Neuralink's chip issue—where some of its threads "retracted" spontaneously from its first human patient's brain—is a known problem that's existed for years, Reuters reports Wednesday, citing five sources connected to the company who are aware of the longstanding issue. All of the sources are anonymous because they have signed non-disclosure agreements with Neuralink.
Neuralink hasn't changed the chip's design yet because the issue was deemed too low-risk to bother addressing, according to the report. Neuralink's previous controversial tests on animals indicated that thread retraction was possible, and the US Food and Drug Administration (FDA) was supposedly aware of the potential issue as well.
In response to a request for comment, an FDA representative tells PCMag that it "does not discuss or disclose conversations it may be having with any particular sponsor," but says it receives "regular progress reports" to assess "safety and data quality."
"These progress reports should include a summary of all anticipated and unanticipated adverse effects," the FDA continues, adding that it will continue to "monitor the safety of those enrolled in the study for Neuralink’s implant device."
Last week, Neuralink shared an update on its first human patient, noting toward the end of its post that an undisclosed number of the N1 chip's small thread wires had disconnected unexpectedly. "In the weeks following the surgery, a number of threads retracted from the brain, resulting in a net decrease in the number of effective electrodes," the post reads.
Neuralink said it tweaked an algorithm so that it could continue to capture data on the chip despite the disconnected wiring. "We modified the recording algorithm to be more sensitive to neural population signals, improved the techniques to translate these signals into cursor movements, and enhanced the user interface," the post continues, claiming that the changes resulted in a "rapid and sustained improvement." If more threads come loose, however, Neuralink may not be able to fix the problem without first removing the chip entirely.
Neuralink was co-founded by Tesla and SpaceX CEO Elon Musk with the initial goal of creating a brain chip for humans that could allow people to control computers using only their thoughts. The FDA authorized human trials last year. Since then, Neuralink has publicized some of the successes of its first human patient, Noland Arbaugh, who is quadriplegic but can now beat his friends playing video games with only his mind.
US lawmakers have repeatedly asked the FDA why it didn't investigate Neuralink further before beginning its human trials, however. US Rep. Earl Blumenauer sent a letter to the FDA earlier this year citing "troubling evidence" around Neuralink's alleged animal testing violations, as well as inadequate record-keeping and uncalibrated medical instruments.
PCMag has reached out to Neuralink for comment.
Editor's Note: This story has been updated to include comment from the FDA.