Neurotechnology: The Next Frontier

神经技术：下一个前沿

 

Brain-computer interfaces may change what it means to be human

脑机接口可能会改变对人的定义

 

Technologies are often billed as transformative. For William Kochevar, the term is justified. Mr Kochevar is paralysed below the shoulders after a cycling accident, yet has managed to feed himself by his own hand. This remarkable feat is partly thanks to electrodes, implanted in his right arm, which stimulate muscles. But the real magic lies higher up. Mr Kochevar can control his arm using the power of thought. His intention to move is reflected in neural activity in his motor cortex; these signals are detected by implants in his brain and processed into commands to activate the electrodes in his arms.

 

人们常用“具变革性”来宣传某种技术。对威廉·科切瓦尔（William Kochevar）来说，这个词并无夸张。一次自行车事故后，科切瓦尔自肩部以下瘫痪，但还是能自己用手吃饭。这个非凡的成就部分要归功于植入他右臂用来刺激肌肉的电极，但真正施展魔力的还在更高的部位：科切瓦尔可以用意念控制手臂。他移动手臂的意图反映在他大脑运动皮层的神经活动中，而他大脑中的植入物会探测到这些信号并将之转化成指令，激活他手臂里的电极。

 

An ability to decode thought in this way may sound like science fiction. But brain-computer interfaces (BCIs) like the BrainGate system used by Mr Kochevar provide evidence that mind-control can work. Researchers are able to tell what words and images people have heard and seen from neural activity alone. Information can also be encoded and used to stimulate the brain. Over 300,000 people have cochlear implants, which help them to hear by converting sound into electrical signals and sending them into the brain. Scientists have “injected” data into monkeys’ heads, instructing them to perform actions via electrical pulses.

 

用这种方式解码思想听起来可能像科幻小说。但是像科切瓦尔使用的“脑门”（BrainGate）系统之类的脑机接口证明思维控制的确可以实现。研究人员仅凭人们的神经活动就能知道他们听到了哪些词语、看到了哪些图像。信息还可以经编码用于刺激大脑。超过30万人已经植入了人工耳蜗，这种装置把声音转换成电信号，再将信号传入大脑，帮助人们听到声音。科学家还曾将数据“注射”到猴子的大脑里，通过电脉冲命令它们做出动作。

 

The pace of research into BCIs and the scale of its ambition are increasing. Both America’s armed forces and Silicon Valley are starting to focus on the brain. Facebook dreams of thought-to-text typing. Kernel, a startup, has $100m to spend on neurotechnology. Elon Musk has formed a firm called Neuralink; he thinks that, if humanity is to survive the advent of artificial intelligence, it needs an upgrade. Entrepreneurs envisage a world in which people can communicate telepathically, with each other and with machines, or acquire superhuman abilities, such as hearing at very high frequencies.

 

脑机接口的研究进程正在加快，并且越来越雄心勃勃。美国军方和硅谷都开始关注大脑。Facebook希望能实现“思想转文字”，让大脑直接输出文字。创业公司Kernel获得了一亿美元的融资，用于研发神经技术。伊隆·马斯克成立了一家名为Neuralink的公司，他认为人工智能出现后，人类如果还想生存下去，就需要升级。在企业家们设想的世界中，人们可以通过心灵感应与他人或机器交流，或是获得超人般的能力，比如能听到非常高频的声音。

 

These powers, if they ever materialise, are decades away. But well before then, BCIs could open the door to remarkable new applications. Imagine stimulating the visual cortex to help the blind, forging new neural connections in stroke victims or monitoring the brain for signs of depression. By turning the firing of neurons into a resource to be harnessed, BCIs may change the idea of what it means to be human.

 

这些能力即便真能实现，也要到几十年后。但在那之前，脑机接口或许会打开通往非凡新应用的大门。想象一下，人类或许可以通过刺激视觉皮层来帮助盲人视物，为中风患者建立新的神经连接，或是监控大脑是否有抑郁症的迹象。脑机接口将神经元放电转化为一种可利用的资源，在此过程中或许会改变对人的定义。

 

That thinking feeling

思维的感觉

 

Sceptics scoff. Taking medical BCIs out of the lab into clinical practice has proved very difficult. The BrainGate system used by Mr Kochevar was developed more than ten years ago, but only a handful of people have tried it out. Turning implants into consumer products is even harder to imagine. The path to the mainstream is blocked by three formidable barriers – technological, scientific and commercial.

 

持怀疑态度的人对此嗤之以鼻。事实证明，把医用脑机接口从实验室带到临床实践中就非常困难。科切瓦尔使用的“脑门”系统是十几年前开发的，但试用过的人屈指可数。将植入物变为消费品更加难以想象。脑机接口要成为主流面临三大难以逾越的障碍：技术、科学和商业。

 

Start with technology. Non-invasive techniques like an electroencephalogram (EEG) struggle to pick up high-resolution brain signals through intervening layers of skin, bone and membrane. Some advances are being made – on EEG caps that can be used to play virtual-reality games or control industrial robots using thought alone. But for the time being at least, the most ambitious applications require implants that can interact directly with neurons. And existing devices have lots of drawbacks. They involve wires that pass through the skull; they provoke immune responses; they communicate with only a few hundred of the 85bn neurons in the human brain. But that could soon change. Helped by advances in miniaturisation and increased computing power, efforts are under way to make safe, wireless implants that can communicate with hundreds of thousands of neurons. Some of these interpret the brain’s electrical signals; others experiment with light, magnetism and ultrasound.

