Positive Technology Journal

Effects of movement imagery and electromyography-triggered feedback on arm hand function in stroke patients in the subacute phase.

Clin Rehabil. 2007 Jul;21(7):587-94

Authors: Hemmen B, Seelen HA

OBJECTIVE: To investigate the effects of movement imagery-assisted electromyography (EMG)-triggered feedback (focused on paretic wrist dorsiflexors) on the arm-hand function of stroke patients. DESIGN: Single-blinded, longitudinal, multicentre randomized controlled trial. Measurements were performed (on average) 54 days post stroke (baseline), three months later (post training) and at 12 months post baseline. SETTING: Two rehabilitation centres. SUBJECTS: Twenty-seven patients with a first-ever, ischaemic, subacute stroke. INTERVENTIONS: A reference group received conventional electrostimulation, while the experimental group received arm-hand function training based on EMG-triggered feedback combined with movement imagery. Both groups were trained for three months, 5 days/week, 30 minutes/day, in addition to their therapy as usual. MAIN MEASURES: Arm-hand function was evaluated using the upper extremity-related part of the Brunnstrom Fugl-Meyer test and the Action Research Arm test. RESULTS: During training, Brunnstrom Fugl-Meyer scores improved 8.7 points and Action Research Arm scores by 19.4 points (P < 0.0001) in both groups relative to baseline results, rising to 13.3 and 28.4 points respectively at one year follow-up (P < 0.0001). No between-group differences were found at any time. CONCLUSIONS: EMG-triggered feedback stimulation did not lead to more arm-hand function improvement relative to conventional electrostimulation. However, in contrast to many clinical reports, a significant improvement was still observed in both groups nine months after treatment ceased.

A brain-computer interface with vibrotactile biofeedback for haptic information.

J Neuroengineering Rehabil. 2007 Oct 17;4(1):40

Authors: Chatterjee A, Aggarwal V, Ramos A, Acharya S, Thakor NV

ABSTRACT: BACKGROUND: It has been suggested that Brain-Computer Interfaces (BCI) may one day be suitable for controlling a neuroprosthesis. For closed-loop operation of BCI, a tactile feedback channel that is compatible with neuroprosthetic applications is desired. Operation of an EEG-based BCI using only vibrotactile feedback, a commonly used method to convey haptic senses of contact and pressure, is demonstrated with a high level of accuracy. METHODS: A Mu-rhythm based BCI using a motor imagery paradigm was used to control the position of a virtual cursor. The cursor position was shown visually as well as transmitted haptically by modulating the intensity of a vibrotactile stimulus to the upper limb. A total of six subjects operated the BCI in a two-stage targeting task, receiving only vibrotactile biofeedback of performance. The location of the vibration was also systematically varied between the left and right arms to investigate location-dependent effects on performance. RESULTS AND CONCLUSIONS: Subjects are able to control the BCI using only vibrotactile feedback with an average accuracy of 56% and as high as 72%. These accuracies are significantly higher than the 15% predicted by random chance if the subject had no voluntary control of their Mu-rhythm. The results of this study demonstrate that vibrotactile feedback is an effective biofeedback modality to operate a BCI using motor imagery. In addition, the study shows that placement of the vibrotactile stimulation on the biceps ipsilateral or contralateral to the motor imagery introduces a significant bias in the BCI accuracy. This bias is consistent with a drop in performance generated by stimulation of the contralateral limb. Users demonstrated the capability to overcome this bias with training.

Novel Design of Interactive Multimodal Biofeedback System for Neurorehabilitation.

Conf Proc IEEE Eng Med Biol Soc. 2006;1:4925-4928

Authors: Huang H, Chen Y, Xu W, Sundaram H, Olson L, Ingalls T, Rikakis T, He J

A previous design of a biofeedback system for Neurorehabilitation in an interactive multimodal environment has demonstrated the potential of engaging stroke patients in task-oriented neuromotor rehabilitation. This report explores the new concept and alternative designs of multimedia based biofeedback systems. In this system, the new interactive multimodal environment was constructed with abstract presentation of movement parameters. Scenery images or pictures and their clarity and orientation are used to reflect the arm movement and relative position to the target instead of the animated arm. The multiple biofeedback parameters were classified into different hierarchical levels w.r.t. importance of each movement parameter to performance. A new quantified measurement for these parameters were developed to assess the patient's performance both real-time and offline. These parameters were represented by combined visual and auditory presentations with various distinct music instruments. Overall, the objective of newly designed system is to explore what information and how to feedback information in interactive virtual environment could enhance the sensorimotor integration that may facilitate the efficient design and application of virtual environment based therapeutic intervention.

Effects of electromyography biofeedback-assisted relaxation on pain in patients with advanced cancer in a palliative care unit.

Cancer Nurs. 2007 Sep-Oct;30(5):347-53

Authors: Tsai PS, Chen PL, Lai YL, Lee MB, Lin CC

Most patients with advanced cancer experience pain. However, many cancer patients do not find satisfaction with conventional treatment of pain relief. This study examined the effect of electromyography (EMG) biofeedback-assisted relaxation on cancer-related pain in advanced cancer patients. We hypothesized that changes in EMG activity in frontal muscles underlie the efficacy of EMG biofeedback-assisted relaxation. This was a randomized control study. The experimental group (n = 12) received 6 EMG biofeedback-assisted relaxation sessions over a 4-week period, whereas the control group (n = 12) received conventional care. The primary efficacy measure was the level of pain, measured by the Brief Pain Inventory. Findings from this study show that relaxation training supplemented with visual and auditory EMG biofeedback signals is effective in reducing cancer-related pain in advanced cancer patients, possibly through a mechanism of attenuation of physiological arousal. Electromyography biofeedback-assisted relaxation training may be used along with medications for effective pain management in patients with advanced cancer.

Controlled evaluation of a neurofeedback training of slow cortical potentials in children with Attention Deficit/Hyperactivity Disorder (ADHD).

Behav Brain Funct. 2007 Jul 26;3(1):35

Authors: Drechsler R, Straub M, Doehnert M, Heinrich H, Steinhausen HC, Brandeis D

ABSTRACT: BACKGROUND: Although several promising studies on neurofeedback training in Attention Deficit/Hyperactivity Disorder (ADHD) have been performed in recent years, the specificity of positive treatment effects continues to be challenged. METHODS: To evaluate the specificity of a neurofeedback training of slow cortical potentials, a twofold strategy was pursued: First, the efficacy of neurofeedback training was compared to a group training program for children with ADHD. Secondly, the extent of improvements observed in the neurofeedback group in relation to successful regulation of cortical activation was examined. Parents and teachers rated children's behaviour and executive functions before and after treatment. In addition, children underwent neuropsychological testing before and after training. RESULTS: According to parents' and teachers' ratings, children of the neurofeedback training group improved more than children who had participated in a group therapy program, particularly in attention and cognition related domains. On neuropsychological measures children of both groups showed similar improvements. However, only about half of the neurofeedback group learned to regulate cortical activation during a transfer condition without direct feedback. Behavioural improvements of this subgroup were moderately related to neurofeedback training performance, whereas effective parental support accounted better for some advantages of neurofeedback training compared to group therapy according to parents' and teachers' ratings. CONCLUSIONS: There is a specific training effect of neurofeedback of slow cortical potentials due to enhanced cortical control. However, non-specific factors, such as parental support, may also contribute to the positive behavioural effects induced by the neurofeedback training.

Cortical activation changes induced by visual biofeedback tracking training in chronic stroke patients.

NeuroRehabilitation. 2007;22(2):77-84

Authors: Cho SH, Shin HK, Kwon YH, Lee MY, Lee YH, Lee CH, Yang DS, Jang SH

Objectives: We tried to examine whether visual biofeedback tracking training (VBTT) can improve both the gait performance and cortical activation pattern in chronic stroke patients. Design: We enrolled 10 chronic hemiparetic patients with stroke(mean age 46.3 +/- 5.19 years). The patients were randomly assigned to the training group (5 patients) or the control group (5 patients). VBTT was to follow the PC-generated sine waves with the knee joint electrogoniometer, and the two sine waves should appear as close to overlapping as possible on the PC monitor. The training was performed for 39 minutes/day, 5 days/week, for 4 weeks. Pre-training and post-training accuracy of tracking, functional status of gait, and functional MRI (fMRI) were measured. fMRI was performed at 1.5 T in parallel with timed knee flexion-extension movements at a fixed rate. Results: The accuracy of the tracking performance, walking speed, and motor scale for gait improved in the training group. Primary sensorimotor cortex (SM1) cortical activation shifted significantly from the unaffected to the affected hemisphere in the training group. Conclusions: We demonstrated that cortical activation changes occurred with gait function improvement in chronic stroke patients throughout the 4-week VBTT program. It seems that the cortical reorganization was induced by VBTT.

Direct instrumental conditioning of neural activity using functional magnetic resonance imaging-derived reward feedback.

