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Lefty Or Righty? Brain Stimulation Can Change Hand Preference

Are you left-handed or right-handed? A simple question, yes, but not when it comes to which hand your brain favors.

Transcranial Magnetic Stimulation

Researchers at UC Berkeley decided to do an experiment to see if hand preference could be changed.

They took 33 right-handed people and applied transcranial magnetic stimulation (TMS) to the posterior parietal cortex region of the brain. The parietal cortex plays a role in understanding spatial relationships and planning movements.


Researchers found that stimulating the left side of the parietal cortex increased the use of the left hand. The left hemisphere controls body movement for the right half of your body and vice versa.

Stimulating the parietal cortex disrupted the neurons that govern motor skills. In other words, this stimulation handicapped the right half of the body.

Future Use Of The Study

The study shows that TMS can manipulate what side of the body is in use. This is important for the future of stroke and/or other brain injury rehabilitation treatment.

Researchers are unable to answer why there is competition between hand preference. However, it makes sense that we change our hand preference for each unique situation we encounter.

Read More:

  • Right or left? Brain stimulation can change the hand you favor (UC Berkeley News)

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