Inter-hemispheric and spectral power analyses of binaural beat effects on the brain

Binaural beats are said to occur when two tones of different frequencies are presented to each ear, with the resulting perception being that of a single tone and a frequency midway between the two stimuli. It has found use in applications that purport to have the ability to relax the brain and other positive medical outcomes. This research considers the effects of binaural beats on the brain, following the assumption that the human brain has the tendency to change its dominant electroencephalography (EEG) frequency towards the frequency of the external stimulus. First, we considered the difference in spectral power of EEG frequencies for a group of individuals when in an entrained state (exposed to binaural beats) and a relaxed state (not exposed to binaural beats). Secondly, we assessed whether the effects of binaural beats affect the right and left hemisphere of the brain uniformly, and if so, to what extent this interhemispheric relationship can be seen. The results of this research show that hemispheric synchronisation affects all 5 subjects. Spectral power analysis revealed that 3 of the 5 subjects exhibited a difference in spectral power in the entrained state versus the relaxed state, especially in the frontal cortex but rather, in contradiction to the reports by others, as the effect was opposite, that is, entrainment reduces the spectral power, instead of causing an increase. The conclusion (based on the limited pool of subjects) is that there is some evidence to support that binaural beats do affect the brain but, in certain cases, negatively, and therefore, its usage should be weighed carefully.