J Neurosci. 2007 Jul 11;27(28):7498-507

Authors: Bray S, Shimojo S, O'Doherty JP

EEG biofeedback in the treatment of attention deficit hyperactivity disorder.

Altern Med Rev. 2007 Jun;12(2):146-151

Authors: Friel PN

The effects of neurofeedback training in the cognitive division of the anterior cingulate gyrus.

Int J Neurosci. 2007 Mar;117(3):337-57

Authors: Cannon R, Lubar J, Congedo M, Thornton K, Towler K, Hutchens T

This study examines the efficacy of neurofeedback training in the cognitive division of the anterior cingulate gyrus and describes its relationship with cortical regions known to be involved in executive functions. This study was conducted with eight non-clinical students, four male and four female, with a mean age of twenty-two. Learning occurred in the ACcd at significant levels over sessions and in the anterior regions that receive projections from the AC. There appears to be a multidimensional executive circuit that increases in the same frequency in apparent synchrony with the AC and it may be possible to train this sub-cortical region using LNFB.

Are complex psychotherapies more effective than biofeedback, progressive muscle relaxation, or both? A meta-analysis.

Psychol Rep. 2007 Feb;100(1):303-24

Authors: Stevens SE, Hynan MT, Allen M, Braun MM, McCart MR

A meta-analysis of 26 studies was conducted to assess whether more complex forms of psychotherapy would be superior to control treatments of either biofeedback, progressive muscle relaxation, or both. Consistent with hypotheses, more complex treatments provided a small, significant improvement over biofeedback and progressive muscle relaxation (r = .09). A subset of the more complex behavioral treatments accounted for most of this small incremental effectiveness of more complex treatments (r = .15). Possible sources of this incremental effectiveness are discussed.

Brain potentials associated with outcome expectation and outcome evaluation.

Neuroreport. 2006 Oct 23;17(15):1649-53

Authors: Yu R, Zhou X

Feedback-related negativity is a negative deflection in brain potentials associated with feedback indicating monetary losses or response errors. Feedback-related negativity is studied primarily in paradigms in which participants experience negative outcomes that appear to be contingent upon their previous choices. This study investigated whether feedback-related negativity can be elicited by a randomly assigned cue indicating potential monetary loss. The expected loss or win can be materialized or averted depending on participants' performance in a subsequent game. Compared with the win cue, the loss cue elicited a weak but significant feedback-related negativity-like effect. It is suggested that the anterior cingulate cortex, which generates feedback-related negativity, may function as a pre-warning system that alerts the brain to get ready for future events.

Annotation: neurofeedback - train your brain to train behaviour.

J Child Psychol Psychiatry. 2007 Jan;48(1):3-16

Authors: Heinrich H, Gevensleben H, Strehl U

BACKGROUND: Neurofeedback (NF) is a form of behavioural training aimed at developing skills for self-regulation of brain activity. Within the past decade, several NF studies have been published that tend to overcome the methodological shortcomings of earlier studies. This annotation describes the methodical basis of NF and reviews the evidence base for its clinical efficacy and effectiveness in neuropsychiatric disorders. METHODS: In NF training, self-regulation of specific aspects of electrical brain activity is acquired by means of immediate feedback and positive reinforcement. In frequency training, activity in different EEG frequency bands has to be decreased or increased. Training of slow cortical potentials (SCPs) addresses the regulation of cortical excitability. RESULTS: NF studies revealed paradigm-specific effects on, e.g., attention and memory processes and performance improvements in real-life conditions, in healthy subjects as well as in patients. In several studies it was shown that children with attention-deficit hyperactivity disorder (ADHD) improved behavioural and cognitive variables after frequency (e.g., theta/beta) training or SCP training. Neurophysiological effects could also be measured. However, specific and unspecific training effects could not be disentangled in these studies. For drug-resistant patients with epilepsy, significant and long-lasting decreases of seizure frequency and intensity through SCP training were documented in a series of studies. For other child psychiatric disorders (e.g., tic disorders, anxiety, and autism) only preliminary investigations are available. CONCLUSIONS: There is growing evidence for NF as a valuable treatment module in neuropsychiatric disorders. Further, controlled studies are necessary to establish clinical efficacy and effectiveness and to learn more about the mechanisms underlying successful training.

EEG neurofeedback: a brief overview and an example of peak alpha frequency training for cognitive enhancement in the elderly.

