EEG Operant Conditioning Research Articles

Relative Power of Specific EEG Bands and Their Ratios during Neurofeedback Training in Children with Autism Spectrum Disorder.

Neurofeedback is a mode of treatment that is potentially useful for improving self-regulation skills in persons with autism spectrum disorder. We proposed that operant conditioning of EEG in neurofeedback mode can be accompanied by changes in the relative power of EEG bands. However, the details on the change of the relative power of EEG bands during neurofeedback training course in autism are not yet well explored. In this study, we analyzed the EEG recordings of children diagnosed with autism and enrolled in a prefrontal neurofeedback treatment course. The protocol used in this training was aimed at increasing the ability to focus attention, and the procedure represented the wide band EEG amplitude suppression training along with upregulation of the relative power of gamma activity. Quantitative EEG analysis was completed for each session of neurofeedback using wavelet transform to determine the relative power of gamma and theta/beta ratio, and further to detect the statistical changes within and between sessions. We found a linear decrease of theta/beta ratio and a liner increase of relative power of gamma activity over 18 weekly sessions of neurofeedback in 18 high functioning children with autism. The study indicates that neurofeedback is an effective method for altering EEG characteristics associated with the autism spectrum disorder. Also, it provides information about specific changes of EEG activities and details the correlation between changes of EEG and neurofeedback indexes during the course of neurofeedback. This pilot study contributes to the development of more effective approaches to EEG data analysis during prefrontal neurofeedback training in autism.

ELECTROENCEPHALOGRAPHIC BIOFEEDBACK IMPROVES FOCUSED ATTENTION IN ATTENTION DEFICIT/HYPERACTIVITY DISORDER

EEG biofeedback (so called neurofeedback) is considered as an efficacious treatment for ADHD. We propose that operant conditioning of EEG in neurofeedback training mode, aimed to mitigate inattention and low arousal in ADHD, will be accompanied by changes in EEG bands' relative power. Patients were 18 children diagnosed with ADHD. The neurofeedback protocol (“Focus/Alertness” by Peak Achievement Trainer, Neurotek, KY) used to train patients has focused attention training procedure, which according to specifications, represents wide band EEG amplitude suppression training. Quantitative EEG analysis was completed on each of 25 min long twelve sessions to determine the relative power of each of the EEG bands of interest throughout each session, and from the first session to the last session. Additional statistical analysis was performed to determine significant changes in relative power within sessions (from minute 1 to minute 25), and between sessions (from session 1 to session 12) for an individual patient. We performed analysis of relative power of Theta, Alpha, Low and High Beta, Theta/Alpha, Theta/Beta, and Theta/Low Beta and Theta/High Beta ratios. We performed also analysis between the “Focus”measure and changes in relative power of above EEG rhythms and their ratios. Additional secondary measures of patients’ post-neurofeedback outcomes were assessed using an audio-visual selective attention test (IVA + Plus) and behavioral evaluation scores from Aberrant Behavior Checklist. We found that, as expected, Theta/Low Beta and Theta/Alpha ratios decreased significantly from Session 1 to Session 12 and from minute 1 to minute 25 within sessions. The ‘Focus” measure of protocol showed high negative correlation with both Theta/Alpha and Theta/Beta ratios. The findings regarding EEG changes resulting from self-regulation training along with behavioral evaluations will help in elucidation of neural mechanisms of neurofeedback aimed to improve focused attention and alertness in ADHD.

The Effects of Neurofeedback in the Default Mode Network: Pilot Study Results of Medicated Children with ADHD

Children with attention deficit hyperactivity disorder (ADHD) have difficulty activating the Default Mode Network (DMN) in a resting or quiet state. The DMN function assists in processing and understanding a person's internal, reflective world and the world of self and others. Neurofeedback (NFB), a type of EEG operant conditioning, trains self-regulation skills using a brain–computer interface. The hardware and software have audio/video capabilities to correct irregular brainwave patterns and regional cerebral blood flow associated with mental health and cognitive concerns. Individual treatment sessions usually last approximately 20 min; to gain the largest overall treatment effect, NFB users need to experience about 30 to 40 sessions. This study randomly assigned 12 children diagnosed with ADHD and currently on a stimulant medication to a treatment or control group. Subjects in the treatment group completed 40 NFB sessions. Pre- and posttest fMRIs were administered on the treatment and control groups. E...

