Why do we sleep? | Russell Foster

Translator: Changbin Lin Reviewer: Bighead Ge

What I'd like to do today is talk about one of my favorite subjects,

我今日想講一個我好鍾意嘅話題

and that is the neuroscience of sleep.

就係睡眠嘅神經科學

Now, there is a sound --

依家，仔細聽下呢個聲音

(Alarm clock)

（鬧鐘響）

Ah, it worked!

啊，響啦

A sound that is desperately familiar to most of us,

一個我哋大家都覺得熟悉又絕望嘅聲音

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

無錯就係鬧鐘聲

And what that truly ghastly, awful sound does

而呢種驚怵又恐怖嘅聲音

is stop the single most important behavioral experience

會停止人類最緊要嘅行為體驗

that we have, and that's sleep.

即係瞓覺

If you're an average sort of person,

如果你係普通人

36 percent of your life will be spent asleep,

你生命裏面 36% 時間用喺瞓覺

which means that if you live to 90,

即係話如果你有 90 歲

then 32 years will have been spent entirely asleep.

就會有 32 年嘅時間用嚟瞓覺

Now what that 32 years is telling us is that sleep at some level is important.

呢個數字話畀我哋知

睡眠某種意義上好重要

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

但我哋好多人唔會反思一下睡眠

We throw it away.

We really just don't think about sleep.

我哋確實唔關心瞓覺嘅事

And so what I'd like to do today is change your views,

所以我今日想改變大家嘅觀念

change your ideas and your thoughts about sleep.

改變大家對睡眠嘅概念

And the journey that I want to take you on,

而我會帶你哋由舊時開始

we need to start by going back in time.

"Enjoy the honey-heavy dew of slumber."

我哋返到去「安享甜絲絲嘅美夢」 呢句說話

Any ideas who said that?

有無人知道呢句話出自邊度？

Shakespeare's Julius Caesar.

係莎士比亞嘅《凱撒大帝》

Yes, let me give you a few more quotes.

好，等我讀多幾個經典句子

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

「美夢啊，溫柔的美夢，

你猶如天然溫柔嘅護士，

how have I frighted thee?"

我點會怕你？」

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

又係莎士比亞，嚟自…都係唔講

the Scottish play.

嚟自一部蘇格蘭戲劇

(Laughter)

（笑聲）

From the same time:

同一時代有另一句嘢：

"Sleep is the golden chain that ties health and our bodies together."

「睡眠係一條金鍊，

將我哋健康同身體綁埋一齊。」

Extremely prophetic, by Thomas Dekker, another Elizabethan dramatist.

呢句極具先見之明嘅話 出自 Thomas Dekker

另一個伊莉莎白時代嘅劇作家

But if we jump forward 400 years,

但如果將時間跳到 400 年後

the tone about sleep changes somewhat.

人類對睡眠嘅態度就有所變化

20 世紀初愛迪生話︰

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

"Sleep is a criminal waste of time and a heritage from our cave days."

「睡眠浪費時間，

仲係山洞時代遺留嘅嘢。」

Bang!

砰！

（笑聲）

(Laughter)

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

如果我哋回顧 80 年代

你哋或者會記得

that Margaret Thatcher was reported to have said,

戴卓爾曾經講過「睡眠係懦夫行為」

"Sleep is for wimps."

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

仲有惡名昭彰嘅…佢叫咩名？

the infamous Gordon Gekko from "Wall Street" said,

《華爾街》惡名昭彰嘅 Gordon Gekko 講過︰

"Money never sleeps."

「金錢永不睡」

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

咁 20 世紀嘅我哋又點睇睡眠？

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

我哋用愛迪生發明嘅燈泡 侵佔晚上，強佔黑夜

to invade the night, and we occupied the dark,

and in the process of this occupation,

喺呢個搶佔過程裡面

我哋幾乎將睡眠當做病態

we've treated sleep as an illness, almost.

We've treated it as an enemy.

我哋將睡眠當做敵人

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

依家最好嘅情況 係我哋仍然接受到需要睡眠

但最壞嘅情況可能係

and at worst perhaps many of us think of sleep

as an illness that needs some sort of a cure.

好多人認為睡眠係一種要醫嘅病

And our ignorance about sleep is really quite profound.

