一説起寶貝的英語啟蒙，網絡上流傳着各種互相矛盾的育兒知識，比如“幾歲開始學英語?”有人説必須三歲以後，有人説兩歲開始都晚了。寶爸寶媽都聽懵了，孩子學英語，究竟從幾歲開始? 美國華盛頓大學教授做過一次演講：「嬰兒的天才語言能力」，把專業的知識，講得很清楚易懂，能解答你的不少問題。下面是小編為大家收集關於TED英語演講：幾歲學英語效果最好，歡迎借鑑參考。
演講者：Patricia Kuhl
演講稿
I want you to take a look at this baby. What you're drawn to are her eyes and the skin you love to touch.
我想讓大家看看這個嬰兒。吸引大家關注的是她的眼睛，以及讓人忍不住摸摸的皮膚。
But today I'm going to talk to you about something you can't see -- what's going on up in that little brain of hers. The modern tools of neuroscience are demonstrating to us that what's going on up there is nothing short of rocket science. And what we're learning is going to shed some light on what the romantic writers and poets described as the "celestial openness" of the child's mind.
但今天我要講些你看不到的東西，在她的小腦袋瓜裏的東西。當代神經科學的研究工具展示出我們對嬰兒腦袋裏的東西知之甚少。我們要知道的，是讓浪漫作家和詩人產生靈感，並稱之為孩子心智的 “非凡的通慧”。
What we see here is a mother in India, and she's speaking Koro, which is a newly discovered language. And she's talking to her baby. What this mother -- and the 800 people who speak Koro in the world -- understands [is] that, to preserve this language, they need to speak it to the babies.
大家這兒看到的是印度的一位母親，她講克羅語，這是一種新發現的語言。她對她的孩子説這種語言。這位母親和世界上説克羅語的800人明白要保留這種語言，他們必須對嬰兒説這種語言。
And therein lies a critical puzzle. Why is it that you can't preserve a language by speaking to you and I, to the adults? Well, it's got to do with your brain. What we see here is that language has a critical period for learning. The way to read this slide is to look at your age on the horizontal axis.
在這裏有個關鍵的問題。為什麼要是對你和我，成年人説一種新語言卻不能保留它?這是和你的大腦有關。這兒我們看到有個學習語言的關鍵期。讀懂這幅圖的方法是看你在橫軸上的年齡。
And you'll see on the vertical your skill at acquiring a second language. Babies and children are geniuses until they turn seven, and then there's a systematic decline. After puberty, we fall off the map. No scientists dispute this curve, but laboratories all over the world are trying to figure out why it works this way
你再對應看縱軸上，你悉得第二外語的能力。嬰兒和孩子是語言天才，直到7歲然後語言系統會呈下降趨勢。青春期後，如圖我們語言能力衰退。科學家們確信這曲線圖的情況，但是全世界的實驗室 都試圖查明這到底是怎麼回事。
Work in my lab is focused on the first critical period in development -- and that is the period in which babies try to master which sounds are used in their language. We think, by studying how the sounds are learned, we'll have a model for the rest of language, and perhaps for critical periods that may exist in childhood for social, emotional and cognitive development.
在我實驗室的工作主要是研究第一個關鍵期。這個時期是關於嬰兒試着掌握他們語言中的聲音。我們認為通過研究這些被嬰兒學會的聲音，我們會給學習其他語言一個模式， 或許關鍵期也出現在孩童期，也為了研究社會，情感和認知發展。
So we've been studying the babies using a technique that we're using all over the world and the sounds of all languages. The baby sits on a parent's lap, and we train them to turn their heads when a sound changes -- like from "ah" to "ee." If they do so at the appropriate time, the black box lights up and a panda bear pounds a drum. A six-monther adores the task.
我們一直研究嬰兒使用的技巧，也是全世界使用的語言技巧和所有語言的聲音技巧。嬰兒坐在父母的膝上，我們訓練他們，當聽到一個聲音 從“ah”到 “ee” 他們就轉頭。如果他們一聽到就轉頭，黑盒子就會亮、會出現一隻敲鼓的熊貓。六個月大的嬰兒喜歡這個測試。
What have we learned? Well, babies all over the world are what I like to describe as "citizens of the world." They can discriminate all the sounds of all languages, no matter what country we're testing and what language we're using, and that's remarkable because you and I can't do that.
我們從中瞭解到什麼呢?全世界的嬰兒 就如我所述的是世界公民;他們能區分所有語言的所有聲音，不管測試在哪一國，用哪種語言。令人驚訝的是你我卻做不到這點。
We're culture-bound listeners. We can discriminate the sounds of our own language, but not those of foreign languages. So the question arises: when do those citizens of the world turn into the language-bound listeners that we are?
我們是受制於文化侷限的聽眾。我們只能區分我們自己語言的聲音，但分不清外語的那些聲音。所以問題隨之產生，這些小小世界公民在什麼時候變成受制於文化侷限的聽眾?
