下一个前沿：利用思维控制机器

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.

这种解读思维的能力听上去像科幻故事，但克切瓦尔先生使用的“大脑之门”脑机接口证明，思维控制机器是可行的。仅靠解读神经活动，研究人员就能知道一个人听到的话语和看到的图像。信息也能通过编码来刺激大脑。目前已有30多万人植入人工耳蜗，将声音转化为电子信号并发送给大脑，帮助他们听到声音。

As our Technology Quarterly in this issue explains, 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 Neuralix; 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.

正如本期《科技季刊》就该话题所言，脑机接口的研发速度不断加快，雄心规模不断扩大。美军和硅谷都开始专注大脑研究，“脸书”梦想开发出思维转文字系统。创业公司Kernel在神经技术领域已投入1亿美元。埃伦·马斯克创立了“神经联通”公司（Neuralix）；他认为人类要想在未来人工智能时代生存下来，自身必须升级。在企业家畅想的世界里，人类能通过心电感应与他人和机器进行交流，人类有可能获得超能力，例如在极高频率下听到声音。

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.

这些能力需要数十年成为现实，但在此之前，脑机接口可能开启惊人的新用途。试想刺激视觉皮层去帮助盲人，为中风患者重建神经连接，或监测大脑里的抑郁信号。通过将神经元的传递变为可利用的资源，脑机接口对人类的意义可能发生改变。

That thinking feeling

思维感觉

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.

怀疑者对此嗤之以鼻，医学上的脑机接口从实验室走向临床十分困难。克切瓦尔先生使用的“大脑之门”系统是十多年前研发的，但只有少数人试用过。植入装置走向消费品市场，难度更难以想象。脑机接口走向主流面临三大难题：技术、科学、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.

首先说说技术，脑电图（EEG）等非侵入性技术对脑皮层、头骨、脑膜造成干扰，所以难以捕捉大脑里的高清信号。脑电图描记器有所进步，可用于玩虚拟现实游戏，或仅靠思维来控制工业机器人。但就目前而言，最具雄心的用途需要植入装置与神经元进行直接交流。现有设备存在诸多缺点：需要将电线穿过头骨；激起人体免疫反应；仅能与850亿神经元中的数百个进行交流。但这可能很快发生改变，得益于微型化技术的进步和运算能力的提高，科学家正在研发安全无线的植入装置，能与数十万个神经元进行交流。有的植入装置能解读大脑电子信号，有的用于光、磁力、超声波实验。

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.

解决了技术问题，另一问题隐约出现。大脑仍是一个有待探索的领域，科学家对其工作原理知之甚少，尤其是记忆的形成等复杂功能。动物实验比较先进，但人类实验存在困难。但即便现在，科学家对皮层运动区等部位已经有深入了解。完整的知识体系也不是必不可少，机器学习能识别神经活动的各种模式；大脑本身不费吹灰之力便能掌握脑机接口的控制技巧。另外，神经技术将会揭示更多的大脑秘密。

Like a hole in the head

毫无必要

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.

第三个障碍是商业化的现实困境。医学设备通过审批需要时间、资金、专业技术。只有当人们觉得它有实用功能时，消费类用途才能成功。有些脑机接口用途没有必要，例如在无指输入领域，优秀的语音助理比大脑植入装置更为简单。消费者赞同开颅术的观点似乎也不靠谱。但是，大脑植入装置已成为某些疾病的既定治疗手段。约有15万人接受过电极式大脑深层电激疗法，帮助患者控制帕金森病。

Elective surgery can become routine, as laser-eye procedures show.

选择性外科手术可能像眼科激光手术一样变得普及。

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.

这一切表明神经技术先驱们畅想的未来之路充满艰辛，但并非不能实现。但无论有多艰难，当人类用奇思妙想去解决问题时，不看好前景是不明智的。今后几年，技术进步可能开辟人类与大脑交流的新途径。许多最初用途在恢复运动和感官上大有希望，但能力增强无论在军用还是民用领域都将引发许多担忧。隐私明显令人担忧：内心的声音可能无处可藏。另一个是安全担忧：如果大脑能接通互联网，有可能被非法入侵。第三个担忧是不平等：获得超级认知能力可能无人能敌，除非存在永生的精英。机器被植入神经回路会引发身份和代理问题，伦理学家已经着手解决这些问题。

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.

这些问题并非迫在眉睫，但也不是纯粹的幻想。科技改变人类的生活方式，大脑里蕴藏着下一个前沿。