而我哋對睡眠嘅無知 其實係幾發人深省

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

點解咁講？

點解我哋潛意識會冇咗瞓覺？

Well, it's because you don't do anything much while you're asleep, it seems.

答案似乎係

你喺瞓覺期間做唔到任何嘢

你唔會食嘢，你唔會飲水，仲做唔到愛

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

And you don't have sex.

Well, most of us anyway.

嗯，起碼大部份人都係咁

And so, therefore it's --

於是…

Sorry.

唔好意思

It's a complete waste of time, right?

瞓覺係完全浪費時間？錯

Wrong.

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

其實睡眠係我哋生物學裡面 重要嘅一部份

and neuroscientists are beginning to explain

神經科學家正準備解釋 點解睡眠會咁重要

why it's so very important.

So let's move to the brain.

我哋嚟講下大腦

Now, here we have a brain.

依家，我哋有一個大腦

This is donated by a social scientist,

呢個腦由一位社會科學家捐贈

佢哋話，佢哋唔知呢件係乜

and they said they didn't know what it was or indeed, how to use it, so --

或者唔知點樣用佢，所以…

(Laughter)

（笑聲）

Sorry.

唔好意思

So I borrowed it.

於是我借嚟用下

I don't think they noticed. OK.

我諗佢地唔會發現嘅。好啦

(Laughter)

（笑聲）

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

我想講嘅係

當你瞓著嗰陣，大腦唔會休息

this thing doesn't shut down.

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

其實，對比起清醒狀態

熟睡嘅時候大腦部份區域會更加活躍

during the sleep state than during the wake state.

The other thing that's really important about sleep

另一樣非常緊要嘅嘢係

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

睡眠並非源自腦內嘅單一結構

而係源自腦嘅唔同地方

but is to some extent a network property.

If we flip the brain on its back --

如果我哋返轉個腦 令佢底部向上…

I love this little bit of spinal cord here --

我鍾意脊髓呢部分

this bit here is the hypothalamus,

呢點就係下丘腦

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

下丘腦裡面有一大塊好得意嘅結構

not least the biological clock.

唔單只有生理時鐘

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

雖然生理時鐘話我哋聽幾時起身

when it's good to be asleep,

幾時瞓覺

and what that structure does is interact

呢個結構仲會同下丘腦其他區域互動

with a whole raft of other areas within the hypothalamus,

the lateral hypothalamus, the ventrolateral preoptic nuclei.

包括外側下丘腦、腹外側視前核

All of those combine,

佢哋一齊發送訊號落去腦幹呢度

and they send projections down to the brain stem here.

The brain stem then projects forward

跟住腦幹用神經傳導物

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

一種令我哋保持清醒 令我哋出現意識嘅嘢

with neurotransmitters that keep us awake

發送訊息

經過腦皮質呢一塊美麗嘅皺褶區域

and essentially provide us with our consciousness.

所以睡眠其實係 大腦唔同部份互動嘅結果

So sleep arises from a whole raft

of different interactions within the brain,

and essentially, sleep is turned on and off

所以，睡眠係大腦一系列 相互作用嘅結果

as a result of a range of interactions in here.

好啦，我哋接落嚟睇啲咩？

OK. So where have we got to?

We've said that sleep is complicated

我哋已經知道睡眠係一個複雜過程

and it takes 32 years of our life.

佢佔用我哋一生人 32 年時間

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

但我冇解釋到睡眠係乜嘢嚟

So why do we sleep?

咁點解我哋要瞓覺？

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

對你哋嚟講，科學家無共識一啲都唔怪

as scientists, we don't have a consensus.

There are dozens of different ideas about why we sleep,

因為我哋科學家有好多唔同嘅解釋

我會重點講下其中三個

and I'm going to outline three of those.

The first is sort of the restoration idea,

第一個解釋

就係認為睡眠係為咗恢復精力

and it's somewhat intuitive.

咁嘅解釋好主觀

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

實質上，我哋日間消耗好多嘢

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

於是就喺夜晚補充、替換 重建所有已消耗嘅嘢

And indeed, as an explanation, it goes back to Aristotle,

其實個解釋係嚟自亞里士多德

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

即係 2300 年前嘅答案

It's gone in and out of fashion.

