3 clues to understanding your brain | VS Ramachandran

譯者: Yesbydefault 倪文娟 審譯者: Adrienne Lin

Well, as Chris pointed out, I study the human brain,

是的，就如克里斯的介紹，我研究人類的腦

the functions and structure of the human brain.

人類大腦的功能和結構。

And I just want you to think for a minute about what this entails.

請大家試想一下，這牽涉到什麼？

Here is this mass of jelly, three-pound mass of jelly

人腦像一團三磅重的果凍，

you can hold in the palm of your hand,

它可以放在手掌裡，

and it can contemplate the vastness of interstellar space.

它能思索浩瀚的星際空間，

It can contemplate the meaning of infinity

能思索『無限』的含義，

and it can contemplate itself contemplating on the meaning of infinity.

甚至能思索自身思索『無限』含義的這件事。

And this peculiar recursive quality that we call self-awareness,

這種獨特的遞迴自省特質，稱為自我意識。

which I think is the holy grail of neuroscience, of neurology,

我認為這是神經科學和神經病學的終極目標和意義，

and hopefully, someday, we'll understand how that happens.

希望有朝一日，我們能夠解開這個謎題。

OK, so how do you study this mysterious organ?

那麼，我們要如何研究這個神秘的器官呢？

I mean, you have 100 billion nerve cells,

人腦有1000億個神經元細胞，

little wisps of protoplasm, interacting with each other,

每個都是一小束原生質，彼此交互作用，

and from this activity emerges the whole spectrum of abilities

從這些活動中，產生出多不勝數的能力

that we call human nature and human consciousness.

即所謂人性和人的意識。

How does this happen?

這是怎麼產生的呢？

Well, there are many ways of approaching the functions of the human brain.

研究人腦功能的方法很多，

One approach, the one we use mainly,

其中，最常採用的方法

is to look at patients with sustained damage to a small region of the brain,

是觀察大腦中，一小部分區域遭受持續性損傷的病人，

where there's been a genetic change in a small region of the brain.

研究已經發生某種基因改變的這一小部分腦區，

What then happens is not an across-the-board reduction

這並不是全面性喪失

in all your mental capacities,

所有的心智能力，

a sort of blunting of your cognitive ability.

而是認知能力變得遲鈍，

What you get is a highly selective loss of one function,

這是一種特定功能的喪失，

with other functions being preserved intact,

而其他功能則完好無損。

and this gives you some confidence in asserting

我們幾乎可以確定，

that that part of the brain is somehow involved in mediating that function.

大腦的這個區域影響該功能，

So you can then map function onto structure,

我們便可把功能對應到結構上，

and then find out what the circuitry's doing

得知這部分神經迴路是如何產生

to generate that particular function.

這個特定的功能，

So that's what we're trying to do.

這就是我們的目標。

So let me give you a few striking examples of this.

讓我向大家說明幾個驚人的例子，

In fact, I'm giving you three examples, six minutes each, during this talk.

我要提出3個例子，每段說明6分鐘，

The first example is an extraordinary syndrome called Capgras syndrome.

首先，是一種非常奇特的『凱卜葛拉斯症候群』(Capgras Syndrome)。

If you look at the first slide there,

在第一張幻燈片裡

that's the temporal lobes, frontal lobes, parietal lobes, OK --

顯示的是顳葉(temporal lobes)、額葉(frontal lobes)和頂葉(parietal lobes)

the lobes that constitute the brain.

這些是構成大腦的腦葉

And if you look, tucked away inside the inner surface of the temporal lobes --

仔細看，你會發現顳葉的皮層內部

you can't see it there --

(這張圖裡看不出來)

is a little structure called the fusiform gyrus.

是一種稱為梭狀回(fusiform gyrus)的微小結構

And that's been called the face area in the brain,

它被稱為腦的『臉部區域』

because when it's damaged, you can no longer recognize people's faces.

如果這個區域損傷，你就會喪失辨識別面孔的能力

You can still recognize them from their voice

你還是可以從聲音辨識其人

and say, "Oh yeah, that's Joe,"

例如，你會說：『對，這個人是喬』

but you can't look at their face and know who it is, right?

但你卻無法看著別人的臉認出這是誰

You can't even recognize yourself in the mirror.

你甚至認不出鏡中的自己

I mean, you know it's you because you wink and it winks,

你對鏡中人眨眼，那人也會對你眨眼

and you know it's a mirror,

而且你知道那是一面鏡子

but you don't really recognize yourself as yourself.

可是卻認不出那個人就是你自己

OK. Now that syndrome is well known as caused by damage to the fusiform gyrus.

我們已知這種症候群是由於梭狀回損傷所導致

But there's another rare syndrome, so rare, in fact,

但還有一種非常罕見的症候群

that very few physicians have heard about it, not even neurologists.

連許多醫生、甚至神經科醫生都未曾聽聞，

This is called the Capgras delusion,

叫做『凱卜葛拉斯妄想症』(Capgras Delusion)

and that is a patient, who's otherwise completely normal,

一個原本腦部功能正常的人

has had a head injury, comes out of coma,

頭部受到損傷，從昏迷中醒來以後，

otherwise completely normal, he looks at his mother

其他腦部功能都很正常，但是他看到自己的母親

and says, "This looks exactly like my mother, this woman,

卻說：『這人看上去跟我母親一模一樣，

but she's an impostor.

但她是個冒牌貨，

She's some other woman pretending to be my mother."

是個假扮我母親的女人。』

Now, why does this happen?

為什麼會這樣呢？

Why would somebody -- and this person is perfectly lucid and intelligent

為什麼這個人理智、且完全清醒

in all other respects, but when he sees his mother,

其他各腦部功能均完好，但是看到自己的母親，

his delusion kicks in and says, it's not mother.

