Motif Neurotech has developed a brain-computer interface that only needs to penetrate the skull, and has completed human testing

In the world of brain-computer interfaces, Neuralink seems to have caught everyone's attention.

Not long ago, the company posted a video on the X (formerly Twitter) platform showing the company's first human subject to receive a brain implant, which was named Telepathy.

The subject was a 29-year-old man with paralysis below the shoulder, and after being implanted with a chip, he could play chess with his brain and move the cursor. He said in the video that learning to control it was "like using the Force."

The human trial caused a stir, not because the subjects had completed a special task.

In fact, scientists succeeded in moving the cursor with a brain implant back in 2006, and it caused a sensation only because of its advanced technology.

The device it uses is small and wireless. The electrodes inside the device are thin and fragile and must be implanted into the brain by a robot.

At the same time, Elon Musk, the founder of Neuralink, is also a character who brings his own traffic, and he has "boasted" about the company's technology, and many people are paying attention to his words and actions.

Musk is known to be interested in using chips to enhance the brain, not just to restore functions lost due to injuries.

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But Neuralink isn't the only company trying to use brain-computer interfaces to help people who have lost the ability to move or speak.

With funding from Bill Gates and Jeff Bezos, New York-based Synchron has implanted brain-computer interface devices in 10 people.

Last week, it launched a patient registry program in preparation for a larger clinical trial.

And now, let's take a look at what other companies are developing brain chips, how they're progressing, and what different technologies and approaches they're employing.

Most companies working in this space have the same goal: to get enough information from the brain to interpret the user's intent.

This is to help people who can't move or speak easily communicate, either by helping them control the computer cursor or by converting their brain activity into speech or text.

There are many ways to classify these devices, but Jacob Robinson, a bioengineer at Rice University in the United States, likes to classify them based on how invasive they are.

It's a technical trade-off. The deeper the electrode, the more invasive and risky the surgery required for implantation.

But deeper electrodes will also be closer to the brain activity that these companies want to record, as they can capture higher-resolution information.

For example, ask the device to decode speech. That's what companies like Neuralink and Paradromics are aiming for.

Jacob Robinson is the CEO and co-founder of Motif Neurotech, a company that is developing a brain-computer interface that only penetrates the skull (more on that later).

In contrast, Neuralink's device is equipped with electrodes that enter the cerebral cortex. Robinson calls it "just a few millimeters above the surface."

Two other companies, Austin-based startup Paradromics and Blackrock Neuroteh, have also developed chips that can penetrate the cortex.

"This allows you to get closer to the neurons and get information about what each brain cell is doing," Robinson said. ”

Closer proximity to neurons and more electrodes that can "listen" to their activity are able to increase the speed or "bandwidth" of data transmission. The greater the bandwidth, the more likely the device is to convert brain activity into speech or text.

In terms of the number of participants, Blackrock Neurotech is way ahead. Since 2004, its UTAH array has been implanted in dozens of people. Many academic laboratories in the United States use this array.

It is this array that forms the basis of Blackrock's MoveAgain device, which received breakthrough device designation from the U.S. Food and Drug Administration in 2021. But Robinson says it could have lower bandwidth than Neuralink's devices.

"Paradromics has the highest bandwidth interface, but they haven't shown that in humans yet," Robinson said. ”

Its electrodes are placed on a chip the size of a watch battery, but the device requires a separate wireless transmitter that needs to be implanted in the chest and connected to a brain implant by wires.

All of these high-bandwidth devices have a drawback, though. Synchron founder Tom Oxley said in a 2022 TED talk that they all require craniotomy, but "the brain really doesn't like to have a needle stuck in it."

Synchron has developed an array of electrodes mounted on a stent, which is exactly the same device that doctors use to support blocked arteries.

The device, called Stentrode, can be delivered through an incision in the neck into a blood vessel above the motor cortex.

This unique delivery method avoids craniotomy. But placing the device above the brain rather than inside it limits the amount of data it can capture, Robinson said.

He doubted that the device would be able to capture enough data to move the cursor, but it would be enough to generate clicks. "They can click yes or no, up or down. He said.

Newcomer Precision Neuroscience, founded by former Neuralink executives, has developed an array of flexible electrodes thinner than a human hair, similar to a piece of tape. It slides over the top of the cortex through a small incision.

The company launched its first human trial in 2023. In these preliminary studies, the array was temporarily implanted in people who were undergoing brain surgery for other reasons.

Last week, Robinson and his colleagues reported on Science Advances the first human test of the Motif Neurotech device, which only penetrates the skull.

They temporarily placed the small, battery-free device above the motor cortex of a patient who was already scheduled for brain surgery.

The device is called Digitally Programmable Over-brain Therapeutic (DOT). When they start the device, they see the patient's hand moving.

The ultimate goal of Motif devices is not to generate movement, as they have set their sights on a completely different application: alleviating mood disorders.

"Of all the people with spinal cord injuries, there are many, many people who have severe depression, and the medication doesn't work for them," Robinson said. Their desperation is no different from that of ordinary people, but it is not known. ”

But studies have shown that the device is strong enough to stimulate the brain, which is the first step towards the goal of practical use.

According to reports, the device is located above the brain, so it cannot capture high-bandwidth data. But because Motif isn't trying to decode speech or help people move the cursor with their brains, it doesn't need that much data either.

"Your mood changes far less quickly than the words come out of your mouth," Robinson said. ”

It remains to be seen which of these companies will come out on top, but as the field has come to fruition, controlling things with the brain no longer seems to be a science fiction plot.

Still, these devices will be used primarily for people with serious physical impairments.

As for what Neuralink calls "redefining the boundaries of human capabilities" and "expanding the way we experience the world," don't expect brain implants to achieve these goals anytime soon.

Support: Ren

Typesetting: Luo Yi