Two hemispheres each doing half the work of being you.

兩個半腦各分擔一半的工作

Half your vision goes to each and half your movement directed by each.

它們各自接收一半的視野，各自負責控制一半的活動

Right controls left

右腦控制左邊的

and left controls right.

左腦控制右邊的

Your two brains co-ordinate through a wire of nerves, but

這兩個半腦透過神經連接進行合作

this wire can be cut, and was, for a time, used as an epilepsy treatment.

但這連接的神經可以被切斷，過去有段時間， 切斷神經常被用來當作治療癲癇的一種手術

After the cut, people seemed the same, though their brain was split in-twain.

切斷神經連結之後，人們外表看起來沒有改變， 但是他們的大腦已經一分為二

Except, some post-split patients described that while selecting their morning outfit with

不過，有些裂腦手術的患者說，當他們早上用右手挑選

right hand, left might come along to disagree.

要穿的衣服時，左手會表示反對

Actually, left hand might quite often disagree, which these split-brain patients found frustrating.

事實上，左手很常反對，讓這些裂腦患者很挫折

What's happening?

發生了什麼事？

To investigate, remember, right brain sees and controls one half, while

深入研究之前，請記得右腦控制一半的身體和視覺，

left brain controls and sees the other.

左腦控制另一半的身體跟視覺

But only left brain can speak.

但只有左腦能夠說話

"Hello."

「哈囉。」

Because that's where the speech center is located.

這是因為語言中樞位於左腦

Right brain, without this, is mute.

右腦沒有語言中樞，因此不能說話

In normal brains, this doesn't matter because each half communicates across the wire with the other.

在正常的大腦中這無關緊要， 因為兩邊的半腦可以透過神經連接和另一半溝通

But, split-brains can't, and thus, you can show just the right brain a word, ask the person:

但，分開的半腦不能互相溝通， 因此你可以讓右腦讀一個字，然後問那個人：

"What did you see?",

「你看到什麼？」

and you'll hear: "Nothing."

他會說：「什麼都沒看到。」

Because, left speaking brain saw nothing.

因為左腦什麼都沒看到

Meanwhile, right brain will use its hand to pick the object out of a pile hidden from left brain.

同時，右腦會用它的手舉起左腦看不到的東西

This is deeply creepy.

真讓人毛骨悚然

Ask "Why are you holding the object?" and speaking left brain will make up a

問他「你為什麼要拿那個東西？」 那左腦就會回答一個可能的答案

plausible sounding, but totally wrong, reason.

但那個理由完全不是真的

"I always wanted to learn how to solve one of these."

「我一直都想學怎麼解這個。」

Left brain isn't lying; it's just doing what brains do:

左腦不是在說謊，它只是在做腦子該做的事：

creating a story that explains its past actions to its current self, a behavior which does rather cast doubt

替自己的過去創造一個故事，以解釋 過去的行為給現在的自己聽。這個行為的確讓人懷疑

onto the notion of free will (but that's a story for another time).

人們是否真的有自由意志（但那是另一個議題了）

Creating reasons for why it does things is just something

給自己做的事情創造理由只是左腦

left brains do.

平常就在做的事

It happens in normal, healthy humans all the time, and if you think about it closely, you

正常、健康的人平常就會這樣， 而且如果你仔細想想，你就會知道

know you've done this.

你也會這樣

Back to experiments.

回到實驗：

Give right brain an object, ask the person "What's in your hand?" and they won't be able to say.

給右腦一個東西，問那個人「你手上有什麼」 那他們會答不出來

"I'm not holding anything."

「我手上啥也沒有。」

And, when asked to draw, a split-brain can draw two separate objects

如果你叫他畫畫，一個裂腦的人可以同時用兩隻手

simultaneously, with each hand, in a way unsplit-brains find challenging.

畫兩個東西，頭腦沒有分開的普通人很難做到這件事

These experiments on split-brain patients are deeply unsettling

這些對裂腦患者的實驗讓人不安

because they really point in the direction of a mute separate... intelligence...

因為這表示有一個沈默的…智慧體…

Something...

就在…

Living in the skull.

我們的頭骨裡面

You can even ask questions of a split-brain and get disagreement on the answer.

你甚至可以問一個裂腦的人問題， 他會對自己答案意見不合

So, if your brain is split, who is the 'you' in this situation?

所以，如果你的大腦是分裂的，那「你」在哪一邊？

From the outside, it's tempting to think of the part of the brain that's speaking as the person, but

從外在來看，我們可能會把能說話的半腦當作那個人，

something is hearing and answering questions.