Biofeedback in the treatment of epilepsy

This review traces the application of electroencephalographic (EEG) operant conditioning, or biofeedback, from animal research to its emergence as an alternative treatment for the major types of seizure disorder. Initial animal studies focusing on brain mechanisms that mediate learned behavioral inhibition revealed a uniquely correlated 12- to 15-Hz EEG rhythm localized to sensorimotor cortex. We labeled this the sensorimotor rhythm, or SMR. The similarity of the SMR to the known EEG spindle pattern during quiet sleep led to the novel idea of attempting to increase the SMR using EEG operant conditioning. The hypothesis was that this might produce a corresponding increase in sleep spindle activity, thus establishing a common EEG marker for the state of motor inhibition. Results supported this hypothesis but led also to the accidental discovery of an anticonvulsant effect on drug-induced seizures in cats and monkeys. Continuing animal studies identified a pattern of neurophysiologic responses correlated with the SMR in primary motor pathways. These and other findings were indicative of reduced motor excitability. Simultaneously, we undertook studies in human epileptic subjects that documented a significant reduction in seizure incidence and severity, together with EEG pattern normalization. This work expanded internationally, resulting in numerous well-controlled group and single-case studies summarized in recent meta-analyses. Exciting new findings in functional neuroimaging/EEG correlation studies provide a rational model for the basis of these clinical effects. In recognition of the diversity of clinical applications of EEG biofeedback and the complexity of seizure disorders, this review also details specific methods used in our EEG biofeedback program.

Meta-Analysis of EEG Biofeedback in Treating Epilepsy

About one third of patients with epilepsy do not benefit from medical treatment. For these patients electroencephalographic (EEG) biofeedback is a viable alternative. EEG biofeedback, or neurofeedback, normalizes or enhances EEG activity by means of operant conditioning. While dozens of scientific reports have been published on neurofeedback for seizure disorder, most have been case series with too few subjects to establish efficacy. The purpose of this paper is to meta-analyze existing research on neurofeedback and epilepsy. We analyzed every EEG biofeedback study indexed in MedLine, PsychInfo, and PsychLit databases between 1970 and 2005 on epilepsy that provided seizure frequency change in response to feedback. Sixty-three studies have been published, 10 of which provided enough outcome information to be included in a meta-analysis. All studies consisted of patients whose seizures were not controlled by medical therapies, which is a very important factor to keep in mind when interpreting the results. Nine of 10 studies reinforced sensorimotor rhythms (SMR) while 1 study trained slow cortical potentials (SCP). All studies reported an overall mean decreased seizure incidence following treatment and 64 out of 87 patients (74%) reported fewer weekly seizures in response to EEG biofeedback. Treatment effect was mean log (post/pre) where pre and post represent number of seizures per week prior to treatment and at final evaluation, respectively. Due to prevalence of small groups, Hedges's g was computed for effect size. As sample heterogeneity was possible (Q test, p=.18), random effects were assumed and the effect of intervention was -0.233, SE = 0.057, z = -4.11, p<.001. Based on this meta-analysis, EEG operant conditioning was found to produce a significant reduction on seizure frequency. This finding is especially noteworthy given the patient group, individuals who had been unable to control their seizures with medical treatment.

