Professor Zeki and John Romaya of the Wellcome Laboratory of Neurobiology analysed the activity of the neural circuits in the brain that lit up when the volunteers were viewing photos of the hated person.
They found that the hate circuit includes parts of the brain called the putamen and the insula, found in the sub-cortex of the organ. The putamen is already known to be involved in the perception of contempt and disgust and may also be part of the motor system involved in movement and action.
"Significantly, the putamen and the 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,"
One major difference between love and hate appears to be in the fact that large parts of the cerebral cortex – associated with judgement and reasoning – become de-activated during love, whereas only a small area is deactivated in hate.