And the answer: before their first birthdays. What you see here is performance on that head-turn task for babies tested in Tokyo and the United States, here in Seattle, as they listened to "ra" and "la" -- sounds important to English, but not to Japanese. So at six to eight months the babies are totally equivalent. Two months later something incredible occurs. The babies in the United States are getting a lot better, babies in Japan are getting a lot worse, but both of those groups of babies are preparing for exactly the language that they are going to learn.
答案是：一歲之前這裏看到的是扭轉頭測試效果，用來測試日本東京和美國西雅圖的嬰兒，讓他們聽ra和la的發音，這兩個發音在英文裏很重要，在日語裏卻沒有。對於6到8個月的嬰兒，他們的測試結果完全相似。2個月之後便產生明顯變化，在美國的嬰兒掌握這些發音比較好，在日本的嬰兒卻差很多，但是這兩組的嬰兒均蓄勢待發地要學習語言。
So the question is: what's happening during this critical two-month period? This is the critical period for sound development, but what's going on up there? So there are two things going on. The first is that the babies are listening intently to us, and they're taking statistics as they listen to us talk -- they're taking statistics. So listen to two mothers speaking motherese -- the universal language we use when we talk to kids -- first in English and then in Japanese.
問題在於，在這個2個月的關鍵期發生了什麼?在聲音開發的這關鍵期到底發生什麼了? 主要是兩件事。第一嬰兒不斷地專心聽我們説話，並且做統計他們統計這些聲音。聽聽2位母親説的親情用語，這是我們對孩子説的通用語言媽媽語，首先是英語，然後是日語。
(Video) English Mother: Ah, I love your big blue eyes -- so pretty and nice.
(視頻)説英語的媽媽：啊，我多愛你大大的藍眼睛，這麼漂亮，這麼好看。
Japanese Mother: [Japanese]
説日語的媽媽：[日語]
Patricia Kuhl: During the production of speech, when babies listen, what they're doing is taking statistics on the language that they hear. And those distributions grow. And what we've learned is that babies are sensitive to the statistics, and the statistics of Japanese and English are very, very different. English has a lot of Rs and Ls. The distribution shows.
帕特里夏·庫爾：在語言生成的期間，當嬰兒聆聽時，他們同時也在統計他們聽到的語言。區分這些聲音的能力在變強。我們瞭解到的是嬰兒對統計很敏感，日語和英語的聲音統計是非常，非常不同的。
And the distribution of Japanese is totally different, where we see a group of intermediate sounds, which is known as the Japanese "R." So babies absorb the statistics of the language and it changes their brains; it changes them from the citizens of the world to the culture-bound listeners that we are. But we as adults are no longer absorbing those statistics. We're governed by the representations in memory that were formed early in development.
英語有很多R和L音如分佈圖所示，日語的分佈圖則是完全不同的。我們在這兒看到一組中間音，它們是日語的R音。嬰兒吸收語言的統計數據，這改變了他們的大腦;這就是把他們從世界公民，變成像我們一樣受文化侷限的聽眾。但我們成年人不再吸收這些統計。我們受我們早期形成的 記憶性語言的影響。
So what we're seeing here is changing our models of what the critical period is about. We're arguing from a mathematical standpoint that the learning of language material may slow down when our distributions stabilize. It's raising lots of questions about bilingual people. Bilinguals must keep two sets of statistics in mind at once and flip between them, one after the other, depending on who they're speaking to.
所以我們在這兒看到的關鍵期是如何改變我們的語言模式。我們從數學角度爭論學習語言材料的能力會放慢下來，當我們語言分佈的能力趨於穩定時， 這也引出很多關於雙語者的問題。雙語者在腦中同時必須記住2組統計，並能任意切換，決定於他們與誰交流。
So we asked ourselves, can the babies take statistics on a brand new language? And we tested this by exposing American babies who'd never heard a second language to Mandarin for the first time during the critical period. We knew that, when monolinguals were tested in Taipei and Seattle on the Mandarin sounds, they showed the same pattern.
那麼我們自問，嬰兒能不能統計一種全新的語言?我們測試了這個，通過給美國嬰兒聽他們從沒聽過的第二種語言，這是在關鍵期時他們第一次聽到普通話。我們得知，當我們讓台北和西雅圖的單語者接觸普通話聲音，他們顯示同樣的模式。
Six to eight months, they're totally equivalent. Two months later, something incredible happens. But the Taiwanese babies are getting better, not the American babies. What we did was expose American babies during this period to Mandarin. It was like having Mandarin relatives come and visit for a month and move into your house and talk to the babies for 12 sessions. Here's what it looked like in the laboratory.
在6到8個月大時他們辨音能力幾乎相同2個月之後，一些不可思議的事情發生了。但這次台灣嬰兒表現好，而不是美國的嬰兒。我們所做的是在這關鍵期讓美國的嬰兒多接觸普通話。這就好像説普通話的親戚來拜訪了一個月，住到你家和嬰兒上了12節普通話課。 在實驗室它看起來就像這樣。
(Video) Mandarin Speaker: [Mandarin]
(視頻)普通話説者：[普通話]
PK: So what have we done to their little brains? (Laughter) We had to run a control group to make sure that just coming into the laboratory didn't improve your Mandarin skills. So a group of babies came in and listened to English. And we can see from the graph that exposure to English didn't improve their Mandarin.
