Name: なぜ脳は眠るのか？ (Why Does My Brain Sleep?)
Uploaded: 2021-01-14T04:38:36.000Z
Duration: 1 h 16 min 34 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

MATTHEW WALKER: It's a pleasure to be here.

And I want to start with a standard disclaimer, which is

that when most speakers look to their audience and they see

people who are falling asleep or nodding off, it can be

However, based on the topic of today's presentation, I'm

almost going to actively encourage that kind of

In fact, knowing what I know particularly about the

relationship between sleep and memory, it's actually the

greatest form of flattery for me to see people like you not

being able to resist the urge to strengthen what I'm telling

So feel free just to sort of ebb and flow in and out of

consciousness throughout the entire talk.

And the talk itself is really going to come in at four main

Firstly, I want to spend some time telling you about what

sleep actually is, the different types, it's

And then after that, I'll tell you about the variety of

different functions, plural, that we're starting to

So I'll tell you about the role of sleep in promoting

But I'll also then tell you how sleep can go beyond simply

Sleep seems to be intelligent in that it can cross-link new

pieces of information together so you can come up with

And then finally, I'll describe a role of sleep

beyond information processing into your mental health and

how sleep seems to be critical for emotional regulation,

preparing specific brain circuits for next day social

Coming on to what sleep is, and I do love this picture.

You can just kind of get a sense of the quality and the

If we're going on that whole savanna grasslands kind of

side street by the way, I just want to come

Firstly, what a strange morphology for a creature.

Have you ever wondered how something that

Would you like to know how a giraffe sleeps?

Firstly, despite such bizarre anatomy, sleep will still find

Second, and more generally, in every species that we've

studied to date, sleep, or something that looks very much

What that means is that sleep has fought its way through

vehemently every step along the evolutionary pathway.

If that's true, sleep must be essential at some of the most

And that's exactly what we're starting to discover.

And sleep in terms of mammalian species at least has

been broadly separated into two main types, as

On the one hand, we have non-rapid eye movement sleep

And non-REM sleep has been further subdivided into four

separate stages, unimaginatively called stages

or a creative bunch of sleep researchers.

So increasing in the depth of sleep, stages 3 and 4 are

those really deep stages of dreamless sleep.

And they're often grouped together under the term

Because of these slow, lazy brain waves that happen during

That's not that your brain is dormant by any stretch of the

What it means is that vast portions of your brain,

hundreds of thousands of neurons, have all decided to

synchronize together and sing together in time.

It's a phenomena like no other brain state that we know of.

It's a strange phenomena and we still don't truly

On the other hand, we have rapid eye movement sleep or

REM sleep named, not after the popular Michael Stipe pop

band, but because of these bizarre, horizontal, shuttling

eye movements that occur during this stage of sleep.

And again, we don't truly understand why your eyes move

And it turns out that these two types of sleep, REM and

non-REM, will play out in a battle for brain domination

And that sort of cerebral war is going to be won and lost

every 90 minutes and replayed every 90 minutes.

And what that creates is a standard architecture of