October 29, 2008

Hate And Love Activate Same Areas Of Brain

Scientists at University College London (UCL) may have finally found an answer to explain the fine line between love and hate.

UCL researchers Semir Zeki and John Paul Romaya discovered that brain scans of volunteers who were shown images of people they hated revealed activity that occurs in the same areas set off by romantic love.

"This linkage may account for why love and hate are so closely linked to each other in life," wrote UCL researchers Semir Zeki and John Paul Romaya in a report about the study. 

"Our results show that there is a unique pattern of activity in the brain in the context of hate."

The researchers showed 17 men and women photos of someone the volunteers said they hated --all either former lovers, work rivals or a famous politician.  The participants were also shown pictures of three familiar, neutral individuals.   

The scientists obtained brain scans of the participants, and identified patterns within different areas of the brain the researchers dubbed a "hate circuit".  These areas include structures in the cortex and sub-cortex, and exhibit a pattern distinct from emotions such as fear, threat and danger, Zeki told Reuters.  This area would switch on when people saw the faces they hated, the researchers said.

"As far as we can determine it is unique to the sentiment of hate even though individual sites within it have been shown to be active in other conditions that are related to hate," they wrote.

One part of the brain that became activated was an area believed critical in predicting other people's actions, something important for confronting a hated enemy, said the researchers.

The brain activity also occurred in the insula and putamen, areas that also become activated when people view faces of loved ones.  Zeki said scientists have linked the regions to stressful situations and aggressive action.

However, the study found significant differences as well.  A larger part of the cerebral cortex, an area associated with judgment and reasoning, de-activates with love compared to hate.  And while both emotions are all-consuming passions, people in love may be less judgmental and critical, while needing to keep focus when dealing with a hated rival, the scientists said.

"It is more likely that in the context of hate the hater may want to exercise judgment in calculating moves to (cause) harm," Zeki said in a statement.

The research was published in the Public Library of Science journal PLoS One.


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