All the Actually Important Stuff Neuralink Just Announced

While Elon Musk has been busy taking over Twitter, his brain-computer interface company Neuralink has been working on refining its technology, which is aimed at creating implants that allow a direct line of communication between the human brain and computers.

Called brain-computer interfaces, or BCIs for short, these systems use tiny electrodes placed in the brain to “read” signals from nearby neurons. Software then decodes these signals into commands or actions, such as moving a cursor or a robotic arm. In 2019, Musk claimed his company’s device would eventually allow people to achieve a “symbiosis with artificial intelligence.” 

The company, founded in 2016, is still far from merging our brains with AI. In a livestreamed “show and tell” event Wednesday evening, the Neuralink team presented a grab bag of improvements to its technology. Musk did say that Neuralink has begun submitting paperwork for a human clinical trial to the Food and Drug Administration and hopes to implant a Neuralink device in a patient in six months. “We've been working hard to be ready for our first human, and obviously we want to be extremely careful and certain that it will work well before putting a device in a human,” Musk said. 

He revealed that the company’s first two intended applications for its technology would be to help people with paralysis use their digital devices seamlessly and to restore vision in those who have lost their eyesight. “Even if someone has never had vision ever, like they were born blind, we believe we can still restore vision,” Musk said. While the presentation didn’t show any proof of vision restoration, it did include a video demonstration of how Neuralink’s implant had been used to stimulate a visual sensation—a flash of light—in a monkey’s brain.

The Neuralink team also demonstrated how its surgical robot inserts electrode threads, using a dummy filled with a gelatinous “brain proxy” material. These electrode threads both stimulate the brain and capture outgoing signals. “It’s capable of maneuvering these tiny threads that are only on the order of a few red blood cells wide and inserting them reliably into a moving grain while avoiding vasculature,” said D. J. Seo, the company’s vice president of implant. “It's quite good at doing this reliably.” During the presentation, it took about 15 minutes for the robot to plant 64 threads into the dummy.

“The robotic arm is the biggest advancement so far because of how precise and how quick it is to do the electrode insertion, especially when you’re talking about putting thousands of electrodes in the brain,” said Marvin Andujar, assistant professor of computer science and engineering at the University of South Florida, who isn’t involved with Neuralink. 

Researchers have been developing BCIs since the 1960s, but the devices are still considered experimental and none are commercially available. Only a few dozen people around the world have been outfitted with these interfaces as part of research studies, which have given paralyzed volunteers the ability to translate thoughts into speech, feel sensation again, and move a wheelchair. But the technology is still in its infancy. 

The most widely tested brain implant is the Utah array—a hard silicon square with 100 tiny protruding needles. Each about a millimeter long, the needles have electrodes on their tips that capture brain signals. But these rigid devices can cause scarring to nearby tissue, which over time can interfere with their recording ability. By contrast, one of Neuralink’s innovations are the flexible threads attached to its implant. 

Neuralink is also trying to improve on existing BCIs that require clunky setups and invasive brain surgery; instead, the company’s sewing-machine-like robot could install electrodes by punching them into the brain through a small hole in the skull. Plus, the device transmits brain signals wirelessly, unlike most current BCIs, which rely on external cables that connect to a computer from the top of a person’s head.

Neuralink has been testing its prototype in pigs and monkeys, and in April 2021, the company posted a video of a macaque playing the video game Pong hands-free thanks to two brain implants the company installed in its brain. (The feat had already been achieved by a person with a BCI 15 years before.) 

In a company update in 2020, pigs implanted with the coin-sized Neuralink device trotted onto a stage so Musk could demonstrate the safety of the implant, as well as its ability to record neural activity from the pigs’ brains. (He described the device as “a Fitbit for your skull with tiny wires.”) One pig had an implant in its brain at the time of the demonstration, and another previously had one but had it removed beforehand. Meanwhile, the brain signals from the pig were broadcast on a screen. 

The company’s current implant, which is the size of a quarter, contains 1,000 electrodes, or channels, capable of recording and stimulating nearby neurons. But on Wednesday, Neuralink staff said they were working on a next-generation chip with more than 4,000 channels in a chip of the same size.

Although Neuralink may be the most recognizable, a handful of other companies are also working on brain implants and grappling with common problems such as safety, longevity, and what they can get the implant to do.

Two former Neuralink employees have started their own BCI ventures. Last year saw the launch of Science Corp, headed by former Neuralink president Max Hodax, and Precision Neuroscience, established by Benjamin Rapoport, another original member of Musk’s team. In a November 21 blog post on the company’s website, Science Corp staffers revealed their concept for a neural interface targeted at restoring eyesight in people with retinitis pigmentosa and dry age-related macular degeneration, two forms of serious blindness that don’t have good treatment options. The company is working on demonstrating safety data in animals, according to the blog post.

Meanwhile, Precision Neuroscience is developing a thin, flexible brain implant for paralysis that lays on top of the brain and could be installed through a small slit in the head, rather than drilling a hole into the skull. According to Rapoport, the company has tested its device in pigs and is hoping to get a green light from the Food and Drug Administration in 2023 to implant it in a human patient.

Rival BCI outfit Synchron has already moved forward with human studies. The New York-based company is testing a matchstick-sized neural implant that doesn’t require open brain surgery. The stent-like device is threaded through a small slit in the neck up through the jugular vein and pushed into the brain. The device is meant to allow people with paralysis to wirelessly control digital devices through thought.

In a small study in Australia, the Synchron implant allowed four patients with amyotrophic lateral sclerosis, or ALS, to do online tasks such as banking, shopping, and emailing, according to preliminary data presented by the company in March. Last December, one patient used the device to compose the first tweet sent by BCI. The company has since implanted an additional patient as part of a study in the US. That trial will include up to six participants. 

One of the big questions about these implants is how long they’ll last in the brain. In August, 36-year-old Nathan Copeland set the record for the longest time anyone’s ever had a brain-computer interface implanted: over seven years and three months. 

“There's a trade-off. The smaller that you make the electrodes, there's less tissue interaction with the brain itself,” says Sumner Norman, chief BCI scientist at Agency Enterprise Studio, a Los Angeles-based software company developing operating systems for neural interfaces. That’s a good thing, he says, “but it does make the electrodes themselves more susceptible to the brain environment, which could limit their longevity.”

Neuralink engineers also spoke to the need to make battery charging quick and safe, and to make the implant unobtrusive. Showing images of a monkey implanted with the device, Musk noted that they had miniaturized it to the point that it matched the thickness of the piece of skull that had been removed to insert it. 

“I could have a Neuralink device implanted right now and you wouldn't even know. Hypothetically,” he said to audience cheers. “Maybe one of these demos—in fact, one of these demos, I will.”