Can magnet turn a left-hander to right-handed?

A powerful magnetic field can temporarily confuse the brain and alter our hand preference.

Last Updated: Sep 28, 2010, 16:02 PM IST

London: A powerful magnetic field can temporarily confuse the brain and alter our hand preference, a new study has found.

In an extraordinary experiment by researchers at the University of California found that volunteers hand choice was changed when they were subjected to a powerful magnetic field.

Although the effects lasted till the magnet was switched on, the study threw light on the origin of hand choice in the brain, the researchers said.

It also highlighted that how it is easy to change people`s behaviour with magnets, they added.

Dr Flavio Oliveira, who led the study, said: "We are not really looking at handedness, but at hand choice. We found that in situations where people are almost equally likely to
use their left or right hand we can make them use their left hand more by stimulating this part of the brain."

"Before you reach out to press an elevator button or grab a coffee cup your brain is making a decision about which hand to use. We are handicapping one of the hands so that the other one wins," Dr Oliveira was quoted as saying by the Daily Mail.

Earlier this year, a similar study showed that magnetic therapy can alter people`s moral judgements -- and make them behave more thoughtlessly.

For the new study, which looked at how the brain decides which hand to use for a simple task such as picking up a pencil or pressing the button on a lift, the researchers asked
right-handed volunteers to reach with either hand towards an object on a table.

They then disrupted the volunteer`s brain using a powerful hand-held magnet used in a type of therapy called transcranial magnetic stimulation.

According to the scientists, the magnet generates a magnetic field on a small part of the skull which creates weak electric currents in the brain. The currents interfere with nearby brain cells and prevent them from firing normally.

During the study, the magnet was placed next to the left and right "posterior parietal cortex" -- a region that deals with planning and working out the relationship between three dimensional objects.

When the magnet was placed on the left side of the brain region, the volunteers used their left hand more frequently than when the magnet was switched off.

Applying the magnet to the right side of the region made no difference, found the scientists who detailed their findings in the journal Proceedings of the National Academy of Sciences.

Bureau Report