Nice article. F.Y.I when mentioning the ELF frequencies and how they can effect the mind. 7.83 Hertz is known as the Schumann Resonance and is actually the frequency the earth resonates at. There are quite a few experiments were people were shown that without that frequency they become depressed and lethargic. This is not some hocus pocus. It is not that expensive to build your own E.E.G machine and measure your own brainwaves with your computer and see what frequencies it operates at and with doing various activities.