单选题 English speakers pick up pitch in the right hemispheres of their brains, but speakers of certain other languages perceive it on the left as well. It all depends on what you want to learn from pitch, Donald Wong of the Indiana School of Medicine in Indianapolis told the meeting last week.
Earlier studies have shown that when an English speaker hears pitch changes, the right prefrontal cortex leaps into action. This fits in with the idea that emotive nuances of language—which in English are often carried by the rise and fall of the voice—are perceived on the fight.
But in "tonal" languages like Thai, Mandarin and Swedish, pitch not only carries emotional information, but can also alter the meaning of a word. Wong and his colleagues suspected that a speaker of tonal language would register pitch in .the left side of the brain—in particular Broca"s area, which processes the linguistic content of language.
To test this, the team asked English speakers and Thai speakers to listen to 80 pairs of Thai words, and tracked the blood flow in their brains using positron emission tomography. The volunteers had to decide whether the two words sounded the same, either by consonant or by tone. In some eases, the words had no intelligible meaning.
None of the words was emotionally charged, so even when Thai speakers could understand them, there was no fight-side activation. But sure enough the Thai speakers consistently lit up the left side of the brain, especially Broca"s area, while the English speakers did not.
The researchers are now planning to repeat the experiment with Thai speakers using whole sentences, complete with emotional information. "Both hemispheres will be engaged." predicts Wong.