TED演講 | 為什么青少年容易沖動？科學家給你答案！

我們也可以使用功能磁共振成像，簡稱fMRI 它可以拍攝視頻，這樣就可以在試驗者 進行某項活動中，比如思考或感受某些東西時 記錄拍攝下大腦的活動情況。

So many labs around the world are involved in this kind of research, and we now have a really rich and detailed picture of how the living human brain develops, and this picture has radically changed the way we think about human brain development by revealing that it's not all over in early childhood, 

現在世界上很多實驗室都參與了這項研究 所以我們就得出了很豐富 很詳盡的圖片，解密了人腦的發育情況，同時這張照片從根本上顛覆了我們以往對人腦發育的觀念 通過告訴我們發育的過程不完全都在幼兒階段。

and instead, the brain continues to develop right throughout adolescence and into the '20s and '30s.

相反，大腦會繼續發育貫穿整個青春期，一直到20多歲甚至30多歲

So adolescence is defined as the period of life that starts with the biological, hormonal, physical changes of puberty and ends at the age at which an individual attains a stable, independent role in society.It can go on a long time.

所以青春期也被定義為 生命中生理和荷爾蒙轉變的開端 當人們在社會中獲得一個穩定和獨立的身份時 也就標志這青春期的結束了。有時青春期會持續很久很久。

One of the brain regions that changes most dramatically during adolescence is called prefrontal cortex. So this is a model of the human brain, and this is prefrontal cortex, right at the front. Prefrontal cortex is an interesting brain area. 

大腦其中的一個區域，叫前額葉皮層， 它在青春期階段是最活躍的。 這個是人腦的一個模型 這里是前額葉皮層，就在前面這里 前額葉皮層是非常有意思的一個大腦區域 

It's proportionally much bigger in humans than in any other species, and it's involved in a whole range of high level cognitive functions, things like decision-making, planning, planning what you're going to do tomorrow or next week or next year, 

相對其他物種而言 人類的前額葉皮層是大很多的 它涉及到大量的高級認知功能 ，例如決策 計劃，計劃明天要做的事情 或者下周或明年的 

inhibiting inappropriate behavior, so stopping yourself saying something really rude or doing something really stupid. It's also involved in social interaction, understanding other people, and self-awareness.

對不恰當行為的抑制，像阻止你 說一些粗魯的話或做一些傻事 它還涉及到社交方面 包括理解他人和自我意識

So MRI studies looking at the development of this region have shown that it really undergoes dramatic development during the period of adolescence. So if you look at gray matter volume, for example, gray matter volume across age from age four to 22 years increases during childhood, which is what you can see on this graph. 

所以MRI對前額葉皮層的發育的研究 揭示了它確實在青春期階段 有著非同尋常的發育情況 舉個例子，如果你去看大腦灰質 從4歲起到22歲的大腦灰質 會在童年時期會增加，也就是現在在圖表上你能看到的 

It peaks in early adolescence. The arrows indicate peak gray matter volume in prefrontal cortex. You can see that that peak happens a couple of years later in boys relative to girls, and that's probably because boys go through puberty a couple of years later than girls on average, 

在早期的青春期會到達頂峰 箭頭指的就是大腦灰質在前額葉皮層 達到的鋒點，你會發現要達到這個鋒點 男孩會相對比女孩要慢幾年 

and then during adolescence, there's a significant decline in gray matter volume in prefrontal cortex. Now that might sound bad, but actually this is a really important developmental process, because gray matter contains cell bodies and connections between cells, 

這大概是因為男孩平均要比女孩 晚那么幾年經歷青春期 在青春期階段，大腦灰質 在前額葉皮層會出現一個明顯的下降 聽起來似乎有些不安 但這確實一個極其重要的發育階段 因為大腦灰質包涵了細胞體 還有細胞之間的聯系，

the synapses, and this decline in gray matter volume during prefrontal cortex is thought to correspond to synaptic pruning, the elimination of unwanted synapses. This is a really important process. It's partly dependent on the environment that the animal or the human is in, and the synapses that are being used are strengthened, 

也就是突觸 在前額葉皮層到了一個需要對突觸進行修剪 去除掉一些不必要的突觸的這一階段 大腦灰質也就會減少 這是非常關鍵的階段 一部分取決于動物或人類居住的環境 那些有價值的突觸會茁壯發育 

and synapses that aren't being used in that particular environment are pruned away. You can think of it a bit like pruning a rosebush. You prune away the weaker branches so that the remaining, important branches, can grow stronger, 

而在那個特定的環境里 那些沒什么存在必要的突觸則會被剔除掉 你可以把它當成是修剪盆栽 把那些奄奄一息的枯枝敗葉修剪掉 這樣那些剩下的，重要的枝干，就會茁壯成長 

and this process, which effectively fine-tunes brain tissue according to the species-specific environment, is happening in prefrontal cortex and in other brain regions during the period of human adolescence.

