Neuralink: Key Features and Concerns

Neuralink, a company founded by entrepreneur Elon Musk with the goal of revolutionizing brain-computer interfaces, has implanted a device for reading brain signals in a human for the first time. This was revealed in a tweet by Musk published on January 29.

Brain-computer interfaces record and decode brain activity to allow people with severe paralysis to control computers, robotic arms, wheelchairs, or other devices using only their thoughts. In addition to Neuralink’s device, other similar devices are in development, and some have already been tested in humans.

Researchers in the field of neurotechnology are cautiously observing Neuralink’s human trials. Mariska Vansteensel, a neuroscientist at the University Medical Center Utrecht in the Netherlands and president of the International Brain-Computer Interface Society, hopes that Neuralink will be able to demonstrate the device’s safety and its effectiveness in measuring brain signals both in the short and long term.

However, there is dissatisfaction due to a lack of detailed information. There is no confirmation of the start of the trials other than Musk’s tweet. The main source of public information is a study brochure inviting people to participate, but it lacks details such as the implantation site and the exact criteria for evaluating trial results.

The trial is not registered on ClinicalTrials.gov, an online repository curated by the U.S. National Institutes of Health. Many universities require researchers to register trials and their protocols in such a public repository before recruiting participants. Additionally, many medical journals require such registration as a condition for publishing results, in line with ethical principles aimed at protecting clinical trial volunteers.

What Makes the Neuralink Chip Different?

Like Blackrock Neurotech in Salt Lake City, Utah, Neuralink targets the activity of individual neurons—a method that requires electrodes to penetrate the brain. Other companies are developing electrodes that sit on the brain’s surface—some of which are easily removable—to record averaged signals produced by groups of neurons. Neuroscientists have long argued that data from individual neurons is necessary for complex thought decoding. However, recent studies show that averaged signals can enable decoding of complex cognitive processes, such as inner speech. Synchron, a company from New York, has demonstrated that a low-speed surface brain-computer interface can provide basic but reliable smartphone control.

Like Synchron’s system, Neuralink’s system is fully implantable and wireless. This is a first for brain-computer interfaces that record individual neuron activity. Previous systems required a physical connection to a computer through a port in the skull, which posed an infection risk and limited everyday use.

The Neuralink chip contains 64 flexible polymer threads, providing 1,024 recording sites for brain activity, according to the company’s study brochure. This is significantly more than Blackrock Neurotech’s brain-computer interfaces, the only other system for recording individual neurons that has been implanted long-term in humans. As a result, the Neuralink implant has the potential to greatly increase the bandwidth of brain-machine communication. This represents a significant improvement over current technologies, such as Blackrock’s devices, which have already been used by several users. Neuralink promotes the flexibility of its threads and reports the development of a robot for implanting them into the brain.

Now, it remains to be seen which systems work best in terms of safety, signal quality, durability, and user experience. “We all need to play the long game for the benefit of patients,” says Tim Denison, a neuroengineer at the University of Oxford.

What Will Scientists Learn from Neuralink’s Human Trials?

Neuralink has released little information about the goals of its trial and does not respond to interview requests from journalists. However, experts expect that safety will be the top priority at the start of the trials. This includes monitoring the immediate effects of the device, says Denison—“nothing like strokes, bleeding, vessel damage, and so on”—as well as infections and long-term monitoring to ensure the device remains safe after implantation.

The Neuralink study brochure states that volunteers will be monitored for five years. The study will focus on analyzing the device’s functional capabilities. Volunteers are expected to regularly use the implant to control a computer at least twice a week and provide feedback on their user experience.

Mariska Vansteensel, a neurobiologist at the University Medical Center Utrecht in the Netherlands, would like to know whether the quality of detected neural signals deteriorates over time, which is a common issue with existing devices. “You can’t easily replace the electrodes after implantation,” she says. “If after a month they show impressive decoding results, that will be impressive. But I want to see long-term results.”

Denison is also interested in how the wireless system works outside of laboratory conditions.

What Are Scientists’ Concerns About Neuralink’s Brain-Computer Interface?

Now that human trials have begun, the safety and well-being of volunteers is a key concern. The trial was approved by the U.S. Food and Drug Administration (FDA), which had previously rejected Neuralink’s application. However, some researchers are concerned that the trial is not registered on ClinicalTrials.gov. “I assume that the FDA and Neuralink are following an approved plan to some extent,” says Denison. “But we don’t have the protocol. So we don’t know what’s happening.”

Transparency is also important for the people these brain-computer interfaces are intended to help. Ian Burkhart, co-founder of the BCI Pioneers Coalition in Columbus, Ohio, was paralyzed after breaking his neck in a diving accident and used a Blackrock array in his brain for 7.5 years. He is excited about what Neuralink might achieve. But, he says, “They could do a much better job with the amount of information they provide, instead of making everyone guess. It’s especially important for patients who are eagerly waiting for new technology to improve their lives.”