TED英⽂演讲青少年时期⼤脑的独特思维模式
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演讲者：Sarah Jayne Blakemore
演说题⽬：青少年时期⼤脑的独特思维模式
为什么青少年总容易冲动⾏事？是他们的⼤脑在那个时期有独特的思维模式。认知神经学家Sarah博⼠就此做了⼀番研究，发现了青少年时期⼤脑独特的运作规律和特点，⼀起来了解⼀下。
中英⽂对照翻译
Fifteen years ago, it was widely assumed that the vast majority of brain development takes place in the first few years of life. Back then, 15 years ago, we didn't have the ability to look inside the living human brain and track development across the lifespan.
15年前，⼤多数⼈认为⼈类⼤脑最重要的发育阶段是在⽣命开始的头⼏年进⾏的在过去，15年前，我们还做不到探究⼈脑的内部活动的情况以及追踪它在⽣命中的发育过程。
In the past decade or so, mainly due to advances in brain imaging technology such as magnetic resonance imaging, or MRI, neuroscientists have started to look inside the living human brain of all ages, and to track changes in brain structure and brain function,
在过去10年左右，主要是依靠脑成像技术的发展像磁共振成象，简称MRI，神经科学家已经开始了探究不同年龄的⼈脑内部情况，并记录下⼤脑结构和功能的不同变化，
so we u structural MRI if you'd like to take a snapshot, a photograph, at really high resolution of the inside of the living human brain, and we can ask questions like, how much gray matter does the brain contain, and how does that change with age?
如果需要⽣成影像，我们可以使⽤结构磁共振成像，可以拍出⾼分辨率的⼈脑内部图这样我们就可以提出⼀些问题了，例如⼤脑⾥有多少脑灰质会随着年龄变化⽽变化吗？
And we also u functional MRI, called fMRI, to take a video, a movie, of brain activity when participants are taking part in some kind of task like thinking or feeling or perceiving something.
我们也可以使⽤功能磁共振成像，简称fMRI 它可以拍摄视频，这样就可以在试验者进⾏某项活动中，⽐如思考或感受某些东西时记录拍摄下⼤脑的活动情况。
So many labs around the world are involved in this kind of rearch, 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,
现在世界上很多实验室都参与了这项研究所以我们就得出了很丰富很详尽的图⽚，解密了⼈脑的发育情况，同时这张照⽚从根本上颠覆了我们以往对⼈脑发育的观念通过告诉我们发育的过程不完全都在幼⼉阶段。
and instead, the brain continues to develop right throughout adolescence and into the '20s and '30s.
相反，⼤脑会继续发育贯穿整个青春期，⼀直到20多岁甚⾄30多岁
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.
所以青春期也被定义为⽣命中⽣理和荷尔蒙转变的开端当⼈们在社会中获得⼀个稳定和独⽴的⾝份时也就标志这青春
所以青春期也被定义为⽣命中⽣理和荷尔蒙转变的开端当⼈们在社会中获得⼀个稳定和独⽴的⾝份时也就标志这青春期的结束了。有时青春期会持续很久很久。
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.
⼤脑其中的⼀个区域，叫前额叶⽪层，它在青春期阶段是最活跃的。这个是⼈脑的⼀个模型这⾥是前额叶⽪层，就在前⾯这⾥前额叶⽪层是⾮常有意思的⼀个⼤脑区域
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,
相对其他物种⽽⾔⼈类的前额叶⽪层是⼤很多的它涉及到⼤量的⾼级认知功能，例如决策计划，计划明天要做的事情或者下周或明年的
inhibiting inappropriate behavior, so stopping yourlf saying something really rude or doing something really stupid. It's also involved in social interaction, understanding other people, and lf-awareness.
对不恰当⾏为的抑制，像阻⽌你说⼀些粗鲁的话或做⼀些傻事它还涉及到社交⽅⾯包括理解他⼈和⾃我意识
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 increas during childhood, which is what you can e on this graph.
