BBC今天引用美國(guó)西北大學(xué)的研究人員的話說(shuō)，操雙語(yǔ)對(duì)大腦是一種訓(xùn)練，相當(dāng)于“健腦體操”，讓大腦更健康。研究人員對(duì)參加試驗(yàn)的48名身體健康的大學(xué)生的大腦對(duì)不同聲音的反應(yīng)進(jìn)行檢測(cè)。其中，23人能操雙語(yǔ)。 

科學(xué)家利用電極記錄接受實(shí)驗(yàn)者的腦波圖形變化，發(fā)現(xiàn)實(shí)驗(yàn)室里安靜的環(huán)境下，能說(shuō)雙語(yǔ)者與只能說(shuō)英語(yǔ)者的腦波反應(yīng)圖形是相似的。但是，在嘈雜的環(huán)境中，操雙語(yǔ)者的大腦對(duì)聲音的處理能力顯然更優(yōu)越。他們能更好的集中在重要的信息上，比如主講者的聲音，而擋住其它分散精力的聲音，比如閑聊的背景聲。 

實(shí)驗(yàn)報(bào)告作者之一Viorica Marian博士說(shuō)，人們用玩填字游戲和其它活動(dòng)來(lái)保持腦力，但其實(shí)學(xué)習(xí)并使用雙語(yǔ)所帶來(lái)的效果更顯著，包括注意力、抑制力和對(duì)聲音的解碼能力。此前進(jìn)行的類似調(diào)查還顯示，使用雙語(yǔ)有助于防止早老性癡呆。 

這樣的話，英、美等英語(yǔ)國(guó)家的人因?yàn)槟刚Z(yǔ)就是國(guó)際通用語(yǔ)言，大多數(shù)人不需要學(xué)習(xí)一門外語(yǔ)，就少了做“健腦體操”的機(jī)會(huì)，很容易收到環(huán)境的干擾，可能會(huì)顯得比較“笨”一些。去年一個(gè)旅游網(wǎng)站Hotels.com的調(diào)查顯示，2/3的英國(guó)人一個(gè)外語(yǔ)單詞也不會(huì)說(shuō)，20%的受訪者居然不懂近鄰法國(guó)人的口頭禪Bonjour(你好)。特別英國(guó)年輕人最“不思進(jìn)取”，47%的16至24歲的人表示，他們從未在生活中說(shuō)過(guò)學(xué)校里學(xué)過(guò)的外語(yǔ)。 

Being bilingual 'boosts brain power'

Learning a second language can boost brain power, scientists believe. 

The US researchers from Northwestern University say bilingualism is a form of brain training - a mental "work out" that fine-tunes the mind. 

Speaking two languages profoundly affects the brain and changes how the nervous system responds to sound, lab tests revealed. 

Experts say the work in Proceedings of the National Academy of Sciences provides "biological" evidence of this. 

For the study, the team monitored the brain responses of 48 healthy student volunteers - which included 23 who were bilingual - to different sounds. 

They used scalp electrodes to trace the pattern of brainwaves. 

Under quiet, laboratory conditions, both groups - the bilingual and the English-only-speaking students - responded similarly. 

But against a backdrop of noisy chatter, the bilingual group were far superior at processing sounds. 

They were better able to tune in to the important information - the speaker's voice - and block out other distracting noises - the background chatter. 

'Powerful' benefits
 
And these differences were visible in the brain. The bilingualists' brainstem responses were heightened. 

Prof Nina Kraus, who led the research, said: "The bilingual's enhanced experience with sound results in an auditory system that is highly efficient, flexible and focused in its automatic sound processing, especially in challenging or novel listening conditions." 

Co-author Viorica Marian said: "People do crossword puzzles and other activities to keep their minds sharp. But the advantages we've discovered in dual language speakers come automatically simply from knowing and using two languages. 

"It seems that the benefits of bilingualism are particularly powerful and broad, and include attention, inhibition and encoding of sound." 

Musicians appear to gain a similar benefit when rehearsing, say the researchers. Past research has also suggested that being bilingual might help ward off dementia.