Navigation Links
Right or left? Brain stimulation can change which hand you favor

BERKELEY Each time we perform a simple task, like pushing an elevator button or reaching for a cup of coffee, the brain races to decide whether the left or right hand will do the job. But the left hand is more likely to win if a certain region of the brain receives magnetic stimulation, according to new research from the University of California, Berkeley.

UC Berkeley researchers applied transcranial magnetic stimulation (TMS) to the posterior parietal cortex region of the brain in 33 right-handed volunteers and found that stimulating the left side spurred an increase in their use of the left hand.

The left hemisphere of the brain controls the motor skills of the right side of the body and vice versa. By stimulating the parietal cortex, which plays a key role in processing spatial relationships and planning movement, the neurons that govern motor skills were disrupted.

"You're handicapping the right hand in this competition, and giving the left hand a better chance of winning," said Flavio Oliveira, a UC Berkeley postdoctoral researcher in psychology and neuroscience and lead author of the study, published this week in the journal Proceedings of the National Academy of Sciences.

The study's findings challenge previous assumptions about how we make decisions, revealing a competitive process, at least in the case of manual tasks. Moreover, it shows that TMS can manipulate the brain to change plans for which hand to use, paving the way for clinical advances in the rehabilitation of victims of stroke and other brain injuries.

"By understanding this process, we hope to be able to develop methods to overcome learned limb disuse," said Richard Ivry, UC Berkeley professor of psychology and neuroscience and co-author of the study.

At least 80 percent of the people in the world are right-handed, but most people are ambidextrous when it comes to performing one-handed tasks that do not require fine motor skills.

"Alien hand syndrome," a neurological disorder in which victims report the involuntary use of their hands, inspired researchers to investigate whether the brain initiates several action plans, setting in motion a competitive process before arriving at a decision.

While the study does not offer an explanation for why there is a competition involved in this type of decision making, researchers say it makes sense that we adjust which hand we use based on changing situations. "In the middle of the decision process, things can change, so we need to change track," Oliveira said.

In TMS, magnetic pulses alter electrical activity in the brain, disrupting the neurons in the underlying brain tissue. While the current findings are limited to hand choice, TMS could, in theory, influence other decisions, such as whether to choose an apple or an orange, or even which movie to see, Ivry said.

With sensors on their fingertips, the study's participants were instructed to reach for various targets on a virtual tabletop while a 3-D motion-tracking system followed the movements of their hands. When the left posterior parietal cortex was stimulated, and the target was located in a spot where they could use either hand, there was a significant increase of the use of the left hand, Oliveira said.


Contact: Yasmin Anwar
University of California -- Berkeley

Related medicine news :

1. Women Can Safely Get Pregnant Right After Miscarriage, Study Shows
2. Write the Right Words Answers What-to-Write Questions
3. CWRU study finds visually impaired people get insulin pen dosages right
4. Highlighting a Bright Spot in a Down Economy, Career Step to Re-launch Online Healthcare Training Program
5. Full reproductive and sexual health rights essential for maternal health goals
6. Bright Green Leadership Partners with TriplePundit to Help Businesses Improve Their Green Marketing Online
7. Henry Ford Hospital: New left-side heart pump improves right-side heart function
8. Dedicate Server and VPS Hosting Provider Company HostRightNow Technologies Partners with SmarterTools Inc.
9. Pennsylvania's Newest Power Companies Right in Your Neighbor's Back Yard
10. Citizen Stock Launches Industry's First Rights Managed Database of Images Shot Exclusively Against White
11. With the Right Approach, Plastic Surgery for Teens and Young Adults is Now a Positive Experience
Post Your Comments:
(Date:11/29/2015)... (PRWEB) , ... November 29, 2015 , ... Khanna Vision ... Board of Ophthalmology on November 25th 2015. Peer Certification by the Board ... of his specialty. Certification in Ophthalmology is first obtained after the completion of three ...
(Date:11/29/2015)... IL (PRWEB) , ... November 29, 2015 , ... Effective ... In addition starting on Black Friday Target is offering a “Buy One ... This is a rare opportunity to purchase IguanaMed at a discounted price. ...
(Date:11/28/2015)... (PRWEB) , ... November 28, 2015 , ... Trying to ... has created the COUCH BUDDY. "I conceived of this design due to personal experience ... for couch users. It promotes relaxation and convenience, as well as increases support. It ...
(Date:11/27/2015)... Angeles, CA (PRWEB) , ... November 27, 2015 , ... ... conversation at the recent 2015 American Dental Association meeting in Washington D.C. revolved around ... help protect a patient’s overall health. The talk stressed the link between periodontal disease ...
(Date:11/27/2015)... , ... November 27, 2015 , ... A team of ... ways to treat it. Surviving Mesothelioma has just posted the findings on the website. ... Hospital Zurich analyzed the cases of 136 mesothelioma patients who were treated with chemotherapy ...
Breaking Medicine News(10 mins):
(Date:11/26/2015)... 26, 2015 3D bioprinting market ... to a new report by Grand View Research Inc. Rising ... which demands kidney transplantation is expected to boost the market ... for organ transplantation. --> 3D bioprinting market ... to a new report by Grand View Research Inc. Rising ...
(Date:11/26/2015)... , November 26, 2015 ... of the "2016 Future Horizons and ... Abuse Testing Market: Supplier Shares, Country Segment ... to their offering. --> ... "2016 Future Horizons and Growth Strategies ...
(Date:11/26/2015)... India , November 26, 2015 ... --> adds ... Report" and "Investigation Report on China ... and 2021 forecasts data and information ... . ...
Breaking Medicine Technology: