From the video...
Daniel Goleman: My co-author of the book Altered Traits is a neuroscientist, Richard Davidson. He has a lab at the University of Wisconsin. It’s a very large lab, he has dedicated scanners, he has about 100 people working there, and he was able to do some remarkable research where he flew Olympic level meditators—who live in Nepal or India typically, some in France—he flew them over to the lab and put them through a protocol in his brain scanners and did state-of-the-art tests and the results were just astounding. We found, for example, or he found that their brain waves are really different.

Perhaps the most remarkable findings in the Olympic level meditators has to do with what’s called a gamma wave. All of us get gamma for a very short period when we solve a problem we’ve been grappling with, even if it’s something that’s vexed us for months. We get about half second of gamma; it’s the strongest wave in the EEG spectrum. We get it when we bite into an apple or imagine biting into an apple, and for a brief period, a split-second, inputs from taste, sound, smell, vision, all of that come together in that imagined bite into the apple. But that lasts very short period in an ordinary EEG.

What was stunning was that the Olympic level meditators, these are people who have done up to 62,000 lifetime hours of meditation, their brainwave shows gamma very strong all the time as a lasting trait just no matter what they’re doing. It’s not a state effect, it’s not during their meditation alone, but it’s just their every day state of mind. We actually have no idea what that means experientially. Science has never seen it before.
Superhumans: The remarkable brain waves of high-level meditators — by Daniel Goleman