Things that change the world: Brain’s ‘Hate Circuit’ Identified

This is your brain on “hate”:

Hating another individual lights up brain areas associated with disgust, contempt and also — romantic love.

Zeki S, Romaya JP (2008) Neural Correlates of Hate. PLoS ONE 3(10): e3556. doi:10.1371/journal.pone.0003556

Astonishing.

Drs. Zeki and Romaya have previously studied “love”. Because, in that cosmic fashion, love and hate are so connected, they chose to study hatred of an individual (as opposed to hatred of a “group”). Subjects could hate for whatever reason they wanted, whether the object of the “hate” was a public figure or known personally, provoked or unprovoked.

Interestingly, of the 17 subjects (10 male), most chose ex-lovers or work competitors. One female chose a very famous political figure.  Whether people “feared” and “hated” is unclear, but perhaps the results account for any “fear” confounding effects.

Subjects were shown the face of the “hated” person, and their brains were scanned.  (See the full paper for the methods), and the degree of hatred was assessed using a generally accepted “hate” questionnaire.

Viewing a hated face resulted in increased activity in the medial frontal gyrus, right putamen, bilaterally in premotor cortex, in the frontal pole and bilaterally in the medial insula. Three areas where activation correlated linearly with the declared level of hatred were the right insula, right premotor cortex and the right fronto-medial gyrus.

Drs. Zeki and Romaya  make another startling observation:

the “hate deactivation” area is close to the “obsessive compulsive” brain.  Cooling down from hate

. . .[involves] the right superior frontal gyrus. The deactivated locus in the frontal cortex is close in position to the one which previous studies had shown to be negatively correlated with obsessive-compulsive states [citation omitted], a deactivation hypothesized to relate to a shift in attention from extrapersonal space to an internal experience associated with anxiety. . . .

This explains the intensity and ferocity of haters — just like people with OCD cannot help but to pursue a single goal without rest. (I wonder if there is a reward-deficiency syndrome going on:  The putamen, found in both love and hate, has low-activity dopamine receptor 2 (D2 receptors); see here, for example. ).

Behaviorally and cognitively “hate” encompasses three attributes (to which the “hate” questionnaire is aimed): “. . .(a) negation of intimacy, when an individual seeks a distance from the hated person. This is usually because the hated person arouses feeling of revulsion and disgust, exactly the opposite of the desire for greater intimacy in the context of love; (b) passion, expressing itself in intense anger at, and fear of, the hated person; and (c) devaluation of the hated person through expressions of contempt.”

What switches love to hate? The fork in the neural road seems to be come before step  “a” above — the negation of intimacy. Here’s what I think is missing: imagination.  Or confabulation.

Hate, like love, involves making assumptions about the other, a “theory of mind”.  In love, you assume the object of your desire acts with sweetness and light; in hate, you believe the object of your desire acts despicably.

What about “hate” based upon misreading of social cues?  For instance, those with negative attributional bias show “hate” that, to the outside observer, appears to be totally unprovoked.  (Dr. Aaron Beck, in his book, “Prisoners of Hate,” describes this happening to him at a book signing: a random person accused Dr. Beck of feeling superior, and, therefore, by definition, considering this random person “less than.”)  There is a profound disconnect somewhere in those who confabulate the negative motivations of others.

“Confabulation” — making stuff up — may be associated with reduced activity in a region of medial ventro-caudal PFC/basal forebrain.

Yet, there are also “neglected” areas of the brain involved in hate — like the area producing “compassion”.  Is there a hemispheric neural traffic jam?  Brain hemisphere “task assignment”, the ability to use both sides of the brain, and the ability to switch rapidly between both brain hemispheres are all impaired to some extent in various conditions noted by impaired compassion (as distinct from empathy), like schizophrenia or borderline personality  or bipolar disorders. (Here, for example, is a PNAS paper about white matter growth in childhood onset schizophrenia).  Serotonin and serotonin receptor levels and locations probably also play a role in the aggression.

I’ve been waiting for this publication, ever since the original advert in Craig’s List for volunteers. Do people who feel love also feel hate? Do people who hate feel love? Can you feel love and hate at the same time? Is hatred what’s left over when you remove the ability to feel compassion for another? Do animals feel hate?

