“The main idea is to use different objects to focus one’s attention, and it could be a focus on sensations of breathing, or emotions or thoughts, or observing any type of body sensations,” she said. “But it’s about bringing the mind back to the here and now, as opposed to letting the mind drift.”
http://well.blogs.nytimes.com/2011/01/28/how-meditation-may-change-the-brain/?src=me&ref=general