and I know this personally.

現在聽到腦震盪這詞 比起以往更加恐懼，

I played 10 years of football,

這是我個人感受。

was struck in the head thousands of times.

我打美式足球已經有十年了，

And I have to tell you, though, what was much worse than that

頭部被擊中數千次。

was a pair of bike accidents I had where I suffered concussions,

不過我想告訴你， 比起這事還有更糟的

and I'm still dealing with the effects of the most recent one

就是被兩架單車撞致腦震盪，

today as I stand in front of you.

這件事近期仍然影響我日常生活

There is a fear around concussion

幸好今日我可如常站在你們面前。

that does have some evidence behind it.

對於腦震盪仍然圍繞著恐懼

There is information that a repeated history of concussion

因為背後確實有些證據。

can lead to early dementia, such as Alzheimer's,

還有一些資訊 重複顯示腦震盪的歷史

and chronic traumatic encephalopathy.

可能會導致早期老年癡呆症， 例如:阿爾茨海默氏症，

That was the subject of the Will Smith movie "Concussion."

以及慢性創傷性腦病。

And so everybody is caught up in football and what they see in the military,

由威爾‧史密斯主演的《震盪效應》是一部2015年美式足球傳記劇情片，就是今日的主題。

but you may not know

電影中講述每個人都要了解美式足球 就好像在軍中所看到平凡事一樣，

that bike riding is the leading cause of concussion for kids,

可能你未必知道

sports-related concussion, that is.

對於兒童來說踏單車 是引致腦震盪的主要原因，

And so another thing that I should tell you

那麼，運動與腦震盪是有關連。

that you may not know

還有另一件事我應該告訴你

is that the helmets that are worn in bicycling and football

可能你未必知道

and many activities,

踏單車也好，踢美式足球也好 都必須配戴頭盔

they're not designed or tested

還有其他戶外運動亦需要配戴，

for how well they can protect your children against concussion.

由於現時的運動頭盔 並沒有仔細設計或進行測試

They're in fact designed and tested

故此難易保護兒童防止腦震盪發生。

for their ability to protect against skull fracture.

實際上在設計及測試方面

And so I get this question all the time from parents,

應要有預防及保護頭骨骨折能力。

and they ask me,

所以每時每刻 我都從家長那兒得到這個問題，

"Would you let your own child play football?"

他們問我，

Or, "Should I let my child play soccer?"

"你會讓你的孩子踢美式足球嗎？"

And I think that as a field,

又或者會問，"我應該讓我的孩子踢美式足球嗎？

we're a long way from giving an answer with any kind of confidence there.

作為一個前美式足球員，

So I look at that question from a bit of a different lens,

當中要找到答案 的確還有很長的路要走。

and I want to know, how can we prevent concussion?

稍為從不同的角度 去看這條問題，

Is that even possible?

我們應如何預防腦震盪？

And most experts think that it's not,

真的有可能嗎？

but the work that we're doing in my lab

大多數專家認為這是不可能的，

is starting to reveal more of the details around concussion

不過在這項研究已經在我的實驗室進行中

so that we can have a better understanding.

我會開始披露更多 與腦震盪有關的細節

The reason we're able to prevent skull fracture with helmets

讓我們有更好的理解。

is because it's pretty simple. We know how it works.

我們之所以配戴頭盔 主要用來預防頭骨破裂

Concussion has been much more of a mystery.

就是這麼簡單。 我們明明知道頭盔的作用。

So to give you a sense of what might be happening in a concussion,

可惜腦震盪仍然充滿著謎團。

I want to show you the video here

你會覺得腦震盪沒可能發生的，

that you see when you type into Google,

我想在這裡放影少少片段

"What is a concussion?"

你亦可以鍵入到谷歌，

The CDC website comes up,

鍵入"什麼是腦震盪？"

and this video essentially tells the whole story.

也可在疾病預防控制中心的網站上找到，

What you see is the head moves forward,

整個足本的影片。

the brain lags behind,

現在留意這個頭部向前移動，

then the brain catches up

大腦先向後撞到，

and smashes into the skull.

然後大腦再向後傾

It rebounds off the skull

並撞向頭骨。

and then proceeds to run into the other side of the skull.

