文｜AlphaEngineer，作者｜费斌杰
In the summer of 2016, Musk founded Neuralink in California, United States, focusing on invasive brain-computer interfaces.
If SpaceX and Tesla are Musk's ambitions to change the world, then what Neuralink is doing is changing humanity itself.
After years of development, brain-computer interface technology has become more and more mature. In January of this year, Neuralink performed its first human surgical implantation, which allowed the subjects to achieve "telepathy", and the results were amazing, and 10 surgeries are expected to be performed this year.
However, for such an important technological revolution, research data is lackluster.
Just last week, Musk took 4 senior executives of Neuralink to conduct a live broadcast, summarizing the latest technical progress and development blueprint of Neuralink, which is breathtaking.
This research material is very valuable, and I will explain the essence of it to you.
I believe that after reading this article, you will have a new understanding of the technical status of brain-computer interface and the future of human-computer symbiosis.
As a friendly reminder, please always be aware as you read this article: this is the cutting-edge technology of reality, not science fiction.
Neuralink的首款产品：Telepathy（心灵感应）
The Slyphids
Telepathy works by allowing people with Neuralink devices to directly control their phones or computers with their minds.
You know, once you're able to control your phone and computer, basically you can control anything.
The overall interaction process only needs to be thought by the brain, and there is no eye tracking device involved.
This product can help many people with brain injuries or spinal cord injuries by allowing them to reconnect their brains with their bodies.
Noland, the first subject of Neuralink, showed himself the whole process of playing Civilization 6 through Telepathy through a live broadcast after the operation.
Through Telepathy, the paralyzed Noland regains digital independence, allowing him to control a computer using his mind alone, without the need to move his body or his family.
Interestingly, Noland can use Telepathy at any time and anywhere, even during aircraft flights.
In the image below, Noland is using Telepathy to create a cat meme at 30,000 feet.
The Neuralink team tracked Noland's use of Telepathy after surgery, basically spending more than 70 hours a week watching videos, reading books, playing games, using browsers, etc.
If we think of the "bed" as a product, we use the "bed" for a total of about 56 hours per week (7 days a week× 8 hours a day).
Noland's weekly use of Telepathy far exceeds the use of "beds", which is enough to prove the value of Telepathy's products.
Not only to help you regain your physical functions, but to give you superpowers
Neuralink's goal is not just to help paralyzed patients regain their previous neurological functions, but to give them superpowers that far surpass those of normal humans.
If you think of the human brain as a biological computer, the communication bandwidth between the brain and external devices is very low, usually only 1 bit per second.
There are 86,400 seconds in a day, which means that you will input fewer bits to any one device each day.
The communication bandwidth between the brain and external devices will become an important bottleneck hindering the symbiosis between humans and machines. Brain-computer interfaces can break through this bottleneck.
By implanting a device in the brain, Neuralink is currently able to achieve a communication speed of 10 bits per second, and the goal in the future is to reach the megabit level.
Musk believes that when the whole brain interface is realized, the external communication bandwidth of the human brain may be increased to the Gigabit level.
The current Noland implant is the original version of the product, with 64 threads with 16 electrodes on each thread.
After a period of training, Noland was able to beat the previous human world record of 9.5 BPS in the cursor-controlled test.
The next generation of Telepathy devices will have only 8 electrodes per thread and 3000 channels.
When we are able to place each electrode wire precisely, the number of electrodes needed on each wire can be reduced.
In other words, the bandwidth of the device can be easily doubled by placing the electrode wires more precisely.
Musk believes that it won't be long before patients using Neuralink devices will be able to communicate at a faster rate than able-functioning humans.
In the future, there may be players in esports who use brain-computer interfaces.
How it works: Reading and writing to neurons in the brain through implanted devices
Neuralink's implanted devices are capable of reading and writing electrical signals to the brain.
The brain is a mysterious organ, but at the end of the day, it operates through electrical signals.
So, as long as you can read and write these electrical signals, you can interact with the brain.
In order to implant these tiny electrode wires in the patient's brain, a small piece of the skull, almost a few centimeters in diameter, is removed by a surgical robot and then replaced with an implanted device.
In this way, neurons have the ability to read and write electrical signals.
The implanted device is completely wireless and communicates via Bluetooth.
Bluetooth was chosen because almost every electronic device has Bluetooth communication, which allows Neuralink to interact with almost any device.
In the future, Neuralink will design its own unique communication protocol to ensure that data transmission is truly secure and reliable.
The implanted device can be inductively charged via an electromagnetic pad.
The current version implanted in Noland's body can be used for 4-5 hours on a single charge, and the charging time is about a few minutes.
The next version will double the duration of use without increasing the charging time, to almost 8 hours at a time.
Neuralink's goal is to truly enable all-day use, with inductive charging in the sleeve or pillow.