這個會根據物種及環境不同 而高效調整大腦組織的過程 就是在人類的青春期階段 在前額葉皮層和其他大腦區域進行的

So a second line of inquiry that we use to track changes in the adolescent brain is using functional MRI to look at changes in brain activity across age. So I'll just give you an example from my lab. 

我們用來記錄青春期大腦變化 的第二輪調查，就是用功能磁共振成像 來探究不同年齡大腦活動的變化情況 這里我舉個發生在我實驗室里的例子。 

So in my lab, we're interested in the social brain, that is the network of brain regions that we use to understand other people and to interact with other people. So I like to show a photograph of a soccer game to illustrate two aspects of how your social brains work. So this is a soccer game.

在我的實驗室里，我們對社會大腦很感興趣， 就是我們與他人溝通交流 的大腦區域網絡。 我會給你們看一張足球賽的圖片 跟你們分析下社會性大腦工作時的兩個方面 這就是一場足球賽。

Michael Owen has just missed a goal, and he's lying on the ground, and the first aspect of the social brain that this picture really nicely illustrates is how automatic and instinctive social emotional responses are, so within a split second of Michael Owen missing this goal, 

邁克爾歐文剛剛的射門沒有命中， 所以他躺在地上，這張圖片詮釋了 社交情緒反應是多么自動自覺的 這是社會腦的第一個層面， 所以就在歐文沒射中球門的那一瞬間，

everyone is doing the same thing with their arms and the same thing with their face, even Michael Owen as he slides along the grass, is doing the same thing with his arms, and presumably has a similar facial expression, and the only people who don't are the guys in yellow at the back--

每個人的手都是同樣的動作 同樣的表情，甚至歐文也是這樣 在他劃過草地時，他也是同樣的手勢 估計他的面部表情也差不多 而唯一不為所動的那個人， 就是背后穿黃色球衣的了

and I think they're on the wrong end of the stadium, and they're doing another social emotional response that we all instantly recognize, and that's the second aspect of the social brain that this picture really nicely illustrates, 

我覺得他們是場上占不到什么優勢的人 他們有著不一樣的社交情緒反應 我們能馬上認出來，這就是社會腦的第二個層面 也在圖片上很好地表現出來 

how good we are at reading other people's behavior, their actions, their gestures, their facial expressions, in terms of their underlying emotions and mental states. So you don't have to ask any of these guys.

它揭示了我們對他人行為的理解程度 按照潛在的情緒和精神狀態 解讀他人的舉動，他人的手勢，還有他們的面部表情 所以你不用去問他們中的任何一人。

You have a pretty good idea of what they're feeling and thinking at this precise moment in time.So that's what we're interested in looking at in my lab. 

 就能對這個時候他們的情感和思想 有一個頗為準確的理解。這就是我的實驗室所感興趣的事。

So in my lab, we bring adolescents and adults into the lab to have a brain scan, we give them some kind of task that involves thinking about other people, their minds, their mental states, their emotions, 

在實驗室里，我們召集了青少年和成年人 進行大腦掃描，我們給他們分配任務 涉及了他們對他人，自己的思想，自己的精神狀態， 以及對自己的情緒的思考 

and one of the findings that we've found several times now, as have other labs around the world, is part of the prefrontal cortex called medial prefrontal cortex, which is shown in blue on the slide, and it's right in the middle of prefrontal cortex in the midline of your head. 

和其他實驗室一樣，目前我們多次發現的一點是 前額葉皮層的一個部分 叫做內側前額葉皮質，就是藍色那部分， 就在前額葉皮質的正中間 在腦袋的正中央。

This region is more active in adolescents when they make these social decisions and think about other people than it is in adults, and this is actually a meta-analysis of nine different studies in this area from labs around the world, and they all show the same thing, that activity in this medial prefrontal cortex area decreases during the period of adolescence. 

