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 entirely different approach to neural interface communication. Scientists recorded the firing of neurons in Dennis DeGray’s brain as he visualized himself writing words with a pen on a legal pad, trying to recreate the different hand movements required for each letter. He mentally typed thousands of words for the system to reliably recognize unique patterns of neural activity specific to each letter and output words on a screen. “You really learn to hate M’s after a while,” he told me with characteristic good humor of his. Ultimately, the method was extremely successful. DeGray was able to type up to 90 characters or 18 words per minute, more than double the speed of his previous efforts with a cursor and virtual keyboard. He is the fastest mental typist in the world. “Sometimes I get going so fast it’s just a big blur,” he said. “My concentration gets to a point where it’s not uncommon to be reminded to breathe.”

The achievements in brain-computer interfaces to date have been based on a combination of invasive and non-invasive technologies. Many scientists in the field, including those who work with DeGray, rely on a series of surgically embedded pointed electrodes produced by a Utah-based company, Blackrock Neurotech. The Utah Array, as it’s known, can differentiate signals from individual neurons, providing more refined control of connected devices, but the surgery it requires can lead to infection, inflammation and scarring, which can contribute to the eventual degradation of the cell. signal strength. Interfaces that reside outside the skull, such as EEG-reliant headsets, are currently limited to eavesdropping on the collective firing of groups of neurons, sacrificing power and precision for safety. To further complicate the situation, 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 off-the-shelf headsets don’t solve any real-world problems, and the most powerful systems in clinical studies are too impractical for everyday use.

With this problem in mind, Elon Musk’s company Neuralink has developed a series of flexible polymer wires with more than 3,000 tiny electrodes attached to a bottle-cap-sized wireless radio and signal processor, as well as a robot. who can surgically implant the threads into the brain, bypassing the blood vessels to reduce swelling. Neuralink has tested its system on animals and has said it will begin human trials this year.

New York-based Synchron has developed a device called a Stentrode that doesn’t require open-brain surgery. It is a four centimeter self-expanding tubular network of electrodes, which is inserted into one of the main blood vessels of the brain through the jugular vein. Once placed, a Stentrode detects local electrical fields produced by nearby groups of neurons in the motor cortex and transmits the recorded signals to a wireless transmitter embedded in the chest, which passes them on to an external decoder. In 2021, Synchron became the first company to receive FDA approval to conduct human clinical trials of a permanently implantable brain-computer interface. So far, four people with various levels of paralysis have received Stentrodes and used them, some in combination with eye-tracking and other assistive technologies, to control unattended personal computers at home.

Philip O’Keefe, 62, of Greendale, Australia, received a Stentrode in April 2020. Due to amyotrophic lateral sclerosis (ALS), O’Keefe can only walk short distances, is unable to move his left arm, and is losing the ability to speak clearly. . At first, he explained, he had to concentrate intensely on the imagined movements necessary to operate the system; in his case, think about moving the left ankle for different lengths of time. “But the more you use it, the more it’s like riding a bike,” he said. “You get to a stage where you don’t think as much 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 a few letters.” In December, O’Keefe became the first person in the world to post on Twitter. using a neural interface: “No need for keystrokes or voices,” he mentally wrote. “I created this tweet just thinking about it. #helloworldbci”

Thomas Oxley, a neurologist and founding CEO of Synchron, believes future brain-computer interfaces will sit between LASIK and cardiac pacemakers in terms of cost and safety, helping people with disabilities regain the ability to relate to their physical environment. and a rapidly evolving digital environment. “Beyond that,” he says, “if this technology allows anyone to interact with the digital world better than with an ordinary human body, that’s where it gets really interesting. To express emotions, to express ideas, everything you do to communicate what’s going on in your brain has to happen through muscle control. Brain-computer interfaces will finally allow the passage of information that goes 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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