It makes sense that if you're using part of your brain a lot, it's going to get worked out and there's going to be more stuff in that area to support increased usage. In a sense, that's all we're seeing.
The area where we see these differences is involved in both the modulation of functions like heart rate and breathing and also the integration of emotion with thought and reward-based decision making - a central switchboard of the brain.
Our results suggest that meditation can produce experience-based structural alterations in the brain. We also found evidence that meditation may slow down the aging-related atrophy of certain areas of the brain.