What makes a lefty myths and mysteries persist

But that could change. But to truly study handedness, researchers have to look to the brain. To study the motor cortex, researchers often look at how much oxygen is being consumed in parts of the brain during tasks via fMRI, or through a different technique that assesses connections within the nervous system called transcranial magnetic simulation TMS.

Using these techniques, researchers have identified connections between cortex development and handedness. So, in left-handers, the right part of the motor cortex is better developed. But, the imbalance is much less strong. If motor cortex development differs based on handedness, then what would happen if a person suddenly lost the ability to use his or her dominant hand?

In that case, it turns out lefties might have an advantage. Beyond movement, other brain functions like the ability to recognize faces are also tied to handedness and brain organization. You must log in or sign up to reply here. Show Ignored Content. Your name or email address: Do you already have an account? No, create an account now. Yes, my password is: Forgot your password?

Login Register New Post. Search Media New Media. View Donations. Open New Ticket. Despite such challenges, 10 to 12 percent of the human population has historically preferred the left hand. Nobody knows for sure, but new research supports a body of evidence that suggests genetics have a hand in it all. In the meantime, the myth remains that lefties are more artistic. Like many traits, handedness is probably determined by a complex interaction between genes and the environment, experts figure.

Left-handers are more likely to have a left-handed relative. But researchers have yet to find the gene or set of genes that pick one hand over the other. Most scientists agree that handedness exists on a continuum.

The idea helps explain why some people bowl with their left but hold a spoon in their right. Truly ambidextrous people, who have indifferent preference for either hand, are extremely rare. In a new study, researchers measured the width of elbows in living people and in skeletons from a medieval British farming community. The researchers assumed the 9-to-1 ratio of handedness would match the ratio of bigger right to left elbows. The prediction held true in the modern-day group, but not for the medieval bones.

The findings will be published in the April issue of the journal Current Anthropology. In popular culture, the topic of left-handedness is usually introduced by presenting a long list of famous people who possess this trait, which has cemented the idea of the brilliant left-handers. And yet this may be more legend than fact: some claim to have traced the sources and assert that there is no reliable data on many of the names on the lists.

In other cases there are nuances: Mark Twain was a right-handed man who was forced to write with the left because of the rheumatism that affected him on the right. In the case of Leonardo da Vinci, it is said that he drew with the left and painted with the right , until an injury rendered his right hand useless. As far as historical figures are concerned, it is no surprise that finding evidence of left-handed women is even more difficult. This was the case for Michelangelo , a left-handed sculptor who trained himself to paint with his right hand.

This imposition gave rise to famous ambidextrous figures, such as scientist Nikola Tesla. But even discounting dubious or false cases, names like Da Vinci, Michelangelo or Tesla seem to support the idea of the left-handed genius. Is there any truth in this? There does exist some specialisation of the cerebral hemispheres and their regions in some functions, and it is well known that each of them controls the opposite half of the body. However, the idea that each person is dominated by one hemisphere or the other, and that left-handers use the creative right side of their brains more, is just a myth.

In fact, if left-handedness simply consisted of an inversion of the cerebral hemispheres, the mystery would be solved. These data suggest variations in brain wiring in left-handed people, an idea confirmed by neuroimaging studies. According to Douaud, lefties have structural differences in the white matter tracts —the large neural highways—that connect language regions.