呢個解釋曾經流行，但後來又式微

It's fashionable at the moment

because what's been shown is that within the brain,

佢宜家又流行嘅原因

係因為研究發現

a whole raft of genes have been shown to be turned on only during sleep,

大腦內有一批基因 只會喺瞓覺嗰時活動

and those genes are associated with restoration and metabolic pathways.

而呢啲基因同恢復精力 以及新陳代謝途徑有關

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

所以個發現其實係支持恢復精力假說

What about energy conservation?

咁保存能量假說呢？

Again, perhaps intuitive.

同樣，雖然話瞓覺係用嚟蓄卡路里

You essentially sleep to save calories.

但個假說可能好主觀

Now, when you do the sums, though, it doesn't really pan out.

就算我哋真係計埋卡路里

個假說都好難有說服力

If you compare an individual who has slept at night,

如果你對比一個人夜晚瞓足 同冇瞓但唔郁

or stayed awake and hasn't moved very much,

瞓覺一晚只能夠慳大概 110 卡路里

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

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

相當於一隻熱狗嘅熱量

Now, I would say that a hot dog bun

我認為，一隻熱狗嘅熱量

is kind of a meager return

對於睡眠呢種咁複雜 又牽涉大腦多個地方嘅行為嚟講

for such a complicated and demanding behavior as sleep.

實在係杯水車薪

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

所以我唔多相信保存能量假說

But the third idea I'm quite attracted to,

我會比較欣賞第三個假說

which is brain processing and memory consolidation.

就係大腦處理同記憶固化假說

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

我哋知道，如果你要去學一樣嘢

但又唔夠瞓

and you sleep-deprive individuals,

the ability to learn that task is smashed.

咁基本就學唔到嘢

It's really hugely attenuated.

睡眠不足會大大削弱學習能力

So sleep and memory consolidation is also very important.

所以睡眠同記憶固化都係非常緊要

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

但事情唔係話將知識放入記憶咁簡單

and recalling it.

你仲要搵返佢哋

What's turned out to be really exciting

令人興奮嘅係

我哋之所以面對複雜問題時 仍然能夠提出解決方案

is that our ability to come up with novel solutions to complex problems

全靠我哋都喺夜晚瞓覺

is hugely enhanced by a night of sleep.

實質上，睡眠可以為我哋帶嚟三重優勢

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

Sleeping at night enhances our creativity.

夜晚嘅睡眠會增加我哋嘅創意

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

原因似乎係，喺個腦裡面

重要嘅神經同重要嘅突觸會相互連結

those neural connections that are important,

those synaptic connections that are important,

are linked and strengthened,

變得更加強大

while those that are less important tend to fade away and be less important.

而無咁緊要嘅神經同突觸 趨向消失、式微

OK.

咁我哋依家有三個理論 解釋點解要睡眠

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

and I think the important thing to realize is that the details will vary,

但我哋要知道，每個理論嘅細節都唔同

and it's probable we sleep for multiple different reasons.

我哋好可能因為唔同原因而瞓覺

But sleep is not an indulgence.

但係，睡眠並非一種嗜好

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

佢唔係可以隨便話有就有

I think that sleep was once likened to an upgrade

我諗睡眠類似飛機嘅坐位升級

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

相當於由經濟艙升到上商務艙

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

但唔係升到去頭等艙

The critical thing to realize is that if you don't sleep,

大家要明白嘅重點係

如果你唔瞓覺，你就飛唔到

you don't fly.

去唔到想要嘅地方

Essentially, you never get there.

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

我哋現今社會嘅一大特點係

is that we are desperately sleep-deprived.

我哋有嚴重嘅睡眠不足

So let's now look at sleep deprivation.

所以依家我哋就嚟睇下睡眠不足

社會上好多人都唔夠瞓

Huge sectors of society are sleep-deprived,

睇一睇呢啲睡眠時間

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

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

50 年代，數據顯示

大部份人每晚瞓大約八個鐘

were getting around eight hours of sleep a night.

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

依家，我哋每晚瞓少個半到兩個鐘

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

所以我哋都係瞓六個半鐘嘅人

For teenagers, it's worse, much worse.

但對細路嚟講，情況更差

They need nine hours for full brain performance,

要有完整嘅腦部運作 佢哋就需要九個鐘睡眠

and many of them, on a school night, are only getting five hours of sleep.

