外语学习能让你变得更敏锐

　　The ability to speak two languages can make bilingual people better able to pay attention than those who can only speak one language, a new study suggests.

　　一项新研究结果显示，同只能讲一种语言的人相比，能说两种语言的双语者能够更好地集中注意力。

　　Scientists have long suspected that some enhanced mental abilities might be tied to structural differences in brain networks shaped by learning more than one language, just as a musician’s brain can be altered by the long hours of practice needed to master an instrument.

　　长期以来，科学家们一直怀疑，一些人思维能力的提升可能与学习多种语言的过程中形成的大脑网络结构差异有关，正如音乐家们为掌握一种乐器而进行长时间练习之后，其大脑结构会发生改变。

　　Now, in a study published in the Poceeding of the National Academy of Sciences, researchers at Northwestern University for the first time have documented differences in how the bilingual brain processes the sounds of speech, compared with those who speak a single language, in ways that make it better at picking out a spoken syllable, even when it is buried in a babble of voices.

　　如今，发表在《美国国家科学院院刊》上的一项研究结果显示，美国西北大学(Northwestern University)的研究者首次证明了双语者的大脑在处理语音时的不同之处。与讲单一语言的人相比，双语者更善于识别人们说出的音节，即使这些音节被淹没在嘈杂声音里。

　　That biological difference in the auditory nervous system appears to also enhance attention and working memory among those who speak more than one language, they say.

　　这一听觉神经系统上的生物学差异似乎还加强了能说多种语言的人集中注意力的能力和工作记忆。

　　“Because you have two languages going on in your head, you become very good at determining what is and is not relevant,” says Dr. Nina Kraus, a professor of neurobiology and physiology at Northwestern, who was part of the study team. “You are a mental juggler.”

　　参与了这项研究的西北大学神经生物学和生理学教授克劳斯博士说，由于你的脑子里运行着两种语言体系，你会变得非常善于决定哪些声音有意义，哪些声音没有意义;你的思维就如同在表演杂技一般。

　　In the new study, Kraus and her colleagues tested the involuntary neural responses to speech sounds by comparing brain signals in 23 high school students who were fluent in English and Spanish to those of 25 teenagers who only spoke English. When it was quiet, both groups could hear the test syllable — “da” — with no trouble, but when there was background noise, the brains of the bilingual students were significantly better at detecting the fundamental frequency of speech sounds.

　　在这项新研究中，克劳斯和她的同事们通过对比两组受试者的大脑信号，测试了他们对声音的下意识神经反应。这两组受试者中，一组是23名能讲流利英语和西班牙语的高中生，另一组是25名只会讲英语的十几岁的青少年。当周围环境安静时，两组受试者都能听到测试音节“da”，而且毫不费力。但是如果背景嘈杂，讲双语的学生明显更善于识别语音的基本频率。

　　“We have determined that the nervous system of a bilingual person responds to sound in a way that is distinctive from a person who speaks only one language,” Kraus says.

　　克劳斯说，我们已经得出结论，双语者的神经系统对声音的反应方式与只能讲一种语言的人明显不同。

　　Through this fine-tuning of the nervous system, people who can master more than one language are building a more resilient brain, one more proficient at multitasking, setting priorities, and, perhaps, better able to withstand the ravages of age, a range of recent studies suggest.

　　最近的一系列研究表明，通过这种神经系统的微调，那些可掌握一种以上语言的人们将其大脑建设得更富弹性。他们的大脑在执行多重任务和决定事情的优先级别时会更为熟练，甚至可能经得起岁月的无情摧残。

　　Indeed, some preliminary research suggests that people who speak a second language may have enhanced defenses against the onset of dementia and delay Alzheimer’s disease by an average of four years, as WSJ reported in 2010.

　　其实正如《华尔街日报》2010年所报道的，一些初步研究结果表明，会说第二外语的人可能不仅增强了对痴呆症发病的抵御能力，还将老年痴呆症的发作平均延缓了四年。

　　The ability to speak more than one language also may help protect memory, researchers from the Center for Health Studies in Luxembourg reported at last year.

　　健康研究中心驻卢森堡的研究人员去年称，具备说一种以上语言的能力可能还有助于人们保护记忆力。

　　After studying older people who spoke multiple languages, they concluded that the more languages someone could speak, the better: People who spoke three languages were three times less likely to have cognitive problems compared to bilingual people. Those who spoke four or more languages were five times less likely to develop cognitive problems.

　　在研究了会说多国语言的老年人后，这些研究者总结认为，能说越多语言对人越好，因为他们发现，说三种语言的人其产生认知问题的可能性比讲两种语言的人要小三倍，能说四种或以上语言的人出现认知问题的可能性比双语者要小五倍。

　　Not so long ago, people worried that children who grew up learning two languages at once were at a developmental disadvantage compared with those who focused on only one.

　　不久前，人们还在担心，相比成长过程中只专注学习一门语言的孩子，那些同时学习两种语言的孩子会处于成长劣势。

　　New research suggests that even babies have little trouble developing bilingual skills.

　　新研究结果表明，即使婴儿在发展双语技巧方面都不存在什么困难。

　　Researchers at the University of British Columbia's Infant Studies Centre reported that babies being raised in a bilingual family show from birth a preference for each of the native languages they heard while still in the womb and can readily distinguish between them.

　　加拿大英属哥伦比亚大学婴儿研究中心的研究人员称，在双语家庭中长大的宝宝从一出生就显示出对其在子宫中听到的两种母语的偏好，并且很容易就能将两者区分开来。

　　Moreover, bilingual infants appear to learn the grammars of their two languages as well as babies learning a single language, even when the two languages are as different from one another as English and Japanese, or English and Punjabi.

　　此外，在语法学习方面，双语婴儿似乎能与只学习一种语言的婴儿学得一样好，哪怕这两种语言就像英语和日语或者英语和旁遮普语一样极不相同。