Richard R. Davidson PNAS paper from 2004:
Long-term meditators self-induce high-amplitude gamma synchrony during mental practice
https://pmc.ncbi.nlm.nih.gov/articles/PMC526201
Daniel Goleman has summarized the main finding of this paper in this video:
Peter Gamma from www.petergamma.org has investigated this topic a lot in recent years. And his hypothesis is that the most striking finding of meditation researchers in Switzerland in recent years are changes in the face of Swiss neuroscientist Alex Gamma:
Alex Gamma before meditating assisted by a brain scanner:
Alex Gamma after meditating assisted by a brain scanner:
That the changes in Alex Gammas face are induced by meditation is only a speculation of Peter, but he believes this hypothesis is true. It could be eventually induced by a computer program which said Alex which meditation practice to choose. And the effect was then eventually analyzed with a brain scanner.
Alex is a neuroscientist with many skills. He is also an expert about ecstasy and gave interviews on Swiss TV:
After these findings we previously discussed on www.petergamma.org in recent years, Peter Gamma, Director of the Meditation Research Institute Switzerland (MRIS):
came to the following conclusion.
The Meditation Research Institute Switzerland (MRIS) will continue to be a private project of Peter on his personal website in near future. It is a website Peter is updating at home. During the last 20 years, Peter did no find any new striking findings in the field of meditation research in Switzerland. Peter does not know of a Swiss study in the field of meditation research from which he would believe that it has the potential to be supported by for instance the Swiss National Science Foundation (SNSF).
The SNSF is the primary funding agency in Switzerland. It funds basic research in all scientific disciplines, paying particular attention to the support of early career researchers.