Right-handers, but not left-handers, are biased to select their dominant hand

New study sheds light on what causes us to choose right over left

2011-03-09

(Press-News.org) Milan, Italy, 8 March 2011 – The vast majority of humans – over 90% – prefer to use their right hand for most skilled tasks. For decades, researchers have been trying to understand why this asymmetry exists. Why, with our two cerebral hemispheres and motor cortices, are we not equally skilled with both hands? A study from the University of Aberdeen in the UK, published in the April 2011 issue of Elsevier's Cortex (http://www.sciencedirect.com/science/journal/00109452), suggests that the explanation may stem from actions that require us to use both hands at the same time, which may bias right-handers toward choosing their right hands.

Gavin Buckingham, now a postdoctoral researcher at the Centre for Brain and Mind at the University of Western Ontario in Canada, and his PhD supervisor Dr. David Carey, asked left- and right-handed participants to reach first toward a pair of targets with both hands at the same time and, immediately afterwards, toward a new single target with only their closest hand. Just before they began the reach, subjects were given a short vibratory pulse on one of their hands, giving them a clue about where the new target would appear, and hence which hand should perform this second portion of the reach. On a small proportion of trials, the pulse was given to the wrong hand, which meant that subjects had to restrain the reach with this incorrectly-cued hand in order to make the reach with the correct hand.

The right-handed subjects had far greater trouble dealing with this incorrect cue when it was given to their right hands, making more mistakes and taking longer to successfully inhibit the reaches, almost as if the right hand was already pre-selected to carry on during the bimanual reach. The left-handed subjects showed no such asymmetries, suggesting that they are less inherently biased to select one hand over the other.

These findings build on a series of studies from the same researchers which have indicated that right-handers have their attention largely directed at their right hands during bimanual tasks. "One explanation for these data is that hand choice is related to hemispheric specialisation for speech and language" says Dr Carey. "Many left-handed people have "right-handed" brains, which weakens the typical bias towards choosing their dominant left hand."

### Notes to Editors: The article is "Asymmetries in motor attention during a cued bimanual reaching task: Left and right handers compared" by Gavin Buckingham, Julie C. Main, David P. Carey, and appears in Cortex, Volume 47, Issue 4 (April 2011), published by Elsevier in Italy. Full text of the article featured above is available to members of the media upon request. Please contact the Elsevier press office, newsroom@elsevier.com. To schedule an interview, contact Dr. Gavin Buckingham, gbucking@uwo.ca.

About Cortex Cortex is an international journal devoted to the study of cognition and of the relationship between the nervous system and mental processes, particularly as these are reflected in the behaviour of patients with acquired brain lesions, normal volunteers, children with typical and atypical development, and in the activation of brain regions and systems as recorded by functional neuroimaging techniques. It was founded in 1964 by Ennio De Renzi. The Editor in-chief of Cortex is Sergio Della Sala, Professor of Human Cognitive Neuroscience at the University of Edinburgh. Fax: 0131 6513230, e-mail: cortex@ed.ac.uk. Cortex is available online at http://www.sciencedirect.com/science/journal/00109452

About Elsevier Elsevier is a world-leading publisher of scientific, technical and medical information products and services. The company works in partnership with the global science and health communities to publish more than 2,000 journals, including The Lancet and Cell, and close to 20,000 book titles, including major reference works from Mosby and Saunders. Elsevier's online solutions include SciVerse ScienceDirect, SciVerse Scopus, Reaxys, MD Consult and Nursing Consult, which enhance the productivity of science and health professionals, and the SciVal suite and MEDai's Pinpoint Review, which help research and health care institutions deliver better outcomes more cost-effectively.

A global business headquartered in Amsterdam, Elsevier employs 7,000 people worldwide. The company is part of Reed Elsevier Group PLC, a world-leading publisher and information provider, which is jointly owned by Reed Elsevier PLC and Reed Elsevier NV. The ticker symbols are REN (Euronext Amsterdam), REL (London Stock Exchange), RUK and ENL (New York Stock Exchange).

ELSE PRESS RELEASES FROM THIS DATE:

Boy toddlers need extra help dealing with negative emotions

2011-03-09

URBANA – The way you react to your two-year-old's temper tantrums or clinginess may lead to anxiety, withdrawal and behavior problems down the road, and the effect is more pronounced if the child is a boy who often displays such negative emotions as anger and social fearfulness, reports a new University of Illinois study. "Young children, especially boys, may need their parents' help working through angry or fearful emotions. If you punish toddlers for their anger and frustration or act as if their fears are silly or shameful, they may internalize those negative emotions, ...

