A chip implanted in the cerebral cortex would enable paralyzed patients to operate computers and robots with their minds. The era of mind-controlled machines is dawning, but there are always differences between reality and science fiction.
Force of will
Born Matt Nagle in Massachusetts, USA, Nagle was once an average high school student, strong and athletic, and good at football. in 2001, at the age of 20, Nagle was stabbed in the neck when he was involved in a fight on the beach. The stabbing not only ended his athletic career, it took away his mobility completely: his body was completely paralyzed from the neck down due to a severe spinal cord injury.
He was confined to a wheelchair and relied on others for the simplest things. But now things are different: in one particular experiment, he managed to adjust the volume of the TV, switch channels, and then turn to the computer screen to move the cursor to an e-mail. When he opens the e-mail, it contains the reassuring words, "You're doing a great job.
Yes, very well, and Nagle did it all himself, not by hand, although he didn't move his fingers - in fact, he still can't move them - but only his mind. In the area of his cerebral cortex responsible for movement is a tiny chip that records signals of neural activity and transmits them to a special device outside the body. The latter interprets Nagle's wishes from the neural activity, translates them into commands and sends them to a computer or television set.
The chip, called "Brain Gate," was developed by neuroscientist John Donoghue of Brown University in the United States and manufactured by Massachusetts-based Cyberkinetics. The chip is very small, as we can see from the picture, it is much smaller than a one-cent coin. There are 100 electrodes on the chip, 96 of which can be used to record neural signals. Each electrode is 1 millimeter long and arranged in a 10×10 array, with the electrodes 400 microns away from each other.
The chip is placed in the first motor area of Nagle's cerebral cortex, the main area that controls voluntary movement. A 13-centimeter-long wire connects the chip to a titanium base that is anchored to Nagle's skull. The signals recorded by the chip are transmitted through the base to an external device, where they are amplified and decoded into commands. In the image below, Nagle is using his mind to control the cursor on the screen in front of him, trying to move it into the little orange square.
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With the help of the Brain Door, Nagle can also mind-control a robotic hand to open or close, grab a piece of candy and put it to the side, and even pinch a piece of candy with his robotic hand. to the side, and even pinched Donoghue, who was in charge of the study, with his robotic hand.
Interpreting thoughts
This may not seem like much of an achievement compared with the practical need to help paralyzed people regain their mobility, much less the powerful "transformers" that combine the human body with computers in science fiction. However, this achievement is the culmination of decades of neuroscience, computer science and engineering achievements, the chip complexity and system performance are the highest in similar experiments to date. In previous experiments that implanted chips in the brain, people could only use their minds to control a computer cursor to make limited horizontal movements.
Everything we think, think, and do is ultimately rooted in neural activity. The cerebral cortex, full of folds and grooves, is the body's supreme command organ. Nerves in other parts of the body transmit and carry out commands from the brain, and the spinal cord is the pathway between the peripheral nerves and the brain. Many people with paralysis still have good brains and are able to give commands normally, but there is just something wrong with the transmission channel or the final executor. "The goal of BrainGate and similar studies is to bypass the malfunctioning limbs, get direct access to the brain's commands, and use an artificial system to carry them out.
A fundamental difficulty is that brain commands are not as straightforward as "land in Normandy tomorrow", and are harder to decipher than military codes. This isn't because of secrecy or pretense, but because there are tens of billions of nerves in the brain that are constantly active, resting, dying, and being reborn, and we don't know much about this super-complex system. (There's even a philosophical question here: is the human brain sufficiently sophisticated to understand how it works on its own?) Electronic systems, no matter how sophisticated, are ridiculously crude and simple compared to the brain. The way the brain generates and communicates instructions was never designed for a chip or an EEG machine.
Human understanding of the brain is still a drop in the ocean, and we can still pretty much think of it as a complete black box: we can see the results of its calculations, but we don't know how it really works inside. Fortunately, even in a black box, as long as its activities are not disorganized, after enough attempts, one can more or less figure out the rules.