再回彈到頭骨

And what you'll notice is highlighted in this video from the CDC,

然後繼續進行 到了另一邊的頭骨。

which I'll note was funded by the NFL,

由疾控中心提供這影片當中 顯然你都注意到，

is that the outer surface of the brain,

這是國家美式足球聯盟贊助，

where it was to have smashed into the skull,

那是大腦表面的四周，

looks like it's been damaged or injured, so it's on the outer surface of the brain.

頭骨明顯被撞擊，

And what I'd like to do with this video

看起來大腦表面周邊， 像已損毀或受創。

is to tell you that there are some aspects that are probably right,

我估計做這段影片

indicative of what the scientists think happens with concussion,

目的想告訴你 某些觀點可能是對的，

but there's probably more that's wrong with this video.

表明了有科學家認為 曾經產生過腦震盪，

So one thing that I do agree with, and I think most experts would,

不過這段影片中 有很多地方弄錯了。

is that the brain does have these dynamics.

有一件事我與大多數專家都認同的，

It does lag behind the skull

就是大腦曾有動力學的變化。

and then catch up and move back and forth and oscillate.

確實頭骨先向後

That we think is true.

再向前繼而前後擺動。

However, the amount of motion you see in the brain in this video

我認為這是事實。

is probably not right at all.

然而，從影片中 可以看到大腦擺動次數

There's very little room in the cranial vault,

但這點可能沒根據。

only a few millimeters,

在大腦與頭頂骨之間 有一個很細的空間，

and it's filled entirely with cerebral spinal fluid,

只有幾毫米，

which acts as a protective layer.

而且完全充滿腦脊髓液，

And so the brain as a whole probably moves very little inside the skull.

這角色就是要充當一個保護層。

The other problem with this video

因為整個大腦 在頭骨內變化得很少。

is that the brain is shown

這影片內另一個問題

as a kind of rigid whole as it moves around,

是大腦的顯示

and that's not true either.

作為一種堅硬的整體 怎可以四處移動，

Your brain is one of the softest substances in your body,

而事實並非如此。

and you can think of it kind of like jello.

你的大腦是你的身體上 最柔軟的物質之一，

So as your head is moving back and forth,

你能想到的它有點像果凍。

your brain is twisting and turning and contorting,

所以當你的頭部來來回回移動著，

and the tissue is getting stretched.

你的大腦就會彎彎曲曲的 旋轉和被扭曲，

And so most experts, I think, would agree

及組織會被拉長。

that concussion is not likely to be something that's happening

所以大多數專家，我想，都會同意

on this outer surface of the brain,

腦震盪不太可能 像這樣子發生的

but rather it's something that's much deeper

在大腦表面周邊，

towards the center of the brain.

對比起其他東西 這是更深層

Now, the way that we're approaching this problem

接近大腦中心點。

to try to understand the mechanisms of concussion

現在，用我們的方式 去解說這個問題

and to figure out if we can prevent it

嘗試去理解 腦震盪的機制

is we are using a device like this.

假設我們可以預防 便更要弄清楚

It's a mouthguard.

我們使用類似的設備。

It has sensors in it that are essentially the same

這是一個牙套。

that are in your cell phone:

牙套上有一個感應器 本質是相同的

accelerometers, gyroscopes,

這是在你的手機上：

and when someone is struck in the head,

加速度計，陀螺儀，

it can tell you how their head moved

當有人頭部被擊中，

at a thousand samples per second.

這兩部儀器可以告訴你 他們的頭部是怎樣移動

The principle behind the mouthguard is this:

舉例說每秒一千樣。

it fits onto your teeth.

背後的原理 該牙套是這樣的：

Your teeth are one of the hardest substances in your body.

將牙套套在你的牙齒上。

So it rigidly couples to your skull

你的牙齒是身體上最堅硬的物質之一。

and gives you the most precise possible measurement

也是堅固地連接到你的頭骨

of how the skull moves.

並為你提供最精確合適的測量

People have tried other approaches, with helmets.

頭骨是如何移動的。

We've looked at other sensors that go on your skin,

人們嘗試 其他的方法，配帶頭盔。

and they all simply move around too much,

或會利用其他感應器 就是你的皮膚，

and so we found that this is the only reliable way

因為左右走動太多，

to take a good measurement.

所以我們發現，牙套感應器 是唯一可靠的方法

So now that we've got this device, we can go beyond studying cadavers,

也是取得最好的測量方式。

because you can only learn so much about concussion

這個設備我們現在已經擁有了， 並利用屍體作為研究，

from studying a cadaver,

因此想了解更多關於腦震盪

and we want to learn and study live humans.