但是有某個東西在聆聽和回答問題

And, though right brain can't speak, it does understand faces, which left brain can't.

還有，雖然右腦不能說話， 但它可以認得臉孔，左腦就不能

If this is you, you don't know who your friends and family are in a crowd.

如果這是你的話，你就沒法 在人群中找到你的朋友或家人

This act of cutting exposes two minds in one head, and the talking mind

把大腦切開就會產生兩個心靈，會說話的那個

doesn't know there's someone else in the house.

不知道還有別人在房子裡

The left brain can describe the situation it's in, but nonetheless will constantly be surprised by

左腦可以描述它所處的情況， 但時常會被右腦的行動嚇到，

right brain's actions and explain them away.

再編出解釋

There's a question to be asked here:

我們在此要問一個問題：

Why, after separation, does right brain not totally freak out, but instead plays

為什麼右腦在分開以後，沒有嚇到發瘋，反而

along helpfully, answering questions, and listening to left-brain's dumb stories about what's happening.

依舊試圖幫忙、回答問題、 聽左腦的解釋怎麼了的笨故事

- It's the best pony... I don't know.

—因為這隻是最棒的彩虹小馬…我其實不知道

- Speculation time...

猜測時間：

But, one answer is the cutting doesn't make right brain a separate... intelligence... consciousness... person?

其中一個答案是，把大腦分開並沒有讓右腦變成獨立…有智慧…有意識…的人？

but rather it has always been. In normal people, perhaps right brain rose up as a companion without a choice.

右腦其實一直都這樣。在正常人身上， 或許右腦是一個沒有選擇的伙伴

Feeling at first somewhat equal partners, but then, as speech develops that it can't participate in, that

它一開始是平等的伙伴，不過隨著語言區的成長， 語言成為生活核心的一部份

increasingly becomes the central point of life, it resigns to mutely co-ordinate with left brain.

但右腦無法參與，只能無聲地幫助左腦

At this moment, in your normal head, there are two of you watching this video:

此時你正常的頭殼裡，有兩個你正在看這影片：

one having a 'mind = blown' moment, and the other mentally rolling its eye at the obviousness of it all.

其中一個正在「目瞪口呆」，另一個 毫不意外的翻白眼

In split-brains, right doesn't freak out because not a whole lot has really changed.

在分開的大腦中，右腦沒有嚇傻， 因為對它來說事情沒啥改變

You might not agree, and maybe arguing right now at why it can't be possible, exactly as we would expect

你可能不同意，可能會說這為什麼不可能。 就如我們預期

talking left brain to do.

會說話的左腦會做的事

Speculation aside, split-brain patients show, at the very least, that in the mind, there is a separate...

把這些猜測先放一邊，裂腦患者顯示， 只要在正確的場合，在他們心中，

something that can hear and understand and respond, given the right circumstances.

有另一個可以聆聽、理解、並回答的東西

Your brain isn't entirely yours.

你的大腦不僅僅只是你的

Who is you?

你是誰？

You is two.

你是二合一。

[soft music]

[輕鬆的音樂]

[Grey's voice morphing into Kurzgesagt's voice] But we can go deeper. You are many.

[Grey的聲音變成Kurzgesagt 的聲音] 但我們可以進一步深入

[Kurzgesagt's voice] The pile of meat that's your body is made up of trillions of tiny individuals that have a life of their own.

[ Kurzgesagt 的聲音 ] 構成你的那團肉是由 上兆擁有自我生命的小物體組成的

[Kurzgesagt's voice] So, at which point do the many become one?

[ Kurzgesagt 的聲音 ] 所以，怎樣一堆東西算是一個？

[Kurzgesagt's voice] What makes lots of tiny things you?

[ Kurzgesagt 的聲音 ] 這一大堆小東西怎樣才算是你？

[Kurzgesagt's voice] Click here to go to our channel and watch the next part.

[ Kurzgesagt 的聲音 ] 點此到我們的頻道並觀賞下一部份

[Grey's voice] Seriously. If you haven't checked out Kurzgesagt, then you don't know what you're missing.

[ Grey 的聲音 ] 說認真的，如果你還沒看過 Kurzgesagt， 那你根本不知道你錯過了什麼

Kurgaset?

Kurgaset?

Kurtzgaset?

Kurtzgaset?

I never know.

要怎麼念啊？