God helmet
n. A headpiece that simulates a religious or spiritual experience by stimulating certain areas of a person's brain using electromagnetic waves .
The two nuns experienced intense bursts of alpha waves in the brains, common in a reflective and relaxed state such as meditation. They also had intense activity in the left occipital region at the back of the brain — which is not what the scientists were expecting in the wake of research by Michael Persinger, a controversial researcher at Laurentian University in Sudbury who has developed the so-called God helmet. He uses the device to stimulate the right side of the brain, including the parietal lobe, with low-level electromagnetic radiation. In 80 per cent of subjects, this induces the sensation that there is a presence in the room. Many weep and say they feel God nearby.
—Anne McIlroy, “Hard-Wired for God,” The Globe and Mail, December 06, 2003
The findings suggest that our attitudes to religion are underpinned by biology -that some brains are physically built to be more receptive to divine thought, and that this explains why religion induces apathy in some and fervour in others. One scientist has even built a kind of "God helmet" — a headset that can induce the feeling of an unseen presence by bathing the temples in electromagnetic fields.
—Anjana Ahuja, “God on the brain,” The Times of London, April 17, 2003
2001 (earliest)
God lives somewhere in the temporal and parietal lobes of the brain, along with aliens, angels and dead relatives. To find them at home, put on Michael Persinger's God helmet and ring their doorbells with a magnetic buzz. …

Persinger, head of the Neuroscience Research Group at Sudbury's Laurentian University, is one of a growing number of scientists around the world exploring what physically occurs in the brain during a religious or mystic experience and how to imitate the stimuli that cause those experiences to occur.

He uses a modified motorcycle helmet or a head-circlet device nicknamed the Octopus that contain solenoids — coils of wire — which create a weak but complex magnetic field over the brain's right-hemisphere parietal and temporal lobes. …

Persinger reports that at least 80 per cent of his subjects experience a presence beside them in the room, a sentient intelligent being, or — if they are inclined to atheism — a oneness with the universe.
—Michael Valpy, “Is God all in our heads?,” The Globe and Mail, August 25, 2001