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from document published in "Proceedings of the IANS 11th Forum on
New Arts and Science" ©2001 by the International Association on New Science, 1612 Windsor Court, Fort Collins, CO 80526
Abstract from Binaural Beats and the
F. Holmes Atwater
Abstract This paper describes two studies. A first study measured the neural
accommodation (changes in ongoing or overall brainwave activity) associated with
complex binaural-beat stimuli. A second study, based on the same protocol,
measured changes in ongoing brainwave activity associated with placebo
stimuli. A weak EEG frequency-following response to binaural beating and other
rhythmic stimuli manifests using time-domain averaging brainwave analysis
techniques. Theoretically, this frequency-following response emerges as a
low-amplitude linked series of evoked-potential responses. It is important to
note that these studies examined ongoing brainwave activity (in this case,
central delta and occipital alpha) and not the frequency-following response. Results of the two studies showed that during the binaural beat stimuli,
reductions in the percentages of occipital alpha (bipolar O1-O2) were
significant (individually, p < .05 and together, p < .001) during five of
six free-running EEG recording periods compared to baselines. During these same
recording periods reductions in the percentages of central delta (bipolar C3-C4)
were similarly significant during four of six periods compared to baselines.
Alpha- and delta-brainwave changes were non-significant during the placebo
stimuli. The extended reticular-thalamic activating system (ERTAS) may be the neural
mechanism behind the observed brainwave changes. The reticular formation of the
brain stimulating the thalamus and cortex (referred to as the ERTAS) governs
cortical brainwave patterns. Acetylcholine, provided via cortico-thalamic
projections, either inhibits or excites areas of the cortex by neutralizing or
enhancing the effects of noradrenaline and serotonin coming to the cortex via
“fountains” from the locus coeruleus and the raphe nuclei.
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