(单词翻译:单击)
Your brain is two brains. Two hemispheres each doing half the work of being you. Half your vision goes to each and half your movement directed by each.
你的大脑是两个半球。两个半球各自承担一半的功能。每个半球接收一半的视觉信息，并控制一半的身体运动。
Right controls left and left controls right. Your two brains co-ordinate through a wire of nerves, but this wire can be cut, and was, for a time, used as an epilepsy treatment.
右半球控制左半身，左半球控制右半身。你的两个大脑通过神经纤维相互协调，但这条神经纤维可以被切断，这曾被用作治疗癫痫。
After the cut, people seemed the same, though their brain was split in-twain.
切断后，人们看似如常，尽管他们的大脑被一分为二。
Except, some post-split patients described that while selecting their morning outfit with right hand, left might come along to disagree.
不过，一些术后患者描述说，当他们用右手选择早晨的服装时，左手可能会不同意。
Actually, left hand might quite often disagree, which these split-brain patients found frustrating. What's happening?
事实上，左手可能经常不同意，这些大脑分割的患者对此感到沮丧。发生了什么？
To investigate, remember, right brain sees and controls one half, while left brain controls and sees the other. But only left brain can speak. "Hello."
为了调查，请记住，右半球看到并控制身体的一侧，而左半球控制并看到另一侧。但只有左半球可以说“你好。”
Because that's where the speech center is located. Right brain, without this, is mute.
因为语言中枢位于左半球。在正常的大脑中，右半球没有语言功能。
In normal brains, this doesn't matter because each half communicates across the wire with the other.
在正常大脑中，这并不重要，因为两个半球通过神经纤维相互交流。
But, split-brains can't, and thus, you can show just the right brain a word, ask the person: "What did you see?", and you'll hear: "Nothing."
但是分割后的大脑不能，因此，如果只向右半球展示一个单词，问这个人看到了什么，你将听不到任何回答。
Because, left speaking brain saw nothing. Meanwhile, right brain will use its hand to pick the object out of a pile hidden from left brain. This is deeply creepy.
因为左半球什么也没看到。与此同时，右半球会用手从左半球看不见的一堆物体中挑选出目标物体。这真是令人毛骨悚然。
Ask "Why are you holding the object?" And speaking left brain will make up a plausible sounding, but totally wrong, reason. "I always wanted to learn how to solve one of these."
问你为什么拿着这个物体，左半球会编造一个听起来合理但完全错误的理由。“我一直想学习如何解决这类问题。”
Left brain isn't lying; it's just doing what brains do: creating a story that explains its past actions to its current self, a behavior which does rather cast doubt onto the notion of free will (but that's a story for another time).
左脑没有撒谎；它只是在履行大脑的正常功能：编造一个故事来向现在的自己解释它过去的行为，这种行为确实对自由意志的概念提出了质疑，但这个问题将留待以后再讨论。
Creating reasons for why it does things is just something left brains do.
为所做的事情找理由不过是左脑的本能。
It happens in normal, healthy humans all the time, and if you think about it closely, you know you've done this. Back to experiments.
这种现象在正常健康的人身上一直存在，如果你仔细思考，就会知道你曾经这样做过。回到实验。
Give right brain an object, ask the person "What's in your hand?" and they won't be able to say. "I'm not holding anything."
给右半球一个物体，问受试者手里拿的是什么，他们将无法说出。“我手里什么都没有。”
And, when asked to draw, a split-brain can draw two separate objects simultaneously, with each hand, in a way unsplit-brains find challenging.
当被要求画画时，大脑分割的患者可以同时用每只手画出两个不同的物体，这对未分割大脑的人来说很有挑战性。
These experiments on split-brain patients are deeply unsettling because they really point in the direction of a mute separate... intelligence... Something... Living in the skull.
这些对大脑分割患者的实验令人深感不安，因为它们实际上指向了一个沉默的、独立的智能。某种东西生活在头骨中。
You can even ask questions of a split-brain and get disagreement on the answer. So, if your brain is split, who is the 'you' in this situation?
