[9][10] The technique of recording neural electrical activity within the brain from electrochemical readings taken from the scalp originated with the experiments of Richard Caton in 1875, whose findings were developed into EEG by Hans Berger in the late 1920s.
As they assume a more stable phase relationship, the amount of energy gradually reduces to zero, with systems of greater frequency slowing down, and the other speeding up.
The theory explains the way that two or more independent, autonomous oscillators with differing rhythms or frequencies, when situated in proximity where they can interact for long enough, influence each other mutually, to a degree dependent on coupling force.
The most familiar examples of neuromotor entrainment to acoustic stimuli is observable in spontaneous foot or finger tapping to the rhythmic beat of a song.
[21][22][23][24] Brainwave entrainment is a colloquialism for 'neural entrainment',[25] which is a term used to denote the way in which the aggregate frequency of oscillations produced by the synchronous electrical activity in ensembles of cortical neurons can adjust to synchronize with the periodic vibration of external stimuli, such as a sustained acoustic frequency perceived as pitch, a regularly repeating pattern of intermittent sounds, perceived as rhythm, or of a regularly rhythmically intermittent flashing light.