Why Elon Musk’s brain transplant is still a long way from making a robot

From our US correspondent,

Control your smartphone or computer by thinking. Restore primitive vision after losing it. Walking again despite spinal cord injury. Increased intelligence or memory. These are some of Elon Musk’s promises Brain transplant from its inception NeuralinkWhich got the green light from the US medical authorities to start The first human clinical trials.

Science or science fiction? 20 minutes evaluates the capabilities of this type of direct neural interface (Brain computer interfaceor BCI, in English) that scientists have been working on for decades.

How does the Neuralink brain implant work?

A robotic surgeon cuts out a small section of the skull of a monkey or a pig

Yet – to insert a smartwatch-sized implant (four stacked 2 euro coins). Then, like a super-sewing machine, it implants 64 elastic threads, thinner than a hair, onto the surface of the brain. Covered with 16 electrodes (1024 in total), these threads are capable of decoding nerve signals or stimulating specific areas of the brain.

The operation takes less than an hour and without general anesthesia. The implant, which communicates via Bluetooth with a computer, is recharged wirelessly by induction. explains neuroscientist Bradley Greger, a research professor at Arizona State University, who has been working for years to restore vision in part by direct stimulation of the visual cortex. According to him, these flexible electrodes, rather than rigid ones like most of those currently used, are the key to implants that can be kept for life.

Implants have been routinely used for thirty years in deep brain stimulation, the scientist recalls, in order to reduce tremors in Parkinson’s patients, with “a very low rate of surgical complications.” Cochlear implants actually stimulate the auditory nerve.

Is computer control a new thought? Two years ago, Neuralink released a video of Pager, a 9-year-old monkey playing Pong through sheer force of thought. Humans were already able to move a slider or control a robotic arm to drink from straws, Greger recallsmore than fifteen years ago

. For the researcher, “Neuralink is moving from a laboratory proof-of-concept to a consumer medical device.” Which could be life-altering for people with neurological movement disorders such as Charcot’s disease, which Stephen Hawking suffered from.

And how does it work?

To perform this magic trick, the Neuralink implant first records neural electrical signals from a monkey playing a game of Pong or moving a light indicator with a joystick. The boss is rewarded with a drop of banana juice when he succeeds in an action. Then the joystick cable is disconnected. The animal sees nothing but fire.

When he presses left/right/up/down, the system decodes the nerve signals that control the muscles of the arm and hand, and follows his intent for action on the screen. Then Neuralink removes the joystick completely. The monkey plays telepathically. Other companies, like Meta, are experimentingWith helmets that don’t require going under the knife

. But “the amount and quality of information that can be exchanged” via electrodes connected directly to the brain is much higher,” Greer insists.

Can we really let the blind see (again)?

If our eye is comparable to a camera that captures light reflected from surrounding objects, the information is processed by the visual cortex. Shapes, colors, movement… What we “see” is actually our brain’s interpretation of electrical signals.

By connecting to a camera, “implants like the one in Neuralink are able to activate neurons by stimulating a specific area of ​​the visual cortex, allowing the patient to perceive flashes of light” in their field of vision, the researcher explains. But who insists forcefully: “It’s very rudimentary vision. We’re talking lines and contours here, without color, just enough to recognize an object – and for now, maybe not a face. But even basic vision can help blind people orient themselves.” Patients tell us that better than nothing. “

Currently, this approach gives better results for people who have lost their sight than for those who were born blind. For the latter, “the visual cortex and neuron connections evolved differently,” but the researcher says he is “convinced” that giving them limited electronic vision will one day be possible. Ultimately, going from 1024 electrodes to double 16000 should improve image resolution.

How do implants help people with paralyzed legs to walk again? I guess, so I’m moving on. Even if we don’t realize it, our movements start in our brain. But when a lesion — partial or total — in the spinal cord interrupts the nerve message, the legs don’t respond. Implants have already enabled patients to walk again in recent years, such as Dutchman Gert-Jan Oscam, whose progress has been chronicled. in nature

last week. The principle is the same as for Neuralink: It involves creating a “bridge” by placing an implant in the brain, and another in the spinal cord, after an injury. Thanks to several months of calibration and advances in artificial intelligence, “the message is forwarded to the nerves and muscles,” specifies Bradley Greer.

Will we ever be humans with intelligence augmented by implants?

If medicine is given priority, Elon Musk does not hide his transhumanist aspirations, with implants that he wants to make as “available” as myopic surgery. According to him, a chip that enhances our cognitive abilities or allows us to interact directly with the machine without being limited by the slowness of our thumbs and eyes embodies “the only solution if we do not want to become obsolete” in the face of the prospect of the emergence of powerful artificial intelligence. Will we be able to store our memories in implants, as in black mirror ? Learn kung fu like Neo inmatrix

, or speaking any language, with the risk of further fundamental inequalities between rich and poor? “It’s speculation and science fiction,” says Greger.

“It is not well understood how complex cognitive information — our ability to understand advanced mathematics, to have certain emotions — is encoded. When we learn to play a musical instrument, the physical structure of our brain changes, with neural connections rewiring. You have to train for years.”

If he doesn’t rule out that science will one day allow us to recreate our neurons, the 50-year-old doesn’t think he’ll ever see this in his lifetime: “This poses many ethical problems. And in all seriousness, I don’t think many people would want to implant a chip in their brain unless they really need it.” According to what was revealed by

Reuters