【TED演讲220】大脑如何幻想出你意识到的现实！
Right now, billions of neurons in your brain are working together to generate a conscious experience -- and not just any conscious experience, your experience of the world around you and of yourself within it. How does this happen? According to neuroscientist Anil Seth, we're all hallucinating all the time; when we agree about our hallucinations, we call it "reality." Join Seth for a delightfully disorienting talk that may leave you questioning the very nature of your existence.
此时此刻，你脑袋中的数十亿个神经元正联手产生意识体验──不是任意的意识，而是一个你置身周遭世界中的意识经验。这过程是如何发生的？神经学家Seth认为，我们时时刻刻处在幻觉里，而被大家共同认可和接受的幻觉却成了「现实」。
演讲者：Anil Seth
演说题目：大脑如何幻想出你意识到的现实
Just over a year ago, for the third time in my life, I ceased to exist. I was having a small operation, and my brain was filling with anesthetic. I remember a sense of detachment and falling apart and a coldness.
就在一年之前，我陷入了人生的第三次休克。当时我正经历一个小手术，我的大脑里满是麻醉剂。我记得，我感到了超脱与分离，还有寒冷的感觉。
How does consciousness happen? Somehow, within each of our brains, the combined activity of many billions of neurons, each one a tiny biological machine, is generating a conscious experience. And not just any conscious experience -- your conscious experience right here and right now. How does this happen?
意识是如何形成的？在每个人的大脑中，有数十亿的神经元以某种方式联合作用，每个小小的神经元都是生物机器，它们创造了每一段意识体验。而且这并不是任意的意识体验，而恰好是你此时此地的意识体验。这是如何发生的？
Answering this question is so important because consciousness for each of us is all there is. Without it there's no world, there's no self, there's nothing at all. And when we suffer, we suffer consciously whether it's through mental illness or pain.
这个问题的答案很重要，因为我们每个人都有意识，没有意识，就没有世界，没有自我，没有一切。当我们经受苦难时，也是有意识地经历着，无论是心理还是身体上的痛苦。
And if we can experience joy and suffering, what about other animals? Might they be conscious, too? Do they also have a sense of self? And as computers get faster and smarter, maybe there will come a point, maybe not too far away, when my iPhone develops a sense of its own existence.
如果我们可以感到快乐和痛苦，其它的动物呢？它们是否也有意识？是否也有自我的认知？而且现在电脑的运转越来越迅速，越来越智能，也许突然之间，也许就在不久的将来，我的 iPhone 会意识到它自己的存在。
I actually think the prospects for a conscious AI are pretty remote. And I think this because my research is telling me that consciousness has less to do with pure intelligence and more to do with our nature as living and breathing organisms. Consciousness and intelligence are very different things. You don't have to be smart to suffer, but you probably do have to be alive.
事实上，我认为距离有意识的人工智能出现还是很遥远的。因为我的研究告诉我，意识不单单是智力的表现，而是更多的有关于我们的本性，作为活着、能呼吸的有机体。意识和智力差别是很大的。就算你不聪明你也会感到痛苦，但前提是你得活着。
In the story I'm going to tell you, our conscious experiences of the world around us, and of ourselves within it, are kinds of controlled hallucinations that happen with, through and because of our living bodies.
在接下来我要讲给你们的故事中，我们对周围世界的意识体验，以及我们自己的存在，都是被控制的错觉，都源自我们的生命体。
But people no longer think that. As biologists got on with the job of explaining the properties of living systems in terms of physics and chemistry -- things like metabolism, reproduction, homeostasis -- the basic mystery of what life is started to fade away, and people didn't propose any more magical solutions, like a force of life or an élan vital.
但现在人们不再这样想了。随着生物学家的研究推进，用物理、化学原理解释生物系统的特性像是新陈代谢，繁衍后代，体内平衡这些——生命的神秘感渐渐消退，人们也不再给出神奇的解释，比如这是生命的力量，生命的热忱之类的。
So as with life, so with consciousness. Once we start explaining its properties in terms of things happening inside brains and bodies, the apparently insoluble mystery of what consciousness is should start to fade away. At least that's the plan.
所以意识其实和生命一样。一旦我们试着解释它的特性，就大脑和身体内部发生的事情而言，什么是意识的不解之谜 就会变得了无生趣。我们计划就是这样的。
So let's get started. What are the properties of consciousness? What should a science of consciousness try to explain? Well, for today I'd just like to think of consciousness in two different ways. There are experiences of the world around us, full of sights, sounds and smells, there's multisensory, panoramic, 3D, fully immersive inner movie.
那么咱们开始。意识的特性是什么？意识科学需要解释什么？那么今天，我想把意识分为两类讨论。一类是我们对于外界的认知，包括影像、声音、气味，这是多感官的、全景的、3D的、身临其境的内心电影。
So perception -- figuring out what's there -- has to be a process of informed guesswork in which the brain combines these sensory signals with its prior expectations or beliefs about the way the world is to form its best guess of what caused those signals. The brain doesn't hear sound or see light. What we perceive is its best guess of what's out there in the world.
