The high noise of modern life may affect speech and language development in the very young, according to a study that found the auditory (听觉的) parts of the brains of young mice are slower to organize properly in the presence of continuous sounds.
Researchers at the University of California, San Francisco, reared a group of rats in an environment of continuous background noise and found that their brain circuits that receive and interpret (解释) sound did not develop at the same rate as animals that were raised in a quieter environment.
Edward F. Chang and Michael Merzenich, co-authors of the study appearing in the journal Science, said that the continuous noise delayed the organization of auditory neurons (神经细胞) during a critical two-to-three-week period after the rat pups were born.
For rats not exposed to the noise, the auditory cortex(皮层) neurons during this period gathered into a smaller area and began developing a selective response to sounds.
But for the noiseexposed rats, this organization was slowed, causing a delay in the development of the ability to discriminate(辨别) specific sound tones. The researchers said it took three or four times longer for the rats raised in a noisy environment to reach the basic bench marks (基准) of auditory development seen in the rat pups not exposed to noises.
Although the rat is not a perfect model for what happens in humans, the authors note, the study does suggest that high levels of noise might possibly affect some language learning in babies.
“These findings suggest that environmental noise, which is monly present in contemporary child-rearing environments, can potentially contribute to auditory and language-related development delays,”the authors wrote in Science.
The authors noted that although the brain development was delayed in rats exposed to the noise, their brains did eventually mature (成熟的) normally.
【小题1】The scientists at California University studied rats .A．of different age groupsB．with different habitsC．in different environmentsD．from different areas【小题2】The rats exposed to noise, pared to those not exposed, .A．were more sensitiveB．were dullerC．grew up more slowlyD．gathered together more quickly【小题3】 The result of the research mainly tells us that noise .A．delays brain developmentB．stops baby growthC．affects speech and languageD．destroys brains【小题4】 The findings of the research are said to have special connections with .A．causes of noisesB．medical scienceC．other living thingsD．human babiesC
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(答案→)C
解析：
【小题1】从文章第二段内容可知,加利福尼亚大学的研究者们养了一些老鼠,进行实验。分别在不断的噪音和相对较安静的环境下进行实验。
【小题2】从文章第五段可以得出the rats exposed to noise要比the rats not exposed to noise反应迟钝。
【小题3】从最后—段内容可以得知,噪音延缓脑的发育。B项是明显错误的。不是毁坏脑子,而是延缓,可知D项是错误的。此题侧重的是对老鼠的实验结果,而C项是对这个结果的进—步推测,所以C是不对的。
【小题4】 文中指出“the study does suggest that high levels of noise might possibly affect some language learning...babies.”由此可以得知,这个科研结果与婴儿有关。