Sunday, May 10, 2009

'Free will' spot found in brain

LONDON: Researchers in France have identified the place where free will resides.

Lead scientist Angela Sirigu, a neuroscientist at the CNRS Cognitive Neuroscience Centre in Bron, say that the place lies towards the back of the brain called the parietal cortex.

The finding was made when a neurosurgeon electrically jolted this region in patients undergoing surgery, they felt a desire to wiggle their finger, roll their tongue or move a limb.

Stronger electrical pulses convinced patients they had actually performed these movements, although their bodies remained motionless, reports New Scientist.

"What it tells us is there are specific brain regions that are involved in the consciousness of your movement," says Sirigu.

Sirigu's team, including neurosurgeon Carmine Mottolese, performed the experiments on seven patients undergoing brain surgery to remove tumours.

In all but one case, the cancers were located far from the parietal cortex and other areas that Mottolese stimulated.

The team's work points to two brain areas involved in the decision to move a limb and then execute the action.

Sirigu believes that the parietal cortex makes predictions about future movements and sends instructions to another brain area, the premotor cortex, which returns the outcome of the movement to the parietal cortex.

The study has been published in the journal Science.

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