From the PLoSOne (emphasis added):

Brain’s ‘Hate Circuit’ Identified

People who view pictures of someone they hate display activity in distinct areas of the brain that, together, may be thought of as a ‘hate circuit’, according to new research by scientists at UCL (University College London).

The study, by Professor Semir Zeki and John Romaya of the Wellcome Laboratory of Neurobiology at UCL, examined the brain areas that correlate with the sentiment of hate and shows that the ‘hate circuit’ is distinct from those related to emotions such as fear, threat and danger – although it shares a part of the brain associated with aggression. The circuit is also quite distinct from that associated with romantic love, though it shares at least two common structures with it.

The results, published October 29 in the online, open-access journal PLoS ONE, are an extension of previous studies on the brain mechanisms of romantic and maternal love from the same laboratory. Explaining the idea behind the research, Professor Zeki said:

“Hate is often considered to be an evil passion that should, in a better world, be tamed, controlled, and eradicated. Yet to the biologist, hate is a passion that is of equal interest to love. Like love, it is often seemingly irrational and can lead individuals to heroic and evil deeds. How can two opposite sentiments lead to the same behaviour?”

To compare their present results with their previous ones on romantic love, Zeki and Romaya studied specifically hate directed against an individual. Seventeen subjects, both female and male, had their brains scanned while viewing pictures of their hated person as well as that of neutral faces with which they were familiar. Viewing a hated person showed activity in distinct areas of the brain that, together, may be thought of as a ‘hate circuit’.

The ‘hate circuit’ includes structures in the cortex and in the sub-cortex and has components that are important in generating aggressive behaviour, and translating this into action through motor planning, as if the brain becomes mobilised to take some action. It also involves a part of the frontal cortex that has been considered critical in predicting the actions of others, probably an important feature when one is confronted by a hated person.

The subcortical activity involves two distinct structures, the putamen and insula. The former, which has been implicated in the perception of contempt and disgust, may also be part of the motor system that is mobilised to take action, since it is known to contain nerve cells that are active in phases preparatory to making a move.

Professor Zeki added: “Significantly, the putamen and insula are also both activated by romantic love. This is not surprising. 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.

“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 judgment and reasoning become de-activated, with hate only a small zone, located in the frontal cortex, becomes de-activated. 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 judgmental regarding the loved person, it is more likely that in the context of hate the hater may want to exercise judgment in calculating moves to harm, injure or otherwise extract revenge.

“Interestingly, the activity in some of these structures in response to viewing a hated face is proportional in strength to the declared intensity of hate, thus allowing the subjective state of hate to be objectively quantified. This finding may have legal implications in criminal cases, for example.”

Unlike romantic love, which is directed at one person, hate can be directed against entire individuals or groups, as is the case with racial, political, or gender hatred. Professor Zeki said that these different varieties of hate will be the subject of future studies from his laboratory.

The Wellcome Laboratory of Neurobiology at UCL is supported by the Wellcome Trust.
Zeki S, Romaya JP (2008) Neural Correlates of Hate. PLoS ONE 3(10): e3556. doi:10.1371/journal.pone.0003556

http://dx.plos.org/10.1371/journal.pone.0003556

(Figure above is Figure 4 from the paper, cropped for only the cross sectional view).

The open-access journal PLoS One (www.plosone.org) is the source for this article. All works published in PLoS ONE are open-access. Everything is immediately available—to read, download, redistribute, include in databases and otherwise use—without cost to anyone, anywhere, subject only to the condition that the original authorship and source are properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.

(Also via PLoS):

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UCL is in the top ten world universities in the 2007 THES-QS World University Rankings, and the third-ranked UK university in the 2008 league table of the top 500 world universities produced by the Shanghai Jiao Tong University. UCL alumni include Marie Stopes, Jonathan Dimbleby, Lord Woolf,
Alexander Graham Bell, and members of the band Coldplay.

The Wellcome Trust
The Wellcome Trust is the largest charity in the UK. It funds innovative biomedical research, in the UK and internationally, spending around £600 million each year to support the brightest scientists with the best ideas. The Wellcome Trust supports public debate about biomedical research and its
impact on health and wellbeing. http://www.wellcome.ac.uk

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