所以MRI对前额叶⽪层的发育的研究揭⽰了它确实在青春期阶段有着⾮同寻常的发育情况举个例⼦，如果你去看⼤脑灰质从4岁起到22岁的⼤脑灰质会在童年时期会增加，也就是现在在图表上你能看到的
It peaks in early adolescence. The arrows indicate peak gray matter volume in prefrontal cortex. You can e that that peak happens a couple of years later in boys relative to girls, and that's probably becau boys go through puberty a couple of years later than girls on average,
在早期的青春期会到达顶峰箭头指的就是⼤脑灰质在前额叶⽪层达到的锋点，你会发现要达到这个锋点男孩会相对⽐⼥孩要慢⼏年
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, becau gray matter contains cell bodies and connections between cells,
这⼤概是因为男孩平均要⽐⼥孩晚那么⼏年经历青春期在青春期阶段，⼤脑灰质在前额叶⽪层会出现⼀个明显的下降听起来似乎有些不安但这确实⼀个极其重要的发育阶段因为⼤脑灰质包涵了细胞体还有细胞之间的联系，
the synaps, and this decline in gray matter volume during prefrontal cortex is thought to correspond to synaptic pruning, the elimination of unwanted synaps. This is a really important process. It's partly dependent on the environment that the animal or the human is in, and the synaps that are being ud are strengthened,
也就是突触在前额叶⽪层到了⼀个需要对突触进⾏修剪去除掉⼀些不必要的突触的这⼀阶段⼤脑灰质也就会减少这是⾮常关键的阶段⼀部分取决于动物或⼈类居住的环境那些有价值的突触会茁壮发育
and synaps that aren't being ud in that particular environment are pruned away. You can think of it a bit like pruning a robush. You prune away the weaker branches so that the remaining, important branches, can grow stronger,
⽽在那个特定的环境⾥那些没什么存在必要的突触则会被剔除掉你可以把它当成是修剪盆栽把那些奄奄⼀息的枯枝败叶修剪掉这样那些剩下的，重要的枝⼲，就会茁壮成长
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.
in prefrontal cortex and in other brain regions during the period of human adolescence.
这个会根据物种及环境不同⽽⾼效调整⼤脑组织的过程就是在⼈类的青春期阶段在前额叶⽪层和其他⼤脑区域进⾏的
So a cond line of inquiry that we u 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.
我们⽤来记录青春期⼤脑变化的第⼆轮调查，就是⽤功能磁共振成像来探究不同年龄⼤脑活动的变化情况这⾥我举个发⽣在我实验室⾥的例⼦。
So in my lab, we're interested in the social brain, that is the network of brain regions that we u 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.
在我的实验室⾥，我们对社会⼤脑很感兴趣，就是我们与他⼈沟通交流的⼤脑区域⽹络。我会给你们看⼀张⾜球赛的图⽚跟你们分析下社会性⼤脑⼯作时的两个⽅⾯这就是⼀场⾜球赛。
Michael Owen has just misd 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 respons are, so within a split cond of Michael Owen missing this goal,
迈克尔欧⽂刚刚的射门没有命中，所以他躺在地上，这张图⽚诠释了社交情绪反应是多么⾃动⾃觉的这是社会脑的第⼀个层⾯，所以就在欧⽂没射中球门的那⼀瞬间，
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--
每个⼈的⼿都是同样的动作同样的表情，甚⾄欧⽂也是这样在他划过草地时，他也是同样的⼿势估计他的⾯部表情也差不多⽽唯⼀不为所动的那个⼈，就是背后穿黄⾊球⾐的了
and I think they're on the wrong end of the stadium, and they're doing another social emotional respo
n that we all instantly recognize, and that's the cond aspect of the social brain that this picture really nicely illustrates,
我觉得他们是场上占不到什么优势的⼈他们有着不⼀样的社交情绪反应我们能马上认出来，这就是社会脑的第⼆个层⾯也在图⽚上很好地表现出来
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 the guys.
它揭⽰了我们对他⼈⾏为的理解程度按照潜在的情绪和精神状态解读他⼈的举动，他⼈的⼿势，还有他们的⾯部表情所以你不⽤去问他们中的任何⼀⼈。
You have a pretty good idea of what they're feeling and thinking at this preci moment in time.So that's what we're interested in looking at in my lab.
就能对这个时候他们的情感和思想有⼀个颇为准确的理解。这就是我的实验室所感兴趣的事。
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,
在实验室⾥，我们召集了青少年和成年⼈进⾏⼤脑扫描，我们给他们分配任务涉及了他们对他⼈，⾃⼰的思想，⾃⼰的精神状态，以及对⾃⼰的情绪的思考
and one of the findings that we've found veral 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.
prefrontal cortex in the midline of your head.
和其他实验室⼀样，⽬前我们多次发现的⼀点是前额叶⽪层的⼀个部分叫做内侧前额叶⽪质，就是蓝⾊那部分，就在前额叶⽪质的正中间在脑袋的正中央。
This region is more active in adolescents when they make the 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 decreas during the period of adolescence.
当青少年在做社交决定以及考虑他⼈时他们⼤脑的这个区域要⽐成年⼈还要活跃，这其实是世界上其他实验室在这个⽅⾯的九个不同研究的荟萃分析他们都表明了⼀样的结果，就是内侧前额叶⽪质的活跃度，会在青春期阶段逐渐减⼩。
And we think that might be becau adolescents and adults u 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 u in my lab.