好多細路，返學嘅日子 得五個鐘頭睡眠時間

It's simply not enough.

咁樣絕對係唔夠

If we think about other sectors of society -- the aged;

我哋仲要考慮埋其他社會組別 例如年紀組別

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

如果你已經上咗年紀

你每次瞓覺都會砸醒

is somewhat disrupted, and many sleep, again,

令到好多時瞓覺少過五個鐘

less than five hours a night.

Shift work.

另外，輪班工作嘅情況好特別

Shift work is extraordinary,

perhaps 20 percent of the working population,

可能有 20% 嘅人要輪班

佢哋嘅生理時鐘並未有調較 去適應夜晚嘅工作需求

and the body clock does not shift to the demands of working at night.

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

同我哋一樣，佢哋嘅生理時鐘 依然係正常嘅日夜週期

So when the poor old shift worker is going home

所以當年紀大嘅輪班員工返屋企

to try and sleep during the day, desperately tired,

想喺日頭訓覺，就會超攰

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

佢哋嘅生理時鐘就會同自己講︰ 「起身啦，係時候起身囉。」

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

所以要返夜嘅輪班員工嘅 睡眠質量通常好差

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

尤其係得五個鐘頭嘅睡眠時間

And then, of course, tens of millions of people suffer from jet lag.

然後仲有幾千萬人經歷捱時差

So who here has jet lag?

我哋呢到有幾多人要捱時差？

Well, my goodness gracious.

哇，都幾多噃

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

真係非常多謝大家無瞓著覺

because that's what your brain is craving.

因為瞓覺正係你哋大腦好想要嘅

One of the things that the brain does is indulge in micro-sleeps,

大腦要做嘅其中一樣嘢就係瞌眼瞓

this involuntary falling asleep,

呢種無意識嘅睡眠 基本上係自己控制唔到嘅

and you have essentially no control over it.

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

瞌眼瞓可能係一種好尷尬嘅事

亦可以係致命

but they can also be deadly.

據估計

It's been estimated that 31 percent of drivers

有 31% 司機起碼一世人 會有一次喺開車嘅時候瞓著

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

and in the US, the statistics are pretty good:

而喺美國，統計指出：

100,000 accidents on the freeway have been associated with tiredness,

十萬單高速公路上面嘅交通事故

同疲勞駕駛 集中唔到精力、瞓著咗有關

loss of vigilance, and falling asleep -- a hundred thousand a year.

一年十萬起事故實在好得人驚

It's extraordinary.

At another level of terror,

更加恐怖嘅事有

we dip into the tragic accidents at Chernobyl

切爾諾貝爾事故 同埋挑戰者號太空船解體

and indeed the space shuttle Challenger,

which was so tragically lost.

兩件事都係慘劇

And in the investigations that followed those disasters,

兩件事嘅調查都發現

長時間嘅輪班工作、警覺性降低 同疲倦過度

poor judgment as a result of extended shift work

and loss of vigilance and tiredness

導致員工出現判斷錯誤

was attributed to a big chunk of those disasters.

亦係呢次災難嘅一大原因

因此，當你攰嘅時候，加上睡眠不足

When you're tired and you lack sleep,

you have poor memory, you have poor creativity,

你嘅記憶力同創造力會降低

個人會更加衝動

you have increased impulsiveness,

and you have overall poor judgment.

於是你整體嘅判斷力下降

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

但接落嚟仲有更衰嘅嘢

（笑聲）

(Laughter)

If you are a tired brain,

想像你係一個好攰嘅大腦

你會渴求一啲嘢去令自己清醒

the brain is craving things to wake it up.

例如藥物、興奮劑

So drugs, stimulants.

咖啡因可以代表 大部份西方國家嘅興奮劑

Caffeine represents the stimulant of choice

across much of the Western world.

西方人大部份日子都靠咖啡因度過

Much of the day is fueled by caffeine,

and if you're a really naughty tired brain, nicotine.

而如果你真係又唔聽話又攰嘅大腦 你就會揀尼古丁

Of course, you're fueling the waking state with these stimulants,

當然

服食呢啲興奮劑 可以支持你嘅清醒狀態

and then, of course, it gets to 11 o'clock at night,

但時間去到夜晚 11 點

大腦會同自己講︰

and the brain says to itself,

"Actually, I need to be asleep fairly shortly.