卻產生錯覺，認為不是他的母親呢？

Now, the most common interpretation of this,

目前最常見的解釋

which you find in all the psychiatry textbooks,

所有精神病學教科書的見解

is a Freudian view, and that is that this chap --

是佛洛伊德式的觀點：當這個男子

and the same argument applies to women, by the way,

(其實女性也有同樣的情形)

but I'll just talk about guys.

(但我就以男性為例討論)

When you're a little baby, a young baby,

(佛洛伊德認為) 男性在嬰兒時期

you had a strong sexual attraction to your mother.

對母親有強烈的性吸引力

This is the so-called Oedipus complex of Freud.

即佛洛伊德所謂的『伊底帕斯』(Oedipus)戀母情結

I'm not saying I believe this,

我並不支持這種論點

but this is the standard Freudian view.

但這是典型的佛洛伊德觀點。

And then, as you grow up, the cortex develops,

隨著成長，腦皮層逐漸生長發育

and inhibits these latent sexual urges towards your mother.

抑制了對母親的潛在性慾。

Thank God, or you would all be sexually aroused when you saw your mother.

謝天謝地，否則你每次看到你母親就會性慾高漲。

And then what happens is,

但是，當頭部受傷，

there's a blow to your head, damaging the cortex,

頭部的打擊損傷了腦皮層，

allowing these latent sexual urges to emerge,

釋放了潛在的性衝動

flaming to the surface, and suddenly and inexplicably

浮現到最表層，突然間，莫名其妙地

you find yourself being sexually aroused by your mother.

你感覺到自己對母親產生了性慾

And you say, "My God, if this is my mom,

於是你想：『天啊，如果這是我媽，

how come I'm being sexually turned on?

我怎麼可能會有性衝動？

She's some other woman. She's an impostor."

她一定是別的女人，是個冒牌貨。』

It's the only interpretation that makes sense to your damaged brain.

你受傷的大腦認為，只有這樣解釋才合理。

This has never made much sense to me, this argument.

但我從不認同這種看法。

It's very ingenious, as all Freudian arguments are --

這個主張就像佛洛伊德所有的理論一樣，非常精闢

(Laughter)

(笑聲)

-- but didn't make much sense because I have seen the same delusion,

但是卻不合理，因為我曾經目睹同樣的錯覺

a patient having the same delusion, about his pet poodle.

發生在一名病患對他的貴賓狗身上。

(Laughter)

(笑聲)

He'll say, "Doctor, this is not Fifi. It looks exactly like Fifi,

他說：『醫生，這不是菲菲吧，牠長的跟菲菲一模一樣，

but it's some other dog." Right?

但牠是另一條狗。』對吧？

Now, you try using the Freudian explanation there.

現在請你套用佛洛伊德的理論解釋看看，

(Laughter)

(笑聲)

You'll start talking about the latent bestiality in all humans,

會認為人類有潛在的戀獸性，

or some such thing, which is quite absurd, of course.

或是其他類似的論點，這都是非常荒謬的。

Now, what's really going on?

所以，實際情形究竟是怎麼回事呢？

So, to explain this curious disorder,

要解釋這種奇怪的症狀，

we look at the structure and functions of the normal visual pathways in the brain.

我們來看看正常人腦視覺通路的結構和功能。

Normally, visual signals come in, into the eyeballs,

正常情況下，視覺訊號通過眼球，

go to the visual areas in the brain.

進入腦中的視覺區域。

There are, in fact, 30 areas in the back of your brain concerned with just vision,

事實上，腦後部有30個專門負責視覺的區域。

and after processing all that, the message goes to a small structure

經過這些區域處理之後，訊號會進入一個微小結構，

called the fusiform gyrus, where you perceive faces.

稱為『梭狀回』，就是感知面孔的地方，

There are neurons there that are sensitive to faces.

那裡有對面孔敏感的神經元。

You can call it the face area of the brain, right?

我們可以稱它為『大腦的面部區』，

I talked about that earlier.

我稍早提過。

Now, when that area's damaged, you lose the ability to see faces, right?

這個區域一旦損壞，你就失去了識別面孔的能力。對吧？

But from that area, the message cascades

但神經訊號還會通過那個區域，

into a structure called the amygdala in the limbic system,

進入大腦邊緣系統(limbic system)的杏仁核(amygdala)，

the emotional core of the brain,

這是腦的情緒核心，

and that structure, called the amygdala,

而這個稱為杏仁核的結構，

gauges the emotional significance of what you're looking at.

會判斷你所看見的物體在情緒上的重要性。

Is it prey? Is it predator? Is it mate?

在你眼前的，是獵物？掠食者？還是配偶？

Or is it something absolutely trivial, like a piece of lint,

還是完全無關緊要的東西，如衣服上的毛球，

or a piece of chalk, or a -- I don't want to point to that, but --

或者一支粉筆。或是，我不想指出來了..

or a shoe, or something like that? OK?

或者是一只鞋子等等，

Which you can completely ignore.

可以毫不理會的東西。

So if the amygdala is excited, and this is something important,

如果杏仁核變得興奮，表示這個東西對你很重要，

the messages then cascade into the autonomic nervous system.

神經訊號就會繼續傳到自主神經系統，

Your heart starts beating faster.

你的心跳會開始加速，

You start sweating to dissipate the heat that you're going to

你會開始出汗，排除因緊張而產生的體熱

create from muscular exertion.

即肌肉緊繃引起的。

And that's fortunate, because we can put two electrodes on your palm

這樣便於偵測，因為我們可以在你的手掌心貼上兩個電極

and measure the change in skin resistance produced by sweating.

來測量汗液導致的皮膚電阻變化。

So I can determine, when you're looking at something,

如此就能判斷，當你看著某樣東西，

whether you're excited or whether you're aroused, or not, OK?

