Neuroplasticity and the brain: two way causation

http://en.wikipedia.org/wiki/Neuroplasticity

http://www.dalailama.com/news/post/104-how-thinking-can-change-the-brain

In each case, monks with the most hours of meditation showed the most dramatic brain changes. That was a strong hint that mental training makes it easier for the brain to turn on circuits that underlie compassion and empathy.

'This positive state is a skill that can be trained,' Prof. Davidson says. 'Our findings clearly indicate that meditation can change the function of the brain in an enduring way.'