The man who controls computers with his mind

In another groundbreaking study published last year, Jaimie Henderson and several colleagues, including Francis Willett, a biomedical engineer, and Krishna Shenoy, an electrical engineer, reported an equally impressive but completely different approach to communication through a neural interface. The scientists recorded neurons firing in Dennis DeGray’s brain as he visualized himself writing words on a notepad with a pen, trying to mimic the different hand movements required for each letter. He mentally wrote thousands of words so that the system could reliably recognize the unique patterns of neural activity specific to each letter and display words on a screen. “You learn to really hate M’s after a while,” he told me in a typically good mood. In the end, the method was very successful. DeGray could type at up to 90 characters or 18 words per minute — more than twice the speed of his previous efforts with a cursor and virtual keyboard. He is the world’s fastest mental typist. “Sometimes I go so fast it’s one big blur,” he said. “My concentration gets to a point where it’s not uncommon for them to remind me to breathe.”

Performance in brain-computer interfaces to date has been based on a mix of invasive and non-invasive technologies. Many scientists in the field, including those who work with DeGray, rely on a surgically embedded array of spiked electrodes manufactured by Blackrock Neurotech, a Utah-based company. The Utah Array, as it’s known, can differentiate the signals from individual neurons, providing more refined control over connected devices, but the surgery it requires can lead to infection, inflammation and scarring, contributing to its eventual deterioration. of the signal strength. Interfaces located outside the skull, such as headsets that rely on EEG, are currently limited to eavesdropping on the collective firing of groups of neurons, sacrificing power and precision for safety. Complicating the situation even more is that most neural interfaces studied in labs require cumbersome hardware, cables, and an entourage of computers, while most commercially available interfaces are essentially remote controls for rudimentary video games, toys, and apps. These commercial headsets don’t solve real problems, and the more powerful systems in clinical trials are too impractical for everyday use.

With this problem in mind, Elon Musk’s Neuralink company has developed a series of flexible polymer wires studded with more than 3,000 tiny electrodes connected to a wireless radio and signal processor the size of a bottle cap, as well as a robot that can surgically implant the wires. in the brain, avoiding blood vessels to reduce inflammation. Neuralink has tested its system on animals and has said it would begin human trials this year.

Synchron, based in New York, has developed a device called a Stentrode, which does not require open brain surgery. It is a four-centimeter, self-expanding tubular grid of electrodes that is inserted through the jugular vein into one of the brain’s major blood vessels. Once in place, a stentrode detects local electric fields produced by nearby groups of neurons in the motor cortex and forwards the recorded signals to a wireless transmitter built into the chest, which relays them to an external decoder. In 2021, Synchron became the first company to receive FDA approval to conduct human clinical trials with a permanently implantable brain-computer interface. So far, four people with varying levels of paralysis have been given Stentrodes and used them, some in conjunction with eye-tracking and other assistive technologies, to control personal computers while unattended at home.

Philip O’Keefe, 62, of Greendale, Australia, received a stentrode in April 2020. Because of amyotrophic lateral sclerosis (ALS), O’Keefe can only walk short distances, cannot move his left arm, and loses the ability to speak clearly. In the beginning, he explained, he had to focus intensely on the imagined movements needed to operate the system — in his case, thinking about moving his left ankle for varying lengths of time. “But the more you use it, the more it’s like riding a bike,” he said. “You get to a point where you don’t think so hard about the move you need to make. You think about the function you need to perform, whether it’s opening an email, scrolling a web page, or typing some letters.” in Dec, O’Keefe became the first person in the world to post on Twitter using a neural interface: “No keystrokes or voices needed,” he wrote in his mind. “I made this tweet thinking about it. #helloworldbci”

Thomas Oxley, a neurologist and the founding CEO of Synchron, thinks future brain-computer interfaces will fall somewhere between LASIK and pacemakers in cost and safety, helping people with disabilities regain the ability to interact with their physical environment and a rapidly evolving environment. digital environment. “Besides,” he says, “when this technology allows one to interact with the digital world better than with an ordinary human body, it really gets interesting. To express emotions, to express ideas – everything you do to communicate what’s happening in your brain has to happen through the control of muscles.Brain-computer interfaces will eventually allow a passage of information beyond the limitations of the human body.And from that perspective, I think the capacity of the human brain is actually going to increase.”

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