Theoretical Basis of Brain-Computer Interface: Precise Partitioning of Brain Functions
The brain is a highly differentiated organ, and you can know exactly which part of the brain is controlling your left hand, right hand, left leg, right leg, and which part is controlling your sight, hearing, and smell.
The neuronal position corresponding to each specific function is highly precise, not obscure.
We all know that the left side of the brain controls the right side of the body and vice versa.
So if you're left-handed, the implanted device should be on the right side of your brain.
To determine the exact location of the hole in the patient's skull, Neuralink's doctors will have the patient do an fMRI.
During imaging, doctors ask paralyzed patients to imagine moving their arms.
Even if a patient can't actually move their arm because of a spinal cord injury, simply imagining moving the arm causes a specific area of the brain to light up in the fMRI scanner, and the location of this neuron is very precise.
So is it possible to achieve telepathy without the need for an implanted device and just a hood on the outside of the head?
Musk thinks the answer is no.
In order for a sensor to obtain accurate neuronal data, it needs to be as close as possible to the source of the signal.
If the sensor is only placed outside the body, it will obtain data on the population response, and it will not be able to make accurate judgments.
Musk gave an example of a factory, which is relatively easy to understand:
If you want to figure out what's going on in the factory, you need to go inside the factory and see it, not put a stethoscope on the outside wall.
The culprit behind the detachment of the implanted device: air pockets
As the first subject of Neuralink, Noland's post-operative performance deserves great attention.
After a few weeks of use, Noland noticed that the cursor's accuracy had dropped and even experienced delays.
After the Neuralink team examined it, they found that 85% of the electrode wires on the implanted device had been displaced, resulting in a significant reduction in the brain signals collected by the device.
Matthew, a neurosurgeon at Neuralink, summed up his experience and concluded that the main culprit for the dislodgement of the implanted device was the air pocket introduced during the craniotomy.
During Noland's implantation procedure, a small amount of air entered the skull to form air pockets. When the air pockets move underneath the implant, they push the implant away from the brain.
Therefore, how to avoid cavitation during surgery is a key issue.
In a typical brain surgery, the surgeon introduces a small amount of air into the skull.
By adjusting the concentration of carbon dioxide in the blood, you can cause a slight expansion or contraction in a specific part of the brain.
Typically, neurosurgeons shrink the brain by lowering the concentration of carbon dioxide in the blood, which gives them more room to operate and avoid damaging brain tissue.
But in future surgeries, Matthew believes that carbon dioxide concentrations should be kept normal or slightly higher so that the patient's brain remains at normal size and shape during surgery, so that the introduction of air pockets can be avoided.
The future of plant equipment: finer, deeper, more precise, and smoother
Finer:
The electrode wires implanted in the human brain are so small that they are only a fraction of the diameter of a human hair.
The reason why the electrode wires are made very small is because our brain is moving all the time, and in order to avoid scarring, it is best to let the electrode wires move together with the brain.
Electrode-implanted surgeries are performed by surgical robots with micron-level precision, surpassing that of any of the world's top surgeons, so that all blood vessels can be avoided and the body's immune response can be avoided.
During Noland's implant surgery, when the surgical robot implanted all the electrodes into his body, not a single drop of blood was seen on the surface of the brain.
Deeper:
Compared to the brains of other animals, human brains are larger and move more violently.
When the patient's skull was opened, the Nueralink team found that the human brain could move up to 3 millimeters as the heart beat and breathed normally, which posed a challenge to keep the implant stable.
The best solution is to insert the electrode wires deeper and control the precise insertion depth of each electrode wire.
More precise:
Anatomically, the brain resembles a folded onion, made up of layers of neurons that cover the surface of the brain and form folds.
The electrodes of the implanted device should be as close as possible to the neurons that encode useful information.
If the electrodes are inserted particularly close to a fold, it may avoid other useful neurons altogether.
Therefore, Matthew believes that in future surgeries, electrodes should be inserted between the vertices of the folds and made sure that they pass through the fifth layer of the cortex.
Flattering:
Another measure to reduce the risk of implantation is to bring the implant flush with the inner contour of the skull.
The device implanted in the first subject, Noland, had a certain gap between the base and the brain, resulting in a non-smooth and flat inside of the skull.
For future implant surgeries, the Neuralink team plans to sculpt the implant surface so that it aligns with the contour of the patient's medial skull surface to minimize the gap between the two.
This effectively reduces the tension on the electrode wires and allows these thin wires to relax as much as possible, so that they do not shrink and detach from the brain.
Musk believes that in the future, Neuralink device implantation surgery will be 100% automated, just like LASIK eye surgery.
If an ophthalmologist has a laser cutter in his hand and trembles to perform vision correction surgery on your eyes, it would be terrible.
The same is true for Neuralink device implantation surgery, which requires a high degree of precision and can only be performed by robots.
The doctor only needs to supervise the surgical robot to make sure that it is set up correctly.