是否感覺興奮？或是有沒有被挑起慾望。對吧？

And I'll get to that in a minute.

這點待會我會進一步說明。

So my idea was, when this chap looks at an object, when he looks at his --

所以我認為，當這個人看著某物時，

any object for that matter, it goes to the visual areas and,

或者任何物體，訊號傳到視覺區

however, and it's processed in the fusiform gyrus,

傳入梭狀回處理

and you recognize it as a pea plant, or a table,

便可認出這是一顆豌豆、一張桌子，

or your mother, for that matter, OK?

或是他的母親，對吧？

And then the message cascades into the amygdala,

接著，訊號繼續傳到杏仁核，

and then goes down the autonomic nervous system.

再傳到自主神經系統。

But maybe, in this chap, that wire that goes from the amygdala to the limbic system,

但是，或許這個病患腦中，從杏仁核到邊緣系統的線路

the emotional core of the brain, is cut by the accident.

即連接大腦控制情緒核心的線路，在事故中被切斷了。

So because the fusiform is intact,

他的梭狀回完好無損，

the chap can still recognize his mother,

所以還能認出他的母親，

and says, "Oh yeah, this looks like my mother."

心想：『是啊，這女人長得跟我母親一樣。』

But because the wire is cut to the emotional centers,

但由於通往情緒中心的線路被截斷了，

he says, "But how come, if it's my mother, I don't experience a warmth?"

他就會懷疑：『如果真是我母親， 為什麼我看見她卻沒有溫暖的感覺？』

Or terror, as the case may be? Right?

或者有些人可能會產生恐懼感，嗯？

(Laughter)

(笑聲)

And therefore, he says, "How do I account for this inexplicable lack of emotions?

於是他會想：『該如何解釋我的欠缺情緒反應呢？

This can't be my mother.

她不可能是我的母親。

It's some strange woman pretending to be my mother."

是某個陌生女人假裝是我的母親。』

How do you test this?

這種現象該如何驗證呢？

Well, what you do is, if you take any one of you here, and put you in front of a screen,

方法是，例如，請你們其中一位觀眾上來站在螢幕前，

and measure your galvanic skin response,

我一邊測量你的皮膚電反應(GSR)，

and show pictures on the screen,

一邊在螢幕上播放圖片給你看。

I can measure how you sweat when you see an object,

我可以測量你看見各個物體時的出汗情形。

like a table or an umbrella. Of course, you don't sweat.

例如，看見桌子或雨傘時，你當然不至於出汗，

If I show you a picture of a lion, or a tiger, or a pinup, you start sweating, right?

如果看到獅子、老虎或性感女郎，你就會冒汗了。對吧？

And, believe it or not, if I show you a picture of your mother --

信不信，如果我給你看你母親的照片，

I'm talking about normal people -- you start sweating.

我是指一般正常人，就會開始流汗，

You don't even have to be Jewish.

不一定是猶太人才有這種反應。 (譯註：猶太媽媽的刻版印象是專橫嘮叨、管教甚嚴)

(Laughter)

(笑聲)

Now, what happens if you show this patient?

同樣的實驗，對前述的病患，反應又是如何呢？

You take the patient and show him pictures on the screen

你把他帶到螢幕前，播放圖片給他看，

and measure his galvanic skin response.

測量他的皮膚電反應(GSR)。

Tables and chairs and lint, nothing happens, as in normal people,

看桌子、椅子、毛球，沒有反應，跟正常人一樣；

but when you show him a picture of his mother,

但是當你給他看他母親的照片，

the galvanic skin response is flat.

皮膚電圖像還是平的，

There's no emotional reaction to his mother,

他對自己的母親也沒有情緒反應，

because that wire going from the visual areas to the emotional centers is cut.

因為從視覺區通往情緒中心的線路被切斷了。

So his vision is normal because the visual areas are normal,

他的視覺沒有問題，因為視覺區功能正常，

his emotions are normal -- he'll laugh, he'll cry, so on and so forth --

他的情緒反應能力也沒有問題，他會哭會笑，等等

but the wire from vision to emotions is cut

但是從視覺到情緒的線路卻阻斷了，

and therefore he has this delusion that his mother is an impostor.

因此他會產生錯覺，認為他母親是冒牌貨。

It's a lovely example of the sort of thing we do:

這個有趣的例子可以說明我們從事的研究，

take a bizarre, seemingly incomprehensible, neural psychiatric syndrome

探究這類奇特、看似無法理解的神經精神症候群，

and say that the standard Freudian view is wrong,

來證明傳統佛洛伊德觀點的謬誤，

that, in fact, you can come up with a precise explanation

事實上，你可以找到精確的解釋，

in terms of the known neural anatomy of the brain.

從已知的大腦神經解剖學找出答案。

By the way, if this patient then goes,

順帶一提，如果這個病人離開，

and mother phones from an adjacent room -- phones him --

他母親從隔壁打電話來，

and he picks up the phone, and he says, "Wow, mom, how are you? Where are you?"

他會接起電話說：『哇，媽，妳好不好？妳在哪裡？』

There's no delusion through the phone.

透過電話，不會產生錯覺。

Then, she approaches him after an hour, he says, "Who are you?

一小時後，當母親走到他面前，他又會問：『妳是誰呀？

You look just like my mother." OK?

妳長得跟我母親一模一樣！』

The reason is there's a separate pathway

原因是，有另一條通路

going from the hearing centers in the brain to the emotional centers,

從腦的聽覺中心通往情緒中心，

and that's not been cut by the accident.

這條通路並沒有被事故切斷。

So this explains why through the phone he recognizes his mother, no problem.

這是為什麼他能透過電話認出母親，毫無問題；

When he sees her in person, he says it's an impostor.

