mindfulness practice leads to increases in regional brain gray matter density

"[MRI] analyses in a priori regions of interest confirmed increases in gray matter concentration within the left hippocampus. Whole brain analyses identified increases in the posterior cingulate cortex, the temporo-parietal junction, and the cerebellum in the *MBSR group compared with the controls. The results suggest that participation in MBSR is associated with changes in gray matter concentration in brain regions involved in learning and memory processes, emotion regulation, self-referential processing, and perspective taking."

Psychiatry Research: Neuroimaging

Volume 191, Issue 1, Pages 36-43 (30 January 2011)

*MBSR, as near as I can tell, appears to be at core a kind of vipassana.