Researchers map the sources of empathy in the brain

Using fMRI, researchers show that both the intuitive and rational parts of the brain likely work in tandem to create empathy.

According to a new study from University of Southern California (USC), both the intuitive and rational parts of the brain (often called right-brain and left-brain) work in tandem to create the sensation of empathy. Even failing to possess a full complement of limbs will not stop your brain from understanding what it is like for someone else to experience pain in one of them. It may, however, change the way your brain does so. In a paper published online July 6, 2011 by Cerebral Cortex, USC researcher Lisa Aziz-Zadeh maps out the way the brain generates empathy, using functional magnetic resonance imaging (fMRI).

Example of an fMRI image. This scan shows the brain of a person who has been asked to look at faces. The image shows increased blood flow in the part of the visual cortex that recognizes faces. Image Credit: NIH

According to Aziz-Zadeh’s findings, empathy for someone to whom you can directly relate – for example, because they are experiencing pain in a limb that you possess – is mostly generated by the intuitive, sensory-motor parts of the brain. However, empathy for someone to whom you cannot directly relate relies more on the rational, logical part of the brain.

Lisa Aziz-Zadeh. Via USC

Though they are engaged in differing degrees depending on the circumstance, it appears that both the intuitive and rational parts of the brain work in tandem to create the sensation of empathy, said Aziz-Zadeh, assistant professor at USC’s Division of Occupational Science and Occupational Therapy. She said:

People do it automatically.

In an experiment, Aziz-Zadeh and a team from USC showed videos of tasks – performed by hands, feet, and a mouth – to a woman born without arms or legs, and also to a group of 13 typically developed women. The videos showed activities such as a mouth eating or a hand grasping an object.

fMRI statistics (yellow) overlaid on an image of the brain compiled from several people (gray). Via Wikipedia

Researchers also showed videos of pain (in the form of an injection) being inflicted on parts of the body.

While the participants watched the videos, researchers scanned their brains using fMRI, then compared the scans, revealing the differing sources of empathy.

In an additional finding, Aziz-Zadeh discovered that when the woman with no limbs viewed videos of tasks being performed that she could also perform – but using body parts that she did not have – the sensory-motor parts of her brain were still strongly engaged. For example, the participant can hold objects but uses a stump in conjunction with her chin to do so, rather than a hand.

If the goal of the action were impossible for her, then another set of brain regions involved in deductive reasoning were also activated.

A nurse practices patient care at Dil Chora Hospital in Ethiopia. Image Credit: U.S. Army Africa

Bottom line: USC researcher Lisa Aziz-Zadeh used fMRI to provide evidence that both the intuitive and rational parts of the brain are involved in empathy. Her findings appear in the online July 6, 2011 issue of Cerebral Cortex.

Via University of Southern California News Releases

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