of my favorite subjects,

是我最愛的主題之一

and that is the neuroscience of sleep.

睡眠的神經科學

Now, there is a sound --

你們現在聽這個聲音

(Alarm clock) --

（鬧鐘聲）

aah, it worked --

啊哈，還可以用

a sound that is desperately, desperately familiar to most of us,

我們都熟悉這令人絕望的聲音

and of course it's the sound of the alarm clock.

當然，因為這是鬧鐘的聲音

And what that truly ghastly, awful sound does

那悲慘又糟糕的聲音所要做的

is stop the single most important behavioral experience

是中斷我們最重要的行為

that we have, and that's sleep.

也就是睡眠

If you're an average sort of person,

如果你和一般人一樣

36 percent of your life will be spent asleep,

一生中有 36% 的時間都花在睡覺上

which means that if you live to 90,

換言之，如果你活到 90 歲

then 32 years will have been spent entirely asleep.

有整整 32 年的時間是在睡覺

Now what that 32 years is telling us

從這 32 年我們可以看出

is that sleep at some level is important.

睡覺有某種程度上的重要性

And yet, for most of us, we don't give sleep a second thought.

然而，大多數的人都認為睡覺沒什麼

We throw it away.

就這樣把睡眠浪費掉

We really just don't think about sleep.

我們真的沒有思考過睡眠這個行為

And so what I'd like to do today

我今天想做的

is change your views,

就是改變你們的觀點

change your ideas and your thoughts about sleep.

改變你們對睡眠的看法、想法

And the journey that I want to take you on,

我想邀請你們來參與一場旅程

we need to start by going back in time.

我們得先回到過去

"Enjoy the honey-heavy dew of slumber."

「享受沉重而甜蜜的睡眠甘露吧。」

Any ideas who said that?

知道這是誰說的嗎？

Shakespeare's Julius Caesar.

莎士比亞的凱薩大帝

Yes, let me give you a few more quotes.

好，我再多給你們一些引言

"O sleep, O gentle sleep, nature's soft nurse,

「噢，睡眠，噢，輕柔的睡眠，大自然的仁慈褓姆

how have I frighted thee?"

我怎麼會害怕你呢？」

Shakespeare again, from -- I won't say it --

這也是莎士比亞，但我不說出處

the Scottish play. [Correction: Henry IV, Part 2]

出自馬克白（更正：應為亨利四世，第二卷）

(Laughter)

（笑聲）

From the same time:

同個時間

"Sleep is the golden chain

「睡眠就像條金鍊子

that ties health and our bodies together."

把健康和身體綁在一起。」

Extremely prophetic, by Thomas Dekker,

湯瑪斯．德克說的，非常有遠見

another Elizabethan dramatist.

也是另一位伊莉莎白時代的劇作家

But if we jump forward 400 years,

如果我們再往後 400 年

the tone about sleep changes somewhat.

對於睡眠的論點就有些改變

This is from Thomas Edison, from the beginning of the 20th century.

這是 20 世紀初，湯瑪斯．愛迪生說的

"Sleep is a criminal waste of time

「睡覺簡直就是浪費時間，

and a heritage from our cave days." Bang.

根本就是原始人留下的遺產。」碰

(Laughter)

（笑聲）

And if we also jump into the 1980s, some of you

如果我們前往 80 年代

may remember that Margaret Thatcher

在座有些人可能記得 瑪格莉特．柴契爾

was reported to have said, "Sleep is for wimps."

被報導曾說過：「弱者才需要睡覺。」

And of course the infamous -- what was his name? --

當然還有聲名狼藉的－名字是什麼來著－

the infamous Gordon Gekko from "Wall Street" said,

來自「華爾街」，聲名狼藉的 高登．蓋科 說過

"Money never sleeps."

「金錢從不睡覺。」

What do we do in the 20th century about sleep?

20 世紀的我們怎麼看待睡覺？

Well, of course, we use Thomas Edison's light bulb

當然，我們用愛迪生發明的燈泡

to invade the night, and we occupied the dark,

來擊退黑暗，佔領了黑暗

and in the process of this occupation,

在這占領的過程中

we've treated sleep as an illness, almost.

我們幾乎把睡眠當作是種疾病

We've treated it as an enemy.

