BBC地平线：不受控制？（2012）

remarkable construction of the brain itself.
人类大脑中有一千亿个神经元
With one hundred billion neurons
被超过一百万亿个神经突触联接在一起
connected by over one hundred trillion synapses,
结构极其复杂
the human brain is immensely complicated.
这就是人类大脑的外观
So this is what a human brain looks like.
这是前侧 这是后侧 有两个大脑半球
This is the front, this is the back, two cerebral hemispheres.
要想弄明白盲视是怎么回事
And if we want to understand what's going on in blindsight,
我要给大家看一下大脑的解剖标本
I need to show you a specimen that's been dissected already.
这是大脑半球的内侧面
And this is the inner surface of the hemisphere.
这个区域就是初级视觉皮层
And this region here is the primary visual cortex,
在盲视中就是这个区域受到了损伤
which is the area that's damaged in blindsight.
视觉皮层通过解读眼睛传来的信♥号♥♥
By interpreting signals flowing from the eyes,
让我们看见外面的花花世界
the visual cortex allows us to see the outside world.
如果这里受损了 就像GY那样
If it's damaged, like in GY,
即使眼睛仍在工作
these signals aren't registered,
这些信♥号♥♥也无法被识别
even if the eyes are still working.
但眼睛到大脑还有一条较古老的视觉通路
But there is another, older, visual pathway from eyes to brain.
事实证明 从眼传出的神经纤维
As it turns out, only about 90 percent of the fibres
仅约百分之九十传送到初级视觉皮层
leaving the eye, terminate in the primary visual cortex.
其余的神经纤维
The remainder of the fibres
传送至大脑的其它中心
head off to other centres in the brain.
其中最重要的就是视上丘
Most important of these is the superior colliculus,
在这里可以看见
which you can see just here.
它的名字与大小并不相符
Its name belies its size.
人类的视上丘也许非常微小
In humans, the superior colliculus might be tiny.
但从进化角度来看 它一直至关重要
But in evolutionary terms, it's always been vital.
在许多其它生物中
In many other creatures
它是大脑中最大的结构之一
it's one of the brain's biggest structures,
它使眼睛对突然的动作迅速定向
geared to rapidly orienting the eyes toward sudden movements.
这种进化的残留物
This evolutionary remnant
就是GY盲视能力的来源
is where GY's blindsight is thought to come from.
尽管他看不见
Despite not being able to properly see,
但他保留了对突然动作的直觉
he retains a primal awareness of sudden movements,
能感觉到有东西
a sense that something is there.
我们不仅需要能辨认出
We need to not only be able to identify
视景中有什么 还需要知道位置
what's out there in the visual scene, but where they are.
因为有捕食者的存在
Because in the case of a predator,
最终我们需要采取逃避行动
ultimately we need to take evasive action.
GY的盲视帮助我们明白了
GY's blindsight helps to show
在人类大脑漫长的进化史中
that in the human brain's long history,
意识的出现晚于潜意识
the unconscious preceded the conscious mind,
却并没有取代它
but it wasn't replaced by it.
潜意识仍然存在 藏匿于视野之外
It's still there today, hidden from view,
但仍时刻警惕着危险
but still on the lookout for danger.
但在人类的日常生活中
But there's another thing
潜意识还有一个作用
that the unconscious does for you each day.
获得所有你在生活中熟练应用的复杂技能
Take all those complex skills you've perfected in life.
事实上 一旦掌握了技能的诀窍
The truth is that once you've got the hang of them,
你就不用将精力全都放在上面了
you barely have to concentrate on them at all.
它们会在潜意识控制下自动完成
They've become automatic, and unconsciously controlled.
但这个过程
How this happens
仍是神经科学的最大谜题之一
is one of neuroscience's biggest mysteries.
核磁共振室
能破解这个谜题的地方就在这里
And the place to solve it is here.
朱利安·多伊恩教授遇到的困难是
The problem for Professor Julien Doyon
人们在生活中的学习过程
is that little of what you learn in life
几乎无法在脑部扫描仪中完成
can be done in a brain scanner.
显然扫描仪内部只有60厘米长
Obviously you have only 60 centimetres in the scanner,
所以难以用来研究机体的活动
and so it's very difficult to study motor movements,
朱利安·多伊恩博士
蒙特利尔大学
比如高尔夫球或是网球中的运动
for example, movements like in golf or a tennis movement,
这些都不能在扫描仪中完成
one cannot do that in the scanner.
研究学习新技能时大脑中发生的改变
The changes that happen inside your brain as you learn new,
这显然并非易事
automatic skills, are clearly not easy to study.