當青少年在做社交決定以及考慮他人時 他們大腦的這個區域 要比成年人還要活躍，這其實是世界上其他實驗室 在這個方面的九個不同研究的薈萃分析 他們都表明了一樣的結果， 就是內側前額葉皮質的活躍度， 會在青春期階段逐漸減小。

And we think that might be because adolescents and adults use a different mental approach, a different cognitive strategy, to make social decisions, and one way of looking at that is to do behavioral studies where by we bring people into the lab and we give them some kind of behavioral task, and I'll just give you another example of the kind of task that we use in my lab.

我們猜測可能是青少年和成年人 在做社交決定時，有著不同的心理活動 不同的認知策略， 研究這個的方法之一就是采用行為研究 我們把人召集進實驗室 分配給他們一些行動任務， 我給你們舉個我們實驗室的任務的例子。

So imagine that you're the participant in one of our experiments. You come into the lab, you see this computerized task. In this task, you see a set of shelves. Now, there are objects on these shelves, on some of them, and you'll notice there's a guy standing behind the set of shelves, and there are some objects that he can't see. They're occluded, from his point of view, with a kind of gray piece of wood. This is the same set of shelves from his point of view. Notice that there are only some objects that he can see, whereas there are many more objects that you can see. Now your task is to move objects around. The director, standing behind the set of shelves, is going to direct you to move objects around, but remember, he's not going to ask you to move objects that he can't see. This introduces a really interesting condition whereby there's a kind of conflict between your perspective and the director's perspective. So imagine he tells you to move the top truck left. There are three trucks there. You're going to instinctively go for the white truck, because that's the top truck from your perspective, but then you have to remember, 'Oh, he can't see that truck, so he must mean me to move the blue truck,' which is the top truck from his perspective. Now believe it or not, normal, healthy, intelligent adults like you make errors about 50 percent of the time on that kind of trial. They move the white truck instead of the blue truck. So we give this kind of task to adolescents and adults, and we also have a control condition where there's no director and instead we give people a rule. We tell them, okay, we're going to do exactly the same thing but this time there's no director. Instead you've got to ignore objects with the dark gray background. You'll see that this is exactly the same condition, only in the no-director condition they just have to remember to apply this somewhat arbitrary rule, whereas in the director condition, they have to remember to take into account the director's perspective in order to guide their ongoing behavior.

想象一下你是我們實驗的參與人員之一 你進到這個實驗室， 你看到這個電腦程序任務。 在這個任務中，你看到幾排的架子。 現在架子上有些擺上了物品， 你會發現有個人站在架子后面， 而且有些物品他是看不到的。 他們被遮住了，從這個角度看 被灰色的木板遮住了。 從他的角度看，這是同樣的架子。 但要注意，他只看得到一些物品， 但你卻能看到更多的。 你的任務就是去移動這些物品。 引導人員，將站在架子后面， 引導你去移動這些物品， 但是要記住，他不會叫你去移動那些 他看不到的物品。這就引出了一個很有意思的情況 在你的角度和引導員的角度之間 會有一種沖突。 假設他叫你去把上面的火車往左移。 但那兒有三輛火車，你會很自然地 去移動白色那輛，因為從你的角度看 它就是上面的火車，但你得知道 “噢，他看不見那輛火車，所以 他是想我去移動藍色的，”就是他的角度 最上面的那輛。現在信不信由你， 像你們一樣正常健康聰明的成年人都會犯錯 在這種試驗中，犯錯幾率高達50%。 他們會移動白色那輛，而不是藍色那輛 話說我們給青少年還有成年人分配了這種任務， 我們有條件控制 一個是沒有引導員，另一個是給他們定規則。 我們告訴他們，好吧，我們會做一樣的事情 這次沒有引導員。 相反，你得忽略那些灰色格子。 你會發現其實條件是完全一樣的， 要記住沒有引導員這一情況 只有規定的要求， 但在有引導員的情況下，他們則需要 考慮引導員的視野角度 這樣才能理解引導員的指令。

Okay, so if I just show you the percentage errors in a large developmental study we did, this is in a study ranging from age seven to adulthood, and what you're going to see is the percentage errors in the adult group in both conditions, 

這個就是在我們較大規模的研究中 得出的犯錯比率， 這是從七歲到成年的一個研究， 你們接下來會看到的就是成人組 在兩種條件下的錯誤比率， 

so the gray is the director condition, and you see that our intelligent adults are making errors about 50 percent of the time, whereas they make far fewer errors when there's no director present, when they just have to remember that rule of ignoring the gray back ground. 

