"Watch this, watch this!" says Pete Halvorson over a high-pitched whir coming from the TV. "When the doctor pulls the drill out of the skull you're going to get a good look straight into the third eye!"

Halvorson is showing me one of the four cranial operations he filmed at a hospital in Mexico in August. I don't consider myself particularly squeamish, but I found myself glancing away from the TV. I hoped Pete didn't think I was bored.

As I turned back to the screen, the whirring stopped, the surgeon removed the drill and a nurse suctioned away the blood and bone fragments. What I saw was a hole that went clear through the skull and stopped just shy of the brain's protective membrane. What Halvorson saw was nothing less than history in the making: a trepanation surgery, performed to help a patient expand her consciousness, and performed at her own request.

Trepanation dates back to the Stone Age. It was practiced by physicians of the ancient world for light head wounds and in the Middle Ages to release evil spirits. But modern Western medicine frowns on trepanation (except to relieve pressure on the brain, after which the piece of skull is replaced), and no doctor in the United States or Western Europe will seriously discuss it, much less perform it, as an elective procedure.

Halvorson, a 54-year-old jewelry designer whose own trepanation hole is visible as a dent in his mostly bald head, believes trepanation can dramatically improve the quality of life for 80 percent of all adults. The benefits he cites include increased mental abilities, more energy and drive, and a heightened self-awareness and a keener perception of reality. He also believes trepanation can help cure depression, stress-related diseases, even multiple sclerosis.

In June, after years of searching, he finally found Dr. David Kirsch in Monterrey, Mexico, who was willing to perform the operation. Eventually, he says, the hospital will accommodate the hundreds of requests Pete receives through his website (www.trepan.com) "This is just the beginning," Pete says. "My long-term goal is to make trepanation available at every outpatient clinic around the world, so that no one will ever have to do what I was forced to do."

In his early 20s, Pete grew distressed over changes in his life--changes some would count as the trappings of adulthood. He felt lethargic, depressed and disconnected. His studies, once a joy, became a chore. "I could barely read through a single page." After dropping out of college Pete, like many young people in the late '60s, embarked on a "quest for expanded consciousness."

In Amsterdam, he met Bart Huges, a former medical student at Amsterdam University who had written a book called "Trepanation: A Cure for Psychosis." Huges, who had been advocating the procedure as a means to permanently increase one's consciousness since the early '60s, had developed a following and attracted publicity ("most of it," Pete says, "was in the tabloids and inaccurate").

In 1972, the 27-year-old Halvorson sat in a small room in Amsterdam before an array of bandages, a hypodermic containing the anesthetic Xylocaine, a scalpel, a drill and four bits. Then, as he'd practiced countless times, he numbed his scalp, made an incision and, hands above head, bored a 3/8 inch hole into his skull. He ran the electric drill by a foot peddle, while watching in a mirror. There was a lot of smoke and blood, which he deflected from his eyes with a tent around his face. The procedure took about an hour. "The first thing I noticed was a sense of euphoria," he recalled. "It's an intense high, a sense of happiness and well-being, nothing wild like LSD. And it's a permanent high that never goes away.

"It's as if somebody suddenly turns on a light," he added, "and you realize, `Wow, I've been in the dark all this time!' It's the opening of the third eye."

The concept of the third eye goes back to ancient Hindu literature, Halvorson says. "The third eye of Shiva was a source of wisdom and illumination, depicted as a fountain coming out of his head. Trepanation was prevalent in those days as a religious practice, and the notion of opening the third eye was a literal reference to trepanation. But over the years the third eye became ritualized and interpreted as a metaphor."

If much of this sounds like a cross between hippie rap and New Age human potential theory, Pete is ready with a lengthy discourse on things like brain pulsations and brain metabolism. He pores over graphs, charts, articles, and other data he has amassed in hopes of convincing the medical profession to take trepanation seriously.

The idea behind the procedure is that a trepanned head gives the brain more room to pulse with each heartbeat, feeding more oxygen to the brain's cells. The hole acts like the soft spot, or fontanel, in a baby's skull, which, Halvorson says, increases the "brain-blood volume" and the brain's ability to function.