「啊，啱啦。我好快要瞓覺。

What do we do about that when I'm feeling completely wired?"

但我依家咁精神，點先瞓得著呢？」

Well, of course, you then resort to alcohol.

於是乎，你就會求助於酒精

Now alcohol, short-term, you know, once or twice,

酒精對於短時間 一至兩次咁輕度鎮靜人嚟講

to use to mildly sedate you, can be very useful.

係非常有用

It can actually ease the sleep transition.

酒精可以令人更舒服咁入睡

But what you must be so aware of is that alcohol doesn't provide sleep.

但你一定要留意，酒精唔會提供睡眠

佢只係提供一種好似睡眠嘅生理表像

A biological mimic for sleep,

it sedates you.

佢只會鎮靜你

So it actually harms some of the neural processing

因此酒精實際上 會阻礙部份神經傳遞

阻礙鞏固記憶同尋找記憶

that's going on during memory consolidation and memory recall.

所以酒精係一種短期急性療法

So it's a short-term acute measure,

but for goodness sake,

但千祈唔好上癮 將酒精當做每晚嘅安眠藥

don't become addicted to alcohol

as a way of getting to sleep every night.

另一樣同睡眠不足有關嘅嘢係肥胖

Another connection between loss of sleep is weight gain.

If you sleep around about five hours or less every night,

如果你每晚瞓唔夠五個鐘

then you have a 50 percent likelihood of being obese.

咁你就有一半可能肥胖

睡眠同肥胖有乜咩關聯？

What's the connection here?

Well, sleep loss seems to give rise to the release of the hormone ghrelin,

睡眠不足可能會增加 胃飢餓素荷爾蒙

又稱飢餓荷爾蒙嘅分泌

the hunger hormone.

Ghrelin is released.

胃飢餓素荷爾蒙釋放之後，上到大腦

It gets to the brain.

The brain says, "I need carbohydrates,"

大腦就會話︰「我要碳水化合物。」

and what it does is seek out carbohydrates and particularly sugars.

於是大腦就開始尋找碳水化合物

尤其係糖分

So there's a link between tiredness

由於壓力係肥胖嘅因由

所以疲倦同壓力係有關

and the metabolic predisposition for weight gain: stress.

攰嘅人特別容易感覺到壓力

Tired people are massively stressed.

And one of the things of stress, of course, is loss of memory,

而壓力嘅其中一個後果係記憶力衰退

which is what I sort of just then had a little lapse of.

就好似我啱啱差啲唔記得想講嘅嘢

但壓力仲有包括好多嘢

But stress is so much more.

如果你突然覺得有壓力，咁樣係冇問題

So, if you're acutely stressed, not a great problem,

but it's sustained stress associated with sleep loss that's the problem.

但如果睡眠不足 導致持續有壓力嘅話

咁就有問題

持續嘅壓力會抑制免疫力

Sustained stress leads to suppressed immunity.

And so, tired people tend to have higher rates of overall infection,

所以疲倦嘅人嘅整體感染率更加高

and there's some very good studies

有一啲好嘅研究證明

showing that shift workers, for example, have higher rates of cancer.

要輪班嘅員工有更高嘅癌症病發率

Increased levels of stress throw glucose into the circulation.

壓力增加會令更加多葡萄糖 流入循環系統裏面

Glucose becomes a dominant part of the vasculature

葡萄糖於是佔血管系統嘅大多數

and essentially you become glucose intolerant.

然後你就因為承受唔到咁多血糖

Therefore, diabetes 2.

而患上糖尿病

Stress increases cardiovascular disease as a result of raising blood pressure.

壓力仲會升高血壓，引致心血管疾病

So there's a whole raft of things associated with sleep loss

所以睡眠不足導致好多病

that are more than just a mildly impaired brain,

而並非僅僅令大腦輕微受損咁簡單

which is where I think most people think that sleep loss resides.

我諗大部份人之前都認為 睡眠不足只會影響大腦

So at this point in the talk, this is a nice time to think,

講到呢到，大家可以諗下自己夠唔夠瞓

"Well, do you think on the whole I'm getting enough sleep?"

So a quick show of hands.

我想問︰

邊個覺得自己有充足睡眠？

Who feels that they're getting enough sleep here?

