http://brainimaging.waisman.wisc.edu/publications/2004/long-term%20meditators%20self-induce%20high-amplitude%20gamma%20synchrony%20during%20mental%20practice.pdf "What we found is that the longtime practitioners showed brain activation on a scale we have never seen before," said Richard Davidson, a neuroscientist at the university's new $10 million W.M. Keck Laboratory for Functional Brain Imaging and Behavior. "Their mental practice is having an effect on the brain in the same way golf or tennis practice will enhance performance." It demonstrates, he said, that the brain is capable of being trained and physically modified in ways few people can imagine."