Clin Neuropsychol. 2007 Jan;21(1):110-29

Authors: Angelakis E, Stathopoulou S, Frymiare JL, Green DL, Lubar JF, Kounios J

Neurofeedback (NF) is an electroencephalographic (EEG) biofeedback technique for training individuals to alter their brain activity via operant conditioning. Research has shown that NF helps reduce symptoms of several neurological and psychiatric disorders, with ongoing research currently investigating applications to other disorders and to the enhancement of non-disordered cognition. The present article briefly reviews the fundamentals and current status of NF therapy and research and illustrates the basic approach with an interim report on a pilot study aimed at developing a new NF protocol for improving cognitive function in the elderly. EEG peak alpha frequency (PAF) has been shown to correlate positively with cognitive performance and to correlate negatively with age after childhood. The present pilot study used a double-blind controlled design to investigate whether training older individuals to increase PAF would result in improved cognitive performance. The results suggested that PAF NF improved cognitive processing speed and executive function, but that it had no clear effect on memory. In sum, the results suggest that the PAF NF protocol is a promising technique for improving selected cognitive functions.

Neurofeedback for Children with ADHD: A Comparison of SCP and Theta/Beta Protocols.

Appl Psychophysiol Biofeedback. 2007 Mar 14;

Authors: Leins U, Goth G, Hinterberger T, Klinger C, Rumpf N, Strehl U

Behavioral and cognitive improvements in children with ADHD have been consistently reported after neurofeedback-treatment. However, neurofeedback has not been commonly accepted as a treatment for ADHD. This study addresses previous methodological shortcomings while comparing a neurofeedback-training of Theta-Beta frequencies and training of slow cortical potentials (SCPs). The study aimed at answering (a) whether patients were able to demonstrate learning of cortical self-regulation, (b) if treatment leads to an improvement in cognition and behavior and (c) if the two experimental groups differ in cognitive and behavioral outcome variables. SCP participants were trained to produce positive and negative SCP-shifts while the Theta/Beta participants were trained to suppress Theta (4-8 Hz) while increasing Beta (12-20 Hz). Participants were blind to group assignment. Assessment included potentially confounding variables. Each group was comprised of 19 children with ADHD (aged 8-13 years). The treatment procedure consisted of three phases of 10 sessions each. Both groups were able to intentionally regulate cortical activity and improved in attention and IQ. Parents and teachers reported significant behavioral and cognitive improvements. Clinical effects for both groups remained stable six months after treatment. Groups did not differ in behavioural or cognitive outcome.

Preliminary Results of an Open Label Study of Heart Rate Variability Biofeedback for the Treatment of Major Depression.

Appl Psychophysiol Biofeedback. 2007 Mar 1;

Authors: Karavidas MK, Lehrer PM, Vaschillo E, Vaschillo B, Marin H, Buyske S, Malinovsky I, Radvanski D, Hassett A

Major depressive disorder (MDD) is a common mood disorder that can result in significant discomfort as well as interpersonal and functional disability. A growing body of research indicates that autonomic function is altered in depression, as evidenced by impaired baroreflex sensitivity, changes in heart rate, and reduced heart rate variability (HRV). Decreased vagal activity and increased sympathetic arousal have been proposed as major contributors to the increased risk of cardiovascular mortality in participants with MDD, and baroreflex gain is decreased. Study objectives: To assess the feasibility of using HRV biofeedback to treat major depression. Design: This was an open-label study in which all eleven participants received the treatment condition. Participants attended 10 weekly sessions. Questionnaires and physiological data were collected in an orientation (baseline) session and Treatment Sessions 1, 4, 7 and 10. Measurements and results: Significant improvements were noted in the Hamilton Depression Scale (HAM-D) and the Beck Depression Inventory (BDI-II) by Session 4, with concurrent increases in SDNN, standard deviation of normal cardiac interbeat intervals) an electrocardiographic estimate of overall measure of adaptability. SDNN decreased to baseline levels at the end of treatment and at follow-up, but clinically and statistically significant improvement in depression persisted. Main effects for task and session occurred for low frequency range (LF) and SDNN. Increases in these variables also occurred during breathing at one's resonant frequency, which targets baroreflex function and vagus nerve activity, showing that subjects performed the task correctly Conclusions: HRV biofeedback appears to be a useful adjunctive treatment for the treatment of MDD, associated with large acute increases in HRV and some chronic increases, suggesting increased cardiovagal activity. It is possible that regular exercise of homeostatic reflexes helps depression even when changes in baseline HRV are smaller. A randomized controlled trial is warranted.

From diagnostics to therapy-conceptual basis for real-time movement feedback in rehabilitation medicine.

