Just over 100 days ago, Elon Musk’s neurotech startup Neuralink placed an implant in the brain of its first human patient: 29-year-old quadriplegic Noland Arbaugh.
Arbaugh is the first participant in Neuralink’s PRIME study, which tests a brain-computer interface (or BCI) that aims to help people with full-body paralysis control outside technology using their thoughts.
But in the weeks following the initial surgery, “a number” of the electrode-containing threads that are used to record neural activity retracted from Arbaugh’s brain, the company wrote in a blog post Wednesday. In simple terms, that decreased the number of effective electrodes, along with the number of bits-per-second (BPS) measured. The BPS is the primary way Neuralink is assessing the speed and accuracy of cursor control. Neuralink did not specify how many threads retracted.
Each implant has 64 threads, which are so fine that they can’t be inserted by the human hand, according to the company. The surgery itself involves attaching the implant — called the “Link” — directly to the brain to read neural signals.
In response to the hiccup, Neuralink was able to modify its recording algorithm to make it more sensitive to brain signals, improved how the implant translates signals into cursor movements, and enhanced the user interface, to get around the receded threads. “These refinements produced a rapid and sustained improvement in BPS, that has now superseded Noland’s initial performance,” the company wrote.
“I think it should give a lot of people a lot of hope for what this thing can do for them, first and foremost their gaming experience, but then that’ll translate into so much more and I think that’s awesome,” Arbaugh said in a statement. With the Link, Arbaugh said he was even beating his friends at games that he “should not be beating them in.”
Arbaugh said in a March livestream on Musk’s X that he became a quadriplegic after a diving incident roughly 8 years ago.
While Neuralink’s performance is currently limited to the digital realm, it said its future plans include bringing the implant’s functionality to the physical world, including through the control of robotic arms and wheelchairs.
Musk first announced Neuralink in 2017 with the aim of creating “ a generalized brain interface to restore autonomy to those with unmet medical needs” through its implantable brain chips. But Neuralink raised alarm bells after more than a thousand animals were killed during the company’s early trials, leading to accusations of animal abuse and a lawsuit from a physicians group. The company received federal approval from regulators last May, and claims its operations are safe.