When volunteers were shown photos of ex-lovers from a recent break-up while lying inside a functional MRI scanner, their brains showed significant activity in the same regions that become aroused when people experience painful sensations in their body like being pinched or holding a hot cup of coffee. Photograph by: Mark Ralston, AFP/Getty Images Love, it turns out, really can cut like a knife. Researchers using state-of-the-art scanners that show people's brains at work have found for the first time that the same sensory regions in the brain activated in response to physical pain light up during intense experiences of rejection. When volunteers were shown photos of ex-lovers from a recent break-up while lying inside a functional MRI scanner, their brains showed significant activity in the same regions that become aroused when people experience painful sensations in their body like being pinched or holding a hot cup of coffee. "This idea that 'my feelings hurt' may well be more than a metaphor," said University of Michigan social psychologist Dr. Ethan Kross, lead author of the article published in the Proceedings of the National Academy of Sciences. His isn't the first group to have said that social rejection and physical pain can feel like the same experience. "Lots of people have been talking about this," Kross said. "But this really provides a direct pathway that shows how rejection may actually manifest itself in the body." It not only adds new meaning to Nazareth's iconic rock ballad, Love Hurts "love hurts, love scars, love wounds, and mars" but the study also suggests intense rejection may lead to body-wide pain problems, such as fibromyalgia, or other pain symptoms or disorders. It also offers new insight into how our emotional states play out in our bodies. The researchers tried to capitalize on something almost everyone has experienced: an unwanted romantic break-up. "We thought: It doesn't get more intense than that," Kross said. "In some ways, it's the prototypical social-rejection experience." For their study, the researchers recruited 40 people who had an unwanted break up with a partner within the past six months. Each volunteer performed two tasks while undergoing functional MRI scans. First, the volunteer looked at a headshot of an ex and thought about how it felt during their break-up. The volunteer then viewed a photo of a friend of the same sex as their former partner and thought about a recent positive experience they shared. That was the "social rejection" task. During the "physical pain" task, a thermal device was attached to volunteers' forearms and turned up going from warm to "painful". Kross stressed that the researchers didn't burn people; the painful temperature was akin to holding a hot cup of coffee, without a sleeve. Both kinds of experiences led to activation in a network of brain regions associated with distress. But researchers also found that both rejection and physical pain led to activation in brain regions related to actual pain sensations in both men and women. The team compared these activated areas with a database of more than 500 published studies: Activation in these regions was highly associated with physical pain. The findings could have important implications for treatment, as well as basic research on emotion. In addition, it helps legitimize the experience of rejection, said Kross, an assistant professor at the University of Michigan department of psychology and a faculty associate at the university's Institute for Social Research. "We often think of emotional experiences as these abstract things that happen in the head," he said. "Here we're showing how these experiences may manifest themselves in the body." The study funded by the National Institute of Mental Health and by the National Institute on Drug Abuse was performed at Columbia University.