Biomed Tech (Berl). 2006;51(5-6):299-304

Authors: Schablowski-Trautmann M, Kögel M, Rupp R, Mikut R, Gerner HJ

Recently, locomotion therapy on a treadmill has become part of rehabilitation programs for neurological gait disorders (spinal cord injury, hemiplegia). Instrumental gait analysis is an important tool for quantification of therapy progress in terms of functional changes in a patient's gait patterns. Whereas most of current applications focus on diagnostic assessment of gait, the current paper presents an extension of movement analysis offering enhanced therapeutic options. Specifically, the conceptual basis for application of real-time movement feedback in rehabilitation medicine is outlined and is put into context with recent developments in the field. A first technical realization of these concepts is presented and first results are reported. Furthermore, open questions towards a universal environment for movement feedback in rehabilitation medicine are discussed and future lines of research are identified.

Validating the efficacy of neurofeedback for optimising performance.

Prog Brain Res. 2006;159:421-31

Authors: Gruzelier J, Egner T, Vernon D

The field of neurofeedback training has largely proceeded without validation. Here we review our studies directed at validating SMR, beta and alpha-theta protocols for improving attention, memory, mood and music and dance performance in healthy participants. Important benefits were demonstrable with cognitive and neurophysiological measures which were predicted on the basis of regression models of learning. These are initial steps in providing a much needed scientific basis to neurofeedback, but much remains to be done.

Annotation: Neurofeedback - train your brain to train behaviour.

J Child Psychol Psychiatry. 2007 Jan;48(1):3-16

Authors: Heinrich H, Gevensleben H, Strehl U

Background: Neurofeedback (NF) is a form of behavioural training aimed at developing skills for self-regulation of brain activity. Within the past decade, several NF studies have been published that tend to overcome the methodological shortcomings of earlier studies. This annotation describes the methodical basis of NF and reviews the evidence base for its clinical efficacy and effectiveness in neuropsychiatric disorders. Methods: In NF training, self-regulation of specific aspects of electrical brain activity is acquired by means of immediate feedback and positive reinforcement. In frequency training, activity in different EEG frequency bands has to be decreased or increased. Training of slow cortical potentials (SCPs) addresses the regulation of cortical excitability. Results: NF studies revealed paradigm-specific effects on, e.g., attention and memory processes and performance improvements in real-life conditions, in healthy subjects as well as in patients. In several studies it was shown that children with attention-deficit hyperactivity disorder (ADHD) improved behavioural and cognitive variables after frequency (e.g., theta/beta) training or SCP training. Neurophysiological effects could also be measured. However, specific and unspecific training effects could not be disentangled in these studies. For drug-resistant patients with epilepsy, significant and long-lasting decreases of seizure frequency and intensity through SCP training were documented in a series of studies. For other child psychiatric disorders (e.g., tic disorders, anxiety, and autism) only preliminary investigations are available. Conclusions: There is growing evidence for NF as a valuable treatment module in neuropsychiatric disorders. Further, controlled studies are necessary to establish clinical efficacy and effectiveness and to learn more about the mechanisms underlying successful training.

Biofeedback for robotic gait rehabilitation

Journal of NeuroEngineering and Rehabilitation

By Lars Lunenburger, Gery Colombo and Robert Riener

The significance of sigma neurofeedback training on sleep spindles and aspects of declarative memory.

Appl Psychophysiol Biofeedback. 2006 Jun;31(2):97-114

Authors: Berner I, Schabus M, Wienerroither T, Klimesch W

The functional significance of sleep spindles for overnight memory consolidation and general learning aptitude as well as the effect of four 10-minute sessions of spindle frequency (11.6-16 Hz, sigma) neurofeedback-training on subsequent sleep spindle activity and overnight performance change was investigated. Before sleep, subjects were trained on a paired-associate word list task after having received either neurofeedback training (NFT) or pseudofeedback training (PFT).Although NFT had no significant impact on subsequent spindle activity and behavioral outcomes, there was a trend for enhanced sigma band-power during NREM (stage 2 to 4) sleep after NFT as compared to PFT. Furthermore, a significant positive correlation between spindle activity during slow wave sleep (in the first night half) and overall memory performance was revealed. The results support the view that the considerable inter-individual variance in sleep spindle activity can at least be partly explained by differences in the ability to acquire new declarative information.We conclude that the short NFT before sleep was not sufficient to efficiently enhance phasic spindle activity and/or to influence memory processing. NFT was, however, successful in increasing sigma power, presumably because sigma NFT effects become more easily evident in actually trained frequency bands than in associated phasic spindle activity.