Foundation and Practice of Neurofeedback for the Treatment of Epilepsy

This review provides an updated overview of the neurophysiological rationale, basic and clinical research literature, and current methods of practice pertaining to clinical neurofeedback. It is based on documented findings, rational theory, and the research and clinical experience of the authors. While considering general issues of physiology, learning principles, and methodology, it focuses on the treatment of epilepsy with sensorimotor rhythm (SMR) training, arguably the best established clinical application of EEG operant conditioning. The basic research literature provides ample data to support a very detailed model of the neural generation of SMR, as well as the most likely candidate mechanism underlying its efficacy in clinical treatment. Further, while more controlled clinical trials would be desirable, a respectable literature supports the clinical utility of this alternative treatment for epilepsy. However, the skilled practice of clinical neurofeedback requires a solid understanding of the neurophysiology underlying EEG oscillation, operant learning principles and mechanisms, as well as an in-depth appreciation of the ins and outs of the various hardware/software equipment options open to the practitioner. It is suggested that the best clinical practice includes the systematic mapping of quantitative multi-electrode EEG measures against a normative database before and after treatment to guide the choice of treatment strategy and document progress towards EEG normalization. We conclude that the research literature reviewed in this article justifies the assertion that neurofeedback treatment of epilepsy/seizure disorders constitutes a well-founded and viable alternative to anticonvulsant pharmacotherapy.

An Open Clinical Trial Utilizing Real-Time EEG Operant Conditioning as an Adjunctive Therapy in the Treatment of Crack Cocaine Dependence

ABSTRACT This study investigated the treatment outcome of males dependent on crack cocaine participating in an inpatient treatment facility in which electroencephalographic operant conditioning training (EEG-OC) was added to the treatment protocol. Eighty-seven men were assessed twelve months after completion of the EEG portion of the program. Follow-up procedures of urinalyses, self-report measures, length of residence, and scores on a measure of depression were obtained and showed significant changes after treatment. The addition of EEG-OC to crack cocaine treatment regimens may promise to be an effective intervention for treating crack cocaine abuse and increasing treatment retention.

Neurotherapy with Adults

Several possible conceptualizations of neurotherapy are discussed: EEG operant conditioning; EEG homeostatic normalization; and utilization of EEG biofeedback as a means of accessing particular states of consciousness. Attention is given to how neurotherapy is actually done and when it may be a useful adjunct to psychological or medical therapies. Integration of neurotherapy with the larger framework of cognitive behavior therapy and the biopsychosocial model is discussed. Three case studies of adults involving the use of neurotherapy are described.

Quantitative EEG Assessment During Neuropsychological Task Performance in Adults with Attention Deficit Hyperactivity Disorder

This study evaluated the neuropsychological performance of adults with and without Attention Deficit Hyperactivity Disorder (ADHD) during the Paced Auditory Serial Addition Test (PASAT), Wisconsin Card Sorting Test: Computerized Version 3 (WCST), and the Integrated Visual and Auditory Continuous Performance Test (IVA). Quantitative electroencephalographic (QEEG) data were also collected during task performance to examine differences in cortical activity between groups and tasks. Results suggest that adults with ADHD demonstrated lower levels of performance on the PASAT and IVA, tasks that involve working memory and processing speed, and sustained attention, respectively. Adults with ADHD also had more upper alpha activity during the IVA. Lastly, for the ADHD group, an increased theta/beta ratio during the IVA was significantly related to poorer attentional performance. The current results support reinforcing specific types of cortical activity though EEG operant conditioning (neurofeedback) as a treatment option in adults with ADHD.

Neurofeedback in Psychological Practice.

