There's Neuralink—and There's the Mind-Reading Company That Might Surpass It

WIRED

21-07-2025

Jul 21, 2025 6:00 AM Unlike Elon Musk's brain-computer interface, Synchron's doesn't require open-skull surgery, and it has an OpenAI chatbot baked in. PHOTOGRAPH: STEPHANIE STRASBURG
Mark Jackson is playing a computer game with his mind. As he reclines in bed, three blue circles appear on a laptop screen a few feet away. One turns red: the target. Jackson is in control of a white circle, which he needs to steer into the target without running into the blue obstacles. The game is a bit like Pac-Man . Except instead of a joystick, Jackson uses his thoughts to control his little white circle. To move left, he thinks about clenching his right fist once. To move right, he thinks about doing it twice in a row, like a double click.
Jackson, who is 65 and paralyzed, is good at this game. He steers into the red circle. It turns blue and makes a satisfying ding! He has hit the target. In the next round, the circles change position. He moves to the next round, and the next, and is successful 14 out of 15 times. He's gotten 100 percent at this game before. Then again, he's had some practice.
A couple years ago, surgeons in Pittsburgh implanted Jackson with an experimental brain-computer interface, or BCI. Made by New York–based startup Synchron, it decodes Jackson's brain signals to carry out commands on the laptop and other devices. He's one of 10 people—six in the US and four in Australia—who have received the Synchron implant as part of an early feasibility study. In addition to gaming, the BCI allows him to send text messages, write emails, and shop online.
Jackson's medical saga began about five years ago, when he was living in Georgia and working for a wholesale floral company—his dream job. He thought he had pinched a nerve in his neck. But in January 2021, doctors at Emory University told him the diagnosis was far more serious: amyotrophic lateral sclerosis. A neurodegenerative disease, ALS causes nerve cells in the brain and spinal cord to break down over time, resulting in a gradual loss of muscle control. Jackson's doctor asked if he was interested in joining a clinical trial testing an ALS drug. Jackson said it was a no-brainer. Jackson in his first-floor bedroom. PHOTOGRAPH: STEPHANIE STRASBURG Before his ALS diagnosis, Jackson had taken up woodworking. PHOTOGRAPH: STEPHANIE STRASBURG
But by December 2022, he had lost the ability to type or lift buckets of flowers at his job and had to stop working. He moved in with his brother just outside Pittsburgh. 'The loss of mobility, the loss of independence that goes with this disease,' Jackson says, 'it's a lot to take in, it's a lot to process.' He tried to stay positive even as his disease progressed. When the drug trial ended in summer 2023, he was eager to join another study that had a chance of helping his ALS.
Synchron's BCI trial was just getting underway at the University of Pittsburgh. While the implant wouldn't slow the progression of Jackson's ALS, it could give him back some of the autonomy he'd lost to the disease. 'I was immediately excited about it,' Jackson says.
He started the vetting process in July 2023, and six weeks later Jackson was in the operating room. In a roughly three-hour-long procedure, surgeons first inserted the Stentrode, a wire-mesh tube about the size of a matchstick, into his jugular vein at the base of his neck. Using a catheter, they carefully threaded the device up through the vessel, past the ear, and into the side of the head to rest against the motor cortex, the part of the brain that controls voluntary movement. Then they inserted a small rectangular device below Jackson's collarbone, which processes the brain signals and beams them via infrared outside the body. Those signals are collected by a paddle-shaped receiver that sits on Jackson's chest, then sent via a wire to a unit that translates them into commands. When the system is hooked up, a pair of green lights shines through his shirt.
After the surgery, making that initial connection took months. Jackson's chest was swollen from the procedure, which interfered with the signal quality. Plus, the external unit can only be so far away from the internal one. It took so much trial and error that Jackson worried it would never work. 'There was a lot of anticipation,' he says. When the units finally connected in October 2023, Jackson felt a huge release of tension.
When a person is outfitted with a BCI, they're asked to think about doing specific actions, such as opening and closing their fist, so that the system learns to associate that pattern of brain activity with that specific action. It does this by using AI-powered software to decode and interpret those neural signals. Even though Jackson is paralyzed and can't actually move his hand, the neurons associated with that movement still fire when he attempts to make a fist. It's that movement intention that BCIs are designed to read.
If Synchron's process sounds like a lot to undergo, consider that other brain implants involve, well, brain surgery. Synchron's main competitor, Elon Musk's Neuralink, removes a piece of skull and replaces it with a coin-sized device that hooks directly into the brain tissue via 64 robotically positioned wire threads. Musk's company has implanted seven volunteers with its device so far. Some have even been discharged from the hospital the day after their procedure. While invasive implants like Neuralink's carry the risk of brain tissue damage and bleeding, blood clots and stroke are the main concerns with Synchron's device. Any kind of implanted device carries the risk of infection.
Synchron's approach has allowed it to pull ahead in the race to commercialize brain implants. While it has raised just $145 million to date to Neuralink's $1.3 billion, it has attracted funding from big names like Jeff Bezos and Bill Gates. Musk himself reportedly considered investing when development at Neuralink was stalled. And the company keeps expanding the functionalities of its BCI, making it compatible with a range of existing consumer technologies.
