大脑的语言中心

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In 1865, Pierre Paul Broca pinpointed the part of the brain responsible for language by autopsying brains of the language-impaired—the region is now called Broca’s area. But more info has been hard to get. Because most brain research is done on animals—and they’re not talking.

The types of human research that we can do—such as brain scans—aren’t detailed enough for identifying words, using grammar, and the act of speech. But in a study published October 16 in the journal Science, researchers found a way around this barrier.

Some epileptics who don’t respond to drugs undergo brain surgery. Before cutting, surgeons implant electrodes to determine the exact site of the problem and to test healthy regions. So the researchers piggy-backed on the procedure by giving three patients language tests.

Patients thought of a word, changed its tense or number and silently articulated it. The scientists were able to pinpoint these activities, all within Boca’s area. And the whole process took place within the 600 milliseconds that previous studies found was the time it takes for a person to go from zero to speaking. Researchers have thus now looked at the inner workings of Broca’s area—and communicated their findings.

—Cynthia Graber