但与老朋友的一次偶然谈话
But a chance conversation with an old friend
让朱利安想到了最不寻常的解决办法
led Julien to a most unusual solution -
编织
knitting.
朗达·阿姆泽尔
那时 我们在聊天
At the time, we were actually carrying on a conversation
就像现在这样 他看见我在织毛衣
like this, and he saw me knitting.
我对她说
'I said to her,'
你做这动作好像是完全自动的
"It looks like this movement is completely automatic for you.
你一边织毛衣一边还能说话
"You basically do your movements and you're able to talk."
然后他说 可以好好利用这个活动
And then he said, "Oh, this would be a great activity to use,
但在扫描仪中 你只能躺着
"But if you were in the scanner, you'd have to lie there,
完全静止 肩膀不能动
"Very, very still, not move your shoulders and knit
平躺着编织 有人能做到吗
"lying on your back. Can people do that?"
我说 任何一个会自动编织的人都能做到
And I said, "Well, any knitter who's automatic can do that!"
但仅观察一位有经验的编织者
But simply seeing into the mind of an experienced knitter wasn't
不足以揭示学习新技能时大脑中的处理过程
enough to reveal how the process of learning a new skill occurs.
朱利安需要一种方法来比较
What Julien needed was a way of comparing how the brain
自动执行动作时的大脑活动
performs automatically
和开始学习时的大脑工作
with how it works when it's starting to learn.
这是个相当艰难的任务
It was a rather tricky task.
但之后朗达告诉我一件很重要的事 她说
'But then Rhonda told me something very important, she said,
织毛衣有两种方法
'"There are two approaches to knit,'
如果我要换一种织法
"And if I try to knit with this other approach,
用另一种技术 就好像重新开始
"This other technique, that would be like starting again,
我需要思考接下来的动作
"I would need to think about the movements that I have to make,
就要从头开始学
"And learn from scratch."
这启发了朱利安
For Julien, this was a revelation.
于是神经科学历史上
And so began one of the most
最为多彩的实验之一诞生了
colourful experiments in neuroscience history.
今天 朱利安将在朗达编织时扫描她的脑部
Today, Julien will be scanning Rhonda's brain as she knits.
朱利安会给你毛衣针...
So Julien's going to give you the needles...
她将先用她自小就学会的织法
She will start with the style of knitting she's been doing
进行编织
since she was a child,
这个动作在她的潜意识中已经完全自动了
and which is now completely automated in her unconscious mind.
马上要开始了 我们会到另一边去
We're all ready to start, we're going to go to the other side.
磁核共振
好了 朗达 你怎么样
OK, Rhonda. How are you?
我很好 很放松
'I'm fine, very relaxed.'
好 我将会要求你
OK, I'm going to ask you to produce
做30秒的编织动作
knitting movements for about 30 seconds.
准备开始
编织
好 开始吧
OK, here we go...
现在朗达正在织毛衣 这个动作
So, here Rhonda is producing movements which she has been
她已经练习数年 现在完全自动了
practising for years that are completely automatic for her.
屏幕上很快出现了一些数据
Data soon starts appearing on screen.
我们可以看见纹状体非常活跃
And we can see that there is a lot of activity in the striatum.
朗达织毛衣时 她大脑深处的纹状体在活动
As Rhonda knits, the striatum, deep in the brain,
与她复杂的自动动作相匹配
coordinates her complex automated movements.
这是个相当高效的过程
It's a wonderfully streamlined process.
但小组想观察的是
But what the team wants to see
当学习的过程开始时大脑的活动
is what happens when the learning process begins.
如果我们之后再要求她用不熟悉的织法
If we were then asking her to do the knitting
进行编织 我们就能看见
with a technique that she's not familiar with then we'd see
一种非常不同的脑部活动模式
perhaps a very different pattern of activity.
准备开始
小组现在要再做一次测试
The team now runs the test one more time.
好了吗
All right?
-好了 -开始了
- All right. - Here we go.
准备开始
编织
好了 我们看见初级运动皮层
OK, so we're starting to see some activity
开始活跃
in the primary motor cortex.
还发现小脑两侧
And you're starting to see some activity
也开始活跃
in both sides of the cerebellum, as well.
我们认为这些区域在最初对
We think that those regions at the beginning are important
确定产生动作的最佳方式很重要
to try to figure out what's the best way to produce movements.
无论编织还是杂耍 学习技能时
When you learn a skill, from knitting to juggling,
大脑的多个部位 尤其是小脑
multiple parts of your brain, especially the cerebellum,
都在努力协调你的新动作
work hard to coordinate your new movements.
但在练习时 有一些重要的事发生了