According to scientists from Harvard and Boston University, meditation produces enduring changes in emotional processing in the brain according to an article published in November of 2012 in the journal Frontiers in Human Neuroscience.
Researchers trained people with one of two different types of meditation, mindful meditation and compassionate meditation over an 8 week period. They measured activity in the brain using functional MRIs 3 weeks before the study and at 3 weeks after and noted what happened to areas of the brain related to compassion. They found the those people who learned compassionate meditation had a different and more loving response 3 weeks after the course even when not meditating.