Advances in technology occasionally allow for innovations in the practice of psychology. Neurofeedback is one such modality; in it, individuals learn to change patterns of brain waves through operant conditioning. Research shows that a number of neurological and psychological disorders can be characterized by distinctive EEG patterns and that neurofeedback may help clients to change those patterns. The evidence regarding neurofeedback’s efficacy for attention-deficit/hyperactivity disorder (ADHD), depression, and other disorders is reviewed. Using control group designs, four different research teams have found neurofeedback to be effective for ADHD participants; research on outcomes for other disorders is at a much more preliminary stage. Practicing psychologists are encouraged to explore the potential of this alternative and distinctly psychological modality. Neurofeedback, also known as EEG biofeedback or EEG operant conditioning, is an emerging modality with the potential of becoming an important part of effective psychological practice. Neurofeedback is a process whereby individuals learn to selfregulate their brain waves. Preliminary findings indicate that teaching individuals to alter electrocortical activity may have beneficial effects for attention-deficit/hyperactivity disorder (ADHD). Other research is ongoing to determine the effectiveness of neurofeedback for other disorders as well, including depression and schizophrenia. Its promise notwithstanding, neurofeedback has been virtually ignored by the mainstream investigators and clinicians. Even accounting for the absence of conclusive empirical efficacy, a process that combines two pillars of psychology— operant conditioning and brain function— deserves greater attention from the psychological community. With this article we hope to call attention to this modality by presenting some of the history and research pertaining to brain wave self-regulation.

EEG operant conditioning (biofeedback) and traumatic brain injury.

A review is presented of the currently sparse literature about EEG operant conditioning or biofeedback as a treatment to reduce symptomology and patient complaints following a traumatic brain injury. The paper also evaluates the general use of quantitative EEG (QEEG) to assess traumatic brain injury and to facilitate EEG biofeedback treatment. The use of an age matched reference normative QEEG database and QEEG discriminant function are presented as a method to evaluate the nature or neurological basis of a patient's complaints as well as to individualize an efficient and optimal feedback protocol and to help evaluate the efficacy of the biofeedback therapy. Univariate and multivariate statistical issues are discussed, different classes of experimental designs are described and then a "double blind" research study is proposed in an effort to encourage future research in the area of EEG biofeedback for the treatment and rehabilitation of traumatic brain injury.

Basic concepts and clinical findings in the treatment of seizure disorders with EEG operant conditioning.

Two issues concerning sensorimotor EEG operant conditioning, or biofeedback, as a therapeutic modality for the treatment of seizure disorders are the focus of this review. The first relates to the question of whether relevant physiological changes are associated with this procedure. This question is addressed through review of an extensive neurophysiological literature that is likely unfamiliar to many clinicians but that documents both immediate and sustained functional changes that are consistent with elevation of seizure thresholds. The second focuses on the clinical efficacy of this method and whether it should carry the designation of "experimental". This designation is challenged through an assessment of over 25 years of peer-reviewed research demonstrating impressive EEG and clinical results achieved with the most difficult subset of seizure patients.

Self-Regulation of the Brain and Behavior

I: Neurophysiological Mechanisms That Regulate Brain Potential Changes.- 1 Neuronal Mechanisms Underyling the Generation of Field Potentials.- 2 Electrogenesis of Slow Potentials of the Brain.- 3 Central Gating Mechanisms That Regulate Event-Related Potentials and Behavior.- II: Self-Regulation of EEG Frequency Bands and Its Application to the Treatment of Human Epilepsy.- Section A: EEG Frequency Bands.- 4 Classification and Overview of CNS Electrical Activity Tested on Operant Conditioning.- 5 Focused Arousal, 40-Hz EEG, and Dysfunction.- Section B: EEG Biofeedback in the Treatment of Epilepsy.- 6 Operant Conditioning of Single Neurons in Monkeys and Its Theoretical Application to EEG Operant Conditioning in Human Epilepsy.- 7 The Role of Sensorimotor Rhythmic EEG Activity in the Etiology and Treatment of Generalized Motor Seizures.- 8 Applications of Operant Conditioning of the EEG for the Management of Epileptic Seizures.- 9 Biofeedback Control in Epilepsy and Neuroses.- III: Operant Control of Event-Related and Slow Potentials of the Brain.- Introduction: Event-Related Brain Potentials.- The Editors.- Section A: Self-Regulation of Evoked Potentials.- 10 Biofeedback of Very Early Potentials from the Brain Stem.- 11 Operantly Controlled Somatosensory Brain Potentials: Specific Effects on Pain Processes.- 12 Operant Control of Evoked Potentials: Some Comments on the Learning Characteristics in Man and on the Conditioning of Subcortical Responses in the Curarized Rat.- Section B: Meaning and Regulation of Slow Brain Potentials.- 13 Performance Enhancements with Cortical Negative Slow Potential Shifts in Monkey and Human.- 14 Regulation of Slow Brain Potentials Affects Task Performance.- 15 Operant Control of Slow Brain Potentials: A Tool in the Investigation of the Potential's Meaning and Its Relation to Attentional Dysfunction.- IV: Theoretical Considerations and Models.- The Editors.- Section A: Subjective Experience and the Activation of CNS Activity.- 16 On the Relationships Among Subjective Experience, Behavior, and Physiological Activity in Biofeedback Learning.- 17 Dead Souls: Or Why the Neurobehavioral Science of Emotion Should Pay Attention to Cognitive Science.- 18 Goal-Directed Behavior and Self-Regulation in the Organism.- Section B: The Operant Approach and the Concept of Control in the Self-Regulation of the Brain.- 19 Concepts of Control in Biofeedback.- 20 Operant Mechanisms in Physiological Regulation.- References.- Author Index.