所以说感知——或者说搞明白那是什么是一个“已知”的猜测过程。大脑将这些感觉信号与之前对世界的预期或信念相结合，做出是什么产生了这些信号的最佳猜想。大脑是看不见也听不见的。我们所感知到的是它对外界事物的最佳猜测。
Let me give you a couple of examples of all this. You might have seen this illusion before, but I'd like you to think about it in a new way. If you look at those two patches, A and B, they should look to you to be very different shades of gray, right? But they are in fact exactly the same shade. And I can illustrate this.
我举些例子说明一下吧。你之前可能有过这样的错觉，但我希望你能重新思考一下。 当你看这两块区域时，A和B，它们是深浅不同的灰色，对吧？但实际上它们颜色是一样的。我能解释这一现象。
If I put up a second version of the image here and join the two patches with a gray-colored bar, you can see there's no difference. It's exactly the same shade of gray. And if you still don't believe me, I'll bring the bar across and join them up. It's a single colored block of gray, there's no difference at all. This isn't any kind of magic trick.
如果我再在这儿加上第二版图像用灰条连接这两块区域，你会发现，它们毫无差别。它们的灰度完全一样。如果你还不相信我，我把灰条移走，把它们重合在一起。它们是一样的灰度，完全相同。这不是什么魔术。
OK, so what's going on here? The remarkable thing is the sensory information coming into the brain hasn't changed at all. All that's changed is your brain's best guess of the causes of that sensory information. And that changes what you consciously hear.
所以到底是怎么回事？值得注意的是进入大脑的感受信息完全没有改变。变了的，只是你脑中的猜测，对感受信息的猜测。而这改变了你下意识所听到的东西。
All this puts the brain basis of perception in a bit of a different light. Instead of perception depending largely on signals coming into the brain from the outside world, it depends as much, if not more, on perceptual predictions flowing in the opposite direction. We don't just passively perceive the world, we actively generate it. The world we experience comes as much, if not more, from the inside out as from the outside in.
这些使大脑的感知基础处于不同的亮度中。感知并不单纯取决于外界传入脑中的信号，而是更多地取决于反向流动的感知预测。我们并非被动地感受着世界，相反，我们积极地创造着一切。我们对于世界的意识体验既是由内而外的，也是由外到内的。
Let me give you one more example of perception as this active, constructive process. Here we've combined immersive virtual reality with image processing to simulate the effects of overly strong perceptual predictions on experience. In this panoramic video, we've transformed the world -- which is in this case Sussex campus -- into a psychedelic playground.
我再举一个感知的例子，这是一个积极的，有建设性的过程。我们将沉浸式虚拟现实与图像处理结合起来，模拟我们体验中相当强烈的 感知预测。在这段全景影像中，我们重塑了世界——我们把苏塞克斯校园变为一个迷幻的游乐场。
We've processed the footage using an algorithm based on Google's Deep Dream to simulate the effects of overly strong perceptual predictions. In this case, to see dogs. And you can see this is a very strange thing. When perceptual predictions are too strong, as they are here, the result looks very much like the kinds of hallucinations people might report in altered states, or perhaps even in psychosis.
我们用谷歌的“深层梦想”的算法处理了这段视频，来模拟我们在相当强烈的感知预测下的真实体验。在这种情况下，我们看到了狗狗。你可以看到这些很奇怪。当感知预测太过强烈，正如这一案例中，画面看起来就像是幻觉。人们看起来像是变形的状态，甚至像患有精神病一样。
But we shouldn't take it for granted. There are in fact many different ways we experience being a self. There's the experience of having a body and of being a body. There are experiences of perceiving the world from a first person point of view.
但我们不应视之为理所当然。有很多方式可以体验自我。我们可以体验拥有一个身体 掌控这个身体。 我们可以体验以第一视角来认知这个世界。
There are experiences of intending to do things and of being the cause of things that happen in the world. And there are experiences of being a continuous and distinctive person over time, built from a rich set of memories and social interactions.
我们可以体验试着去做某事或是成为世上发生的事情的缘由。我们还可以体验随着时间流逝，基于丰富的记忆及社会相互作用我们仍是一个与众不同的人。
Many experiments show, and psychiatrists and neurologists know very well, that these different ways in which we experience being a self can all come apart. What this means is the basic background experience of being a unified self is a rather fragile construction of the brain. Another experience, which just like all others, requires explanation.
许多实验表明，精神病学家和神经学家其实非常了解我们体验自我的这些不同的方式是相互独立的。这意味着对于大脑而言，成为一个统一的自我的体验是很脆弱的。另一个与之相似的体验需要进一步解释。
So let's return to the bodily self. How does the brain generate the experience of being a body and of having a body? Well, just the same principles apply. The brain makes its best guess about what is and what is not part of its body. And there's a beautiful experiment in neuroscience to illustrate this. And unlike most neuroscience experiments, this is one you can do at home. All you need is one of these. And a couple of paintbrushes.
