The company reported in a blog post yesterday that several threads retracted from the brain in the weeks following the implant procedure. The retraction led to a net decrease in the number of effective electrodes and a reduction in data bits-per-second (BPS), which measures the speed and accuracy of the patient’s ability to use the BCI technology to control a computer mouse cursor. Elon Musk-backed Neuralink did not disclose why some threads retracted unexpectedly.
The Wall Street Journal reports that people familiar with the trial’s events speculated that the threads separated due to air trapped inside the patient’s skull after surgery in a condition called pneumocephalus. The problem does not appear to cause safety issues in people with the BCI implanted. However, WSJ said that Neuralink considered removing the Link implant as a precaution.
Link’s BCI threads record neural activity through 1024 electrodes distributed across 64 threads, according to Neuralink’s website. These highly flexible, ultra-thin threads are essential to minimizing damage during implantation and after.
To mitigate the issue, Neuralink reported modifying the recording algorithm to be more sensitive to neural population signals. It also improved the techniques for translating these signals into cursor movements and enhanced the user interface.
“These refinements produced a rapid and sustained improvement in BPS, that has now superseded [the patient]’s initial performance,” the company said. “In the future we intend to extend the Link’s functionality to the physical world to enable control of robotic arms, wheelchairs, and other technologies that may help increase independence for people living with quadriplegia.”
In February, Elon Musk reported in a “Spaces” event on X that the implant had positive early clinical trial results.
Neuralink has also reported on its website that the patient has achieved things that weren’t possible before the implant.
“In the weeks since his surgery, [the participant] has used the Link to control his laptop from various positions, including while lying down in bed. He plays online computer games with friends (Chess, Civilization VI), browses the internet, live streams, and uses other applications on his MacBook, all by controlling a cursor with his mind,” the company said in a blog post.
What is the Neuralink implant?
Neuralink previously announced the first-in-human implant in January. Musk posted on X (formerly Twitter) to confirm the implant, which took place on Jan. 28.
“The first human received an implant from Neuralink yesterday and is recovering well,” Musk posted. “Initial results show promising neuron spike detection.”
The company won a regulatory nod in May of last year for a first-in-human implant, and in September, it opened recruitment for its clinical trial. Musk also announced in August 2023 that Neuralink brought in $280 million, and the company added a further $43 million in November.
Neuralink is developing an implant about the size of a coin. Musk says the company plans to call its first product “Telepathy.”
The implant is rechargeable remotely and accompanied by electrode-laced threads that extend further into the brain. Neuralink also has an R1 robot that can be programmed to implant the BCI system while avoiding vasculature.
The company designed its system to enable users to control a computer or mobile device anywhere they go.
Neuralink’s rocky past
While some experts are ‘cautiously excited’ about the start of Neuralink’s human trial, Nature Journal has reported that some neuroscientists have frustrations about the lack of detailed information — and no confirmations that the study has begun besides a tweet from the company’s owner entrepreneur Elon Musk.
“What I hope to see is that they can demonstrate that it is safe. And that it is effective at measuring brain signals — short term, but, most importantly, long term,” Mariska Vansteensel, a neuroscientist at University Medical Centre Utrecht in the Netherlands and president of the international BCI Society, told the Nature Journal.
The main source of information on the human trial of the BCI technology is a study brochure that encouraged people to participate in the study. There are no details explaining where the implantations are performed or what the trial outcome will assess. However, the brochure does mention that volunteers will be followed for five years and that the trial will assess the device’s functionality, with study participants using the implant twice a week to control a computer and provide feedback on the experience while using the BCI.
Despite the positive updates on in-human implants, Neuralink has also been in the news recently for the wrong reasons.
Reuters reported about a year ago that the U.S. government would look into Neuralink after reports of errors resulting in repeated experiments, with more animals losing their lives as a result.
Now, following a letter from U.S. lawmakers urging the SEC to look into Neuralink’s monkey deaths (reported by Wired in November), Musk denied the allegations of gruesome deaths as a result of the BCI implant.
Business Insider reported that, at The New York Times’ Dealbook conference, Musk said the test monkeys live in “monkey paradise.” He went on to say that the implant set for first-in-human testing never directly caused a monkey’s death.
Neuralink was also reportedly fined for violating rules related to the movement of hazardous materials.