把睡眠當作是敵人

At most now, I suppose, we tolerate the need for sleep,

我現在敢假設，大多數人都忍住不睡

and at worst perhaps many of us think of sleep

最糟的是，有多數人覺得睡覺是種病

as an illness that needs some sort of a cure.

需要治療的一種病

And our ignorance about sleep is really quite profound.

我們對睡眠的種種無知還真不是蓋的

Why is it? Why do we abandon sleep in our thoughts?

為什麼會這樣？為什麼不想要睡覺？

Well, it's because you don't do anything much

因為當你睡覺的時候

while you're asleep, it seems.

看起來你沒有在做什麼

You don't eat. You don't drink.

你沒有吃喝

And you don't have sex.

沒有發生性行為

Well, most of us anyway.

大多數的人沒有

And so therefore it's --

所以

Sorry. It's a complete waste of time, right? Wrong.

睡覺完全是浪費時間，對嗎？錯

Actually, sleep is an incredibly important part of our biology,

事實上，睡覺對我們的身體非常重要

and neuroscientists are beginning to explain why

神經科學家正開始研究它並解釋為什麼

it's so very important.

睡眠這麼重要

So let's move to the brain.

從大腦開始吧

Now, here we have a brain.

這裡有個腦袋

This is donated by a social scientist,

這是一個社會科學家捐贈的

and they said they didn't know what it was,

他們說他們不知道這是什麼

or indeed how to use it, so --

或是不知道該怎麼使用

(Laughter)

（笑聲）

Sorry.

不好意思

So I borrowed it. I don't think they noticed. Okay.

我借了這個腦袋我想他們應該沒發現

(Laughter)

（笑聲）

The point I'm trying to make is that when you're asleep,

重點是，你們在睡覺的時候

this thing doesn't shut down.

大腦不會停止運作

In fact, some areas of the brain are actually more active

事實上，有些區塊的活動量還增加了

during the sleep state than during the wake state.

相較於清醒的狀態之下

The other thing that's really important about sleep

另一件關於睡眠之所以重要的事

is that it doesn't arise from a single structure within the brain,

睡眠並非起於大腦單一組織

but is to some extent a network property,

而是有點像網絡

and if we flip the brain on its back --

如果把大腦翻到背面

I love this little bit of spinal cord here --

我喜歡這一小部分的脊髓

this bit here is the hypothalamus,

這叫做下丘腦

and right under there is a whole raft of interesting structures,

下丘腦下方，有一塊很有趣的組織

not least the biological clock.

尤其是生理時鐘

The biological clock tells us when it's good to be up,

生理時鐘告訴我們什麼時候該起床

when it's good to be asleep,

什麼時候該睡覺

and what that structure does is interact

下視丘下方那塊組織所要做的

with a whole raft of other areas within the hypothalamus,

就是和下丘腦內的其他區塊

the lateral hypothalamus, the ventrolateral preoptic nuclei.

外側下丘，腦側室前視核這些區塊來往

All of those combine, and they send projections

這些區塊會發送信號

down to the brain stem here.

到腦幹

The brain stem then projects forward

腦幹再把信號傳送出去

and bathes the cortex, this wonderfully wrinkly bit over here,

讓腦皮層收到信號就是這塊皺褶很漂亮的區塊

with neurotransmitters that keep us awake

神經傳送素會讓我們醒著

and essentially provide us with our consciousness.

最重要的就是讓我們有意識

So sleep arises from a whole raft

所以睡覺是起因於

of different interactions within the brain,

大腦內許多地方的互動

and essentially, sleep is turned on and off

更重要的，我們睡覺或不睡覺

as a result of a range of interactions in here.

是因為這一系列的互動

Okay. So where have we got to?

好，我們現在講到哪了？

We've said that sleep is complicated

我們說到了睡眠很複雜

and it takes 32 years of our life.

花了人生中的 32 年

But what I haven't explained is what sleep is about.

我還沒解釋是：為什需要睡眠

So why do we sleep?

為什麼要睡覺？

And it won't surprise any of you that, of course,

科學家對此也沒有一致的答案

the scientists, we don't have a consensus.

這也不會令人驚訝

There are dozens of different ideas about why we sleep,

有很多不同的想法解釋為什麼要睡覺

and I'm going to outline three of those.

我摘要其中三點

The first is sort of the restoration idea,

第一點說的是修復

and it's somewhat intuitive.

