Trepanation

Trepanation is the creation of a hole in the skull to enhance brain function. Trepanation works under the theory that by creating a hole in the skull, brain blood volume is changed and brain function is enhanced, creating a "permanent high" or enlightenment of sorts. While trepanation has a number of very convincing advocates, the vast majority—including many people who have gone through the procedure—hold that it is primarily a placebo effect.

You can learn more about trepanation at the homepage of the International Trepanation Advocacy Group at trepan.com.