sourced from livescience.com:

Meditation alters brain patterns in ways that are likely permanent, scientists have known. But a new study shows key parts of the brain actually get thicker through the practice.

Brain imaging of regular working folks who meditate regularly revealed increased thickness in cortical regions related to sensory, auditory and visual perception, as well as internal perception -- the automatic monitoring of heart rate or breathing, for example.

The study also indicates that regular meditation may slow age-related thinning of the frontal cortex.

"What is most fascinating to me is the suggestion that meditation practice can change anyone's gray matter," said study team member Jeremy Gray, an assistant professor of psychology at Yale. "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."

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The research was led by Sara Lazar, assistant in psychology at Massachusetts General Hospital. It is detailed in the November issue of the journal NeuroReport.

The study involved a small number of people, just 20. All had extensive training in Buddhist Insight meditation. But the researchers say the results are significant.

Most of the brain regions identified to be changed through meditation were found in the right hemisphere, which is essential for sustaining attention. And attention is the focus of the meditation.

Other forms of yoga and meditation likely have a similar impact on brain structure, the researchers speculate, but each tradition probably has a slightly different pattern of cortical thickening based on the specific mental exercises involved.