Do people cringe when you
sing? You've got company. But researchers have found that only 1 in 20
people truly has amusia, the technical term for tone deafness. Tests have
shown that some people with bad singing voices hear music just fine.
Amusics are a smaller group with a perceptual problem: They can't pick out
differences in pitch or follow the simplest tunes, reports the September
2007 issue of the Harvard Health Letter.
Brain scans haven't revealed major anatomical differences in amusics,
but more sophisticated tests have uncovered some subtle variations. In a
study comparing amusics to people with normal musical ability, researchers
used a brain imaging and statistical technique to measure the density of
the white matter (which consists of connecting nerve fibers) between the
right frontal lobe, where higher thinking occurs, and the right temporal
lobes, where basic processing of sound occurs. The white matter of the
amusics was thinner, which suggests a weaker connection. Moreover, the
worse the tone deafness, the thinner the white matter.
Some experts believe there's a great deal of overlap between how the
brain handles music and how it handles speech, which also has elements of
pitch and rhythm. Others, though, believe that musical perception and
thinking occur separately from other functions, and that our brains are
predisposed toward developing centers and networks dedicated exclusively to
music.
Harvard Health Letter
health.harvard.edu