Experts estimate that at least 10% of people could be tone deaf - unable to sing in tune. Researchers at Harvard Medical School compared the brains of tone-deaf people to other people using a sophisticated imaging technique called diffusion tensor imaging. They found differences in the nerve fibres that link the perceptual and motor regions of the brain. These fibres, called the arcuate fasciculus, are known to be involved in linking music and language perception with vocal production. The study found that the arcuate fasciculus was smaller and had less fibres in tone-deaf people and one branch of the arcuate fasciculus in the right hemisphere could not be detected at all in the tuneless.
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