就是只能從屍體上學習，

So where can we find a group of willing volunteers

如要從活生生的人類當中研究的話。

to go out and smash their heads into each other on a regular basis

需要找一群志願者

and sustain concussion?

定期去粉碎他們的頭部

Well, I was one of them,

並要認定已遭受了腦震盪？

and it's your local friendly Stanford football team.

對吧，我就是他們其中之一，

So this is our laboratory,

你們本地友好 斯坦福大學美式足球隊。

and I want to show you

就在我的實驗室在中，

the first concussion we measured with this device.

我想展示給你們看

One of the things that I should point out is the device has this gyroscope in it,

我們用這設備進行了 第一次腦震盪測量。

and that allows you to measure the rotation of the head.

我想指出今次是利用 陀螺儀裝置設備，

Most experts think that that's the critical factor

來測量頭部旋轉情況。

that might start to tell us what is happening in concussion.

因為大多數專家認為 這就是關鍵因素

So please watch this video.

正式開始告訴我們 腦震盪是如何形成。

Announcer: Cougars bring extra people late, but Luck has time,

請先觀看這段影片。

and Winslow is crushed.

評述員︰ 美洲獅遲遲才帶人來， 但盧克仍有時間，

I hope he's all right.

可惜與溫思勞撞過正面。

(Audience roars)

我希望他沒事。

Top of your screen,

（影片中觀眾怒吼一聲）

you'll see him come on just this little post route,

請留意螢光幕上方，

get separation, safety.

他好像沿著一條小小的路線衝過去，

Here it comes at you in real speed. You'll hear this.

被撞到彈開了，幸好沒大礙。

The hit delivered by --

聽說就在這裡才會感受到真正的速度。

David Camarillo: Sorry, three times is probably a little excessive there.

交由命運安排 --

But you get the idea.

大衛卡馬里奧：對不起，撞擊三次 實在有一點過分。

So when you look at just the film here,

你有什麼想法。

pretty much the only thing you can see is he got hit really hard and he was hurt.

當你只是在這裡看著的影片時，

But when we extract the data

幾乎你可以看見唯一的事情 就是他們真正被撞擊和受傷。

out of the mouthguard that he was wearing,

但當我們提取資料時

we can see much more detail, much richer information.

發現原來他有配戴牙套的，

And one of the things that we noticed here

我們可以看到更詳細的， 更豐富的信息。

is that he was struck in the lower left side of his face mask.

以及我們在這裡看到其中的一件事情發生

And so that did something first that was a little counterintuitive.

就是他面具左下方被撞擊到。

His head did not move to the right.

第一時間覺得有點不合常理。

In fact, it rotated first to the left.

他的腦部沒有移動到右邊。

Then as the neck began to compress,

事實上，腦部應先轉動到左邊。

the force of the blow caused it to whip back to the right.

然後隨著頸部開始受壓，

So this left-right motion was sort of a whiplash-type phenomenon,

由衝擊力引致腦部迅速撞回右邊。

and we think that is probably what led to the brain injury.

所以這個左右移動 類似那種揮鞭現象，

Now, this device is only limited in such that it can measure the skull motion,

我們認為就是這樣 導致了腦部受傷。

but what we really want to know is what's happening inside of the brain.

由於，這種裝置只局限於 測量頭骨移動，

So we collaborate with Svein Kleiven's group in Sweden.

所以我們真的很想知道 在大腦內究竟發生了什麼變化。

They've developed a finite element model of the brain.

故此我們在瑞典，與斯韋恩·凱文的研究小組合作。

And so this is a simulation

他們已經利用有限元素法 去探討大腦。

using the data from our mouthguard from the injury I just showed you,

這是一種模擬狀態

and what you see is the brain --

研究數據主要來自損壞的牙套資料 就是我剛才這段影片，

this is a cross-section right in the front

從這片段的大腦你可以看到什麼 --

of the brain twisting and contorting as I mentioned.

前面就是大腦右邊橫切面

So you can see this doesn't look a lot like the CDC video.

正如我所提及的 大腦有扭曲及被扭斷。

Now, the colors that you're looking at

你們現在看到的 與疾控中心的影片完全不同

are how much the brain tissue is being stretched.

現在，你看到的顏色