Scientists have been studying the brain activity of monkeys and humans with the help of electronic devices for many years, but much of this basic research was not done to develop brain chips. The earliest electroencephalographs, invented in the 1930s, used electrodes placed on the scalp to pick up electrical signals generated by brain activity. The earliest experiments with mind-controlled machines were done using EEGs, and this is still an important area of research today. However, the signals received by an EEG are the "average result" of billions of brain nerve activities and are relatively vague. If the signals generated by individual nerves could be received directly, the instructions would be interpreted much more finely.
In 1991, German scientists connected the nerves of a live leech to a semiconductor chip, and succeeded in picking up nerve signals with the chip. This type of experimentation has since been extended to mammals, particularly monkeys - after all, it's hard to get valuable references from lab rats in studies of human brain function. The monkeys were trained to perform specific actions while their brain activity was observed, and in a large number of repeated attempts, which nerves sent which signals for which actions were analyzed.
Rapid Response
Everyone's brain operates on the same basic principles, but the specifics are different. So before anyone can use the mind-control machine's system, he or she needs to undergo "initial training" to adapt it to the way his or her brain works. For example, the experimenter thinks in different directions, such as left, right, up, down, etc. The system records the signals corresponding to the different thoughts, summarizes the patterns, and learns to understand the experimenter's thoughts. This process is a bit like learning a new language in a foreign country.
In the Gateway to the Brain experiment, Nagle spent only a few minutes "training" the system, and was soon able to get it to open emails, play simple computer games, and control robots correctly as he intended. While existing EEG systems take weeks or even months to adapt to a particular person, BrainGate is much faster.
The results of the Brain Gate experiments were published in the July 13, 2006 issue of the British journal Nature. The same issue also featured an article by U.S. scientist Gopal Santhanam and others discussing another software approach to interpreting neural signals. While other scientists, including John Donoghue, currently interpret neural activity as the movement of a virtual hand or the trajectory of a computer cursor, Santhanam et al. seek to simplify the problem to speed up the interpretation process.
Their research targeted another region in the monkey's brain, the premotor area, which is involved in making exercise plans. By picking up signals from this region, Santhanam et al. don't pursue the exercise process itself, but instead predict where the exercise is aimed. To use an analogy, while the traditional method analyzes the route, "300 kilometers south, then 100 kilometers west," the new method predicts directly, "Target Luoyang." After trial and error and optimization, the new method is able to extract the correct target location from about 100 neural activities in 250 milliseconds. That's roughly equivalent to processing 6.5 bits of information per second, and a human can type 15 (English) words per second at that rate, which is faster than any existing technology.
If this approach is adapted for use in brain chips, it is expected to further improve the performance of similar devices such as BrainGate. But there are many drawbacks to the implanted chip approach. Performance aside, a technology that involves drilling holes in the brain and stuffing things in it is definitely less appealing than wearing a hat (which is what some of today's electroencephalograms can roughly be seen as), which is why many researchers still favor electroencephalograms, even though they are at a disadvantage when it comes to the accuracy of signal interpretation.
Going under the knife in the head is daunting anyway, with the risk of infection where the wires run, and the question of how long the chip will work reliably. "The external decoding device that BrainGate uses now is too large, and it's inconvenient to have so many things attached to your head. There are still a lot of technical difficulties to overcome before the chip can really be used to improve the quality of life of paralyzed people, many of whom are young.
Some scientists also hope to use brain chips to create new pathways between the brain and motor nerves to help patients regain physical mobility. But this involves some very deep issues (such as proprioception -- why people can close their eyes and know the location of their body parts), faced with more than just technical difficulties, but also need to breakthroughs in basic research.
Sabio: With the idea controller, you can control a robot as long as you use thought in your mind. From then on, humans can live without even moving their fingers.
Big Fatty: Too envious, it's like heaven!
Johnnie: I also want to live on such a planet!
Sabio: ...... really think so? But that's not paradise.
--Machine Cat - Journey to the Labyrinth