噢，哇，都幾犀利，非常好

Oh. Well, that's pretty impressive.

Good. We'll talk more about that later, about what are your tips.

我哋遲啲再講呢樣嘢，同埋一啲小知識

So most of us, of course, ask the question,

我哋好多人，都會問一個問題

我點先知道我夠瞓？

"How do I know whether I'm getting enough sleep?"

其實係無絕對答案

Well, it's not rocket science.

If you need an alarm clock to get you out of bed in the morning,

如果你朝早要用鬧鐘叫醒你

if you are taking a long time to get up,

如果你要好長時間先起到身

if you need lots of stimulants,

如果你需要大量興奮劑

if you're grumpy, if you're irritable,

如果你脾氣好差、好容易發嬲

if you're told by your work colleagues that you're looking tired and irritable,

如果你嘅同事話你睇起嚟好攰、好燥

chances are you are sleep-deprived.

咁你就好大機會睡眠不足

Listen to them. Listen to yourself.

聽你周圍嘅人講，聽你自己嘅聲音

What do you do?

咁你要點做？

Well -- and this is slightly offensive --

嗯，冇禮貌咁講︰

sleep for dummies.

就係要上傻瓜睡眠課

(Laughter)

（笑聲）

Make your bedroom a haven for sleep.

要令你嘅臥室成為瞓覺天堂

The first critical thing is make it as dark as you possibly can,

最重要嘅係，整到佢有咁黑得咁黑

and also make it slightly cool.

亦都要整到間房涼爽

Very important.

記住，至少喺瞓覺前半個鐘較暗個環境

Actually, reduce your amount of light exposure

at least half an hour before you go to bed.

Light increases levels of alertness and will delay sleep.

因為光會增加警覺性，推遲睡眠時間

我哋大多數人瞓覺之前 要做嘅最後一件事係咩？

What's the last thing that most of us do before we go to bed?

我哋企喺個好光嘅浴室度

We stand in a massively lit bathroom,

一邊望住塊鏡一邊刷牙

looking into the mirror cleaning our teeth.

It's the worst thing we can possibly do before we go to sleep.

但呢樣其實係我哋瞓覺之前 最唔應該做嘅事

閂手機，熄電腦

Turn off those mobile phones. Turn off those computers.

Turn off all of those things that are also going to excite the brain.

閂曬所有可以刺激大腦嘅嘢

Try not to drink caffeine too late in the day,

日頭都唔好太遲飲咖啡

ideally not after lunch.

最好唔好遲過午飯飲

Now, we've set about reducing light exposure before you go to bed,

我哋講咗瞓覺前要較暗環境

but light exposure in the morning

但朝頭早陽光照射 反而會對生理時鐘嘅日夜週期有益

is very good at setting the biological clock to the light-dark cycle.

So seek out morning light.

所以朝早要有陽光射著

Basically, listen to yourself.

基本上，要聆聽自己，平靜落嚟

Wind down.

Do those sorts of things

做一啲你知道可以令自己進入夢鄉嘅嘢

that you know are going to ease you off

into the honey-heavy dew of slumber.

OK.

好，以上都係關於睡眠嘅事實

That's some facts. What about some myths?

咁有冇睡眠嘅謠言？

Teenagers are lazy.

細路仔好懶？唔係

No. Poor things.

佢哋天生嘅生物傾向性 令佢哋遲瞓覺、遲起身

They have a biological predisposition to go to bed late and get up late,

所以就畀佢哋唞下

so give them a break.

We need eight hours of sleep a night.

我哋每晚要瞓八個鐘 只係一個平均數

That's an average.

部份人要瞓多啲，部份人要瞓少啲

Some people need more. Some people need less.

And what you need to do is listen to your body.

而你要做嘅，係聆聽自己嘅身體

Do you need that much or do you need more?

你到底要瞓多啲，定瞓少啲？

Simple as that.

就係咁簡單

Old people need less sleep.

老人家唔需要瞓咁耐？錯

Not true.

The sleep demands of the aged do not go down.

老人家嘅睡眠時間並無減少

Essentially, sleep fragments and becomes less robust,

佢哋嘅睡眠時間愈嚟愈零碎

而且質素冇咁好

but sleep requirements do not go down.

