Brain scans have revealed that those who regularly practiced yoga had larger brain volume in the somatosensory cortex (maps the body), superior parietal cortex (involved in directing attention), visual cortex (perhaps because of visualization techniques), hippocampus, precuneus and the posterior cingulate cortex (the last two involved in our concept of self).
http://www.scientificamerican.com/article/how-yoga-changes-the-brain/