Neuralink's Human Trials: Inside the "Telepathy" Chip and What It Means for the Future of BCI

Brain-computer interfaces (BCIs) have moved from science fiction into reality in 2024. With Neuralink successfully implanting its N1 device into a second human patient, the world is getting a real-time look at how this technology functions outside of a lab. This isn’t just about moving a cursor; it is about restoring digital autonomy to individuals with quadriplegia.

The Hardware: Understanding the N1 Implant

To understand the breakthroughs happening right now, you first need to understand the hardware involved. The device, often referred to as the “Link,” is roughly the size of a coin. It replaces a small piece of the skull and sits flush with the bone.

The magic lies in the threads. The N1 implant features 64 ultra-thin threads containing a total of 1,024 electrodes. These threads are so fine that a human hand cannot manipulate them. Neuralink built a specific surgical robot, the R1, to insert these threads into the motor cortex of the brain.

Once implanted, the device records neural activity and transmits it wirelessly via Bluetooth to an external app. The app decodes these signals into actions, allowing the user to control a computer mouse or keyboard simply by intending to move.

Patient One: Noland Arbaugh's Experience

In January 2024, Noland Arbaugh became the first human to receive the Neuralink implant. Arbaugh, who is paralyzed from the shoulders down due to a diving accident, provided the first public validation of the system.

Within weeks, Arbaugh demonstrated the ability to play online chess and the strategy game Civilization VI for hours at a time. He also played Mario Kart against his father. He described the experience as using “The Force,” noting that he simply looked at a spot on the screen and imagined the cursor moving there.

The Retraction Issue

The first trial was not without engineering hurdles. A few weeks after surgery, Neuralink engineers noticed a decrease in the amount of data coming from the device. It turned out that nearly 85% of the threads had retracted or pulled back from the brain tissue.

This happened because the brain moves slightly inside the skull as we breathe or move our heads. Neuralink engineers solved this without additional surgery. They modified the recording algorithm to be more sensitive to neural population signals rather than single neuron spikes. This software update restored Arbaugh’s cursor control accuracy.

Patient Two: "Alex" and New Capabilities

In August 2024, Neuralink announced the successful implantation of its second participant, identified as “Alex.” The surgery took place at the Barrow Neurological Institute in Phoenix, Arizona.

Learning from the first trial, Neuralink adjusted their surgical measures for Alex to prevent the thread retraction issue. They minimized the gap between the implant and the brain surface to reduce tension on the threads. Early data suggests this has been successful, with no significant thread retraction observed in the first few weeks.

Gaming and 3D Design

Alex has pushed the capabilities of the device further than Arbaugh. While Arbaugh focused on strategy games, Alex has successfully played first-person shooter games like Counter-Strike 2. This requires a higher level of speed and precision, as the user must aim and click simultaneously using only mental commands.

Furthermore, Alex has used the implant to learn computer-aided design (CAD) software. Using Fusion 360, he designed a custom mount for his Neuralink charger, which was then 3D printed. This marks a significant shift from passive consumption (watching videos) or simple gaming to productive, creative work.

How Neuralink Compares to Competitors

While Elon Musk’s company generates the most headlines, they are not the only player in the BCI space. Several other companies are racing toward commercialization with different technical approaches.

  • Synchron: This company uses a different method entirely. Instead of open brain surgery, they insert their device (the Stentrode) through the jugular vein, similar to a heart stent. It sits in a blood vessel near the motor cortex. Synchron has already implanted their device in multiple patients in the U.S. and Australia. It is less invasive but offers lower data resolution than Neuralink.
  • Precision Neuroscience: Founded by a Neuralink co-founder, this company uses a thin film array that sits on top of the brain rather than penetrating it. Their “Layer 7 Cortical Interface” aims to provide high data bandwidth without damaging brain tissue.
  • Blackrock Neurotech: A veteran in the space, their “Utah Array” has been used in research settings for decades. Their technology is proven but has traditionally required wired connections through the skull, though they are working on wireless versions.

The Road to FDA Approval

Currently, Neuralink is operating under an Investigational Device Exemption (IDE) from the FDA. This allows them to conduct the PRIME Study (Precise Robotically Implanted Brain-Computer Interface) to evaluate safety and initial functionality.

The path to a commercially available medical device is long. The company must prove that the device is safe for long-term implantation (years, not months) and that the surgical robot is reliable across different surgeons and hospital settings.

Looking ahead, the company has teased a future device called “Blindsight,” aimed at restoring vision to the blind, and another unnamed project intended to bridge severed spinal cord connections to restore body movement. However, the current focus remains strictly on the N1 “Telepathy” implant for computer control.

Frequently Asked Questions

Who is eligible for the current Neuralink trials? The PRIME Study is currently looking for individuals who have limited or no ability to use both hands due to cervical spinal cord injury or Amyotrophic Lateral Sclerosis (ALS). Candidates must be at least 22 years old and have a consistent caregiver.

Does the surgery hurt? The brain itself has no pain receptors. However, general anesthesia is used during the surgery because it involves an incision in the scalp and removing a small portion of the skull bone. Patients are unconscious during the procedure.

How much will the Neuralink implant cost? There is no commercial price yet as it is an experimental device. Some industry analysts estimate that early surgeries could cost insurance companies upwards of \(40,000 to \)50,000, similar to other complex neurostimulator implants (like deep brain stimulation for Parkinson’s), but this is speculative.

Can the device be removed? Yes. Neuralink states that the device is designed to be upgradeable and reversible. If a patient wants it removed or needs a newer model, the R1 robot is capable of removing the implant, though any brain surgery carries inherent risks of tissue damage or infection.

Is the device connected to the internet? The implant connects via Bluetooth to a nearby computer or smartphone. While the implant itself does not have a direct Wi-Fi chip, the computer it controls is connected to the internet, which creates theoretical cybersecurity risks that engineers are actively working to mitigate.