但是當他看到母親本人，卻說她是假冒者。

OK, how is all this complex circuitry set up in the brain?

大腦究竟是如何建構發展出如此複雜的迴路呢？

Is it nature, genes, or is it nurture?

是先天、基因、還是後天的作用？

And we approach this problem

要解開這個謎題，

by considering another curious syndrome called phantom limb.

可透過研究另一種奇特的症候群，稱為『幻肢』。

And you all know what a phantom limb is.

各位都知道幻肢是什麼

When an arm is amputated, or a leg is amputated, for gangrene,

當一條手臂或腿因為壞疽被切除，

or you lose it in war -- for example, in the Iraq war,

或在戰爭(如伊拉克戰爭)中失去，

it's now a serious problem --

我們發現這會產生嚴重的問題

you continue to vividly feel the presence of that missing arm,

傷者仍能強烈地感受到那條已經失去的手臂的存在，

and that's called a phantom arm or a phantom leg.

這就是所謂的幻臂(phantom arm)或幻腿(phantom leg)。

In fact, you can get a phantom with almost any part of the body.

事實上，身體任何部位都有可能產生這種幻肢現象，

Believe it or not, even with internal viscera.

甚至連內臟器官都有可能。

I've had patients with the uterus removed -- hysterectomy --

我有位病人，做子宮切除術除去了子宮，

who have a phantom uterus, including phantom menstrual cramps

她得了幻子宮症，還會有幻經痛

at the appropriate time of the month.

每個月都會定期感到經痛。

And in fact, one student asked me the other day,

甚至，前幾天還有學生問我，

"Do they get phantom PMS?"

她們有沒有幻經前症候群？

(Laughter)

(笑聲)

A subject ripe for scientific enquiry, but we haven't pursued that.

這頗值得科學研究，但我們還沒有探討過。

OK, now the next question is,

好了，接下來的問題是：

what can you learn about phantom limbs by doing experiments?

我們能透過實驗，對幻肢現象獲得什麼了解？

One of the things we've found was,

我們發現，

about half the patients with phantom limbs

半數的幻肢病患，

claim that they can move the phantom.

宣稱自己可以移動那條幻肢。

It'll pat his brother on the shoulder,

能用幻肢拍兄弟的肩膀，

it'll answer the phone when it rings, it'll wave goodbye.

能在電話鈴響時拿起聽筒，還能揮手道別。

These are very compelling, vivid sensations.

這些感覺真實而強烈，

The patient's not delusional.

病患並不是在妄想。

He knows that the arm is not there,

他們明知道手臂已經不在了，

but, nevertheless, it's a compelling sensory experience for the patient.

但感覺還是非常強烈。

But however, about half the patients, this doesn't happen.

不過，另一半病患倒是沒有這種現象。

The phantom limb -- they'll say, "But doctor, the phantom limb is paralyzed.

病患會說：『醫生，我的幻肢麻痺了，

It's fixed in a clenched spasm and it's excruciatingly painful.

緊繃痙攣，無法動彈，劇烈疼痛。

If only I could move it, maybe the pain will be relieved."

如果我能移動它，疼痛或許會減輕。

Now, why would a phantom limb be paralyzed?

奇怪的是，既然是幻肢，為什麼會麻痺癱瘓呢？

It sounds like an oxymoron.

這不是自相矛盾嗎？

But when we were looking at the case sheets, what we found was,

我們研究病歷表發現，

these people with the paralyzed phantom limbs,

這些感覺幻肢癱瘓的病患，

the original arm was paralyzed because of the peripheral nerve injury.

手臂還在時，曾經因為周圍神經受傷而癱瘓，

The actual nerve supplying the arm was severed,

控制手臂的神經被切斷，

was cut, by say, a motorcycle accident.

例如，若病患因機車事故，切斷實際的手臂神經，

So the patient had an actual arm, which is painful,

他(尚未切除)的手臂會感到疼痛，

in a sling for a few months or a year, and then,

吊著繃帶好幾個月或一整年。後來，

in a misguided attempt to get rid of the pain in the arm,

為了消除疼痛，判斷失當，

the surgeon amputates the arm,

被外科醫師做了截肢手術，

and then you get a phantom arm with the same pains, right?

結果形成幻臂，而且疼痛還是存在。

And this is a serious clinical problem.

這是非常嚴重的臨床問題。

Patients become depressed.

病患變得憂鬱沮喪，

Some of them are driven to suicide, OK?

有些人甚至因而自殺。

So, how do you treat this syndrome?

那麼，這種症候群該如何治療呢？

Now, why do you get a paralyzed phantom limb?

首先要問的是，為什麼有人會覺得幻肢麻痺？

When I looked at the case sheet, I found that they had an actual arm,

我研究病歷，發現他們的手臂還確實存在時，

and the nerves supplying the arm had been cut,

控制該手臂的神經被切斷，

and the actual arm had been paralyzed,

導致該手臂麻痺，

and lying in a sling for several months before the amputation,

吊在繃帶裡，癱瘓了好幾個月，才被截肢。

and this pain then gets carried over into the phantom itself.

截肢前的疼痛，卻持續延伸到幻臂裡。

Why does this happen?

為什麼會這樣呢？

When the arm was intact, but paralyzed,

當手臂尚未切除，但麻痺時，

the brain sends commands to the arm, the front of the brain, saying, "Move,"

前腦發送指令給手臂，命令它：『移動！』

but it's getting visual feedback saying, "No."

但視覺卻回應大腦說：『動不了。』

Move. No. Move. No. Move. No.

『動！』『動不了。』『動！』『動不了。』...

And this gets wired into the circuitry of the brain,

這個反覆模式被固著在大腦的神經迴路中，

and we call this learned paralysis, OK?

