From Scientific American:
Like athletes or musicians, people who practice meditation can enhance their ability to concentrate—or even lower their blood pressure. They can also cultivate compassion, according to a new study. Specifically, concentrating on the loving kindness one feels toward one’s family (and expanding that to include strangers) physically affects brain regions that play a role in empathy. “There is such a thing as expertise when it comes to complex emotions or emotional skills, such as the one of cultivating benevolence,” says Antoine Lutz, a neuroscientist at the University of Wisconsin–Madison who led the study. “That raises the possibility that you can train someone to cultivate this positive emotion.”
Lutz and his colleagues, including Neuroscientist Richard Davidson, director of the university’s Waisman Center for Brain Imaging where the study was conducted, took fMRI scans of the brains of 16 veteran meditators as well as 16 others who had started with no meditation experience but received cursory training before they carried out a series of tests. During these tests, the researchers measured the flow of blood in the brains of both the veterans (some of them Tibetan monks) and the American novices as the subjects did or did not meditate on compassionate feelings while being subjected to various sounds with positive and negative connotations.