Study analyzes role of PARP enzyme in eukaryotes

2011-03-09

An Ohio State University molecular biologist leveraged a supercomputer to help better define the family tree of a group of enzymes that have been implicated in a wide range of human diseases and are important targets for anti-cancer therapies. Along with several OSU colleagues, Rebecca S. Lamb, Ph.D., an assistant professor of Molecular Genetics, recently analyzed the evolutionary history of the poly(ADP-ribose)polymerase (PARP) superfamily. These proteins are found in eukaryotes, a wide range of organisms – animals, plants, molds, fungi, algae and protozoa –whose ...

As we sleep, speedy brain waves boost our ability to learn

2011-03-09

Scientists have long puzzled over the many hours we spend in light, dreamless slumber. But a new study from the University of California, Berkeley, suggests we're busy recharging our brain's learning capacity during this traditionally undervalued phase of sleep, which can take up half the night. UC Berkeley researchers have found compelling evidence that bursts of brain waves known as "sleep spindles" may be networking between key regions of the brain to clear a path to learning. These electrical impulses help to shift fact-based memories from the brain's hippocampus ...

How long does a tuning fork ring?

2011-03-09

This release is available in German. From the wooden bars in a xylophone or the head of a drum, to the strings and sound box of a guitar or violin, musical instruments are the most familiar examples of mechanical resonators. The actual mechanical vibrations of these instruments create acoustic waves that we hear as sound. The purity of the emitted tone is intimately related to the decay of the vibration amplitude, that is, the mechanical losses of the system. A figure of merit for mechanical losses is the quality factor, simply called "Q", which describes the number ...

First census finds surprisingly few white sharks off California

2011-03-09

In the first census of its kind, research led by UC Davis and Stanford University found that there are far fewer white sharks off central California than biologists had thought. The study, published today in the journal Biology Letters, is the first rigorous scientific estimate of white shark numbers in the northeast Pacific Ocean. It is also the best estimate among the world's three known white-shark populations (the others are in Australia/New Zealand and South Africa). The researchers went out into the Pacific Ocean in small boats to places where white sharks congregate. ...

Cleansing the soul by hurting the flesh: The guilt-reducing effect of pain

2011-03-09

Lent in the Christian tradition is a time of sacrifice and penance. It also is a period of purification and enlightenment. Pain purifies. It atones for sin and cleanses the soul. Or at least that's the idea. Theological questions aside, can self-inflicted pain really alleviate the guilt associated with immoral acts? A new study published in Psychological Science, a journal of the Association for Psychological Science, explores the psychological consequences of experiencing bodily pain. Psychological scientist Brock Bastian of the University of Queensland, Australia and ...

March GSA Today: The case for a neoproterozoic oxygenation event

2011-03-09

The Cambrian "explosion" of multicellular animal life is one of the most significant evolutionary events in Earth's history. But what was it that jolted the Earth system enough to prompt the evolution of animals? While we take the presence of oxygen in our atmosphere for granted, it was not always this way. The Neoproterozoic era that preceded the Cambrian explosion of life was witness to a dramatic rise in oxygen levels. It has been widely assumed that the rise in atmospheric oxygen was the essential precursor to the evolution of animals. But the work of Graham Shields-Zhou ...

UNC study finds oral tongue cancer increasing in young, white females

2011-03-09

Chapel Hill, NC – A UNC study released this week in the Journal of Clinical Oncology finds an increasing incidence of squamous cell carcinoma of the oral tongue in young white females in the United States over the last three decades. A team of researchers from UNC Lineberger Comprehensive Cancer Center analyzed data from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) database and found that, between 1975 and 2007, the overall incidence for all ages, genders, and races of the disease was decreasing. However, the incidence of oral tongue ...

Real March Madness is relying on seedings to determine Final 4

2011-03-09

CHAMPAIGN, Ill. — Think picking all the top-seeded teams as the Final Four in your March Madness bracket is your best bet for winning the office pool? Think again. According to an operations research analysis model developed by Sheldon H. Jacobson, a professor of computer science and the director of the simulation and optimization laboratory at the University of Illinois, you're better off picking a combination of two top-seeded teams, a No. 2 seed and a No. 3 seed. "There are patterns that exist in the seeds," Jacobson says. "As much as we like to believe otherwise, ...

It's all in a name: 'Global warming' vs. 'climate change'

2011-03-09

ANN ARBOR, Mich.---Many Americans are skeptical about whether the world's weather is changing, but apparently the degree of skepticism varies systematically depending on what that change is called. According to a University of Michigan study published in the forthcoming issue of Public Opinion Quarterly, more people believe in "climate change" than in "global warming." "Wording matters," said Jonathon Schuldt, the lead author of the article about the study and a doctoral candidate in the U-M Department of Psychology. Schuldt co-authored the study with U-M psychologists ...

Right-handers, but not left-handers, are biased to select their dominant hand

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: