I’m not expert but…

It seems that meditation enlarges certain parts of the brain. Science Daily published an article to this effect. And another article shows that buddhists really are happier.

The danger inherent in this understanding is that it is essentially materialistic. By that I mean that seeing it as a brain function, keeps the understanding as dualistic. Perhaps it might be better to see the changing brain structure as a reflection of a deeper spiritual awakening rather than the cause.