Brainwave entrainment is a method which utilizes frequencies of the brain in order to bring about specific desired thoughts and behavior. In other words, brainwave entrainment is used to induce different brainwave states related to: enhanced focus, relaxation, sleep induction, meditation, etc. With the help of a specific stimulus, aural (audio), photic (visual) or the combination of the two, we naturally induce the brain to respond by synchronizing with the stimulus frequency; this is called the “frequency following response”. The assumption is that the human brain has a tendency to change its dominant Electroencephalography frequency (recording of electrical activity along the scalp) towards the frequency of a dominant external stimulus. This is why we also talk about “brainwave synchronization”.
Neural oscillations are rhythmic or repetitive electrochemical activity in the brain and central nervous system. Such oscillations can be characterized by their frequency, amplitude and phase. Neural tissue can generate oscillatory activity driven by mechanisms within individual neurons, as well as by interactions between them. They may also adjust frequency to synchronize with the periodic vibration of external acoustic or visual stimuli.