灰色的就是有引導員的情況， 你會發現我們聰明的成年人的錯誤率約是50% 但是他們在沒有引導員在場的情況下。 錯誤率會低很多，他們只需 記住去忽略灰色格子這一規定。

Developmentally, these two conditions develop in exactly the same way. Between late childhood and mid-adolescence, there's an improvement, in other words a reduction of errors, in both of these trials, in both of these conditions. 

相應地，這兩種條件的情況 發展幾乎是一樣的，在后兒童期 還有中青春期，都是有所提升， 換句話說，就是在這些試驗中，在這些條件下， 錯誤的幾率會隨年齡增加而減少。

But it's when you compare the last two groups, the mid-adolescent group and the adult group where things get really interesting, because there, there is no continued improvement in the no-director condition. 

但當你比較最后兩組實驗時， 中青春期組和成年組 事情會變得有趣很多 因為在沒有引導員的情況下，也沒有提升的趨勢。

In other words, everything you need to do in order to remember the rule and apply it seems to be fully developed by mid-adolescence, whereas in contrast, if you look at the last two gray bars, there's still a significant improvement in the director condition between mid-adolescence and adulthood, 

也就是說，涉及到記住規則并應用它所需要的一切 似乎都在中青春期已經塵埃落定了 但是相反地， 如果你去看兩條灰色的圖柱 在有引導員的條件下，在中青春期和成年組之間 還是有明顯的提升的 

and what this means is that the ability to take into account someone else's perspective in order to guide ongoing behavior, which is something, by the way, that we do in everyday life all the time, is still developing in mid-to-late adolescence. 

  這就意味著，從他人角度考慮出發 從而運用到實踐中的能力， 而這也是我們日常生活隨處可見的， 這一能力，在青春期的中后期仍在發育中。 

So if you have a teenage son or a daughter and you sometimes think they have problems taking other people's perspectives, you're right. They do. And this is why.

所以如果你有一個兒子或女兒出于青春期 你有時覺得他們在考慮他人感受時做得不夠好 那么你是對的，的確是這樣，這就是原因。

So we sometimes laugh about teenagers. They're parodied, sometimes even demonized in the media for their kind of typical teenage behavior. They take risks, they're sometimes moody, they're very self-conscious. 

所以我們有時會諷刺青少年。 說他們沒什么大腦，有時會在媒體上 丑化他們那種典型的青春期行為， 他們愛冒險，情緒陰晴不定，非常自我。

I have a really nice anecdote from a friend of mine who said that the thing he noticed most about his teenage daughters before and after puberty was their level of embarrassment in front of him. 

我從我朋友那兒聽到一個很有趣的故事 他說這是他在女兒們 青春期前后經常見到的事 就是在他面前的尷尬程度。 

So, he said, 'Before puberty, if my two daughters were messing around in a shop, I'd say, 'Hey, stop messing around and I'll sing your favorite song,' and instantly they'd stop messing around and he'd sing their favorite song. 

她說，“青春期前，如果我的兩個女兒 在商店里胡鬧，我會說，嘿 別鬧了，我給你們唱你們最喜歡的歌，” 然后她們立即安分守己，聽他唱歌 

After puberty, that became the threat.The very notion of their dad singing in public was enough to make them behave.

但青春期過后，唱歌成了威脅。他們爸爸在公眾場合唱歌這一舉動 足以震懾他們的調皮。

So people often ask, 'Well, is adolescence a kind of recent phenomenon? Is it something we've invented recently in the West?' And actually, the answer is probably not. 

所以人們經常問， “那么，青春期是一種新生的現象嗎？ 是西方國家近幾年才發現的嗎？” 其實，答案不然。歷

There are lots of descriptions of adolescence in history that sound very similar to the descriptions we use today.

史上， 有過很多青春期的描寫 與今天那些描述十分相似。

So there's a famous quote by Shakespeare from 'The Winter's Tale' where he describes adolescence as follows: 'I would there were no age between ten and three-and-twenty, or that youth would sleep out the rest; for there is nothing in the between but getting wenches with child, wronging the ancientry, stealing, fighting.'

