J ChildJ Child Neurol. 2006 May;21(5):391-9

Differentiating autistic children with quantitative encephalography: a 3-month longitudinal study.

 Chan AS, Leung WW.

Neurology Laboratory, Department of of Psychology, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China. aschan@psy.cuhk.edu.hk

 The present study used a single-channel quantitative electroencephalographic (EEG) assessment to differentiate autistic children from normal control subjects. One hundred five normal and 17 autistic children participated in the study. In addition to amplitude measures of the frequency bands of delta, theta, alpha, sensorimotor rhythm, and beta and the theta to beta ratio, intra- (6 minutes) and intersessional (3 months) consistencies were also examined. The results indicated that autistic children showed significantly higher quantitative EEG amplitudes in many of the frequency bands than normal children; furthermore, their quantitative EEG activities were found to be relatively unstable within a 6-minute session compared with normal children. Discriminant function analyses revealed that absolute sensorimotor rhythm and beta amplitudes were the best predictors that correctly differentiated autistic children from normal children in the present sample, with a high accuracy rate of 95.2%. In addition, quantitative EEG measurements of normal and autistic children were found to be generally consistent across the 3-month period.PMID: 16901444 [PubMed - indexed for MEDLINE]

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

Annotation: neurofeedback - train your brain to train behaviour.

Heinrich H, Gevensleben H, Strehl U.

Child & Adolescent Psychiatry, University of Erlangen-Nurnberg, Germany. hheinri@arcor.de             

    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. PMID: 17244266 [PubMed - in process]

Pediatrics. 2006 Nov;118(5):e1530-40. Epub 2006 Oct 23

Self-regulation of slow cortical potentials: a new treatment for children with attention-deficit/hyperactivity disorder.

Strehl U, Leins U, Goth G, Klinger C, Hinterberger T, Birbaumer N.

Institute of Medical Psychology and Behavioral Neurobiology, University of Tubingen, Gartenstrasse 29, 72074 Tubingen, Germany. ute.strehl@uni-tuebingen.de

OBJECTIVE: We investigated the effects of self-regulation of slow cortical potentials for children with attention-deficit/hyperactivity disorder. Slow cortical potentials are slow event-related direct-current shifts of the electroencephalogram. Slow cortical potential shifts in the electrical negative direction reflect the depolarization of large cortical cell assemblies, reducing their excitation threshold. This training aims at regulation of cortical excitation thresholds considered to be impaired in children with attention-deficit/hyperactivity disorder. Electroencephalographic data from the training and the 6-month follow-up are reported, as are changes in behavior and cognition. METHOD: Twenty-three children with attention-deficit/hyperactivity disorder aged between 8 and 13 years received 30 sessions of self-regulation training of slow cortical potentials in 3 phases of 10 sessions each. Increasing and decreasing slow cortical potentials at central brain regions was fed back visually and auditorily. Transfer trials without feedback were intermixed with feedback trials to allow generalization to everyday-life situations. In addition to the neurofeedback sessions, children exercised during the third training phase to apply the self-regulation strategy while doing their homework. RESULTS: For the first time, electroencephalographic data during the course of slow cortical potential neurofeedback are reported. Measurement before and after the trials showed that children with attention-deficit/hyperactivity disorder learn to regulate negative slow cortical potentials. After training, significant improvement in behavior, attention, and IQ score was observed. The behavior ratings included Diagnostic and Statistical Manual of Mental Disorders criteria, number of problems, and social behavior at school and were conducted by parents and teachers. The cognitive variables were assessed with the Wechsler Intelligence Scale for Children and with a computerized test battery that measures several components of attention. All changes proved to be stable at 6 months' follow-up after the end of training. Clinical outcome was predicted by the ability to produce negative potential shifts in transfer sessions without feedback. CONCLUSIONS: According to the guidelines of the efficacy of treatments, the evidence of the efficacy of slow cortical potential feedback found in this study reaches level 2: "possibly efficacious." In the absence of a control group, no causal relationship between observed improvements and the ability to regulate brain activity can be made. However, it could be shown for the first time that good performance in self-regulation predicts clinical outcome. "Good performance" was defined as the ability to produce negative potential shifts in trials without feedback, because it is known that the ability to self-regulate without feedback is impaired in children and adults with attention problems. Additional research should focus on the control of unspecific effects, medication, and subtypes to confirm the assumption that slow cortical potential feedback is a viable treatment option for attention-deficit/hyperactivity disorder. Regulation of slow cortical potentials may involve similar neurobiological pathways as medical treatment. It is suggested that regulation of frontocentral negative slow cortical potentials affects the cholinergic-dopaminergic balance and allows children to adapt to task requirements more flexibly.  PMID: 17060480 [PubMed - indexed for MEDLINE]

