New research suggests that meditation is associated with increased cortical thickness. The study, conducted by researchers at Yale, Harvard, Massachusetts General Hospital, and MIT, found that daily meditaters undergo structural changes in the part of the brain related to sensory, cognitive and emotional processing. "What is most fascinating to me is the suggestion that meditation practice can change anyone's grey matter," Gray said. "The study participants were people with jobs and families. They just meditated on average 40 minutes each day, you don't have to be a monk." They speculate that yoga and other kinds of meditation yield the same effects.
New Scientist has more.