我们猜测可能是青少年和成年⼈在做社交决定时，有着不同的⼼理活动不同的认知策略，研究这个的⽅法之⼀就是采⽤⾏为研究我们把⼈召集进实验室分配给他们⼀些⾏动任务，我给你们举个我们实验室的任务的例⼦。
So imagine that you're the participant in one of our experiments. You come into the lab, you e this computerized task. In this task, you e a t of shelves. Now, there are objects on the shelves, on some of them, and you'll notice there's a guy standing behind the t of shelves, and there are some objects that he can't e. They're occluded, from his point of view, with a kind of gray piece of wood. This is the same t of shelves from his point of view. Notice that there are only some objects that he can e, whereas there are many more objects that you can e. Now your task is to move objects around. The director, standing behind the t 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 e. This introduces a really interesting condition whereby there's a kind of conflict between your perspective a
nd 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, becau that's the top truck from your perspective, but then you have to remember, "Oh, he can't e 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 e 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.
想象⼀下你是我们实验的参与⼈员之⼀你进到这个实验室，你看到这个电脑程序任务。在这个任务中，你看到⼏排的架⼦。现在架⼦上有些摆上了物品，你会发现有个⼈站在架⼦后⾯，⽽且有些物品他是看不到的。他们被遮住了，从这个⾓度看被灰⾊的⽊板遮住了。从他的⾓度看，这是同样的架⼦。但要注意，他只看得到⼀些物品，但你却能看到更多的。你的任务就是去移动这些物品。引导⼈
员，将站在架⼦后⾯，引导你去移动这些物品，但是要记住，他不会叫你去移动那些他看不到的物品。这就引出了⼀个很有意思的情况在你的⾓度和引导员的⾓度之间会有⼀种冲突。假设他叫你去把上⾯的⽕车往左移。但那⼉有三辆⽕车，你会很⾃然地去移动⽩⾊那辆，因为从你的⾓度看它就是上⾯的⽕车，但你得知道 “噢，他看不见那辆⽕车，所以他是想我去移动蓝⾊的，”就是他的⾓度最上⾯的那辆。现在信不信由你，像你们⼀样正常健康聪明的成年⼈都会犯错在这种试验中，犯错⼏率⾼达50%。他们会移动⽩⾊那辆，⽽不是蓝⾊那辆话说我们给青少年还有成年⼈分配了这种任务，我们有条件控制⼀个是没有引导员，另⼀个是给他们定规则。我们告诉他们，好吧，我们会做⼀样的事情这次没有引导员。相反，你得忽略那些灰⾊格⼦。你会发现其实条件是完全⼀样的，要记住没有引导员这⼀情况只有规定的要求，但在有引导员的情况下，他们则需要考虑引导员的视野⾓度这样才能理解引导员的指令。
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 ven to adulthood, and what you're going to e is the percentage errors in the adult group in both conditions,
这个就是在我们较⼤规模的研究中得出的犯错⽐率，这是从七岁到成年的⼀个研究，你们接下来会看到的就是成⼈组在两种条件下的错误⽐率，
so the gray is the director condition, and you e that our intelligent adults are making errors about 50 percent of the time, whereas they make far fewer errors when there's no director prent, when they just have to remember that rule of ignoring the gray back ground.
灰⾊的就是有引导员的情况，你会发现我们聪明的成年⼈的错误率约是50% 但是他们在没有引导员在场的情况下。错误率会低很多，他们只需记住去忽略灰⾊格⼦这⼀规定。
Developmentally, the 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 the trials, in both of the conditions.
相应地，这两种条件的情况发展⼏乎是⼀样的，在后⼉童期还有中青春期，都是有所提升，换句话说，就是在这些试验中，在这些条件下，错误的⼏率会随年龄增加⽽减少。
But it's when you compare the last two groups, the mid-adolescent group and the adult group where things get really interesting, becau there, there is no continued improvement in the no-director condition.
但当你⽐较最后两组实验时，中青春期组和成年组事情会变得有趣很多因为在没有引导员的情况下，也没有提升的趋势。
In other words, everything you need to do in order to remember the rule and apply it ems 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,
也就是说，涉及到记住规则并应⽤它所需要的⼀切似乎都在中青春期已经尘埃落定了但是相反地，如果你去看两条灰⾊的图柱在有引导员的条件下，在中青春期和成年组之间还是有明显的提升的
and what this means is that the ability to take into account someone el'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.
这就意味着，从他⼈⾓度考虑出发从⽽运⽤到实践中的能⼒，⽽这也是我们⽇常⽣活随处可见的，这⼀能⼒，在青春期的中后期仍在发育中。
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.
所以如果你有⼀个⼉⼦或⼥⼉出于青春期你有时觉得他们在考虑他⼈感受时做得不够好那么你是对的，的确是这样，这就是原因。
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 lf-conscious.
所以我们有时会讽刺青少年。说他们没什么⼤脑，有时会在媒体上丑化他们那种典型的青春期⾏为，他们爱冒险，情绪阴晴不定，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.
我从我朋友那⼉听到⼀个很有趣的故事他说这是他在⼥⼉们青春期前后经常见到的事就是在他⾯前的尴尬程度。
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.
她说，“青春期前，如果我的两个⼥⼉在商店⾥胡闹，我会说，嘿别闹了，我给你们唱你们最喜欢的歌，” 然后她们⽴即安分守⼰，听他唱歌