你甚至可以向大脑分割的患者提问，并得到不同的答案。那么，如果你的大脑被分割，这种情况下的“你”又是谁呢？
From the outside, it's tempting to think of the part of the brain that's speaking as the person, but something is hearing and answering questions.
从外部来看，人们很容易将说话的大脑部分视为个体本身，但实际上还有其他部分在接收信息和回答问题。
And, though right brain can't speak, it does understand faces, which left brain can't. If this is you, you don't know who your friends and family are in a crowd.
虽然右脑不能说话，但它能理解面部表情，而左脑却不能。如果这是你，你不知道在人群中谁是你的亲朋好友。
This act of cutting exposes two minds in one head, and the talking mind doesn't know there's someone else in the house.
这种切割行为揭示了一个头颅内存在两个独立的意识体，而正在说话的意识不知道房子里还有其他人。
The left brain can describe the situation it's in, but nonetheless will constantly be surprised by right brain's actions and explain them away.
左脑可以描述它所处的情况，但尽管如此，它还是会不断对右脑的行为感到惊讶，并为其辩解。
There's a question to be asked here: Why, after separation, does right brain not totally freak out, but instead plays along helpfully, answering questions, and listening to left-brain's dumb stories about what's happening.
这里有一个问题：为什么在分割后，右半球并没有完全恐慌，而是继续协助，回答问题，倾听左半球讲述正在发生的事情的愚蠢故事？
It's the best pony... I don't know. Speculation time... But, one answer is the cutting doesn't make right brain a separate... intelligence... consciousness... person? but rather it has always been.
这是最好的小马吗……我不知道。推测时间……但一个答案是分割不会让右半球成为一个独立的智力、意识或个体，而是它原本就一直是这样。
In normal people, perhaps right brain rose up as a companion without a choice.
在正常人中，也许右脑是在无选择的情况下成长为一个伴侣。
Feeling at first somewhat equal partners, but then, as speech develops that it can't participate in, that increasingly becomes the central point of life, it resigns to mutely co-ordinate with left brain.
起初感觉像是平等的伙伴，但后来随着语言的发展，右半球无法参与其中，语言逐渐成为生活的中心点，于是它只能默默地与左半球协调。
At this moment, in your normal head, there are two of you watching this video: one having a 'mind = blown' moment, and the other mentally rolling its eye at the obviousness of it all.
此时此刻，在你正常的大脑里，有两个你正在观看这段视频：一个半球感到思维被颠覆的瞬间，另一个半球在心里对这一切的显而易见翻白眼。
In split-brains, right doesn't freak out because not a whole lot has really changed.
在分割的大脑中，右半球不会惊慌失措，因为并没有发生太多变化。
You might not agree, and maybe arguing right now at why it can't be possible, exactly as we would expect talking left brain to do.
你可能不同意，也许现在正在争论为什么这不可能，这正是我们预期左脑会做的事情。
Speculation aside, split-brain patients show, at the very least, that in the mind, there is a separate... something that can hear and understand and respond, given the right circumstances. Your brain isn't entirely yours.
抛开猜测不谈，分割大脑的患者至少表明，在心灵深处有一个独立的部分，在适当的情况下可以听到、理解并作出回应。你的大脑并不完全属于你。
Who is you? You is two. But we can go deeper. You are many. The pile of meat that's your body is made up of trillions of tiny individuals that have a life of their own.
你是谁？你是两个半球。但我们可以更深入。你有很多个个体。你身体的这堆肉是由数万亿个微小个体组成的，他们各自拥有自己的生命。
So, at which point do the many become one? What makes lots of tiny things you? Click here to go to our channel and watch the next part.
那么，在什么时候，众多的部分会合二为一？是什么让许多微小的个体变成了你？单击此处转到我们的频道，观看下一部分。
Seriously. If you haven't checked out Kurzgesagt, then you don't know what you're missing. Kurgaset? Kurtzgaset? I never know.
说真的，如果你还没有看过Kurzgesagt，那么你就不知道自己错过了什么。Kurtzgaset是什么？我永远不知道。