這叫做『習得性癱瘓』（learned paralysis）。

The brain learns, because of this Hebbian, associative link,

大腦以為，因為這種海伯聯結(Hebbian associative link)

that the mere command to move the arm

使這個移動手臂的簡單指令，

creates a sensation of a paralyzed arm.

導致麻痺手臂的疼痛感。

And then, when you've amputated the arm,

截除手臂以後，

this learned paralysis carries over into your body image

這種『習得性癱瘓』蔓延到你的身體意象(body image)，

and into your phantom, OK?

深入幻肢之中。

Now, how do you help these patients?

那麼，該怎麼幫助這些病患呢？

How do you unlearn the learned paralysis,

怎樣拋卻已習得的癱瘓，

so you can relieve him of this excruciating, clenching spasm

解除病患幻臂中劇痛的痙攣？

of the phantom arm?

.

Well, we said, what if you now send the command to the phantom,

於是我們想，要是讓大腦對幻肢發送命令，

but give him visual feedback that it's obeying his command, right?

並讓視覺回應告知大腦，幻肢服從命令，如何？

Maybe you can relieve the phantom pain, the phantom cramp.

或許就會消除幻肢疼痛和痙攣了。

How do you do that? Well, virtual reality.

要怎樣做呢？用虛擬實境(virtual reality)吧？

But that costs millions of dollars.

但那要花好幾百萬。

So, I hit on a way of doing this for three dollars,

我想到一個辦法，只要花3美元，

but don't tell my funding agencies.

不要告訴我的贊助機構。

(Laughter)

(笑聲)

OK? What you do is you create what I call a mirror box.

首先，要做一個『鏡盒』，

You have a cardboard box with a mirror in the middle,

在紙板盒中間放一面鏡子，

and then you put the phantom -- so my first patient, Derek, came in.

然後放置幻肢。我的第一個病患，德瑞克進來，

He had his arm amputated 10 years ago.

他在10年前截除手臂。

He had a brachial avulsion, so the nerves were cut

之前曾經受了臂神經叢撕脫傷(brachial avulsion)，神經被切斷，

and the arm was paralyzed, lying in a sling for a year, and then the arm was amputated.

手臂從此癱瘓，掛著繃帶一年後，接受截肢手術。

He had a phantom arm, excruciatingly painful, and he couldn't move it.

接著產生幻肢，疼痛難當，而且無法自由移動。

It was a paralyzed phantom arm.

他這就是『習得性癱瘓』的手臂。

So he came there, and I gave him a mirror like that, in a box,

他來看病時，我給他一面像這樣的鏡子，在盒子裡

which I call a mirror box, right?

我稱為鏡盒，對吧？

And the patient puts his phantom left arm,

我把病患的幻肢左臂

which is clenched and in spasm, on the left side of the mirror,

(繃緊痙攣的那隻) 放在鏡子左邊，

and the normal hand on the right side of the mirror,

正常的手臂放在鏡子右邊，

and makes the same posture, the clenched posture,

並模仿左臂的姿勢，握緊的姿勢，

and looks inside the mirror. And what does he experience?

然後看著鏡子，你猜他感覺到了什麼？

He looks at the phantom being resurrected,

他感覺幻肢又復活了。

because he's looking at the reflection of the normal arm in the mirror,

因為他看到了鏡中正常手臂的反射鏡像，

and it looks like this phantom has been resurrected.

彷彿他的幻肢重生了。

"Now," I said, "now, look, wiggle your phantom --

然後我說：『現在，擺動一下你的幻臂，

your real fingers, or move your real fingers while looking in the mirror."

(更正)你真正的手指；一面看著鏡子，一面擺動你(左手)真正的手指。』

He's going to get the visual impression that the phantom is moving, right?

他的視覺印象會告訴他，幻肢正在擺動，對吧？

That's obvious, but the astonishing thing is,

這是顯而易見的。但令人驚訝的是，

the patient then says, "Oh my God, my phantom is moving again,

病患叫說：『天啊，我的幻臂居然可以移動了，

and the pain, the clenching spasm, is relieved."

而且那繃緊痙攣的疼痛不見啦！』

And remember, my first patient who came in --

記得嗎？我的首位病患進來——

(Applause)

(掌聲)

-- thank you. (Applause)

謝謝(掌聲)

My first patient came in, and he looked in the mirror,

我的第一個病患來看病時，他看著鏡子，

and I said, "Look at your reflection of your phantom."

我說：『看著你幻肢的鏡像。』

And he started giggling, he says, "I can see my phantom."

他咯咯笑起來，說：『我看得見我的幻肢。』

But he's not stupid. He knows it's not real.

他並不笨，知道這不是真實的，

He knows it's a mirror reflection,

他知道那只是個鏡像，

but it's a vivid sensory experience.

但這卻是非常逼真的體驗。

Now, I said, "Move your normal hand and phantom."

然後我說：『移動你正常的手臂，和幻臂』。

He said, "Oh, I can't move my phantom. You know that. It's painful."

他說：『我沒辦法移動我的幻臂，你知道，很痛啊！』

I said, "Move your normal hand."

我說：『那就移動正常的那隻手吧。 』

And he says, "Oh my God, my phantom is moving again. I don't believe this!

他說：『天啊，我的幻臂又在動了，簡直不敢相信！

And my pain is being relieved." OK?

手也不痛了！ 』

And then I said, "Close your eyes."

接著我說：『閉上眼睛。』

He closes his eyes.

他閉上眼。

"And move your normal hand."

我說：『動一下你正常的那隻手。』

"Oh, nothing. It's clenched again."

他說：『喔，動不了，又繃緊麻痺了。』

"OK, open your eyes."

我說：『睜開眼睛。』

"Oh my God, oh my God, it's moving again!"

