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Science Frontiers ONLINE No. 99: May-Jun 1995 |
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Curious Brain Asymmetries
Perfect pitchers vs. everyone else. An individual possessing perfect pitch can identify any musical note without comparing it to a reference note. It is said to be a uniquely human talent. (But how can we know?) Language, too, is thought to be be a gift accorded only to humans. Is there a biological connection between these "unique" capabilities?
Since language is primarily a left-brain function, it is logical to see if the secret of perfect pitch resides in that half of the brain, too. This is just what a group of researchers headed by G. Schlaug did with the help of magnetic resonance imaging. They compared the planum temporale regions in the brains of 30 musicians (11 with perfect pitch, 19 without) and 30 non-musicians -- all matched for sex and age. The left planum temporale region was larger than the right for both musicians and non-musicians, but in the musicians the asymmetry was twice as great. Furthermore, the musicians blessed with perfect pitch were the most asymmetric of all in this respect.
(Schlaug, Gottfried, et al; "In Vivo Evidence of Structural Brain Asymmetry in Musicians," Science, 267: 699, 1995. Nowak, Rachel; "Brain Center Linked to Perfect Pitch," Science, 267:616, 1995)
Comment. Perfect pitch is nice to have, but why should it have evolved at all seeing it has little survival value? What good is perfect pitch -- or any kind of musical talent -- in tracking animals or grubbing for tubers?
Women vs. men. In another application of magnetic resonance imaging, B. Shaywitz and colleagues at Yale compared the inferior frontal gyrus areas of the brains of men and women engaged in language tests. Specifically, they were being asked whether or not two nonsense words rhymed. Men, they found, use only the left inferior frontal gyrus area, but in women both left and right areas were activated. Conclusion: women, who regularly score better than men in linguistic tests, may acquire this extra capability by harnessing both halves of their brains.
(Aldhous, Peter; "Why Women Are Better with Words," New Scientist, p. 10, February 18, 1995)