Last year, Synchron rolled out a generative chat feature powered by OpenAI to assist users with communication. It also connected its device to the Apple Vision Pro, which Jackson now uses regularly for entertainment. Then came an integration with Amazon Alexa, allowing Stentrode recipients to use the virtual assistant with just their thoughts. And earlier this year, Synchron and Apple introduced a Bluetooth protocol for BCIs, so that when Synchron's system is switched on, it can automatically detect and connect to an iPhone, iPad, or Vision Pro. Synchron is now gearing up for a larger pivotal trial needed for commercialization.
Synchron's Stentrode device is threaded through the jugular vein into the brain. Adobe After Effects
While Musk envisions a transhumanist fusion of mind and machine, Synchron is focused on meeting the immediate needs of people like Jackson who have severe disabilities. If Synchron can get buy-in from insurers and regulators, it could usher in a new era of brain devices that restore communication and movement, treat neurological disorders and mental illness, and detect and monitor brain states and diseases. And though it's not Synchron's goal, its minimally invasive technology could eventually lead to safe, unobtrusive devices that might one day allow anyone to play a video game or surf the web with their thoughts alone.
Tom Oxley, Synchron's cofounder and CEO, didn't exactly set out to start a mind-reading company. After finishing medical school in 2005 at Monash University in Australia, he knew he wanted to specialize in the brain, either neurology or psychiatry—and to do that, he needed to train in internal medicine first. As part of that training, Oxley spent three months in a palliative care clinic for people with ALS. 'It was extremely intense,' he says.
Later, while doing a clinical rotation in the rural region of Mildura, he befriended Rahul Sharma, who was training to be a cardiologist. Sharma would cook Indian food, and they would have long, philosophical conversations about the future of medicine. Sharma told Oxley about the shift from open-heart surgery to minimally invasive techniques that use catheters inserted into blood vessels. Oxley thought, 'What if those techniques made their way over to the brain?' After all, the brain has a vast network of blood vessels. Soon, the two were talking about the possibility of putting stents in the brain to deliver medications, says Sharma, Synchron's cofounder and medical director.
Then, in 2008, Oxley came across a landmark paper in the scientific journal Nature from 2006 describing how two paralyzed patients with a brain implant successfully controlled a computer with their thoughts. One of them was also able to move a robotic arm. To achieve the groundbreaking results, a team from Brown University and Massachusetts General Hospital used a device called the Utah array, a 4- by 4-mm grid with 100 tiny metal spikes. The Utah array penetrates the brain tissue, and electrodes on the spike tips record the firings of individual neurons. Placing the array involves a craniotomy, in which a piece of the skull is temporarily removed. The first person to receive the implant, Matthew Nagle, was able to move a cursor, read emails, play Pong , and draw a circle on a screen.
'At that moment, I got excited about BCI,' Oxley says. While any BCI comes with risks, Jackson says the technology enables him to do more than he ever thought possible. PHOTOGRAPH: STEPHANIE STRASBURG
He and Sharma started thinking about putting electrodes on stents to record from the brain. The idea behind the Stentrode started to take shape. After completing his internal medicine fellowship in 2009, Oxley cold-called the US Defense Advanced Research Projects Agency (Darpa), which was doing research on BCIs. A Darpa program manager thought his invention could be a way for soldiers who had lost limbs to control robotic arms, and invited Oxley to Walter Reed Army Medical Center to pitch his idea.
Darpa ended up funding Oxley and Sharma's half-baked concept to the tune of $1 million, and two years later they formed a company, SmartStent, which eventually became Synchron. The startup received an additional grant of $5 million from the Australian government and, later, another $4 million from Darpa and the Office of Naval Research. They recruited biomedical engineer Nicholas Opie, who was working on a bionic eye at the time, to design the Stentrode, and by 2012, the company had started implanting the device in sheep. In 2019, the first human subject received the Stentrode in an early feasibility study in Australia. (Neuralink's first human surgery was in January 2024.)
Vinod Khosla, whose venture firm has invested in Synchron, thinks the Stentrode could be scaled up more quickly than other BCIs in development that require invasive brain surgery. Those devices would also need specially trained neurosurgeons—or in Neuralink's case, surgical robots. There are far more cardiologists who are trained to implant stents, Khosla says.
But Synchron's approach comes with trade-offs. From inside the blood vessel, its device uses 16 electrodes dotted on the stent's surface to capture brain activity. Because it sits farther away from individual neurons than the Utah array and Neuralink device do, it picks up a weaker signal.
BCI researchers call this the 'stadium effect.' If you're sitting inside a stadium, you can hear the conversations going on around you. If you're sitting outside the stadium, you would hear the roar of a crowd and might be able to discern when a goal has been scored. 'The question is, how much do you need this to hear to do something useful for the subject?' says Kip Ludwig, a professor at the University of Wisconsin-Madison and codirector of the Wisconsin Institute for Translational Neuroengineering, who isn't involved with Synchron.