他說：『天啊，又在動了！』

So, he was like a kid in a candy store.

他興奮地像個糖果店裡的孩子。

So, I said, OK, this proves my theory about learned paralysis

所以我說，這證明了我的習得性麻痺理論，

and the critical role of visual input,

和視覺輸入的關鍵性。

but I'm not going to get a Nobel Prize

但是諾貝爾獎不會頒給我

for getting somebody to move his phantom limb.

只因為我能讓人移動幻肢。

(Laughter)

(笑聲)

(Applause)

(掌聲)

It's a completely useless ability, if you think about it.

仔細想想，這還真是毫無用處的能力哩！

(Laughter)

(笑聲)

But then I started realizing, maybe other kinds of paralysis

但是後來我開始意識到，也許其他類型的癱瘓，

that you see in neurology, like stroke, focal dystonias --

神經病學中的癱瘓，例如中風、局部肌張力不全症(focal dystonia)，

there may be a learned component to this,

或許都有習得的成分，

which you can overcome with the simple device of using a mirror.

都能藉助這種鏡盒來克服。

So, I said, "Look, Derek" --

於是我說：『德瑞克，』

well, first of all, the guy can't just go around carrying a mirror to alleviate his pain --

病患總不能一直隨身帶著鏡盒，來減輕痛苦吧？

I said, "Look, Derek, take it home and practice with it for a week or two.

我說：『德瑞克，鏡盒讓你帶回家，自己練習一兩個禮拜，

Maybe, after a period of practice,

或許反覆練習一段時間，

you can dispense with the mirror, unlearn the paralysis,

你就可以扔掉鏡子，擺脫癱瘓，

and start moving your paralyzed arm,

自由移動幻肢，

and then, relieve yourself of pain."

跟疼痛說再見啦！』

So he said OK, and he took it home.

他說好啊，就帶著鏡盒回家了。

I said, "Look, it's, after all, two dollars. Take it home."

我說：『反正只花我2塊錢而已，你就帶回家吧。』

So, he took it home, and after two weeks, he phones me,

於是他把鏡盒帶回家。兩週後他打來電話來，

and he said, "Doctor, you're not going to believe this."

說：『醫生，你一定不相信。』

I said, "What?"

我說：『不相信什麼？』

He said, "It's gone."

他說：『它不見了。』

I said, "What's gone?"

我說：『什麼不見了？』

I thought maybe the mirror box was gone.

我還以為可能是鏡盒不見了。

(Laughter)

(笑聲)

He said, "No, no, no, you know this phantom I've had for the last 10 years?

他說：『不不不，這個困擾了我10年的幻臂，

It's disappeared."

它不見啦！ 』

And I said -- I got worried, I said, my God,

我有點擔心，我說，天哪！

I mean I've changed this guy's body image,

我改變了他的身體形像，

what about human subjects, ethics and all of that?

但是有關人體主體、倫理道德等等議題呢？

And I said, "Derek, does this bother you?"

我說：『德瑞克，你覺得困擾嗎？』

He said, "No, last three days, I've not had a phantom arm

他說：『不會呀！這三天來，我的幻臂消失了，

and therefore no phantom elbow pain, no clenching,

幻肘關節痛也沒了，也不再肌肉緊繃，

no phantom forearm pain, all those pains are gone away.

幻肢上臂疼痛也沒了，所有疼痛都消失了！

But the problem is I still have my phantom fingers dangling from the shoulder,

不過問題是，我的幻手指還接在肩膀上，

and your box doesn't reach."

你的鏡盒搆不到耶！』

(Laughter)

(笑聲)

"So, can you change the design and put it on my forehead,

『你能不能改一下設計，把鏡盒放在我的前額，

so I can, you know, do this and eliminate my phantom fingers?"

讓我練習消除我的幻手指？ 』

He thought I was some kind of magician.

他以為我會變魔術呢！

Now, why does this happen?

為什麼會發生這種現象呢？

It's because the brain is faced with tremendous sensory conflict.

這是因為大腦受到極大的知覺衝突，

It's getting messages from vision saying the phantom is back.

它收到視覺訊號，說幻肢長回來了；

On the other hand, there's no proprioception,

但另一方面，卻沒有接收到實際的相應訊號，

muscle signals saying that there is no arm, right?

來自肌肉的訊號說手臂不存在，不是嗎？

And your motor command saying there is an arm,

可是運動神經指令也在說手臂存在。

and, because of this conflict, the brain says, to hell with it,

由於這種衝突，大腦乾脆說：『管他的，

there is no phantom, there is no arm, right?

根本沒有幻肢、沒有手臂啦！』

It goes into a sort of denial -- it gates the signals.

大腦陷入某種否認狀態，否認這些訊號。

And when the arm disappears, the bonus is, the pain disappears

當幻臂消失時，好處是疼痛也一併消失，

because you can't have disembodied pain floating out there, in space.

因為總不可能有無形體疼痛在空中漂浮吧？

So, that's the bonus.

所以這是它的好處。

Now, this technique has been tried on dozens of patients

這種療法已經在幾十個病患身上試驗過，

by other groups in Helsinki,

由赫爾辛基的其他醫療團體，

so it may prove to be valuable as a treatment for phantom pain,

以證實它有助於治療幻肢疼痛。

and indeed, people have tried it for stroke rehabilitation.

的確，它已被試用於中風復健。

Stroke you normally think of as damage to the fibers,

一般認為，中風是神經纖維受損，

nothing you can do about it.

無方可治。

But, it turns out some component of stroke paralysis is also learned paralysis,

但是我們發現，其實中風癱瘓也含有習得的成分，

and maybe that component can be overcome using mirrors.

或許這種鏡療法可以用來療癒其習得成分。

This has also gone through clinical trials,

這也已經臨床試驗，

helping lots and lots of patients.

