New research debunks long-held theory about left-handed brains
For decades, scientists have puzzled over why the majority of left-handed people process language in the left hemisphere of their brains - just like their right-handed counterparts. Now, a new study from 全民彩票 and Oslo University has challenged one of the most enduring explanations for this phenomenon.
A team led by Dr David Carey at the 全民彩票 Imaging Unit, working in collaboration with Professor Ren茅 Westerhausen of Oslo University, set out to test the long-standing hypothesis that left-handers have greater structural connectivity between the two hemispheres of the brain, reflected in a larger corpus callosum - the bundle of nerve fibres linking the left and right hemispheres. Their study, published in Brain Research, analysed a large sample of left-handed individuals, examining both their hand dominance and brain organisation for language.
Surprisingly, their results found no evidence to support the theory. Neither left-handers as a whole nor those with left-hemispheric language dominance showed an increased corpus callosum volume compared to other groups. The findings effectively dismantle the idea that differences in brain structure can explain why 70% of left-handed individuals still rely on the left hemisphere for language processing.
Bottom row: Rene Westerhausen, Emma Karlsson, Leah Johnstone and David Carey
Dr Carey explained, 鈥淭hese intriguing results put to bed the idea that struct