Neuralink's implant has more than 1,000 electrodes dispersed across 64 flexible wire threads. More electrodes means more information can be extracted from the brain, but more may not necessarily be better, especially for executing relatively simple tasks such as moving a cursor on a computer screen. 'The minimal viable product is the ability to navigate and select on an iPhone,' Oxley says. 'That's what we think is going to be the basic use case.'
Beyond that, Oxley sees huge potential in using small blood vessels as roads to access new parts of the brain. 'We believe that opens up 10 times more brain coverage,' he says. More Stentrodes across the brain could allow for more natural control and more complex functions.
Synchron's next-generation BCI will not require patients to be physically tethered to the system.
As Synchron moves toward a pivotal trial in 2026, which will enroll between 30 and 50 subjects, it will face some key questions about its technology—namely, what are the benefits and how can those benefits be measured? 'These technologies are so new, and they're providing the opportunity to restore functions that no other device or approach is yet able to restore,' says Leigh Hochberg, a BCI researcher at Massachusetts General Hospital and Brown University, and an author on the 2006 paper that inspired Oxley. There are no 'validated outcome measures that can be easily applied,' he says.
For Synchron's implant to win approval in the US, the Food and Drug Administration will want to see that the benefits outweigh any risks that come with the device. And if it is approved, to what extent will insurers cover the cost for patients? Unlike other drugs and medical devices, BCIs don't treat an underlying condition. They're more akin to assistive devices.
As the field matures and more startups work toward commercialization, companies and regulators are trying to come up with those measures. There are already assessment tools to evaluate a person's functional abilities or quality of life, for example, that could be applied to BCIs.
When I talk to Jackson about this idea, he has no doubt that BCIs will have a positive effect on people's health and well-being—eventually. 'I can see down the road where this would give someone their independence,' he says. For now, though, the setup isn't exactly practical. 'I have to be physically connected with an exterior wire. So the only time that I am using the device itself is when I'm hooked up,' he says. That happens twice a week when he is visited by Synchron's field clinical engineer, Maria Nardozzi, for training sessions. In Synchron's second-generation design, which will be tested in the pivotal trial, the internal and external units will connect wirelessly so that subjects won't have to be tethered to the system.
Despite having a BCI, Jackson still relies on voice assist for most of his needs. 'If I'm being honest, that's the easier route,' he says. But there are times when it fails, or an app might not have a voice assist option. For instance, when he tried to use the payment app Venmo, there wasn't a way to use voice assist to indicate a reason for the payment, a required field.
'The voice assist technology is nowhere near where it needs to be,' Sharma says. Anyone who has used Alexa or Siri knows there are accuracy issues and lag time between a request and the device's response. If BCIs can carry out tasks more naturally than voice assist, Sharma thinks that could tip the scales for users. BCIs also provide more privacy. 'If there are other people in your environment, you may not wish to be sharing what it is you are trying to do or express out loud,' he says. And of course for some patients with paralysis who have lost the use of their voice, a BCI may be their only means of communicating and interacting with the world around them. Jackson and Maria Nardozzi, Synchron's field clinical engineer, during a recent BCI training session. PHOTOGRAPH: STEPHANIE STRASBURG
Jackson realizes he's a bit of a guinea pig. He knows that Synchron's technology will get better, faster, and more seamless over time. He enjoys trying out new apps with his BCI and says his favorite thing to do with it is use the Apple Vision Pro. He can't travel anymore, but the headset can transport him to the Swiss Alps or a temperate rainforest in New Zealand. But there are still things beyond the digital world he wishes he could do that the BCI can't help with yet—painting, for instance, and wood carving.
Above his bed hangs a picture of two yellow fruit warblers. He painted it himself when he was 20 years old. His mother kept it and had it framed. He was looking forward to doing more oil painting in his retirement. Jackson knows, of course, that the nature of ALS is that his condition will inevitably get worse. He could eventually lose his speech and what voluntary movement he has left. He may develop cognitive impairment and not be able to control his BCI anymore; the life expectancy for someone with ALS is two to five years after diagnosis. Of the 10 people who have been outfitted with Synchron's BCI, only Jackson and another participant are still using it. The others stopped either because of how their ALS progressed or because they died.
Before his ALS diagnosis, Jackson had started woodworking. He wanted to learn how to carve birds. A wood carving of a cardinal he bought sits on his nightstand as a reminder of the hobby he'll never return to because of his ALS. 'If there could be a way for robotic arm devices or leg devices to be incorporated down the road,' he says, 'that would be freaking amazing.' Neuralink is testing that capability, but current robotic arms are far from being lifelike. They can perform simple tasks executed in jerky movements. It could be decades before BCIs give people the ability to do something as complicated as carving wood.
For now, Jackson is able to use the BCI to explore art museum apps, but he'd like to find a way to create digital art with his thoughts. And while the setup is still limited in a lot of ways, it enables Jackson to do more than he ever thought possible. He is, after all, able to move objects on a screen without using his hands, his feet, his eyes, his shoulders, his face, or even his voice. 'There's a reason why this is pretty groundbreaking technology,' he says.
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