幫助過許多病患。

OK, let me switch gears now to the third part of my talk,

接下來是我要講的第三部分，

which is about another curious phenomenon called synesthesia.

是關於另一種奇特的現象，叫做『聯覺』(Synesthesia)。

This was discovered by Francis Galton in the nineteenth century.

由弗朗西斯．高爾頓在十九世紀所發現。

He was a cousin of Charles Darwin.

他是達爾文的表親。

He pointed out that certain people in the population,

他發現有些人，

who are otherwise completely normal, had the following peculiarity:

其他方面均無異於常人，卻有如下奇特之處——

every time they see a number, it's colored.

他們看到一個數字時，就能感受到色彩。

Five is blue, seven is yellow, eight is chartreuse,

5是藍色；7是黃色；8是黃綠色；

nine is indigo, OK?

9是紫藍色。

Bear in mind, these people are completely normal in other respects.

記住，這些人其他方面完全正常。

Or C sharp -- sometimes, tones evoke color.

有時，音調也能喚起色彩，

C sharp is blue, F sharp is green,

升C是藍色，升F是綠色，

another tone might be yellow, right?

其他音調可能是黃色等等。

Why does this happen?

為什麼會這樣？

This is called synesthesia. Galton called it synesthesia,

高爾頓把這稱為『聯覺』(synaesthesia)，

a mingling of the senses.

這是一種感覺的混合。

In us, all the senses are distinct.

對我們一般人來說，感覺是各自獨立的，

These people muddle up their senses.

這些人的多種感覺卻會混合。

Why does this happen?

為什麼會這樣？

One of the two aspects of this problem are very intriguing.

這種現象有兩個有趣之處，

Synesthesia runs in families,

聯覺有家族遺傳，

so Galton said this is a hereditary basis, a genetic basis.

因此高爾頓認為這跟遺傳基因有關。

Secondly, synesthesia is about -- and this is what gets me to my point

其次，『聯覺』與某特質有關——(這就是我要傳達的重點)

about the main theme of this lecture, which is about creativity --

就是這個演講的主題：創造力——

synesthesia is eight times more common among artists, poets, novelists

『聯覺』在藝術家、詩人、作家，以及其他創意人中更普遍，

and other creative people than in the general population.

是普通人的8倍。

Why would that be?

為什麼會這樣？

I'm going to answer that question.

我要回答這個問題，

It's never been answered before.

這個問題之前無人解答過。

OK, what is synesthesia? What causes it?

究竟什麼是『聯覺』，成因是什麼？

Well, there are many theories.

相關的理論很多。

One theory is they're just crazy.

一種理論認為，這些人瘋了，

Now, that's not really a scientific theory, so we can forget about it.

這算不上科學理論，所以不多談了。

Another theory is they are acid junkies and potheads, right?

另一個理論是這些人是吸毒者，大麻癮君子。

Now, there may be some truth to this,

這或許有點道理，

because it's much more common here in the Bay Area than in San Diego.

因為『聯覺』人口在灣區比在聖地牙哥多得多。

(Laughter)

(笑聲)

OK. Now, the third theory is that --

第三個理論是，

well, let's ask ourselves what's really going on in synesthesia. All right?

我們要問：『聯覺』到底是怎麼產生的？

So, we found that the color area and the number area

我們發現，圖中的顏色區和數字區

are right next to each other in the brain, in the fusiform gyrus.

在大腦的梭狀回裡彼此相鄰，

So we said, there's some accidental cross wiring

因此，腦中可能發生意外的線路叉接(cross-wiring)，

between color and numbers in the brain.

即顏色區與數字區之間的線路。

So, every time you see a number, you see a corresponding color,

所以，每次看見某個數字，就會同時看見相應的顏色，

and that's why you get synesthesia.

於是產生所謂的『聯覺』。

Now remember -- why does this happen?

記住，為什麼會發生這種現象呢？

Why would there be crossed wires in some people?

為什麼有些人腦中會發生線路叉接呢？

Remember I said it runs in families?

我剛說過，這是家族遺傳的，

That gives you the clue.

這就提供了線索。

And that is, there is an abnormal gene,

有某個異常的基因，

a mutation in the gene that causes this abnormal cross wiring.

一種基因突變，引起了異常的線路叉接。

In all of us, it turns out

其實，我們每個人

we are born with everything wired to everything else.

出生時，腦中線路彼此相連，

So, every brain region is wired to every other region,

所有腦部區域都彼此互通，

and these are trimmed down to create

然後逐漸修整區別，

the characteristic modular architecture of the adult brain.

劃分形成成人腦中，各具不同特徵的模塊。

So, if there's a gene causing this trimming

如果有一個基因控制這種修整過程，

and if that gene mutates,

而它產生突變，

then you get deficient trimming between adjacent brain areas.

那麼相鄰腦區間的修整就不充分了，

And if it's between number and color, you get number-color synesthesia.

若發生在數字和顏色之間，就產生『數字—顏色聯覺症』。

If it's between tone and color, you get tone-color synesthesia.

若發生在音調和顏色之間，就產生『音調—顏色聯覺症』。

So far, so good.

這些解釋都合理。

Now, what if this gene is expressed everywhere in the brain,

要是這個突變基因，在腦中的所有地方都起了作用呢？

so everything is cross-connected?

所有的腦區都相聯的話呢？

Well, think about what artists, novelists and poets have in common,

想想看，藝術家、作家和詩人之間有什麼共通處？

the ability to engage in metaphorical thinking,

他們都具備隱喻思維 (metaphorical thinking) 能力，

linking seemingly unrelated ideas,

把看似無關的概念，加以聯結。

such as, "It is the east, and Juliet is the Sun."

