The basic idea of brainwave entrainment is to use an external periodic stimulus to cause brainwave frequencies to fall into step with it at a frequency corresponding to the intended brain-state (for example, to induce sleep or meditative states). There is good evidence that the human brain has a tendency to change its dominant EEG frequency towards the frequency of a dominant external stimulus. Such a stimulus may be aural, as in the case of binaural or monaural beats and isochronic tones,or light (visual), or a combination of the two with a mind machine.
I had tried kava some years ago when I was in Fiji at a holiday resort. There was a bowl of what looked like (and tasted like) muddy tea. I had a cup of it, and did not notice anything much. So when Irene told me that the Vanuatu kava was much stronger, and the locals said that the kava in Fiji was more like dishwater, I decided I should try the local stuff while I was on Tanna. Continue reading