Gao Xiaorong, a professor at Tsinghua University: The future of the brain may not be as science-fiction as we think.

In the Silicon Valley narrative, the field of brain-computer interfaces is filled with numerous imaginable visions. The brain is no longer just an anatomical diagram in medical textbooks but the next frontier to be transformed by technology. People are told of a future where the brain is deeply integrated with machines, and memory and consciousness will break through biological limitations.

At the intersection of reality and imagination, brain-computer interface companies such as Neuralink and Synchron are continuously advancing clinical trials of brain-computer interfaces. Neuralink has completed craniotomy implantation in a small number of patients, focusing on restoring motor and language functions lost due to paralysis or neurological diseases, and plans to conduct speech cortex experiments in the fourth quarter of 2025 to decode "intended language." Synchron, on the other hand, enables paralyzed patients to control external devices using brain signals through minimally invasive intravascular implantation. The safety and partial restoration of daily functions have been verified in clinical trials, and these achievements are gradually demonstrating the greater potential of brain-computer interface technology.

Facing the rapid development of technology, the public's attention is drawn between two distinct visions. On the one hand, brain-computer interfaces bring hope for recovery to those who have lost certain functions for various reasons. On the other hand, technology tycoons like Elon Musk have stimulated the public's infinite imagination of a better future through frequent marketing and promotion, such as uploading consciousness and "digitizing the self," which has also raised public concerns. In this atmosphere, as these technologies continue to progress, the boundary between science and science fiction is becoming increasingly blurred.

Currently, how is the actual implementation of brain-computer interface technology progressing? Will the scenario of a human-machine war in the movie "The Matrix" be repeated in the future world? When artificial intelligence becomes the new "intelligent agent" in society, what role will brain-computer interfaces play? Recently, we had an in-depth conversation with Gao Xiaorong, a tenured professor at the School of Medicine of Tsinghua University, focusing on the actual capabilities and boundaries of this technology.

Gao Xiaorong provided a more sober perspective: Brain-computer interfaces are not a shortcut to "superhumanization" but a technological exploration centered on repair and assistance under ethical constraints. "Elon Musk's initial vision tended towards 'superhumanization,' which is ethically unacceptable," he pointed out. "Superhuman" concepts such as uploading consciousness and directly reading brain information through brain chips are still unrealistic fantasies at present.

Gao Xiaorong, Tenured Professor and Doctoral Supervisor at the School of Medicine of Tsinghua University

The following is a transcript of the conversation between Tencent Technology and Professor Gao Xiaorong (slightly edited without changing the original meaning):

Tencent Technology: In recent years, the public has had high expectations and even some fantasies about brain-computer interface technology. Especially with Elon Musk's frequent publicity of the potential of brain-computer interfaces and his company Neuralink, concepts such as uploading consciousness and mind control in the future have further stimulated social imagination. In your opinion, where are the real boundaries of brain-computer interfaces? Is it really possible to achieve things like uploading consciousness?

Gao Xiaorong: In terms of principles and goals, brain-computer interfaces can be roughly divided into two categories. One is repair or replacement, which means using technology to help people return to normal levels when their abilities are below "100%." The other is enhancement, which attempts to break through "100%" and endow humans with superhuman abilities. Using a joking metaphor, it's "turning people into supermen."

The so-called "superhumanization" is ethically unacceptable. If there were technologies that could give humans extraordinary abilities, the question of "who can use them and who is qualified to use them" would bring about great unfairness. Elon Musk's initial vision tended towards "superhumanization," but under ethical constraints, he has now shifted towards clinical applications.

On the other hand, there is also the goal of human-machine collaboration. With the development of AI, in，the future society, there will be both human intelligent agents and artificial intelligent agents. How they communicate is a fundamental issue. If the communication gap cannot be bridged, society may become divided, and brain-computer interfaces are a potential means to fill this gap. It can achieve "making things happen as one wishes," for example, directly transmitting human intentions to machines.

In this sense, brain-computer interfaces also contain elements of "transcending human natural limits," but this is a necessary transcendence - it is not for creating supermen but for ensuring the coexistence of humans and machines. As for "uploading consciousness" or "digital immortality," there is absolutely no possibility of achieving them at present.

In the context of such human-machine coexistence, we must rethink how to maintain a "human-centered" society. Some people propose making machines completely human-like, but this is fundamentally impossible. Because humans only have one life, while machines can be turned on and off at any time - they can never truly understand the uniqueness of human existence, especially the ultimate experience of "death." And many human problems are precisely related to death.

Tencent Technology: Putting aside ethical considerations, from the perspective of neuroscience principles and technology, is it possible to achieve functions such as uploading consciousness and mind control through brain-computer interfaces?

Gao Xiaorong: I don't think it's possible at present. Neuroscience principles also do not support achieving these.

Tencent Technology: Elon Musk also mentioned that brain-computer interfaces can treat schizophrenia or autism. Is this achievable?

Gao Xiaorong: This is possible. The brain has a "reward center," and electrical stimulation can produce hallucinations. If the degree of hallucinations can be precisely controlled, treatment can be achieved. In the past, we mainly relied on drugs for control, and now electrical stimulation provides new possibilities. Cochlear implants and artificial retinas are mature examples. From a higher level, this is scientifically feasible, but it must strictly follow ethical and regulatory requirements.

