When large numbers of neurons fire in the brain, electrical activity that can be detected as voltage fluctuations (brainwaves) results. Researchers study brainwaves using equipment like EEG in an attempt to understand what happens when we engage in different activities such as sleeping, speaking or feeling a certain emotion.
Now suppose that we are able to control the brainwave pattern, say by achieving a frequency that corresponds to a particular brain-state like sleep. It can lead to an altered state of the mind, i.e. we might sleep off. A boring lecture can, for example, achieve that result!
Any practice that can cause brainwave frequency to be synchronized with an external stimulus can be called brainwave entrainment. We do know that external stimuli can indeed affect our feelings. Just listen to rhythmic drumbeat in an environment without other distractions.
Human brain seems to have a tendency to change its dominant frequency towards the frequency of a dominant external stimulus that can be aural or visual (sound-related or sight-related) or other. Artists and others interested in altered states of mind have experimented with this phenomenon.
Different kinds of external stimuli are constantly affecting our brains, making us see and hear many things. When the stimulus is consistent and repetitive with a certain wavelike “frequency”, the brain responds by synchronizing its electric cycles to the external rhythm.
What practical benefit can brain entrainment provide?
There have been scientific experiments that involved synchronizing brainwave patterns to those involved in such mental states as intense concentration. Results indicate that significant improvements can be produced in academic performance through these. Practices like meditation have already been observed to produce results in the brain, such as increased relaxation and concentration.
Binaural beats is one way for brainwave entrainment. Slightly different tones are presented to each ear which results in the brain being synchronized to a pulse that is the difference between the frequencies of the two tones, e.g. 10 hertz if one ear receives 495 hertz and the other, 505 hertz. Training in the 15-18 hertz range is reported to have improved the IQ of ADD/ADHD affected children.
Binaural beats involve the use of headphones to deliver different tones to the two ears. A modern development, Isochronic Tones, uses a single tone that is precisely patterned. This technique is reported to enhance the effectiveness of brainwave entrainment.
Though an observed phenomenon, brainwave entrainment does not seem to have yet entered into medical practice. The software authors above have advised users to use it at their own risk. Like meditation and altered states of mind, it seems to reside in a twilight zone between respectable science and esoteric practice.