Quantitative analysis of training, sleep EEG and clinical response to EEG operant conditioning in epileptics

This report is a follow-up to a previous paper which described seizure rate changes with central cortical EEG feedback training in 8 poorly controlled epileptic subjects. Data examined here include associated training compliance and performance, sleep EEG spectra, clinical EEG and anticonvulsant blood levels. The study employed a double-crossover, single-blind ABA design applied to two subgroups of epileptic patients. Both groups had in common two training periods (A 1, A 2) in which either 12–15 c/sec (subgroup I, n = 4) or 18–23 c/sec (subgroup II, n = 4) was reinforced in the absence of 6–9 c/sec, movement or epileptiform discharge, and one training period (B) in which 6–9 c/sec was reinforced in the absence of 12–15 or 18–23 c/sec as well as movement and epileptiform discharge. Training periods occurred primarily in the home and lasted 3 months. Compliance with training instructions and response acquisition were demonstrated. Overall anticonvulsant blood levels were low and unrelated to EEG or seizure changes. Clinical EEG findings corresponded to sleep EEG and seizure rate outcomes. Power spectral analysis of sampled non-REM sleep from all-night EEG recordings obtained after each training phase indicated contingency specific changes which were limited to sensorimotor recordings in subgroup I and corresponded to the pattern of seizure rate changes in this group. EEG changes were also limited to sensorimotor cortex in subgroup II, but were linear and paralleled a progressive decrease in seizure rate. Both groups, however, showed the same pattern of EEG changes with seizure reductions; low and high frequencies were reduced and intermediate, rhythmic frequencies increased. Correlational analysis confirmed this relationship. The pattern, duration and topographic specificity of these changes suggested a normalization of sensorimotor EEG substrates related to the EEG feedback training.

EEG Operant Conditioning for Control of Epilepsy

We report the results of 23 severely epileptic patients who were given EEG feedback training. The paradigm reinforced the patients' 18 Hz activity over the scalp approximation of their focus while suppressing temporalis EMG and low frequency EEG activity. In contrast to other studies using EEG feedback, only 43% of patients showed significant changes in seizure occurrence and a lesser number were felt to have benefited clinically. None of our neuropsychological test parameters were helpful in identifying (prospectively or retrospectively) patients most likely to respond to this treatment. Although a few patients were significantly helped by this training, the mechanism for this effect is unclear.