但係對睡眠嘅要求並無減少

And the fourth myth is early to bed, early to rise

第四個謠言係

早睡早起，身體好，財富高，智力好

makes a man healthy, wealthy and wise.

Well, that's wrong at so many different levels.

呢句話真係大錯特錯

（笑聲）

(Laughter)

There is no evidence that getting up early and going to bed early

完全無任何證據表明 早起早睡會令人更加有錢

gives you more wealth at all.

There's no difference in socioeconomic status.

早起遲起同社會地位並無關係

In my experience,

從我嘅經驗睇嚟

the only difference between morning people and evening people

早起同遲起嘅人主要分別係

早起身嘅人極其自命不凡

is that those people that get up in the morning early

are just horribly smug.

(Laughter)

（笑聲） （掌聲）

(Applause)

OK.

好。最後一部份，最後幾分鐘

So for the last few minutes,

what I want to do is change gears

我想改話題

and talk about some really new, breaking areas of neuroscience,

我想講下神經科學一啲突破性嘅發現

which is the association between mental health,

就係精神健康、精神病 以及睡眠障礙嘅關係

mental illness and sleep disruption.

We've known for 130 years that in severe mental illness,

我哋 130 年前已經知道

有嚴重精神病嘅人都會有睡眠障礙

there is always, always sleep disruption,

but it's been largely ignored.

但好多人都會忽視呢個情況

In the 1970s, when people started to think about this again,

70 年代，當人開始諗返呢樣嘢

they said, "Yes, well, of course you have sleep disruption in schizophrenia,

佢地話：

「係啊，思覺失調病人 當然有睡眠障礙，

because they're on antipsychotics.

因為佢哋食梗抗精神病藥物。

It's the antipsychotics causing the sleep problems,"

係抗精神病藥物造成睡眠問題。」

ignoring the fact that for a hundred years previously,

但佢哋忽略咗

抗精神病藥物出現前嘅一百年 已經有睡眠障礙嘅報告

sleep disruption had been reported before antipsychotics.

So what's going on?

咁點樣呢？

Several groups are studying

有幾班人研究緊抑鬱症 精神分裂、躁鬱症同睡眠障礙

conditions like depression, schizophrenia and bipolar

and what's going on in terms of sleep disruption.

We have a big study which we published last year on schizophrenia,

而且我哋上年發表一個 有關思覺失調嘅大型研究

and the data were quite extraordinary.

個研究數據非常有趣

In those individuals with schizophrenia,

思覺失調病人夜晚大部份時間都會清醒

much of the time, they were awake during the night phase

and then they were asleep during the day.

同埋會喺日頭瞓覺

其他組別就發現 思覺失調病人無 24 小時生理規律

Other groups showed no 24-hour patterns whatsoever --

their sleep was absolutely smashed.

佢哋嘅睡眠節奏完全被破壞

And some had no ability to regulate their sleep by the light-dark cycle.

其中一啲人甚至無辦法 等日夜週期控制佢哋嘅睡眠時間

They were getting up later and later and later and later each night.

佢哋只能夠越嚟越遲起身同瞓覺

It was smashed.

So what's going on?

咁點樣呢？

And the really exciting news

令人興奮嘅係

is that mental illness and sleep are not simply associated,

精神病並非咁簡單同睡眠有關係

but they are physically linked within the brain.

佢哋喺大腦裡面仲會有物理聯繫

The neural networks that predispose you to normal sleep,

而帶畀你正常睡眠嘅神經網絡

give you normal sleep,

同畀你正常精神健康嘅神經網絡 係有關聯嘅

and those that give you normal mental health, are overlapping.

And what's the evidence for that?

有咩證據？

就係對產生正常睡眠 非常重要嘅基因

Well, genes that have been shown

to be very important in the generation of normal sleep,

when mutated, when changed,

當基因突變，或者有任何變化

also predispose individuals to mental health problems.

人就會誘發精神健康問題

上年，我哋公佈咗一個研究

And last year, we published a study

顯示當一個 同思覺失調有關嘅基因變異

which showed that a gene that's been linked to schizophrenia,

when mutated, also smashes the sleep.

睡眠就會嚴重影響

So we have evidence of a genuine mechanistic overlap

所以我哋有證據證明

精神疾病同睡眠障礙有關係

between these two important systems.

