dynamic postural control by auditory biofeedback versus visual biofeedback training

Augmented sensory biofeedback (BF) for postural control is widely used to improve postural stability. However, the effective sensory information in BF systems of motor learning for postural control is still unknown. The purpose of this study was to investigate the learning effects of visual versus auditory BF training in dynamic postural control. Eighteen healthy young adults were randomly divided into two groups (visual BF and auditory BF). In test sessions, participants were asked to bring the real-time center of pressure (COP) in line with a hidden target by body sway in the sagittal plane. The target moved in seven cycles of sine curves at 0.23Hz in the vertical direction on a monitor. In training sessions, the visual and auditory BF groups were required to change the magnitude of a visual circle and a sound, respectively, according to the distance between the COP and target in order to reach the target. The perceptual magnitudes of visual and auditory BF were equalized according to Stevens’ power law. At the retention test, the auditory but not visual BF group demonstrated decreased postural performance errors in both the spatial and temporal parameters under the no-feedback condition. These findings suggest that visual BF increases the dependence on visual information to control postural performance, while auditory BF may enhance the integration of the proprioceptive sensory system, which contributes to motor learning without BF. These results suggest that auditory BF training improves motor learning of dynamic postural control.

The Effects of Auditory Biofeedback Training and Kicking Training on Walking Speeds in Patients with Hemiplegia

The Effects of Auditory Biofeedback Training and Kicking Training on Walking Speeds in Patients with Hemiplegia

Plasticity of fixation in patients with central vision loss

The aim of this study was to explore the plasticity of fixation in patients with central vision loss. Most of these patients use preferred retinal loci (PRLs) in the healthy eccentric part of the retina to fixate, but fixation stability and retinal location are not always optimal for best visual performance. This study examined whether fixation stability and a new PRL location can be trained and whether these changes in ocular motor control transfer into better reading performance. Six patients with age-related macular degeneration participated in the study. Fixation stability measurements, microperimetry, and auditory biofeedback training were performed with the MP-1 microperimeter. The auditory biofeedback was used during five 1-h long training sessions to improve fixation and relocate the PRL. Fixation location and stability were recorded while viewing four different targets: a cross, a letter, a word, and a nine-cycle radial grating. Visual acuity was assessed with the Early Treatment Diabetic Retinopathy Study (ETDRS) chart and reading performance with the MNRead test. The results showed that all patients developed a new PRL in an optimal location for reading, and they were able to use it consistently while viewing different targets. Fixation stability improved 53% after training. Learning transferred to the old PRL even though fixation stability at this location was not trained. All these improvements in ocular motor control translated into better reading performance: reading speed improved 38% and reading acuity and critical print size gained two lines. We conclude that the ability of the ocular motor system to fixate is flexible in patients with central vision loss: a new PRL can be trained, fixation stability can be improved, and learning transfers to an untrained location. These gains in ocular motor control result in better visual performance. This property can be successfully used to optimize the residual vision of patients with central vision loss.

COVARIATION OF SPECTRAL AND NONLINEAR EEG MEASURES WITH ALPHA BIOFEEDBACK

This study investigated how different spectral and nonlinear EEG measures covaried with alpha power during auditory alpha biofeedback training, performed by 13 healthy subjects. We found a significant positive correlation of alpha power with the largest Lyapunov-exponent, pointing to an increased dynamical instability of the EEG accompanying alpha enhancement. Alpha power amplification, moreover, was significantly correlated with a decrease of spectral entropy within the alpha range. This outcome reflects a sharpening of the alpha peak during biofeedback training. The fact that the sharpening effect clearly preceded the increase of alpha amplitude could be exploited in future biofeedback settings.

Changes in Myopia, Visual Acuity, and Psychological Distress after Biofeedback Visual Training

The effects of auditory biofeedback training on myopia, visual acuity (VA), and psychological distress were evaluated in a controlled prospective study involving 55 mildly myopic (< or = -3.5 D) high school students. These myopes were divided into 2 groups, matched for age and dioptric defect: 33 were treated with visual training and 22 were not; 27 emmetropic subjects formed a further control group. Subjects were evaluated at the baseline (T0), at 10 weeks after the end of the treatment (T1), and after an interval of 12 months (T2) from the baseline for: (1) manifest and cycloplegic refraction, and the difference between them (cycloplegic tonus); (2) VA measured with a conventional optotype in all subjects, and also with a computer-generated optotype in the treated group; and (3) psychometric values and personality profile. At T2, myopia had significantly worsened both in the treated and in the control myopes; VA in the treated myopes appeared significantly improved when measured by the conventional optotype, but unchanged when measured by computer. Psychometric scores improved significantly in the treated myopes and in the emmetropic controls. Objectively the autorefractometer showed that 38% of the myopes had voluntary control of positive accommodation, i.e., the ability to increase spherical defect; no voluntary control of negative accommodation was observed. An increase in VA was associated with a significant increase in the foveation time (i.e., the period of time when the target is imaged on the fovea and the eye is motionless), and was partly attributable to a learning effect. In conclusion, biofeedback visual training had a positive effect on psychological distress and subjective VA improvement, but failed to reduce the existing myopia or delay its evolution.

CONTROL OF THE RATIO OF MIDLINE PARIETAL TO MIDLINE FRONTAL EEC ALPHA RHYTHMS THROUGH AUDITORY FEEDBACK

Summary.-The study asks whether voluntary control over the relative appearance of EEG alpha in midline frontal and parietal sites can be achieved with auditory biofeedback training. 16 Ss participated in the training and testing regimen. Ss varied in the number of hour-long single-channel feedback training sessions received. In the test period, dual-channel feedback was given, and Ss were asked to increase the ratio of frontal to parietal alpha and then the reverse. Evidence for small bur significant control is presented. Amount of control was correlated with number of practice sessions. In earlier research Kamiya ( 1962), Nowlis and Kamiya (1970), and

Control of the ratio of midline parietal to midline frontal EEG alpha rhythms through auditory feedback.

The study asks whether voluntary control over the relative appearance of EEG alpha in midline frontal and parietal sites can be achieved with auditory biofeedback training. 16 Ss participated in the training and testing regimen. Ss varied in the number of hour-long single-channel feedback training sessions received. In the test period, dual-channel feedback was given, and Ss were asked to increase the ratio of frontal to parietal alpha and then the reverse. Evidence for small but significant control is presented. Amount of control was correlated with number of practice sessions.