TED英语演讲视频：双语对大脑的益处（含演讲稿）
演说者：Mia Nacamulli
演说题目：
The Benefits of a Bilingual Brain 双语对大脑的益处
https://v.qq.com/txp/iframe/player.html?width=500&height=375&auto=0&vid=g01894zmr06
Hablas Espa?ol? Parlez-vous Fran?ais? 你会说中文吗？
「你会说西班牙语吗？」「你会说法文吗？」「你会说中文吗？」
If you answered, "sí," "oui," or "会"，and you're watching this in English,chances are you belong to the world's bilingual and multilingual majority.
如果你回答：「是」(西班牙文)「是的」(法文)或者「会」，而你又正在观看英文版的影片，那你很有可能属于这世上会双语或者多语的多数人。
And besides having an easier time traveling，or watching movies without subtitles，knowing two or more languages means that your brain may actually look and work differently than those of your monolingual friends.
此外，若你在旅行时碰到较少麻烦，或者看电影时不需要字幕，就能懂两种或两种以上的语言，这代表你的大脑事实上也许看起来、运作起来都有别于你只会一种语言的朋友。
So what does it really mean to know a language?
所以到底什么才叫做「会一种语言」？
Language ability is typically measured in two active parts,speaking and writing,and two passive parts,listening and reading.
语言能力的评估，通常分成两项积极能力：说和写。以及两项消极能力：听和读。
While a balanced bilingual has near equal abilities across the board in two languages,
一个协调的双语者拥有程度几乎相当的两种语言能力，
most bilinguals around the world know and use their languages in varying proportions.
然而，世界上大多的双语者对于自己语言的了解以及使用有着很大的不同。
And depending on their situation and how they acquired each language,they can be classified into three general types.
而且依照不同的状况以及他们学习每种语言的方式，大致上，可将这些双语者分成三类。
For example, let's take Gabriella,whose family immigrates to the US from Peru when she's two-years old.
我们以Gabriella作为例子：她的家人在她两岁的时候，从秘鲁移民至美国
As a compound bilingual,Gabriella develops two linguistic codes simultaneously ，with a single set of concepts, learning both English and Spanish as she begins to process the world around her.
身为一位「复合型双语者」，当她对周遭的世界开始进行认知过程，Gabriella同时发展了两种语言代码为一组概念学习英文和西班牙文两种语言。
Her teenage brother,on the other hand, might be a coordinate bilingual,working with two sets of concepts,learning English in school,
while continuing to speak Spanish at home and with friends.
她的哥哥，可能是个「并列型双语者」，他的大脑里有两组概念在运作：在学校时，学习英文；同时在家或者跟朋友在一起，继续说西班牙文
Finally, Gabriella's parents are likely to be subordinate bilinguals who learn a secondary language by filtering it through their primary language.
最后，当Gabriella的父母学习第二语言时，很有可能成为「从属型双语者」，他们会以自己的第一语言来过滤第二语言。
Because all types of bilingual people can become fully proficient in a language regardless of accent or pronunciation，the difference may not be apparent to a casual observer .
以上所有类型的双语者都可以完全精通他们的第二语言，无论口音或者发音，若不仔细观察，这些差异并不明显。
But recent advances in brain imaging technology have given neurolinguists a glimpse into how specific aspects of language learning affect the bilingual brain.
然而近来，最新的大脑成像技术让神经语言学者，有机会窥探到特定的语言学习区块，是如何影响双语者的脑袋。
It's well known that the brain's left hemisphere is more dominant and analytical in logical processes,
while the right hemisphere is more active in emotional and social ones,though this is a matter of degree,not an absolute split.
大家都知道，左脑半球支配性较强，而且能进行逻辑过程的分析，而右脑在情感和社交方面比较活跃，虽然这种看法，在某种程度上获得认可但也不是百分百正确。
The fact that language involves both types of functions while lateralization develops gradually with age,has led to the critical period hypothesis.
事实上，语言包括两种类型的功能偏侧性随着年龄逐年发展。这个说法，引出所谓「关键时期」的假设。
According to this theory,children learn languages more easily，because the plasticity of their developing brains lets them use both hemispheres in language acquisition,while in most adults, language is lateralized to one hemisphere,
usually the left.
