LOS ANGELES--Music may make the heart sing, but it also exerts a strong tug on the brain. Two studies presented here on Sunday at the annual meeting of the Society for Neuroscience show surprising effects of music on the cerebellum, as well as intriguing new functions for this structure common to vertebrates.
A peach-sized structure at the base of the brain, the cerebellum controls balance and muscle coordination in everything from fish to monkeys. But when neuroscientists Lawrence Parsons and Peter Fox of University of Texas Health Science Center in San Antonio ran PET scans on eight conductors as they listened to a Bach chorale and followed the score, the researchers found that the cerebellum helped the musicians interpret rhythm. When the team altered the rhythm of the chorale so it differed from the score, blood flow to the cerebellum increased, even though the conductors weren't moving a muscle. This indicated that an unexpected sensory, nonmotor function was occurring in this brain region.
The cerebellum's ear for music doesn't end there. According to results presented by neurologist Gottfried Schlaug of the Beth Israel Deaconess Medical Center in Boston, it also responds to musical training. To test whether years of playing an instrument altered the brain, Schlaug and his colleagues compared cerebellum volume in 90 musicians and nonmusicians. The cerebellums of musicians, they found, were 5% larger than those of nonmusicians, suggesting that years of precise finger movements beginning at an early age may stimulate extra nerve growth. The results show that "processing of music is much more distributed than one would expect from simple anatomy," says Hubert Dinse, an auditory physiologist at Ruhr University in Buchum, Germany.