Brain-Computer Interfaces: Neuralink's First Year

The first year of human trials for Neuralink has moved brain-computer interface technology from science fiction into documented medical reality. Founded by Elon Musk, the company set out to help paralyzed patients control digital devices using only their thoughts. The early results from the first human patients reveal major breakthroughs, unexpected hardware challenges, and rapid surgical adjustments.

The PRIME Study and The N1 Implant

In May 2023, the United States Food and Drug Administration cleared Neuralink to begin human clinical trials. This clinical trial is officially named the PRIME Study, which stands for Precise Robotically Implanted Brain-Computer Interface. The study specifically targets individuals with quadriplegia caused by cervical spinal cord injury or amyotrophic lateral sclerosis (ALS).

The hardware at the center of this trial is the N1 implant, internally called the Telepathy device. The N1 is a coin-sized computer chip placed entirely under the scalp, flush with the skull. It contains 1,024 microscopic electrodes distributed across 64 highly flexible polymer threads. Because these threads are thinner than a human hair, human surgeons cannot insert them accurately. To solve this, Neuralink developed the R1 surgical robot to weave the threads directly into the motor cortex of the brain.

Once implanted, the N1 chip reads neural spikes associated with movement intention. It then transmits this data wirelessly via Bluetooth to a custom application on a computer or smartphone. The battery is completely sealed inside the device and charges wirelessly through the skin using a custom inductive charging pad.

Patient Zero: Noland Arbaugh's Experience

On January 28, 2024, a 29-year-old man named Noland Arbaugh became the first human to receive the Neuralink implant. Arbaugh had been paralyzed from the shoulders down following a diving accident eight years prior. The surgery went smoothly, and he returned home the following day.

The initial results were highly successful. Within weeks, Arbaugh demonstrated the ability to control a computer mouse simply by imagining the movement of his hand. Before the implant, he relied on a mouth-operated joystick to use his computer. With the Telepathy device, he quickly learned to browse the internet, post messages on social media platform X, and play complex video games. Arbaugh famously reported playing the strategy game Civilization VI for eight hours straight, stopping only because his implant needed to be recharged. He also played Mario Kart with his friends, successfully steering his vehicle using only neural commands.

The Thread Retraction Challenge

Despite the early success, Neuralink faced a significant medical and engineering challenge about a month after Arbaugh’s surgery. Arbaugh noticed a sharp decline in his cursor speed and accuracy. The system measures performance using a metric called Bits Per Second (BPS), which tracks the speed and precision of cursor control. Arbaugh’s BPS dropped dramatically.

Medical imaging revealed that roughly 85 percent of the 64 microscopic threads had retracted from his brain tissue. The brain naturally pulses and shifts slightly within the skull, and this movement caused the delicate threads to pull out of the motor cortex. This reduced the number of active electrodes capable of reading Arbaugh’s neural signals.

Instead of performing a second surgery to remove or adjust the implant, Neuralink engineers approached the problem through software. They updated the recording algorithm to be far more sensitive to the neural signals picked up by the few remaining threads. They also improved the software that translates those signals into cursor movements. These over-the-air software updates successfully restored Arbaugh’s control, bringing his performance metrics back to their initial high levels.

The Second Patient and Surgical Improvements

Neuralink applied the lessons learned from Arbaugh’s complication directly to their second human trial. In August 2024, a patient known only as Alex received the N1 implant. Alex also suffers from a spinal cord injury that limits the use of his limbs.

To prevent the thread retraction issue seen in the first surgery, the medical team modified the surgical procedure. The R1 robot was programmed to insert the threads deeper into the motor cortex. Furthermore, the surgeons actively reduced the physical gap between the implant sitting in the skull and the surface of the brain. As a result, Neuralink reported no significant thread retraction in Alex’s case.

Alex achieved impressive technical milestones shortly after his surgery. On his second day using the device, he broke the previous world record for brain-computer interface cursor control speed. Alex used the implant to play the fast-paced competitive shooter Counter-Strike 2. Beyond gaming, he used computer-aided design (CAD) software called Fusion 360 to design a custom 3D-printed mount for his Neuralink wireless charger. This demonstrated that the device could handle precise, professional-grade digital tasks.

The Broader Industry and Future Goals

Neuralink is not the only company working on brain-computer interfaces. Competitors like Synchron and Precision Neuroscience are also making significant progress. Synchron, for example, avoids open-brain surgery entirely by delivering its stent-like sensor through the jugular vein. However, Neuralink currently stands out due to its high channel count. By using 1,024 electrodes, the N1 device captures a much higher bandwidth of data than most competing devices, allowing for smoother and more complex digital control.

Looking past the PRIME study, Elon Musk has announced plans for a second Neuralink product called Blindsight. The goal of this future device is to restore vision to people who have lost their sight or were born blind, by stimulating the visual cortex directly. In September 2024, the FDA granted the Blindsight project a Breakthrough Device Designation, which speeds up the development and review process for medical devices that treat irreversible conditions.

Frequently Asked Questions

How does the Neuralink implant get power? The N1 implant has a small, built-in battery that is completely sealed under the skin. It charges wirelessly. The patient places a compact inductive charging hub over the skin where the implant is located, much like placing a wireless charger against the back of a smartphone.

Can the patient feel the implant in their head? According to the first patient, Noland Arbaugh, he cannot feel the device at all once the surgical site healed. The implant sits flush with the skull under the scalp, so there are no wires sticking out of the skin.

Will the device be available to the general public? Currently, the device is strictly limited to medical clinical trials approved by the FDA. It is only available to patients with severe mobility impairments like quadriplegia or ALS. While the company eventually wants to make the technology widely available, widespread public access is still many years away due to the need for extensive safety testing.