All you have to do is sit down, select the module you want to implant, and the surgical robot will do it all in 10 minutes, just like a prosthetic in a Cyberpunk game.
The next big product: Blindsight
After Telepathy, Neuralink is preparing to launch a second product called Blindsight.
As the name suggests, Blindsight's role is to restore sight to patients who are completely blind, even those who have lost both eyeballs.
This sci-fi-sounding feature has been successfully tested in animals, including monkeys.
In order for visual information to be presented in the user's brain, electrical impulses are sent to the neurons in the visual part of the brain, which activates a visual pixel in their brain.
You can send electrical impulses to specific neurons in the monkey's brain, and the monkey receives a visual signal and will see a flashing pixel, and you will notice that the monkey's eyes quickly turn to the position of the pixel.
Note that here there are no pixels on the screen, which are directly activated by the visual cortex in the monkey's brain.
At the moment, Blindsight's resolution is relatively low, and it can only render graphics similar to those of Atari games.
But over time, it may achieve a higher resolution than normal vision, allowing blind people to have "eagle eyes".
Neuralink and Optimus combined: a mechanical prosthetic is expected to become a reality
Currently, Neuralink can communicate with any device with a Bluetooth interface, including Musk's own Optimus Prime humanoid robot.
If a person loses the ability to speak, they can still communicate telepathically with Optimus through Neuralink.
What's even cooler is that you can directly control the physical arm of the Optimus robot to perform various actions by directly mapping brain signals.
At this point, Optimus is your robot clone.
If someone loses an arm or thigh, you can simply use the Optimus hand/leg part and connect it with Neuralink to form your own prosthetic.
In this way, the movement instructions in your brain that would have been transmitted to the biological arm can now be transmitted to your robotic arm, and the experience of using the prosthetic leg will be very natural.
In fact, brain signals may be transmitted to a robotic arm faster than to your biological arm.
Imagine a pianist playing with both a robotic left arm and a biological right arm, and the movements of the robotic left arm may be more sensitive.
Neuralink's next goal is to help paralyzed patients recover and treat mental illness
Paralysis is, essentially, a communication problem.
The motor cortex of the brain sends signals, and the corresponding body trunk receives the signals and makes specific actions.
In people with paralysis, there is a nerve damage in the neck or spine that hinders the transmission of nerve signals.
If we can bridge the electrical signals from the motor cortex of the brain directly over the point of nerve damage, we can essentially solve the problem of paralysis and restore all body functions.
This is a difficult technical problem, but it is achievable from a physical point of view, and requires more experimental data and experience.
At present, Neuralink has completed only one human trial, and it is expected to complete 5-10 human trials this year.
Musk hopes to have thousands of subjects benefit from it in the coming years.
In addition to the problem of paralysis, Neuralink is expected to treat a variety of serious mental illnesses in the future.
Musk believes that mental illness is just a malfunction of the biological computer of the brain, and it is a fault that can be repaired, just like repairing a circuit that has been short-circuited.
In the future, Neuralink is expected to help patients with severe mental illness lead normal lives.
As we get older, our memory deteriorates, and sometimes your grandparents forget who you are and what day of the week it is. Neuralink is also expected to make a breakthrough in this area.
Paradigm Shift in I/O Design: From "Hand" to "Brain"
Almost all current input devices are designed with the human "hand" around it, and Musk refers to the finger as a "small meat stick that can move".
WE USE THESE "LITTLE MEAT STICKS" TO MANIPULATE INTERACTIVE DEVICES SUCH AS MICE, KEYBOARDS, AND XBOX GAMEPADS.
If you can telepathically transmit signals, you can get rid of the dependence on "hands", and these traditional control mechanisms will be revolutionized.
In the future, one can even convey an abstract concept to others telepathically, ensuring 100% lossless communication.
This kind of communication efficiency is incomparable with the means of communication such as language and writing.
The future of symbiosis between humans and AI
The current understanding of the brain is still very rudimentary.
Musk believes that as more human experiments advance, the Neuralink team's understanding of the brain will rapidly deepen.
Before the advent of brain-computer interfaces, people could only study cortical signals through fMRI, which was obviously not enough.
By implanting electrodes in the brain, researchers were able to dramatically improve their understanding of the brain.
Neuralink is significantly undervalued as a research tool that is pushing people to solve the puzzles of the brain and understand the physical nature of human consciousness.
Finally, let's take a look at Musk's definition of Neuralink's short-term, medium-term, and long-term goals and visions:
Short-term goal: to help patients with brain injury, spinal cord injury, and mental illness re-establish the correct connection between the brain and the body.
Medium-term goal: to achieve high-bandwidth connectivity between the human brain and the outside world.
Long-term goal: to reduce the risk of AI to humans by promoting a closer symbiotic relationship between humans and AI.
It's not science fiction, it's a rolling reality.