根据这个理论，孩子们较容易学习语言，因为他们发育中的大脑有可塑性，这让他们可以使用大脑的两个半球来学习语言，而大多数的成人，只使用一个半球来学习语言，通常是左半球。
If this is true, learning a language in childhood may give you a more holistic grasp of its social and emotional contexts.
如果这是真的，若你在孩童时期学习语言，那么在语言使用上的社交和情感的情境，应该会有更完整的理解。
Conversely, recent research showed that people who learned a second language in adulthood exhibit less emotional bias and a more rational approach when confronting problems in the second language than in their native one.
相反地，最近的研究显示，在成人时期学习第二语言的人显示出较少情绪上的偏见，且运用较理性的方式来面对学习第二外语时碰到的困难。（相比于自己在学母语时）
But regardless of when you acquire additional languages ，being multilingual gives your brain some remarkable advantages.
尽管如此，当你在学习其他语言时多重语言者的身分，将为你的大脑带来一些了不起的优势。
Some of these are even visible,such as higher density of the grey matter that contains most of your brain's neurons and synapses,and more activity in certain regions when engaging a second language.
而有些是非常显见的，例如灰质的密度会比较高，灰质中含有大脑大部分的神经元以及突触。你在使用第二语言时，某些脑区域也会更加活跃。
The heightened workout a bilingual brain receives throughout its life can also help delay the onset of diseases, like Alzheimer's and dementia by as much as five years.
若双语者的大脑持续地接收这些增强的练习会帮助延缓一些疾病的发作，像阿兹海默症和失智，最多可延缓五年。
The idea of major cognitive benefits to bilingualism may seem intuitive now,but it would have surprised earlier experts.
双语能享受到许多的好处，这样的想法，在现今也许被视为理所当然。然而，早期的专家会对此概念感到惊讶。
Before the 1960s, bilingualism was considered a handicap that slowed a child's development by forcing them to spend too much energy distinguishing between languages,a view based largely on flawed studies.
在1960年代前，双语的能力被视为一种障碍，会减缓孩子的发展，因为他们被迫花费太多精力，在辨认两种语言的异同，但这种观点大多基于有瑕疵的研究。
And while a more recent study did show that reaction times and errors increase for some bilingual students in cross-language tests,it also showed that the effort and attention needed to switch between languages triggered more activity in,and potentially strengthened, the dorsolateral prefrontal cortex.
而稍微近代的研究显示，一些会双语的学生，当他们在做跨语言测验时反应时间和失误都增加了，此研究也显示了转换两种语言，需要的努力以及专注力，这会引起更多活动产生，也很有可能强化背外侧前额叶。
This is the part of the brain that plays a large role in executive function, problem solving, switching between tasks,and focusing while filtering out irrelevant information.
背外侧前额叶在大脑中，主要扮演着决策功能、问题解决、任务转换以及专注且同时过滤不相关讯息的角色
So, while bilingualism may not necessarily make you smarter,t does make your brain more healthy, complex and actively engaged,and even if you didn't have the good fortune of learning a second language as a child,it's never too late to do yourself a favor，and make the linguistic leap from, "Hello,"
to, "Hola," "Bonjour" or "您好"，because when it comes to our brains,a little exercise can go a long way.
所以，即使双语这项能力，也许无法让你变聪明，但它让你的大脑变得更健康、复杂、有活力。而且即使你并不那么幸运能在孩童时期学习第二语言，帮自己一个忙永远不嫌晚，让你的语言能力能从「Hello」进展到「Hola」(西班牙文)、「Bonjour」(法文)或者「您好」，因为只要涉及到我们的大脑，一点点的练习就能有莫大的帮助。
TED英语演讲视频：如何做个内心真正强大的人？（附视频+演讲稿）
TED英语演讲视频：当键盘侠攻击失控时，我们该怎么办！（含演讲稿）
杨澜经典TED演讲视频：重塑中国的一代人（附视频+音频+演讲稿）