所以我們對他們的小腦袋瓜都做了什麼?(笑聲) 我們還得有一個對照組確保來到實驗室並不能提高普通話的水平。所以這組嬰兒來這兒只聽英語。我們從這圖表看出，在英語條件下的嬰兒沒有提高他們的漢語。
But look at what happened to the babies exposed to Mandarin for 12 sessions. They were as good as the babies in Taiwan who'd been listening for 10-and-a-half months. What it demonstrated is that babies take statistics on a new language. Whatever you put in front of them, they'll take statistics on.
但看看上過12次普通話課的嬰兒的身上都發生了什麼。他們和那些曾聽普通話有 10個半月大的台灣嬰兒一樣棒。這説明了嬰兒對一種新語言也能做統計。不管你在他們面前説了什麼，他們就會統計這語言。
But we wondered what role the human being played in this learning exercise. So we ran another group of babies in which the kids got the same dosage, the same 12 sessions, but over a television set and another group of babies who had just audio exposure and looked at a teddy bear on the screen. What did we do to their brains?
我們也好奇，在這一學習過程中人起了什麼樣的作用。所以我們設置了另一組嬰兒讓他們如法炮製地上12節課，但是在電視機前上課和另一組嬰兒只是通過音頻上課，看電視屏幕上的玩具熊。我們又對他們的腦袋瓜做什麼了?
What you see here is the audio result -- no learning whatsoever -- and the video result -- no learning whatsoever. It takes a human being for babies to take their statistics. The social brain is controlling when the babies are taking their statistics.
我們這兒看到的是音頻結果沒有任何學習效果，視頻結果 也是沒有任何學習效果。只有人才能，幫助嬰兒統計他們的聲音數據。當嬰兒在統計時社會大腦在控制着。
We want to get inside the brain and see this thing happening as babies are in front of televisions, as opposed to in front of human beings. Thankfully, we have a new machine, magnetoencephalography, that allows us to do this. It looks like a hair dryer from Mars. But it's completely safe, completely non-invasive and silent.
我們想了解大腦內部觀察各種變化，探究電視前的嬰兒和與人在一起的嬰兒有何不同。多虧我們有了這台新機器，腦磁圖顯示機，它可以讓我們做到這個。它看上去就像來自火星的吹風機。但它是完全安全的，完全對人無害，而且是靜音的。
We're looking at millimeter accuracy with regard to spatial and millisecond accuracy using 306 SQUIDs -- these are Superconducting QUantum Interference Devices -- to pick up the magnetic fields that change as we do our thinking. We're the first in the world to record babies in an MEG machine while they are learning.
我們的要求是，在空間上精確到毫米、時間上精確到毫秒、使用306 SQUIDs即是超導量子干涉磁量儀用來檢測我們大腦變化的磁場。我們是世界上第一個記錄嬰兒在腦磁圖顯示機下的學習的腦圖。
So this is little Emma. She's a six-monther. And she's listening to various languages in the earphones that are in her ears. You can see, she can move around. We're tracking her head with little pellets in a cap, so she's free to move completely unconstrained.
所以這是小愛瑪，她有6個月大。她正通過耳機聆聽多種語言。大家可以看到，她可以移動。我們用她帽子上的小球，來記錄她的腦圖，所以她完全不受束縛地自由地移動。
It's a technical tour de force. What are we seeing? We're seeing the baby brain. As the baby hears a word in her language the auditory areas light up, and then subsequently areas surrounding it that we think are related to coherence, getting the brain coordinated with its different areas, and causality, one brain area causing another to activate.
這是一個技術上的傑作。我看到什麼了?我們看到嬰兒的大腦。當嬰兒聽到語言中的一個詞大腦中聽覺區域亮起來，然後在它周圍的其它區域也亮起來。我們認為這是有關聯貫性的，讓大腦和其他不同腦區域相協調，一前一後， 一片腦區域激活另一片腦區域。
We are embarking on a grand and golden age of knowledge about child's brain development. We're going to be able to see a child's brain as they experience an emotion, as they learn to speak and read, as they solve a math problem, as they have an idea. And we're going to be able to invent brain-based interventions for children who have difficulty learning.
我們開啟了一個開發兒童大腦知識的宏偉的黃金年代。我們能夠觀察他們的大腦，當兒童體驗到感情，學着説和讀，解決一個數學問題，或當他們有個想法的時候，我們也能為學習有障礙的孩童，發明基於腦的治療方法。
Just as the poets and writers described, we're going to be able to see, I think, that wondrous openness, utter and complete openness, of the mind of a child. In investigating the child's brain, we're going to uncover deep truths about what it means to be human, and in the process, we may be able to help keep our own minds open to learning for our entire lives.
正如詩人和作家所描述的，我想我們能夠看到一種奇妙的融通開放，一個孩子心智的完全開放。在對兒童大腦的研究中，我們會深刻揭示 ，這對人類來説意味着什麼的事實， 在這一過程中，我們或許能幫助我們自身開放心智，在我們一生中不斷地學習。
Thank you.
謝謝。