 

先说技术。像脑电图（EEG）这样的非侵入性技术很难透过层层皮肤、骨骼和脑膜来提取高分辨率的大脑信号。这项技术有所改进，体现在用来玩虚拟现实游戏和仅靠思想控制工业机器人的脑电图帽上。但至少在目前，那些最具雄心的应用仍需要能与大脑神经元直接交互的植入物。现有的设备也有很多缺点，例如都有穿过头骨的电线，还会引起免疫反应，且只能与人类大脑850亿个神经元中的几百个交流。但这种情况可能很快会改变。随着微型化技术的进步以及计算能力的提高，研究人员正在努力制造安全、无线且能与几十万个神经元交流的植入物。它们当中有些解读大脑的电信号，另一些则尝试利用光、磁和超声波信号。

 

Clear the technological barrier, and another one looms. The brain is still a foreign country. Scientists know little about how exactly it works, especially when it comes to complex functions like memory formation. Research is more advanced in animals, but experiments on humans are hard. Yet, even today, some parts of the brain, like the motor cortex, are better understood. Nor is complete knowledge always needed. Machine learning can recognise patterns of neural activity; the brain itself gets the hang of controlling BCIS with extraordinary ease. And neurotechnology will reveal more of the brain’s secrets.

 

攻破了技术壁垒，还要面对另一个障碍。大脑仍然是个非常陌生的领域。科学家们对于它的确切工作原理知之甚少，如果涉及记忆形成这样的复杂功能就更是如此。在动物身上的研究进展更快，但在人体上试验却很困难。不过即便是目前，我们还是加深了对大脑某些部分的了解，如运动皮质。而且这方面的知识并不总要面面俱到。机器学习可以识别神经活动的模式；大脑自己也能游刃有余地控制脑机接口。神经技术还将揭示更多大脑的秘密。

 

Like a hole in the head

就像开“脑”洞

 

The third obstacle comprises the practical barriers to commercialisation. It takes time, money and expertise to get medical devices approved. And consumer applications will take off only if they perform a function people find useful. Some of the applications for brain-computer interfaces are unnecessary – a good voice-assistant is a simpler way to type without fingers than a brain implant, for example. The idea of consumers clamouring for craniotomies also seems far-fetched. Yet brain implants are already an established treatment for some conditions. Around 150,000 people receive deep-brain stimulation via electrodes to help them control Parkinson’s disease. Elective surgery can become routine, as laser-eye procedures show.

 

第三个障碍是难以实现商业化。医疗设备获批需要时间、资金和专业知识。而消费应用只有具备对人们有用的功能时才能大行其道。有些脑机接口的应用并无必要，比如，要想不动手指就能打字，使用好的语音助手比使用大脑植入物更便捷。认为消费者会哭着喊着要做开颅手术的想法似乎也很离谱。但是在某些情况下，大脑植入物已经是一种成熟的治疗手段。大约有15万人通过电极接受深脑刺激，帮助自己控制帕金森氏症。激光眼科手术也已证明选择性手术可以成为常规手术。

 

All of which suggests that a route to the future imagined by the neurotech pioneers is arduous but achievable. When human ingenuity is applied to a problem, however hard, it is unwise to bet against it. Within a few years, improved technologies may be opening up new channels of communications with the brain. Many of the first applications hold out unambiguous promise – of movement and senses restored. But as uses move to the augmentation of abilities, whether for military purposes or among consumers, a host of concerns will arise. Privacy is an obvious one: the refuge of an inner voice may disappear. Security is another: if a brain can be reached on the internet, it can also be hacked. Inequality is a third: access to superhuman cognitive abilities could be beyond all except a self-perpetuating elite. Ethicists are already starting to grapple with questions of identity and agency that arise when a machine is in the neural loop.

 

所有这些都表明，要抵达神经技术先锋们设想的未来，道路虽艰辛，但仍可实现。无论一个问题有多难，一旦人类发挥创造力，赌它无法被攻克就是不明智的。随着技术进步，也许在几年内人们就会开启与大脑沟通的新渠道。很多最先投入应用的脑机接口都是为了实现非常明确的效果：恢复运动和感知能力。但随着应用转向增强人体能力——无论是用于军事目的还是消费活动，就会产生种种担忧。隐私是一个突出的问题：内心声音的庇护所可能会消失。另一个问题是安全：如果能够通过互联网连接上大脑，那么它也可能被黑客攻击。还有第三个问题：不平等。除了自我永续的精英，也许再无人能承担得起获得超人般的认知能力。伦理学家已经开始为机器被引入神经回路所引发的身份认同和主体性问题挠头。

 

These questions are not urgent. But the bigger story is that neither are they the realm of pure fantasy. Technology changes the way people live. Beneath the skull lies the next frontier.

 

这些问题并不紧迫。但更重要的一点是，它们都不属于纯粹幻想。科技改变人类的生存方式。头骨之下是下一个前沿。

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