Prax Kinderpsychol Kinderpsychiatr. 2006;55(5):384-407

[Neurofeedback for children with ADHD: a comparison of SCP- and theta/beta-protocols]

Leins U, Hinterberger T, Kaller S, Schober F, Weber C, Strehl U.

Universitatsklinik fur Psychiatrie und Psychotherapie, Universitat Tubingen. ulrike.leins@med.uni-tuebingen.de

Research groups have consistently reported on behavioral and cognitive improvements of children with ADHD after neurofeedback. However, neurofeedback has not been commonly accepted as a treatment for ADHD. This is due, in part, to several methodological limitations. The neurofeedback literature is further complicated by having several different training protocols. Differences between the clinical efficacy of such protocols have not been examined. This study addresses previous methodological shortcomings while comparing the training of theta-beta-frequencies (theta-beta-group) with the training of slow cortical potentials (SCP-group). Each group comprised of 19 children with ADHD that were blind to group assignment. The training procedure consisted of 30 sessions and a six months follow-up training. Pre-/post measures at pretest, the end of the training and the follow-up included tests of attention, intelligence and behavioral variables. After having already reported intermediate data (Strehl et al. 2004), this paper gives account on final results: Both groups are able to voluntarily regulate cortical activity, with the extent of learned self-regulation depending on task and condition. Both groups improve in attention and IQ. Parents and teachers report significant behavioral and cognitive improvements. Clinical effects for both groups remain stable six months after training. Groups do not differ in behavioral or cognitive outcome variables.  PMID: 16869483 [PubMed - indexed for MEDLINE]

Clin Neurophysiol. 2004 Nov;115(11):2452-60.

The effects of neurofeedback training on the spectral topography of the electroencephalogram.

Egner T, Zech TF, Gruzelier JH.

Division of Neuroscience and Psychological Medicine, Faculty of Medicine, Imperial College London, UK. tegner@fmri.columbia.edu

OBJECTIVE: To investigate the impact of EEG frequency band biofeedback (neurofeedback) training on spectral EEG topography, which is presumed to mediate cognitive-behavioural training effects. In order to assess the effect of commonly applied neurofeedback protocols on spectral EEG composition, two studies involving healthy participants were carried out. METHODS: In Experiment 1, subjects were trained on low beta (12-15 Hz), beta1 (15-18 Hz), and alpha/theta (8-11 Hz/5-8 Hz) protocols, with spectral resting EEG assessed before and after training. The specific associations between learning indices of each individual training protocol and changes in absolute and relative spectral EEG topography was assessed by means of partial correlation analyses. Results of Experiment 1 served to generate hypotheses for Experiment 2, where subjects were randomly allocated to independent groups of low beta, beta1, and alpha/theta training. Spectral resting EEG measures were contrasted prior and subsequent to training within each group. RESULTS: Only few associations between particular protocols and spectral EEG changes were found to be consistent across the two studies, and these did not correspond to expectations based on the operant contingencies trained. Low-beta training was found to be somewhat associated with reduced post-training low-beta activity, while more reliably, alpha/theta training was associated with reduced relative frontal beta band activity. CONCLUSIONS: The results document that neurofeedback training of frequency components does affect spectral EEG topography in healthy subjects, but that these effects do not necessarily correspond to either the frequencies or the scalp locations addressed by the training contingencies. The association between alpha/theta training and replicable reductions in frontal beta activity constitutes novel empirical neurophysiological evidence supporting inter alia the training's purported role in reducing agitation and anxiety. SIGNIFICANCE: These results underline the complexity of the neural dynamics involved EEG self-regulation and emphasize the need for empirical validation of predictable neurophysiological outcomes of training EEG biofeedback protocols. PMID: 15465432 [PubMed - indexed for MEDLINE]

Neuroreport. 2003 Jul 1;14(9):1221-4.