Effects of sensorimotor EEG feedback training on seizure susceptibility in the rhesus monkey

As a follow-up to previous EEG operant conditioning studies in cats both EEG response acquisition and subsequent seizure susceptibility were evaluated in the rhesus monkey. Two groups of four animals each were challenged with a convulsive dose of monomethylhydrazine and both prodrome and seizure characteristics documented with video and polygraphic recordings. One group had previously received 12 weeks of EEG feedback training with food reward provided for the occurrence of rhythmic, central cortical, 12- to 15-cycles/s activity (the sensorimotor rhythm) in the absence of movement and concurrent 8- to 11-cycles/s activity. The second group was studied in another context and received no EEG feedback training. Three of the four training group animals demonstrated a sustained increment of the rewarded response. Compared to controls, the trained group showed a significantly prolonged latency to generalized seizures, fewer total seizures, and enhancement of quiescent behavior during the prodrome. Toxic responses including emesis and motor agitation were comparable among the two groups. These findings support previous observations in cat and man suggesting that enhancement of normal rhythmic EEG patterns in sensorimotor cortex can raise seizure thresholds. A specific alteration of central motor control is proposed as a tentative explanation for this effect.

EEG Operant Conditioning in a Monkey Model: I. Seizure Data

EEG operant conditioning in an alumina-gel monkey model (N = 14) to decrease EMG, to increase 9 Hz or decrease 9 Hz, and to increase 23 Hz (18 Hz and 26 Hz in 2 pilot monkeys), respectively, was not consistently beneficial in reducing seizures. The data suggested: (1) that desynchronization of the EEG by reinforcing 18-26 Hz decreased in some animals the extent and severity of seizures while increasing seizure frequency; (2) that attending during conditioned EMG suppression reduced seizures somewhat; and (3) that the operant conditioning setting became stressful to the majority of monkeys under certain conditions, precipitating status epilepticus, gastrointestinal disturbances, and shock, which culminated in the death of 3 animals. Certain precautions are discussed in the therapeutic application of this technique to epileptic patients.

Operant conditioning of epileptic neurons in monkeys and its theoretical application to EEG operant conditioning in humans

This paper reviews a series of previous reports which summarize the physiology of chronic experimental epileptic foci in monkeys. It is shown that such monkeys can be trained to bidirectionally control the firing rates of normal and epileptic neurons which comprise the epileptic focus. As a result of this acquired operant performance, the monkeys show both a decrease in clinical seizures as well as a decrease in single unit epileptic activity. The EEG correlate of this change in single unit epileptic activity is generalized EEG desynchronization. The conclusion from these data would indicate epileptic neurons can be operantly controlled from and this control is not correlated with any specific EEG pattern. This brings to question the specificity of the SMR in EEG biofeedback paradigms which treat human epilepsy. This author feels that the result from such biofeedback studies are the result of the patient learning to manipulate electrical events within the CNS pathways through which the seizures propagates and is not contingent upon specific EEG frequencies.

Sensorimotor EEG operant conditioning: Experimental and clinical effects

Neurophysiological studies in cats have established a functional relationship between waking 12–15 Hz sensorimotor cortex rhythmic EEG activity (the sensorimotor rhythm or SMR) and a similar pattern during sleep, the sleep spindle. Both result from oscillatory thalamocortical discharge involving ventrobasal thalamus and sensorimotor cortex, and both are associated with a state of suppressed motor excitability. Enhancement of the SMR with operant conditioning methods in the cat clearly led to reduced seizure susceptibility. The experimental application of this approach to seizure control in epileptics has resulted in (A) evidence that EEG patterns can be manipulated significantly in man with operant conditioning, (B) suggestive observations concerning a potential component of pathology in epilepsy, and (C) strong preliminary evidence that SMR operant conditioning in epileptics is specifically therapeutic.

Conditioned EEG desynchronization and seizure occurrence in patients

Five patients with seizures poorly controlled by standard anticonvulsant medication, underwent EEG operant conditioning. The operant paradigm reinforced the production of low voltage fast activity while decreasing frequencies below 10 c/sec. Seizure frequency decreased in 2 patients, seizure severity was attenuated in 2 others, and one patient who was only given reinforcement for scalp EMG suppression showed no change in seizure parameters. Pseudoconditioning and control periods ruled out placebo effects. A rationale for this phenomenon is proposed.