ScienceDaily (Oct. 29, 2008) 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 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 specifically studied hate directed against an
individual. Seven{*filter*} 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.

Journal reference:

Zeki et al. Neural Correlates of Hate. PLoS ONE, 2008; 3 (10): e3556
DOI: 10.1371/journal.pone.0003556
Adapted from materials provided by University College London, via
EurekAlert!, a service of AAAS.

http://www.***.com/