例如，『這是東方，茱麗葉就是太陽。』

Well, you don't say, Juliet is the sun,

你不會說茱麗葉是個太陽，

does that mean she's a glowing ball of fire?

這話難道是指『她是團炙熱的火球』嗎？

I mean, schizophrenics do that, but it's a different story, right?

精神分裂的人會這麼想，但那當別論。

Normal people say, she's warm like the sun,

正常人會說：『她像太陽一樣溫暖』

she's radiant like the sun, she's nurturing like the sun.

『她像太陽一樣明艷照人』、『她像太陽一樣撫慰心靈』

Instantly, you've found the links.

其中的聯繫顯而易見。

Now, if you assume that this greater cross wiring

現在，若假設更大規模的這種線路叉接，

and concepts are also in different parts of the brain,

以及概念，也位於腦的不同區域，

then it's going to create a greater propensity

就會形成更強烈的傾向

towards metaphorical thinking and creativity

突顯有聯覺症者的隱喻思維和創造性。

in people with synesthesia.

.

And, hence, the eight times more common incidence of synesthesia

因此，(某類人群)聯覺症比例是常人的8倍

among poets, artists and novelists.

包括藝術家、詩人和作家等。

OK, it's a very phrenological view of synesthesia.

好，這是非常顱相學(phrenological)的聯覺理論。

The last demonstration -- can I take one minute?

最後再做個實驗——再給我一分鐘好嗎？

(Applause)

(掌聲)

OK. I'm going to show you that you're all synesthetes, but you're in denial about it.

我要向各位展示：你們全都有聯覺症，只是自己不自知罷了。

Here's what I call Martian alphabet. Just like your alphabet,

這張圖，我稱為『火星字母表』，就像英文字母表。

A is A, B is B, C is C.

A是A、B是B、C是C

Different shapes for different phonemes, right?

不同音素對應不同的形狀，對吧？

Here, you've got Martian alphabet.

這是『火星字母表』，

One of them is Kiki, one of them is Bouba.

其中一個是『Kiki』，另一個是『Buba』。

Which one is Kiki and which one is Bouba?

請問哪一個是『Kiki』，哪一個是『Buba』呢？

How many of you think that's Kiki and that's Bouba? Raise your hands.

有多少人覺得這邊是『Kiki』，那邊是『Buba』？請舉手。

Well, it's one or two mutants.

嗯，有一、兩位突變。

(Laughter)

(笑聲)

How many of you think that's Bouba, that's Kiki? Raise your hands.

有多少人覺得這邊是『Buba』，那邊是『Kiki』？請舉手。

Ninety-nine percent of you.

在座百分之九十九的人。

Now, none of you is a Martian. How did you do that?

各位都不是火星人，你們是怎麼認出來呢？

It's because you're all doing a cross-model synesthetic abstraction,

因為各位都在進行跨模塊的『聯覺抽象』，

meaning you're saying that that sharp inflection -- ki-ki,

你覺得那尖尖的形狀看起來像『Kiki』，

in your auditory cortex, the hair cells being excited -- Kiki,

在你的聽覺腦皮層中，聽毛細胞受刺激，『Kiki』

mimics the visual inflection, sudden inflection of that jagged shape.

就像那個鋸齒形狀的視覺曲折，生硬而突然。

Now, this is very important, because what it's telling you

這點非常重要，因為它說明

is your brain is engaging in a primitive --

你的大腦正在進行一種原生的程序

it's just -- it looks like a silly illusion,

雖然它看起來有點可笑，

but these photons in your eye are doing this shape,

但這些光子在你眼中形成這個形狀，

and hair cells in your ear are exciting the auditory pattern,

同時你耳中的聽毛細胞刺激這個聽覺模式，

but the brain is able to extract the common denominator.

但是大腦能夠抽取兩者的共性。

It's a primitive form of abstraction,

這是一種原始形式的抽象。

and we now know this happens in the fusiform gyrus of the brain,

我們現在知道，這發生在大腦的梭狀回，

because when that's damaged,

因為那裡如果受損，

these people lose the ability to engage in Bouba Kiki,

病患就無法判斷『Buba、Kiki』，

but they also lose the ability to engage in metaphor.

也失去隱喻的能力。

If you ask this guy, what -- "all that glitters is not gold,"

若問他：『發亮的未必都是黃金』(譯註：英諺，意同『金玉其外，敗絮其中』)

what does that mean?"

這話什麼意思？

The patient says, "Well, if it's metallic and shiny, it doesn't mean it's gold.

他會說：『意思是，若是金屬且發亮，不表示一定是黃金，

You have to measure its specific gravity, OK?"

得測試它的比重。』

So, they completely miss the metaphorical meaning.

這個病患無法明白其中的比喻涵義。

So, this area is about eight times the size in higher --

這個腦區的體積，在高等靈長類

especially in humans -- as in lower primates.

尤其是人類，是低等靈長類的8倍。

Something very interesting is going on here in the angular gyrus,

角形腦回(angular gyrus)是個很有趣的區域，

because it's the crossroads between hearing, vision and touch,

它是視覺、聽覺和觸覺的交匯處，

and it became enormous in humans. And something very interesting is going on.

人類的角形腦回特別大，因此具備非常複雜的功能。

And I think it's a basis of many uniquely human abilities

我認為它是許多人類特有能力的基礎，

like abstraction, metaphor and creativity.

例如抽象、隱喻，和創造。

All of these questions that philosophers have been studying for millennia,

這些問題，哲學家已經研究上千年了，

we scientists can begin to explore by doing brain imaging,

現在，我們科學家可以利用腦部造影，

and by studying patients and asking the right questions.

研究病患，並提出正確的問題，加以探索。

Thank you.

謝謝。

(Applause)

(掌聲)

Sorry about that.

抱歉。

(Laughter)

(笑聲)