Egner T., Gruzelier J.H. EEG Biofeedback of low beta band components: frequency-specific effects on variables of attention and event-related brain potentials

Clinical Neurophysiology 115 (2004) 131–139
Department of Cognitive Neuroscience and Behaviour, Faculty of Medicine, Imperial College London, St Dunstan’s Road, London W6 8RF, UK
Accepted 8 March 2003Abstract
Objective: To test a common assumption underlying the clinical use of electroencephalographic (EEG) biofeedback training
(neurofeedback), that the modulation of discreet frequency bands is associated with frequency-specific effects. Specifically, the proposal was
assessed that enhancement of the low beta components sensorimotor rhythm (SMR: 12–15 Hz) and beta1 (15–18 Hz) affect different aspects
of attentional processing.
Methods: Subjects (n ¼ 25) were randomly allocated to training with either an SMR or beta1 protocol, or to a non-neurofeedback control
group. Subjects were assessed prior and subsequent to the training process on two tests of sustained attention. The neurofeedback participants
were also assessed on target P300 event-related potential (ERP) amplitudes in a traditional auditory oddball paradigm.
Results: Protocol-specific effects were obtained in that SMR training was associated with increased perceptual sensitivity ‘d prime’ (d0),
and reduced omission errors and reaction time variability. Beta1 training was associated with faster reaction times and increased target P300
amplitudes, whereas no changes were evident in the control group.
Conclusions: Neurofeedback training of SMR and beta1 band components led to significant and protocol-specific effects in healthy
subjects. The data can be interpreted as indicating a general attention-enhancing effect of SMR training, and an arousal-enhancing effect of
beta1 training.
q 2004 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Keywords: EEG biofeedback; Neurofeedback; Beta1 activity; Sensorimotor rhythm; Attention; P300