让我们先回到身体本身。大脑是如何产生成为一个身体的体验的？或者说拥有一个身体？之前的原理同样适用。大脑做出了它的最佳推测，关于哪一部分属于身体，哪一部分不属于。神经科学里有一个很棒的实验可以说明这一点。与大多数神经科学试验不同，这一试验你在家里就可以进行。你只需要这个。再准备一些画笔。
There's one more thing. We don't just experience our bodies as objects in the world from the outside, we also experience them from within. We all experience the sense of being a body from the inside. And sensory signals coming from the inside of the body are continually telling the brain about the state of the internal organs,
还有一点。我们不只是单纯地从外界认知我们的身体，我们也从本身来感受。我们都从本身去感知、体验过身体。这些感觉信号都由身体自身产生，它们不断向大脑汇报身体内器官的状况，
how the heart is doing, what the blood pressure is like, lots of things. This kind of perception, which we call interoception, is rather overlooked. But it's critically important because perception and regulation of the internal state of the body -- well, that's what keeps us alive.
比如心脏是如何跳动的，血压是怎样的，等等。这一类型的感知我们称之为“内感”，常常被我们忽视，但它们却异常重要。因为对于体内状况的感知和规律的了解是使我们活着的条件。
Here's another version of the rubber hand illusion. This is from our lab at Sussex. And here, people see a virtual reality version of their hand, which flashes red and back either in time or out of time with their heartbeat. And when it's flashing in time with their heartbeat, people have a stronger sense that it's in fact part of their body. So experiences of having a body are deeply grounded in perceiving our bodies from within.
还有另一种橡胶手错觉。这是我们苏塞克斯大学实验室的试验。人们看着他们虚拟现实中的手，闪烁着红色，闪烁频率和心率一致或是不同。当闪烁频率和心率一致时，人们会强烈地感到这是他们身体的一部分。所以当我们从内感知我们的身体时可以强烈地感到拥有一个身体。
it's about control and regulation -- keeping the physiological variables within the tight bounds that are compatible with survival. When the brain uses predictions to figure out what's there, we perceive objects as the causes of sensations. When the brain uses predictions to control and regulate things, we experience how well or how badly that control is going.
而是控制和调节——将生理参数保持在与生存相适应的范围内。当大脑用预测判断那是什么的时候，我们感觉物体就是感觉的起因。当大脑用预测控制和调节事物时，我们可以感知到控制的好与坏。
So our most basic experiences of being a self, of being an embodied organism, are deeply grounded in the biological mechanisms that keep us alive. And when we follow this idea all the way through, we can start to see that all of our conscious experiences, since they all depend on the same mechanisms of predictive perception, all stem from this basic drive to stay alive. We experience the world and ourselves with, through and because of our living bodies.
所以我们最基本的自我体验，作为一个具体的有机体的体验，深深扎根于维持我们生存的生物机制中。当我们一路追寻个中原理，我们会发现我们所有的意识体验，都依赖于相同的预测感知机制，因为这一基本的驱动力我们才能活着。通过活着，也正是因为活着我们才能感受世界和我们自己。
Let me bring things together step-by-step. What we consciously see depends on the brain's best guess of what's out there. Our experienced world comes from the inside out, not just the outside in. The rubber hand illusion shows that this applies to our experiences of what is and what is not our body.
让我们一步一步来分析一下。我们有意识看到的东西是基于大脑对外界事物的最佳猜测。我们对世界的体验也会由内而外产生，并不只是由外到内的。橡胶手错觉表明这适用于我们对什么是以及什么不是我们自己身体的体验。
And these self-related predictions depend critically on sensory signals coming from deep inside the body. And finally, experiences of being an embodied self are more about control and regulation than figuring out what's there.
这些与自我相关的预测主要依赖于来自身体深处的感官信号。最后，作为一个具体化的自我的体验，更多的是关于控制和调节，而不是去弄清楚到底是什么。
Finally, our own individual inner universe, our way of being conscious, is just one possible way of being conscious. And even human consciousness generally -- it's just a tiny region in a vast space of possible consciousnesses. Our individual self and worlds are unique to each of us, but they're all grounded in biological mechanisms shared with many other living creatures.
最后，我们内在的小宇宙，我们人类存在意识的方式，只是存在意识的其中一种方式。即使人们普遍都存在意识，在有意识的广阔空间里，它也只是一个很小的区域。自我和世界对我们每个人而言都是独一无二的，但它们都以生物机制为基础，所以同样也适用于其它生物体。
Now, these are fundamental changes in how we understand ourselves, but I think they should be celebrated, because as so often in science, from Copernicus -- we're not at the center of the universe -- to Darwin -- we're related to all other creatures -- to the present day.
如今，我们对于“如何理解自我”有了根本性的改变，我想这是值得庆祝的事情，因为科学界经常引用哥白尼的一句话：我们不是宇宙的中心。达尔文也说过：万物皆相关，直至今日。
With a greater sense of understanding comes a greater sense of wonder, and a greater realization that we are part of and not apart from the rest of nature. And ... when the end of consciousness comes, there's nothing to be afraid of. Nothing at all. Thank you.
我们有更强的理解力，更大的惊奇感，更好的认知力，我们知道我们属于自然界的一部分，密不可分。而且······当我们失去意识时，也无需害怕些什么。根本没什么。谢谢。
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