When attempting to compare how left-handed and right-handed people process information, Professor François Tremblay of the Faculty of Health Sciences and Travis Davidson, a PhD student in human kinetics, made an interesting discovery: about half of the people who considered themselves left-handed were in fact ambidextrous.
Moreover, while some studies claim that left-handed people process information between hemispheres more quickly, it is actually ambidextrous individuals who transfer information at a higher speed. The fact that many left-handed people are actually ambidextrous puts previous study results in question, said Tremblay. In reality, this new finding confirms that individuals who are closest to the ambidextrous spectrum are quicker to accomplish tasks which require both hands (e.g. typing or texting), possibly because their brain is also more interconnected.
Tremblay and his team wanted more accurate results for their research on handedness. Instead of simply asking participants about their handedness, they relied on a series of assessment tools, including questionnaires about hand preference and measures of manual performance.
One of the questionnaires asked participants which hand they prefer to use for various tasks. At the end of the assessment, each participant was placed on a handedness spectrum, from left-handed to right-handed, with ambidextrous candidates in the middle. The performance test assessed right-left differences in manual dexterity. Individuals categorized as ambidextrous performed tasks equally well with both hands. Furthermore, using non-invasive brain stimulation, the researchers also found that ambidextrous individuals not only displayed more efficient dexterity with their two hands, but also showed faster transfer time between the two motor areas of the brain than strict right or left-handers.
The study raises the possibility that it might be far more productive to focus on degrees of handedness, rather than using simple classifications such as right vs. left. It also raises an entire series of new questions: Are ambidextrous people born this way? Did they acquire the ambidextrous skill as left-handed people who were forced to adjust to a right-handed-oriented world?
Tremblay is further investigating issues related to handedness and lateralization processes in the brain. Stay tuned for more findings on this hot topic.
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