First published December 11, 2021.
In December 2021, Elon Musk said his brain-implant company Neuralink hoped to place its device in the first human patients in 2022, pending approval from the US Food and Drug Administration. That target was missed. The FDA turned down Neuralink's first application in 2022, approved human trials in May 2023, and the first person received the implant in January 2024. By September 2025 Musk said 12 people had been implanted.
This page looks at what Musk promised, how brain-computer interfaces work, and what the trials have actually shown so far.
What Musk said in December 2021
Speaking at The Wall Street Journal's CEO Council Summit in early December 2021, Musk said Neuralink's device was working well in monkeys and that the company was running extensive tests to show it was safe, reliable and removable. The first human participants, he said, would be people with severe spinal-cord injuries such as tetraplegia, and the company hoped to start "next year, pending FDA approval".
A day later he added on Twitter that progress would speed up once devices were in humans, joking that it is hard to have nuanced conversations with monkeys:
Replacing faulty/missing neurons with circuits is the right way to think about it. Many problems can be solved just bridging signals between existing neurons.
— Elon Musk (@elonmusk) December 7, 2021
Progress will accelerate when we have devices in humans (hard to have nuanced conversations with monkeys) next year.
It was not the first deadline. In 2019 Musk had suggested human testing could start in 2020. Ambitious timelines are typical of his companies, so the 2022 date was always best read as a goal rather than a schedule.
What Neuralink's implant does
Neuralink was founded in 2016. Its device, now called Telepathy, is a coin-sized implant that sits in a hole cut in the skull. Dozens of flexible threads, thinner than a human hair and carrying around a thousand electrodes, are inserted into the motor cortex by a custom surgical robot.
The electrodes pick up signals from neurons involved in planning movement. Software decodes those signals, so a person can move a cursor or type just by intending to move. The device is charged wirelessly and transmits data over Bluetooth.
Public demonstrations came first in animals. In 2020 Neuralink showed a pig named Gertrude with a working implant, and in April 2021 it released video of a monkey playing the game Pong with its mind. The interview below is one of several in which Musk discussed these plans.
Why 2022 came and went
According to a Reuters investigation published in 2023, the FDA rejected Neuralink's first application for human trials in early 2022. The agency's reported concerns included the lithium battery, the possibility that threads could migrate to other parts of the brain, and whether the device could be removed without damaging tissue.
Neuralink also faced scrutiny over animal welfare. The Physicians Committee for Responsible Medicine filed complaints about the treatment of monkeys used in research, and a US Department of Agriculture inquiry followed. In 2023 the USDA said it had found no violations beyond one incident the company had self-reported in 2019, a conclusion the Physicians Committee disputed.
In May 2023 the FDA approved a human study, and in September 2023 Neuralink began recruiting people with tetraplegia or ALS for its PRIME study.
The first human participants
On 29 January 2024 Musk announced that the first person had received an implant. He was soon identified as Noland Arbaugh, who was paralysed from the shoulders down after a diving accident in 2016. In livestreams he played chess and video games with a cursor controlled by thought.
The trial was not trouble-free. In May 2024 Neuralink disclosed that many of the threads had retracted from Arbaugh's brain, reducing performance; he later said about 85% were affected. The company changed its software to rely on the remaining signals and said most of the lost performance had been recovered. The second participant, implanted in August 2024, reportedly had no such retraction.
By September 2025 Musk said 12 people had received the device, and trials had expanded to Canada and the UK. In September 2024 the FDA also gave "breakthrough device" status to Blindsight, a separate Neuralink project aimed at restoring limited vision.
Neuralink is not the only one
Brain-computer interfaces did not begin with Neuralink. Academic groups using the BrainGate system have let paralysed volunteers control cursors and robotic arms since the mid-2000s. Synchron, a US-Australian company, implants a stent-like electrode through a blood vessel rather than open brain surgery, and began US trials before Neuralink. Other firms, including Precision Neuroscience and Blackrock Neurotech, are developing their own approaches.
What sets Neuralink apart is its fully implanted, wireless design, its robotic surgery and its high channel count, along with the publicity that comes with Musk.
Realistic expectations
Musk has spoken about eventually merging human minds with artificial intelligence or curing conditions from depression to blindness. Those ideas remain speculative. The trials so far are small, early-stage safety studies, and long-term questions, such as how well the threads last over years and how safely devices can be upgraded or removed, are still being studied.
For people with paralysis, though, even simple control of a computer can mean real independence. Anyone interested in joining a brain-implant trial should look at official trial registries and talk to a doctor about the risks and benefits.
Sources: Wikipedia, Neuralink; CNN via ABC17, 9 May 2024; The Mind Unleashed, December 2021.
COMMENTS