這是有點直觀的假設

Essentially, all the stuff we've burned up during the day,

一天中，我們所消耗的精力

we restore, we replace, we rebuild during the night.

我們會在晚上進行修補、替換、重建

And indeed, as an explanation,

這種解釋

it goes back to Aristotle,

可以追朔到亞里斯多德

so that's, what, 2,300 years ago.

差不多是 2300 年前

It's gone in and out of fashion.

這種說法為多數人接受

It's fashionable at the moment because what's been shown

因為在當時人們看到

is that within the brain, a whole raft of genes

是大腦內的一大堆基因

have been shown to be turned on only during sleep,

在睡覺時是有在活動

and those genes are associated with restoration

這些基因都和修補作用

and metabolic pathways.

以及新陳代謝有關聯

So there's good evidence for the whole restoration hypothesis.

所以有證據支持修補假設

What about energy conservation?

那麼關於儲存精力呢？

Again, perhaps intuitive.

這也很直觀

You essentially sleep to save calories.

睡覺重要的就是儲存卡路里

Now, when you do the sums, though,

不過當你把把數字加一加

it doesn't really pan out.

結果並不令人滿意

If you compare an individual who has

如果你把一個在晚上睡覺或是熬夜的人

slept at night, or stayed awake and hasn't moved very much,

這兩種人都並沒有做什麼活動

the energy saving of sleeping is about 110 calories a night.

他們一個晚上差不多存了 110 卡路里

Now, that's the equivalent of a hot dog bun.

等同於一個熱狗麵包

Now, I would say that a hot dog bun

需要這麼多時間以及步驟的睡眠

is kind of a meager return for such a complicated

經過一個晚上之後只有一個熱狗麵包的量

and demanding behavior as sleep.

這確實有點少

So I'm less convinced by the energy conservation idea.

所以我比較不相信儲存精力這種說法

But the third idea I'm quite attracted to,

吸引我的是第三種說法

which is brain processing and memory consolidation.

就是大腦運作以及記憶結合

What we know is that, if after you've tried to learn a task,

就我們所知，在你嘗試學習某樣事物

and you sleep-deprive individuals,

如果你剝奪自己的睡眠

the ability to learn that task is smashed.

那麼，你學習那樣事物的能力就毀了

It's really hugely attenuated.

學習能力大大降低

So sleep and memory consolidation is also very important.

所以睡眠和記憶有重要關連

However, it's not just the laying down of memory

然而，我們並不只是躺下來

and recalling it.

回想記得的事

What's turned out to be really exciting

讓科學家感到驚奇的是

is that our ability to come up with novel solutions

我們發現新方法和解決複雜問題的能力

to complex problems is hugely enhanced by a night of sleep.

會因為睡一覺而大大增強

In fact, it's been estimated to give us a threefold advantage.

事實上，這帶給我們 3 倍的優勢

Sleeping at night enhances our creativity.

睡眠讓我們更具創造力

And what seems to be going on is that, in the brain,

看起來我們腦中

those neural connections that are important,

神經連結會有所改變

those synaptic connections that are important,

重要的突觸連結(譯注：突觸負責將訊號傳往下個神經細胞)

are linked and strengthened,

會被連接和強化

while those that are less important

而比較不重要的連結

tend to fade away and be less important.

會被弱化而顯得更不重要

Okay. So we've had three explanations for why we might sleep,

有三個說法解釋為什麼我們需要睡眠

and I think the important thing to realize is that

我認為瞭解它們的細節很重要

the details will vary, and it's probable we sleep for multiple different reasons.

因為我們睡眠可能有很多原因

But sleep is not an indulgence.

但是睡眠不是浪費

It's not some sort of thing that we can take on board rather casually.

也不是我們可以輕忽看待的事

I think that sleep was once likened to an upgrade

我想睡眠可以比喻為

from economy to business class, you know, the equiavlent of.

從經濟艙升級到商務艙

It's not even an upgrade from economy to first class.

但是還不到頭等艙的等級

The critical thing to realize is that

關鍵在於

if you don't sleep, you don't fly.

缺乏睡眠，就沒有飛馳的思緒

Essentially, you never get there,

你也創造不出任何東西

and what's extraordinary about much of our society these days

但我們現在社會

is that we are desperately sleep-deprived.