Tencent Technology: You also mentioned just now that brain-computer interfaces can serve as a medium between humans and machines and even enhance certain human abilities, but this enhancement has limits. To what extent can it be achieved in the future?

Gao Xiaorong: Some limited "external" abilities are feasible. For example, memory enhancement: Alzheimer's patients often cannot immediately recognize acquaintances when they see them. If a brain-computer interface can detect brain activity and prompt "who this is" and "when and where they met," communication will be much smoother.

A similar scenario also applies to healthy people. For example, when someone sees an acquaintance but can't remember their name for a moment, the system can provide an instant reminder. This kind of enhancement can be understood as "external devices": memory external devices, computing external devices, cognitive external devices, and behavior control external devices. They won't turn humans into "supermen," but they can improve efficiency and experience in specific aspects.

Tencent Technology: Based on your research experience, in current clinical trials, which directions have stronger reliability?

Gao Xiaorong: It's probably related to several directions of brain-computer interface applications. First, motor compensation and rehabilitation, such as controlling prosthetics and hand movements. This area has been doing quite well. Examples include Musk's implantation, the research of Professor Hong Bo in China, the North Brain No. 1, and the research of the Shanghai team. Second is the speech function area, such as helping people who can't speak regain their language ability. This is actually also motor enhancement, but it enhances the tongue. In the future, it may expand to cognitive, emotional, and cultural and entertainment scenarios.

From a technical perspective, all aspects such as signal reading, information decoding, and stimulation feedback are improving. Implantable devices can be stably used for one to two years, but there are still challenges in exceeding three years. If the electrodes are placed outside the dura mater of the brain, their lifespan is longer; if they are placed on the scalp, they can be used at any time, but the signal quality is weaker.

Tencent Technology: Is the biggest challenge currently in the hardware level or the software signal processing level?

Gao Xiaorong: It's both. The progress in the past 30 years has mainly relied on materials science - the electrodes are getting smaller and softer, just like the continuous miniaturization of CPUs. But now, there is a new bottleneck: the number of recording channels has increased from hundreds to thousands and may reach tens of thousands in the future. How to analyze such a large amount of data? This requires artificial intelligence.

The progress of AI is much faster than that of materials science. The capabilities of models may double within a hundred days, while the improvement of materials usually only has an increment of one percent per year. Therefore, in the future, the driving force for breakthroughs in brain-computer interfaces will depend more on AI rather than just materials.

Tencent Technology: In the technical path of brain-computer interfaces, there are invasive, semi-invasive, and non-invasive types. Which approach do you think is more promising?

Gao Xiaorong: All three paths are being explored, and it's hard to say which one is better at present. I once proposed a metaphor called the "Brain-Computer Starlink." Twenty years ago, communication between satellites and mobile phones was almost impossible. Now, with the development of satellite launch technology, the number has increased from one to tens of thousands, and the problem of communication coverage has been solved. Similarly, in the future, if there are enough "nodes" in brain-computer interfaces, it may be like the Starlink, achieving seamless connection at all times.

Tencent Technology: Judging from people's feedback, there are more concerns about invasive methods. How do you view the risks here?

Gao Xiaorong: The concerns are reasonable. Non-invasive devices can be removed at any time, and then they will stop reading brain signals. For invasive devices, once implanted, users cannot confirm whether they are still operating continuously, and they are also more likely to face the risk of being attacked.

Tencent Technology: Many people associate brain-computer interfaces with robots. Compared with traditional control methods, what are its improvements?

Gao Xiaorong: The difference is very significant. Traditional control can only make robots perform simple actions, such as "moving forward, backward, and turning." But it doesn't know your real intention. Brain-computer interfaces can directly transmit the purpose. For example, if you "want to eat an apple," the robot will plan the path autonomously and complete the task, rather than waiting for step-by-step instructions. This difference is like navigation. In the past, we had to tell it every step manually, but now we only need to input the destination.

Tencent Technology: Will there be differences in terms of latency or battery life?

Gao Xiaorong: These are technical issues that can be solved through iteration.

Tencent Technology: Currently, the applications of brain-computer chips are mainly concentrated in the medical field. In the future, which other application scenarios might they expand to?

Gao Xiaorong: I'm particularly optimistic about the elderly care field. For example, when the elderly encounter things they don't know how to operate, they can directly put forward their needs, and robots can assist them in completing the tasks. In addition, it also includes sports rehabilitation, cognitive rehabilitation, emotional support, and cultural and entertainment. It should be emphasized that when entering the emotional and entertainment fields, invasive methods are hardly used, and more reliance is placed on non-invasive or wearable solutions.

Tencent Technology: As the global leaders in brain-computer interface research, what are the main differences in the research progress of China and the United States in this field?

Gao Xiaorong: Generally speaking, it's a "parallel race." China is more advanced in non-invasive and semi-invasive research, while the United States is stronger in invasive research.

Tencent Technology: How many years will it take for the technology to mature?

Gao Xiaorong: I initially thought it would take 60 years, and then I changed it to 30 years. Now it seems that the time may be further shortened, and more mature results are expected to appear within 15 to 20 years. However, it must be admitted that the current technology still has obvious limitations. Take implantable devices as an example. Their lifespan is still measured in "years," and the longest case has only lasted for a few years. Musk once claimed that the device could work stably for a year, but in fact, the electrodes partially fall off after three months. This also shows that we still have a long way to go before achieving "lifetime implantation."

This article is from "Tencent Technology," author: Helen. Republished by 36Kr with permission.