Dr. Micheal Persinger's research is very interesting. He uses a Transcranial Magnetic Stimulation (TMS) for brain entrainment into different states of consciousness. Entrainment (in physics) is a term that refers to two objects vibrating at different frequencies becoming synchronized by being near each other.. like tuning forks effecting each other with vibrations. With a TMS, the same thing is being done with electro-magnetic waves penetrating the brain.
The "God Helmet" has also been used on two high profile psychics Ingo Swann (co-inventor the "remote viewing" process used by Govt intelligence agencies) & Sean Harribance (this is almost never talk about but here is Persinger's paper on it -Psychic Ability - God Helmet
. The results are amazing. In short, the psychics are highly sensitive to the waves. Source of Miracles » Blog Archive » Transcranial Magnetic Stimulations God Helmet Meets a Psychic
Persinger explains that there are a spectrum of experiences that come from the helmet. Some temporal lobes are highly susceptible to the waves (they have incredible experiences) while others are not. Richard Dawkins in the "God Helmet" MindMods CogSciTech Biofeedback & Neurofeedback Blog