News in Science-The anatomy of a broken heart

October 10, 2003
By Anna Sellah
ABC Science Online

A social snub and a big-toe stub can generate a similar response in the brain, suggesting emotional and physical pain are more closely related than was previously thought.

Naomi Eisenberger and Dr Matthew Lieberman of the University of California Los Angeles and Professor Kipling Williams of Macquarie University in Sydney report their new functional magnetic resonance imaging (MRI) study in todayís issue of the journal Science.

The researchers set out to test the idea that the brain responds to social pain in a similar way to physical pain. To do this, they used magnetic resonance imaging (MRI) to observe the blood flow in the brains of 17 subjects as they participated in a virtual ball-tossing video game.

During a baseline phase of the study, the subjects were led to believe they were only observing the game. This was followed by a phase where their virtual playmates stopped throwing them the ball, excluding them from them game.

At this point, there were changes in the brainís blood flow. The anterior cingulate cortex was found became more active, while an area in the prefrontal cortex became less active.

The anterior cingulate cortex is a region of the brain that has previously been linked to physical pain distress, and the prefrontal cortex is already known to manage or regulate distress.

ìThis suggests the anterior cingulate is more important for elaborating feelings of emotional distress, whereas the prefrontal cortex, already implicated in emotional regulationÖcounteracts the painful feeling of being shunned,î comments Dr Jaak Panksepp of Bowling Green State University in Ohio in an accompanying article.

In a further interesting twist to the study, researchers created a situation where participants were excluded from the game, but only in an unintentional way. In this case, the prefrontal cortex did not become activated, suggesting that parts of the brain associated with managing distress can distinguish between a personal snub and an exclusion which is nobodyís fault.

The ancient Greek philosopher, Zeno considered pain to be one of the nine forms of grief, said Panksepp who himself was involved in studies over two decades ago which showed similar results in animals. He described the new study as ìa bold neuroimaging experimentî which sought to discover ìwhether the metaphor for the psychological pain of social loss is reflected in the neural circuitry of the human brainî.

Panksepp suggests that the research may even help explain the physical basis of a broken heart.

ìThroughout history poets have written about the pain of the broken heart. It seems that such poetic insights into the human condition are now supported by neurophysiology findings. Will the opposite also prove to be the case ‚ that socially supportive and loving feelings reduce the sting of pain?,î he asks.

ìWill we eventually discover that the feeling of a broken heart arises from the rich autonomic circuits of the brainís limbic system that control cardiac neurodynamics? Will we find that people we consider ìcoldî or ìwarmî influence different thermoregulatory neural pathways in our brains?î

Panksepp argues the feelings induced by the experimental game in the study by Eisenberger and colleagues are ìa pale shadow of the real-life feelings that humans and other animals experience in response to the sudden loss of social supportî.

ìIt will be interesting to study more intense emotional states arising from profound personal loss with MRI,î he says.