Other work flowed from these studies.

下面嘅研究都基於呢個成果

The first was that sleep disruption

首先，睡眠障礙出現喺 某啲精神疾病發作之前

actually precedes certain types of mental illness,

and we've shown that in those young individuals

我哋發現

嗰啲好有機會患上躁鬱症嘅年輕人

who are at high risk of developing bipolar disorder,

they already have a sleep abnormality

佢哋接受躁鬱症臨床診斷之前

prior to any clinical diagnosis of bipolar.

已經有睡眠異常情況

The other bit of data was that sleep disruption

另外數據說明

睡眠障礙好可能令精神疾病惡化

may actually exacerbate, make worse, the mental illness state.

My colleague Dan Freeman has used a range of agents

我嘅同事 Dan Freeman 用多種藥物 穩定咗研究對象嘅睡眠質量

which have stabilized sleep and reduced levels of paranoia

in those individuals by 50 percent.

同埋減低咗佢哋一半嘅妄想症狀

So what have we got?

咁我哋得到啲咩？

We've got, in these connections, some really exciting things.

我哋當中有一啲好振奮嘅發現

In terms of the neuroscience,

透過了解睡眠同精神疾病 當中嘅神經科學

by understanding these two systems,

we're really beginning to understand how both sleep and mental illness

我哋開始認識

睡眠同精神疾病係點樣 喺大腦裡面生成同受到調節

are generated and regulated within the brain.

The second area is that if we can use sleep

第二樣嘢係

如果我哋可以將睡眠同睡眠障礙 當成早期嘅警號

and sleep disruption as an early warning signal,

then we have the chance of going in.

咁我哋就有機會介入跟進

If we know these individuals are vulnerable,

如果我哋知某啲人 比較容易患上精神疾病

early intervention then becomes possible.

咁就有可能及早介入

And the third, which I think is the most exciting,

第三樣嘢，我認為最震撼人心嘅

is that we can think of the sleep centers within the brain

係我哋可以將大腦裡面嘅睡眠中樞 睇成係新嘅治療目標

as a new therapeutic target.

Stabilize sleep in those individuals who are vulnerable,

只要我哋穩定 容易患精神病嘅人嘅睡眠質量

佢哋就肯定會更加健康

we can certainly make them healthier,

but also alleviate some of the appalling symptoms of mental illness.

同時可以減輕部份嚇人嘅精神病症狀

等我做個總結

So let me just finish.

What I started by saying is: Take sleep seriously.

我一開始講嘅係要重視睡眠

Our attitudes toward sleep are so very different

我哋對睡眠嘅態度 同前工業時代嘅時候好唔同

from a pre-industrial age,

緃使嗰陣嘅人仲要捲入被窩取暖

when we were almost wrapped in a duvet.

但當時嘅人已經直覺知道睡眠嘅重要

We used to understand intuitively the importance of sleep.

And this isn't some sort of crystal-waving nonsense.

呢種直覺並非好似迷信咁無理

This is a pragmatic response to good health.

而其實係對健康好嘅務實做法

If you have good sleep, it increases your concentration,

你瞓得好嘅話

你嘅精神集中度、注意力 決斷力、創造力

attention, decision-making, creativity, social skills, health.

社交技能同身體健康都會提升

If you get sleep, it reduces your mood changes, your stress,

瞓覺會減少情緒起伏幅度、壓力 憤怒程度、衝動程度

your levels of anger, your impulsivity,

and your tendency to drink and take drugs.

同埋減少想飲酒吸毒嘅諗法

And we finished by saying

最後我想講，理解睡眠嘅神經科學

that an understanding of the neuroscience of sleep

is really informing the way we think

令大家反思返我哋 係點樣諗部份精神疾病嘅成因

about some of the causes of mental illness,

and indeed is providing us new ways

同時為我哋對付呢啲極其無奈嘅病

to treat these incredibly debilitating conditions.

提供咗全新嘅方向

Jim Butcher, the fantasy writer, said,

Jim Butcher， 一位奇幻小說作家

話︰「睡眠係神嚟，大家要朝拜佢。」

"Sleep is God. Go worship."

And I can only recommend that you do the same.

所以我只能夠叫你哋 跟住呢句話去做

Thank you for your attention.

多謝

（掌聲）

(Applause)