Brain's 'hate circuit' identified
29 October 2008
The study, published in PLoS One, examines the brain areas that correlate with hate and shows that the areas that form the ‘hate circuit’ are distinct from those related to emotions such as fear, threat and danger - but share at least two common structures with romantic love.
In all, 17 subjects had their brains scanned while viewing pictures of a person they hated, as well as the faces of ‘neutral’ people with whom they were familiar but had no strong feelings about.
Viewing a hated person activated distinct areas of the brain. These included structures and components that are important in generating aggressive behaviour and translating this into action. It also involved a part of the frontal cortex that has been considered critical in predicting the actions of others.
Significantly, the activity involved two distinct structures called the putamen and insula, which are activated by romantic love. The putamen has also been implicated in the perception of contempt and disgust.
The crossover of love and hate is not surprising, according to Professor Semir Zeki, co-author of the study.
“The putamen could also be involved in the preparation of aggressive acts in a romantic context, as in situations when a rival presents a danger. Previous studies have suggested that the insula may be involved in responses to distressing stimuli, and the viewing of both a loved and a hated face may constitute such a distressing signal.”
But, he said, “a marked difference in the cortical pattern produced by these two sentiments of love and hate is that, whereas with love large parts of the cerebral cortex associated with judgement and reasoning become deactivated, with hate only a small zone, located in the frontal cortex, becomes deactivated.”
“This may seem surprising since hate can also be an all-consuming passion, just like love. But whereas in romantic love the lover is often less critical and judgemental regarding the loved person, it is more likely that, in the context of hate, the hater may want to exercise judgement in calculating moves to harm, injure or otherwise extract revenge.”
The study looked specifically at hate directed against an individual. Future studies will investigate hate against groups, as is the case with racial, political or gender hatred.
Image: I Hate How Much I Love You; SheWatchedTheSky, www.flickr.com/photos/shewatchedthesky/2914899358/
References
Zeki S and Romaya J P. Neural Correlates of Hate. PLoS ONE, 29 October 2008.