莎士比亞的《冬天的故事》里有這么一段 他是這么描述青春期的： “孩子與成人之間不再有差別 年輕人要么就去安眠； 因為他們會空虛到 與孩子濫交、做出傷風敗俗的偷竊和斗毆。”

He then goes on to say, 'Having said that, would any but these boiled brains of nineteen and two-and-twenty hunt in this weather?'So almost 400 years ago, Shakespeare was portraying adolescents in a very similar light to the light that we portray them in today, 

他接著說，“話雖如此，但除了那些十幾二十歲 的腦殘少年，還有誰 會在這種天氣出來打獵啊？”所以約在400年前，莎士比亞 描述的青少年就十分類似我們今天所指的青少年 

but today we try to understand their behavior in terms of the underlying changes that are going on in their brain.So for example, take risk-taking. We know that adolescents have a tendency to take risks. They do. 

但如今我們嘗試根據他們， 大腦那些看不到的變化 去理解他們的行為。舉個例子，愛冒險。我們知道青少年 有愛冒險的傾向，真的有的。

They take more risks than children or adults, and they are particularly prone to taking risks when they're with their friends. There's an important drive to become independent from one's parents and to impress one's friends in adolescence. 

他們會比兒童或成人更愛冒險， 而且在和朋友在一起的時候 會更有冒險傾向 在青春期會有個明顯的驅動力 就是遠離父母爭取獨立和在朋友間出類拔萃。 

But now we try to understand that in terms of the development of a part of their brain called the limbic system, so I'm going to show you the limbic system in red in the slide behind me, and also on this brain. 

但現在我們根據他們大腦某部分叫邊緣系統的發育 嘗試去理解他們， 我會在背后的幻燈片里 給你們看下紅色的邊緣系統，這個大腦里也有。 

So the limbic system is right deep inside the brain, and it's involved in things like emotion processing and reward processing. It gives you the rewarding feeling out of doing fun things, including taking risks. It gives you the kick out of taking risks. 

邊緣系統就在大腦的深處， 它涉及了情感處理還有獎勵感處理 在你做有趣的事情時，像冒險 它會產生一種收獲的感覺。 它讓你在冒險中產生快感。 

And this region, the regions within the limbic system, have been found to be hypersensitive to the rewarding feeling of risk-taking in adolescents compared with adults, and at the very same time, the prefrontal cortex, which you can see in blue in the slide here, which stops us taking excessive risks, is still very much in development in adolescents.

這部分區域，在邊緣系統里的區域， 相比成年人，對青少年的冒險產生的收獲感 具有很高的敏感性， 與此同時，前額葉皮層， 在幻燈片顯示藍色的地方， 會阻止我們過多地參與冒險， 但在青春期還是出于發育階段。

So brain research has shown that the adolescent brain undergoes really quite profound development, and this has implications for education, for rehabilitation, and intervention. 

關于大腦的研究表明青少年的大腦 經歷了意義深遠的的發育， 這對教育，康復和介入治療方面，就有所啟示了， 環境，包括教學，

The environment, including teaching, can and does shape the developing adolescent brain, and yet it's only relatively recently that we have been routinely educating teenagers in the West. 

能塑造青少年大腦的發育， 而且是到相當近的一段時期 在西方才對青少年有常規的教育。

All four of my grandparents, for example, left school in their early adolescence. They had no choice. And that's still the case for many, many teenagers around the world today. Forty percent of teenagers don't have access to secondary school education. 

就像，我的四個祖父母 在青春期早期就輟學了，他們也是沒辦法的。 目前世界上很多地方還是存在這樣的情況 百分之四十的青少年 沒有機會進入學校接受初中教育。

And yet, this is a period of life where the brain is particularly adaptable and malleable. It's a fantastic opportunity for learning and creativity.

而且，這個時期，是大腦處于 特別有可塑性的時期。 是學習和培養創新的絕好時機。

So what's sometimes seen as the problem with adolescents — heightened risk-taking, poor impulse control, self-consciousness — shouldn't be stigmatized. 

所以那些常被認為是青少年的問題的情況 高度愛冒險，易沖動不受控制 自我為中心，這些都不應受到指責。

It actually reflects changes in the brain that provide an excellent opportunity for education and social development. Thank you. 

它實際是反映了大腦的變化為教育，社會發展 提供了很好的機遇。謝謝。 

Remark：中文譯文為機翻，望諒解！視頻、演講稿均來源于TED官網