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Entries in left-handed (3)

Monday
Aug132012

Left-Handers Day: The Science of the Southpaw

iStockphoto/Thinkstock(NEW YORK) -- About 10 percent of people write with their left hand -- a trait tenuously tied to intelligence and creativity.  And some experts say this small but steady legion sheds light on the brain.

"There are many things common across all minds and bodies, but there are sometimes striking differences," said Daniel Casasanto, assistant professor of psychology at the New School for Social Research in New York.  "These differences can be key to discovering how something works."

The left hand is guided by the right side of the brain -- the hemispheric home of orientation and intuition -- leading researchers to suspect lefties may be wired differently than their right-handed counterparts.

Despite their minority status, lefties are more likely to excel in music, mathematics and athletics, according to studies.  But left-handedness has also been linked to a higher risk of developmental disorders and mental illness.

"Handedness influences the way people think and feel, and how thoughts and feelings are organized in their brains," said Casasanto, who studies emotional processing in left-handers.  "It turns out to matter in a number of ways."

But despite decades of research, the biological origins of handedness remain a mystery.  It runs in families, suggesting some genetic influence, and can even be seen in the uterus: fetuses suck the right thumb more often than the left.  Some studies suggest stress in the womb might be to blame, as lefties are more likely to be born premature or have a low birth weight.

But forced to adapt to a right-hander's world, lefties are resilient.  Once considered gauche -- even sinister from the Latin word for "on the left" -- they tolerate teasing and, in some cases, attempts to rewire their handedness.

"Everyone assumed I should be able to switch and use my right hand," said Jane Angelich, a 60-year-old lefty from San Francisco.  "It's tough when you're a kid and you're different from everyone else.  But you grow out of it.  Now I love being a lefty."

Monday, Aug. 13, is international Left-Handers Day.

Copyright 2012 ABC News Radio

Tuesday
Sep272011

Lefty Legacy: Demystifying the Southpaw

iStockphoto/Thinkstock(LONDON) -- What do Lady Gaga, Queen Victoria, Michelangelo and President Obama all have in common? Whether signing a bill into law or painting a masterpiece, they all do it southpaw style.

Throughout the ages, lefties have made up a consistent 10 percent of the population, but the reasons behind this minority dexterity remain shrouded in mystery.  In his new book The Puzzle of Left-handedness, author Rik Smits attempts to shed a little light on this mystery, cataloging the lore, science, and historical "whiff of negativity" surrounding left-handedness.

Historically, left-handedness has been associated with all manner of  malady, from mental retardation, to cancer, criminality and working for the devil -- in fact, the word for "left" in Latin is "sinestra," the root word for "sinister." In more recent times, however, some psychologists have postulated that being left-handed is a sign of a strong right brain, and the language skills and creativity that are associated with this hemisphere. This is the argument made by University College London psychologist Chris McManus in his book Right-Hand, Left-Hand.  He also says that throughout history, lefties have made up a larger proportion of high achievers than would be expected given their minority status.

A look at the long list of celebrities, politicians, and historical figures that are southpaw seems to support McManus’  theory. After all, five out of the past seven U.S. presidents were lefties (George W. Bush and Jimmy Carter were not).  Many cultural icons of our day are lefties as well: Oprah, Gaga and Facebook's Mark Zuckerberg, to name a few.

But is there anything inherently special about lefties?

We know that they may be genetically different because a child is twice as likely to be left-handed if one of his parents is and four times as likely if both parents are lefties.  Other theories explaining left-handedness mention disturbances in hormones or slight brain damage while a child is still in the womb.  Smits offers yet another theory in his book: Lefties derive from identical twins.  Because identical twins can sometimes have mirror traits, he postulates that lefties arise when an embryo splits in the womb, leaving one twin righty and the other lefty.

The fact that twins are twice as likely to be lefty as non-twins offers some support to Smits' theory, but his ideas have never been scientifically tested.

For all their mythology, lefties are probably not some form of super-talented genetic mutant, Smits concludes: "Most left-handers are just left-handed, nothing more," he writes.

Copyright 2011 ABC News Radio

Thursday
Feb242011

Concussion Leaves 14-Year-Old Amnesic, Left-Handed

Photo Courtesy - Getty Images(SPANGLE, Wash.) -- After hitting her head during a high school basketball game, Mikayla Wilson lost her memory -- and became a leftie.

The 14-year-old from Spangle, Wash., was shoved to the ground after snatching a rebound during a high school basketball game.

"She didn't black out, she didn't grab her head in obvious injury," Wilson's dad, Michael, told ABC News affiliate KXLY 4. "She just got up and noticed her head hurt a little bit on the back. But basketball these days is a very physical game, and there's lots of contact."

After a fouled Wilson shot her free throws, she played two more quarters for the Liberty High Lancers. It wasn't until the team gathered after the game when Wilson asked her mom, Lorie, "Who are those girls dressed just like I am and why are they looking at me?" that anyone noticed anything wrong.

Wilson was taken to a hospital in nearby Colfax, where a CT scan ruled out skull fractures and bleeding inside the brain. The amnesia, doctors said, was a lingering symptom of a mild traumatic brain injury, better known as concussion.

"The brain has consistency of Jell-O and sits inside the skull, which is nature's helmet. When you hit your head, the brain can shift back and forth, causing injury at the site of impact and distant from it," said Dr. Alan Cohen, chief of pediatric neurosurgery and surgeon-in-chief at UH Rainbow Babies and Children's Hospital in Cleveland.

Concussions are a growing cause of worry in both childhood and professional sports. In December 2009, the National Football League cracked down on when players could return to a game after suffering a blow to the head.

"More and more, we're realizing that there are biochemical changes that go on in the brain during concussion, and that symptoms of post-concussion syndrome, like amnesia, can last for weeks or even months."

It has been nearly three weeks since the injury, and Wilson still can't remember the names of her friends and teammates. She has also switched from writing with her right hand to using her left -- a tweak that even her doctor had never seen.

"She had to sign something, and she grabbed the pen with her left hand," her father said, adding that she didn't notice until he pointed it out. "She said it felt more natural to use her left."

Wilson was ambidextrous as a young child, according to her dad. And although her new left-handed scrawl is imperfect, it's impressive. She has also used chopsticks with her left hand since the injury.

"It's unusual that someone should switch hands after a mild traumatic brain injury," Cohen said, adding that usually people switch hands after developing weakness in the dominant one. "Maybe there's something causing her to be weaker in her right hand. But the fact that she switched without realizing is interesting." 

Copyright 2011 ABC News Radio







ABC News Radio