Neuralink and the Arbaugh Trial — The Brain-Data Layer

The receipts for the brain-data layer of the control grid — the first human being to live with a brain-computer interface, sourced to Neuralink’s own posts, the participant’s own on-record interviews and talks, regulatory filings, and established science and medical press. Where the record is contested, both the company’s account AND the reported scale are surfaced. Noland Arbaugh is a willing, self-publicizing public figure — he gives on-record interviews, live-streams, and keynotes conferences about being Neuralink’s first patient; every medical or personal detail here is one he or Neuralink has publicly disclosed, none sourced to leaked records. Claims about Neuralink’s conduct are attributed to named reporting or to named experts speaking in their professional capacity, with Neuralink’s own responses quoted alongside. No claim here alleges illegality by any party.

This is the brain-signal cut of the body movement in The Last Antibodies; the full six-layer survey is on The Body Layer, and the person is profiled at Neuralink.

Background and the injury

Noland Arbaugh (born 1993/1994) is from Yuma, Arizona. He attended Texas A&M University, studied international studies, and was a member of the Corps of Cadets (Wikipedia — Noland Arbaugh).

In July 2016, at age 22 — the summer after his senior year — Arbaugh was working at Island Lake Camp in Starrucca, Pennsylvania, when he suffered a cervical spinal-cord injury in a shallow-water swimming accident. In his own account: “I got hit in the side of the head at some point as we were getting into the water … My c4 and c5 popped out of place and back into place.” He lost consciousness in the water and was pulled out; the injury left him paralyzed below the shoulders (Big Technology — Full Q&A with Noland Arbaugh; Wikipedia — Noland Arbaugh).

He describes the functional level plainly: “Since I’m a C4, C5, anything below my shoulders, maybe a couple inches below my shoulders, I can’t feel or move.” Emergency surgery did not restore mobility; he rehabbed at Helen Hayes Hospital in New York and Craig Hospital in Colorado, then returned to live with his family in Yuma (Big Technology — Full Q&A; Wikipedia — Noland Arbaugh). Before the implant, the combination of Yuma’s heat and severe spasms in his power chair meant he spent most of his time in bed watching television, with limited caregiving hours and heavy reliance on his family (New Mobility — Noland Arbaugh’s Life as the First Neuralink Recipient).

Why he volunteered

Neuralink opened its first-in-human PRIME Study for recruitment on 2023-09-19 (Neuralink — updates index). Arbaugh heard about it from a friend from military school. His own version is characteristically blunt: “My buddy called me up just randomly drunk on a Wednesday at 11am and he said, ‘Hey, you want to get a chip in your brain?’ I said, ‘Sure. Why not? I got nothing going on.’” He applied the next day and, after roughly three months of screening at Barrow Neurological Institute, was selected as the first participant. He says he kept his expectations deliberately low: “I kept my expectations extremely level through this whole process.” (Big Technology — Full Q&A.)

The surgery and the device

The implant was performed on 2024-01-28 at Barrow Neurological Institute in Phoenix, Arizona — the world’s first human Neuralink implantation. Neuralink marks the anniversary on January 28; the public announcement came the following day, and some outlets date it to the 29th. Arbaugh was discharged the next day with no cognitive impairment reported (Neuralink — Two Years of Telepathy; Wikipedia — Noland Arbaugh). Arbaugh on the procedure: “The surgery was supposed to last between three to six hours. It lasted under two. Everything went so perfectly … they closed me up in an hour and fifty-four minutes.” (Big Technology — Full Q&A.)

The device is the N1 implant: 64 ultra-thin flexible threads carrying 1,024 electrodes, inserted into the motor cortex — the region that plans voluntary movement — by Neuralink’s R1 surgical robot. When Arbaugh intends a movement, motor-cortex neurons fire in patterns the implant captures, digitizes, and transmits over Bluetooth Low Energy to an external device, where a machine-learning decoder trained on his individual neural patterns turns the signal into cursor motion. He does not move physically; the signal path is intention → electrode capture → on-chip digitization → Bluetooth → decoding algorithm → output command (TechTimes — Neuralink BCI After 28 Months; Neuralink — PRIME Study Progress Update: User Experience).

The trial is registered as ClinicalTrials.gov NCT06429735. The FDA granted Neuralink an Investigational Device Exemption to begin human trials in May 2023 (Wikipedia — Neuralink).

What the implant restored

Performance is measured in bits per second (BPS) on a grid cursor task; higher is better. In Neuralink’s own words: “During his first-ever research session, Noland set a new world record for human BCI cursor control of 4.6 BPS. He has subsequently achieved 8.0 BPS and is currently trying to beat scores of the Neuralink engineers using a mouse (~10 BPS).” (Neuralink — PRIME Study Progress Update: User Experience.)

At roughly 100 days post-surgery, Neuralink documented that he controls his laptop cursor from any position, including lying in bed; plays online games with friends such as Chess and Civilization VI; browses the web; live-streams; and used the Link to play Mario Kart on a Nintendo Switch, “something he had not been able to do since his spinal cord injury.” (Neuralink — PRIME Study Progress Update: User Experience.) By August 2025, as relayed by TechTimes, Arbaugh was using the implant about 10 hours a day — for chess, community-college neuroscience coursework, scheduling, and communication. He has named his implant “Eve” and calls it his “brain co-pilot.” (TechTimes — Neuralink BCI After 28 Months.)

At the 2026 Robotics Summit & Expo in Boston (2026-05-28, roughly 28 months post-surgery), he closed the conference by moving physical chess pieces with his thoughts, drawing the event’s final standing ovation. Neuralink’s stated forward direction is to push cursor control to able-bodied levels, add text entry, and extend the Link to “control of robotic arms, wheelchairs, and other technologies.” (TechTimes — Neuralink BCI After 28 Months; Neuralink — PRIME Study Progress Update: User Experience).

The thread-retraction complication

About a month after surgery, a number of the electrode threads retracted from Arbaugh’s brain tissue, cutting the number of functional electrodes and degrading performance. Neuralink’s own account, understated and giving no percentage: “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. This led to a reduction in BPS. In response … 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. These refinements produced a rapid and sustained improvement in BPS, that has now superseded Noland’s initial performance.” (Neuralink — PRIME Study Progress Update: User Experience.)

Neuralink itself never published a figure. Per reporting, approximately 85% of the threads retracted within weeks, dropping effective channels from 1,024 toward a few hundred; the cause is attributed to the brain shifting inside the skull more than Neuralink anticipated and/or the brain’s immune response treating the wires as foreign bodies, with an early theory citing trapped air (pneumocephalus) in the skull after surgery (NBC News — implant suffers setback after threads retract; Popular Science — 85% of Neuralink implant wires detached; TechTimes — Neuralink BCI After 28 Months).

The fix was software, not surgery. Neuralink did not reopen his skull; engineers reworked the decoding algorithm to extract more signal from the surviving electrodes, and Arbaugh’s performance eventually exceeded his pre-retraction benchmark. For subsequent patients, Neuralink changed the surgical technique — reducing post-op air pockets, eliminating the gap between implant and brain, and seating the threads deeper — and reports no later patient experienced retraction at the same scale (TechTimes — Neuralink BCI After 28 Months; Neuralink — PRIME Study Progress Update: User Experience). NBC News reported in May 2024 that Neuralink had known about the wire-retraction problem for years, dating to animal testing — attributed reporting, not settled fact (NBC News — implant suffers setback).

In his own words

Verbatim, on record, safe to quote with attribution.

On reconnection (Neuralink’s published participant quote):

“[The Link] has helped me reconnect with the world, my friends, and my family. It’s given me the ability to do things on my own again without needing my family at all hours of the day and night.”

(Neuralink — PRIME Study Progress Update: User Experience.)

On how seamless it feels:

“Sometimes I forget that I’m even paralyzed and that I’m restricted in the way that I am, because it’s just so seamless.”

On it being a superpower:

“It’s a superpower. When it comes to video games, your brain has to send the signal to your hands and come all the way back up in order for you to move …”

On the low point when the threads retracted:

“I cried in my van on the way to the Neuralink facility. I said, ‘This sucks. It’s awful.’”

“The brain moved much more than what Neuralink anticipated, which kind of blew my mind.”

(All four from Big Technology — Full Q&A.) Recounting the retraction again at the 2026 Robotics Summit: “It sucked. It was really, really hard.” (TechTimes — Neuralink BCI After 28 Months.)

Neuralink’s status, mid-2026

Neuralink’s own figure is 21 participants — “Neuralnauts” — enrolled in trials worldwide as of 2026-01-28, and rising (Neuralink — Two Years of Telepathy; Wikipedia — Neuralink). The second patient (“Alex”) was implanted in August 2024 (Neuralink — PRIME Study Progress Update: Second Participant); the first UK patient (“Paul”) on 2025-10-28. Trials have expanded internationally — US PRIME, Canada (CAN-PRIME, launched November 2024), the UK (GB-PRIME, launched July 2025), and the UAE (Wikipedia — Neuralink; Neuralink — updates index).

On regulatory status: the Investigational Device Exemption for human trials came in May 2023, followed by FDA Breakthrough Device Designations for Blindsight (vision restoration) in September 2024 and for speech restoration in May 2025 — the latter covering ALS, stroke, spinal-cord injury, cerebral palsy, multiple sclerosis, and other neurological conditions. Breakthrough designation grants prioritized FDA review; it is not an approval or a safety/efficacy finding, a common point of misreporting (Neuralink — Breakthrough Device Designation for Blindsight; Neuralink — Breakthrough Device Designation for Speech; Medical Device Network — FDA breakthrough tag for speech, via Wayback).

Elon Musk has said Neuralink aims to move to “high-volume” production and fully automated surgery in 2026. Carolina Aguilar, CEO of INBRAIN Neuroelectronics, reads “high-volume” realistically as “hundreds moving toward low thousands of implants per year” — the gap between the rhetoric and the current install base (The Debrief — Neuralink Reaches 21 Patients).

The critics, in their own fields

On transparency, after early results were announced via social media rather than peer review, several neuroethicists objected. Marcello Ienca (Professor of Ethics of AI and Neuroscience, Technical University of Munich) said the approach “seems to sidestep the established protocols that underpin scientific integrity,” and that a failure to register the trial “violates fundamental ethical guidelines for biomedical research.” L. Syd M Johnson (bioethicist, SUNY Upstate Medical University): “A tweet is not exactly a peer-reviewed scientific report.” Laura Cabrera (neuroethicist, Rock Ethics Institute, Penn State) called for “more rigorous ways” to hold companies to reporting standards comparable to federally funded trials (Forbes — Experts Criticize Neuralink Over Transparency).

On the ethics of the implant itself, two University of Washington professors — Nancy S. Jecker (Bioethics and Humanities, UW School of Medicine) and Andrew Ko (Neurological Surgery, UW) — laid out the standing concerns: neural-data privacy (the risk of “identity theft, password hacking and blackmail” and third-party manipulation of autonomy); device abandonment (“the prospect of losing access after the study ends”); a risk/benefit warning that “at current levels of safety and reliability, the benefit of a permanent implant would have to be large to justify the uncertain risks”; and a justice concern that enhancements could “exacerbate social inequalities if only wealthy citizens have access.” (The Conversation — Two professors unpack the ethical issues.) Kip Ludwig, a neural-engineering expert, assessed Arbaugh’s first public demo in March 2024 as promising but early-stage — a read TechTimes notes 28 months of continuous use has substantially updated (TechTimes — Neuralink BCI After 28 Months).

On animal testing: between 2018 and 2022, at least roughly 1,500 animals (monkeys, pigs, sheep) were used; of at least 23 monkeys in 2017–2020 experiments, roughly 15 died or were euthanized. The USDA opened an animal-welfare investigation in December 2022, and the SEC reopened an investigation in December 2024; the Physicians Committee for Responsible Medicine filed complaints alleging unnecessary suffering. Neuralink says it has since prioritized transparency and reduced reliance on primates. These figures are attributed to reporting and filings, not adjudicated findings (Wikipedia — Neuralink; Princeton Medical Review — Advancements and Ethical Concerns of Neuralink).

The capture frame

The body layer’s promise here is not a strawman. The implant gave a paralyzed man back the internet, chess, coursework, and a measure of independence he names in his own words — “reconnect with … my family,” “forget I’m even paralyzed.” Both registers are true, and both come from the same man: the restoration and the fragility (“the brain moved much more than … anticipated”). The turn is the thread retraction — the interface degraded under simple biology, and the fix was software rewriting how the machine reads him rather than reopening the body. That is the exact body-layer motif: when the flesh will not cooperate, adjust the decoder.

Neural data is the most intimate capture surface yet reached, which is why the named ethicists’ worries — neural-data privacy, autonomy manipulation, device abandonment — are the on-record hooks, and why the gap between Musk’s “high-volume 2026” rhetoric and an install base of 21-and-rising is itself worth watching. The structural claim survives on the receipts alone, without any inference of intent: once a device sits inside the motor cortex and streams decoded intention over Bluetooth, the substrate exists for every other layer of the grid to ride on. Whether it ever does is a separate question the record does not yet answer.

Related research

• The Body Layer — the full six-layer survey (biometric ID, CBDC, BCIs, genetic databases, molecular platforms, continuous monitoring), each program paired with its documented limit.
• The Electrode and the Feed — the neurorights law surrounding this hardware: Chile’s constitutional mental-privacy protection and the Girardi v. Emotiv EEG-deletion ruling.
• Cognitive Capture — How AI Steers the Mind — the mind layer to this body layer, where the nudge runs at the level of the thought itself.
• Neuralink — the profile.