Neurons that comprise the brain work on electrical impulses known as brainwaves. The last century of neurological research has demonstrated that brainwaves of different wavelengths can be indicative of unique emotional and mental states, like a focused awareness, a meditative state, or drowsiness. Brainwaves have been used in medical research and therapy for years. NeuroSky is introducing it to the consumer world.

More information:
http://www.neurosky.com/