卻希望剝奪睡眠

So let's now look at sleep deprivation.

讓我們來看看被剝奪的睡眠

Huge sectors of society are sleep-deprived,

社會中很多人缺乏睡眠

and let's look at our sleep-o-meter.

看看我們的睡眠計量表

So in the 1950s, good data suggests that most of us

在 50 年代，充分的證據顯示

were getting around about eight hours of sleep a night.

大部份人每晚睡 8 小時

Nowadays, we sleep one and a half to two hours less every night,

現在我們相較從前少睡 1.5 到 2 小時

so we're in the six-and-a-half-hours-every-night league.

我們的睡眠落在每晚 6.5 小時的區間

For teenagers, it's worse, much worse.

對青少年而言這尤其嚴重

They need nine hours for full brain performance,

他們需要睡 9 個小時以利大腦運作

and many of them, on a school night,

而大多數人在學期間

are only getting five hours of sleep.

每晚僅睡 5 小時

It's simply not enough.

這跟本不夠！

If we think about other sectors of society, the aged,

讓我們在看看另一群人

if you are aged, then your ability to sleep in a single block

老人晚上的睡眠

is somewhat disrupted, and many sleep, again,

常會被打斷成好幾部份

less than five hours a night.

他們的睡眠同樣低於每晚 5 小時

Shift work. Shift work is extraordinary,

輪班的人

perhaps 20 percent of the working population,

大概佔工作人口的 20 %

and the body clock does not shift to the demands

而生理時鐘不會

of working at night.

依據夜班而調整

It's locked onto the same light-dark cycle as the rest of us.

它依據相同的光暗循環

So when the poor old shift worker is going home

所以當可憐的夜班工作者

to try and sleep during the day, desperately tired,

疲憊的回家休息時

the body clock is saying, "Wake up. This is the time to be awake."

生理時鐘會說：「醒醒啊！現在是白天！」

So the quality of sleep that you get as a night shift worker

夜班工作者的睡眠品質通常很差

is usually very poor, again in that sort of five-hour region.

他們一樣被分在睡 5 小時的這群

And then, of course, tens of millions of people

接著是，當然，有上百萬人

suffer from jet lag.

受時差影響

So who here has jet lag?

在座有誰是呢？

Well, my goodness gracious.

我的天啊！

Well, thank you very much indeed for not falling asleep,

因為你們大腦正渴望睡眠

because that's what your brain is craving.

我得感謝你們沒有睡著

One of the things that the brain does

另一種大腦會進行

is indulge in micro-sleeps,

或沈迷的是微睡眠

this involuntary falling asleep,

這是非自願性的入睡

and you have essentially no control over it.

你根本無法控制這種睡眠

Now, micro-sleeps can be sort of somewhat embarrassing,

微睡眠令人尷尬

but they can also be deadly.

但它們也可能致命

It's been estimated that 31 percent of drivers

大約有 31% 的駕駛

will fall asleep at the wheel at least once in their life,

至少有一次在駕駛中打瞌睡

and in the U.S., the statistics are pretty good:

在美國，統計數據很完整

100,000 accidents on the freeway

10 萬件高速公路意外

have been associated with tiredness,

和疲勞、鬆懈

loss of vigilance, and falling asleep.

及打瞌睡有關

A hundred thousand a year. It's extraordinary.

每年平均 1 萬件！不可思議！

At another level of terror,

在另一個層級的恐怖

we dip into the tragic accidents at Chernobyl

我們看到在車諾比事件

and indeed the space shuttle Challenger,

和挑戰者號太空梭的意外

which was so tragically lost.

都造成悲劇性的損失

And in the investigations that followed those disasters,

在事件調查中發現

poor judgment as a result of extended shift work

延長工作時數造成

and loss of vigilance and tiredness

鬆懈與疲倦降低判斷力

was attributed to a big chunk of those disasters.

是導致悲劇的主因

So when you're tired, and you lack sleep,

所以當你疲倦、缺乏睡眠時

you have poor memory, you have poor creativity,

你的記憶力和創造力都很差

you have increased impulsiveness,

你會變得更衝動

and you have overall poor judgment.

而且判斷能力也會下降

But my friends, it's so much worse than that.

但是還有比這些更糟的事

(Laughter)

（笑聲）

If you are a tired brain,

如果大腦疲憊

the brain is craving things to wake it up.