Alpha neurofeedback improves the maintaining ability of alpha activity.
ABSTRACT The effects of alpha-neurofeedback (ANF) on electroencephalographic alpha-activity were investigated. Each session consisted of a 2.5-min eye-opened state and 17.5-min of ANF, which was divided into 16 1.25-min bins. Alpha amplitudes were gradually increased as the session was repeated. The maximum value at the start of ANF gradually decreased as time passed, but the slowdown of alpha-activity during each session was decreased as the session was repeated. The correlation between alpha-activity at the end of ANF and at the following session's eye-opened state was highly significant. These results showed that ANF enhances the ability of alpha-activity to maintain itself rather than the increase of alpha-amplitude during intrasession and that the maintained alpha-activity during former training remained until the next session.
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ABSTRACT: Neurofeedback (NFB) is emerging as a promising technique that enables self regulation of ongoing brain oscillations. However, despite a rise in empirical evidence attesting to its clinical benefits, a solid theoretical basis is still lacking on the manner in which NFB is able to achieve these outcomes. The present work attempts to bring together various concepts from neurobiology, engineering, and dynamical systems so as to propose a contemporary theoretical framework for the mechanistic effects of NFB. The objective is to provide a firmly neurophysiological account of NFB, which goes beyond traditional behaviorist interpretations that attempt to explain psychological processes solely from a descriptive standpoint whilst treating the brain as a "black box". To this end, we interlink evidence from experimental findings that encompass a broad range of intrinsic brain phenomena: starting from "bottom-up" mechanisms of neural synchronization, followed by "top-down" regulation of internal brain states, moving to dynamical systems plus control-theoretic principles, and concluding with activity-dependent as well as homeostatic forms of brain plasticity. In support of our framework, we examine the effects of NFB in several brain disorders, including attention deficit hyperactivity (ADHD) and post traumatic stress disorder (RISC)). In sum, it is argued that pathological oscillations emerge from an abnormal formation of brain-state attractor landscape(s). The central thesis put forward is that NFB tunes brain oscillations toward a homeostatic set-point which affords an optimal balance between network flexibility and stability (i.e., self organised criticality (SOC)).Frontiers in Human Neuroscience 12/2014; 8(1008). DOI:10.3389/fnhum.2014.01008 · 2.90 Impact Factor
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ABSTRACT: In continuing this three-part review on validation of EEG-neurofeedback for optimal performance evidence is provided for feedback influences on the CNS, the integration of EEG with fMRI methodology as well as anatomical correlates. Whereas parts I and II reviewed the considerable behavioural outcome gains and evidence for their feedback causation, part III lays bare the not inconsiderable methodological and theoretical conundrums. Cardinal assumptions amongst practitioners about specificity of topography, behavioural outcome and frequency bands are critically examined. The hitherto mostly neglected nature of feedback learning is reviewed including evidence of within- and between-session and successive baseline learning; the enduring impact on the tonic EEG; implications for experimental design, individual differences and the trainer-participant interface; distinguishing between the learning and mastery of self-regulation; connectivity, ratio, unidirectional and multimodal feedback protocols. A thorough grounding in human neuroscience plus interpersonal skills are considered prerequisites for scientific advancement and ethically sound practice.Neuroscience & Biobehavioral Reviews 07/2014; 44. DOI:10.1016/j.neubiorev.2014.03.015 · 10.28 Impact Factor
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ABSTRACT: While issues of efficacy and specificity are crucial for the future of neurofeedback training, there may be alternative designs and control analyses to circumvent the methodological and ethical problems associated with double-blind placebo studies. Surprisingly, most NF studies do not report the most immediate result of their NF training, i.e., whether or not children with ADHD gain control over their brain activity during the training sessions. For the investigation of specificity, however, it seems essential to analyze the learning and adaptation processes that take place in the course of the training and to relate improvements in self-regulated brain activity across training sessions to behavioral, neuropsychological and electrophysiological outcomes. To this aim, a review of studies on neurofeedback training with ADHD patients which include the analysis of learning across training sessions or relate training performance to outcome is presented. Methods on how to evaluate and quantify learning of EEG regulation over time are discussed. "Non-learning" has been reported in a small number of ADHD-studies, but has not been a focus of general methodological discussion so far. For this reason, selected results from the brain-computer interface (BCI) research on the so-called "brain-computer illiteracy", the inability to gain control over one's brain activity, are also included. It is concluded that in the discussion on specificity, more attention should be devoted to the analysis of EEG regulation performance in the course of the training and its impact on clinical outcome. It is necessary to improve the knowledge on characteristic cross-session and within-session learning trajectories in ADHD and to provide the best conditions for learning.Frontiers in Human Neuroscience 03/2015; 9:135. DOI:10.3389/fnhum.2015.00135 · 2.90 Impact Factor