Ecological validity of neurofeedback: modulation of slow wave EEG enhances musical performance.

Egner T, Gruzelier JH.

Department of Cognitive Neuroscience and Behaviour, Faculty of Medicine, Imperial College London, UK. t.egner@imperial.ac.uk

Biofeedback-assisted modulation of electrocortical activity has been established to have intrinsic clinical benefits and has been shown to improve cognitive performance in healthy humans. In order to further investigate the pedagogic relevance of electroencephalograph (EEG) biofeedback (neurofeedback) for enhancing normal function, a series of investigations assessed the training's impact on an ecologically valid real-life behavioural performance measure: music performance under stressful conditions in conservatoire students. In a pilot study, single-blind expert ratings documented improvements in musical performance in a student group that received training on attention and relaxation related neurofeedback protocols, and improvements were highly correlated with learning to progressively raise theta (5-8 Hz) over alpha (8-11 Hz) band amplitudes. These findings were replicated in a second experiment where an alpha/theta training group displayed significant performance enhancement not found with other neurofeedback training protocols or in alternative interventions, including the widely applied Alexander technique.  PMID: 12824763 [PubMed - indexed for MEDLINE]

Appl Psychophysiol Biofeedback. 2005 Dec;30(4):347-64.

Can neurofeedback training enhance performance? An evaluation of the evidence with implications for future research.

Vernon DJ.

Department of Applied Social Sciences, Canterbury Christ Church University, Augustine House, Canterbury, Kent, United Kingdom. d.j.vernon@canterbury.ac.uk

There have been many claims regarding the possibilities of performance enhancement training. The aim of such training is for an individual to complete a specific function or task with fewer errors and greater efficiency, resulting in a more positive outcome. The present review examined evidence from neurofeedback training studies to enhance performance in a particular area. Previous research has documented associations between specific cortical states and optimum levels of performance in a range of tasks. This information provides a plausible rationale for the use of neurofeedback to train individuals to enhance their performance. An examination of the literature revealed that neurofeedback training has been utilised to enhance performance from three main areas; sport, cognitive and artistic performance. The review examined evidence from neurofeedback training studies within each of these three areas. Some suggestive findings have been reported with regard to the use of neurofeedback training to enhance performance. However, due to a range of methodological limitations and a general failure to elicit unambiguous changes in baseline EEG activity, a clear association between neurofeedback training and enhanced performance has yet to be established. Throughout, the review highlights a number of recommendations to aid and stimulate future research. PMID: 16385423 [PubMed - indexed for MEDLINE]

Prog Brain Res. 2006;159:421-31.

Department of Psychology, Goldsmiths College, University of London, Lewisham Way, New Cross, London SE14 6NW, UK. j.gruzelier@gold.ac.uk

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. PMID: 17071246 [PubMed - indexed for MEDLINE]

Child Adolesc Psychiatr Clin N Am. 2005 Jan;14(1):83-104, vi.

 Division of Neuroscience and Psychological Medicine, Imperial College London, St. Dunstan's Road, London W6 8RF, United Kingdom. j.gruzelier@imperial.ac.uk

The field of neurofeedback training has proceeded largely without validation. In this article the authors review studies directed at validating sensory motor rhythm, beta and alpha-theta protocols for improving attention, memory, and music performance in healthy participants. Importantly, benefits were demonstrable with cognitive and neurophysiologic measures that were predicted on the basis of regression models of learning to enhance sensory motor rhythm and beta activity. The first evidence of operant control over the alpha-theta ratio is provided, together with remarkable improvements in artistic aspects of music performance equivalent to two class grades in conservatory students. These are initial steps in providing a much needed scientific basis to neurofeedback. PMID: 15564053 [PubMed - indexed for MEDLINE]