Could magnet on head turn you from right to left-handed?



Placing a magnet on your head can temporarily turn you from a right-hander to a left-handed person, a new study suggests.



In an extraordinary experiment researchers used a powerful magnetic field to temporarily confuse the brains of volunteers and change their hand preferences.



The effects lasted only while the magnet was switched on and appears to have caused no lasting changes.

Experiment: Researchers used a powerful magnetic field to temporarily confuse the brains of volunteers and change their hand preferences

But the experiment sheds light on the origins of hand choice in the brain and highlights once again how easy it is to alter people's behaviour with magnets.



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

The new study 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.



Researchers at the University of California, Berkeley, 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.



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.

Researchers disrupted the volunteer's brain using a powerful hand-held magnet

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, the scientists report in Proceedings of the National Academy of Sciences.



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.'



Earlier this year, scientists discovered a real-life 'moral compass' in the brain that controls how we judge other people's behaviour.



The region, which lies just behind the right ear, becomes more active when we think about other people's misdemeanours or good works.



In an experiment, researchers at the Massachusetts Institute of Technology were able to use powerful magnets to disrupt this area of the brain and make people temporarily less moral.

The study highlighted how our sense of right and wrong isn't just based on upbringing, religion or philosophy - but by the biology of our brains.

