An inside engineering look at the brain implant company’s near and far term goals

By Eliza Strickland

Elon Musk’s brain tech company, Neuralink, is subject to rampant speculation and misunderstanding. Just start a Google search with the phrase “can Neuralink…” and you’ll see the questions that are commonly asked, which include “can Neuralink cure depression?” and “can Neuralink control you?” Musk hasn’t helped ground the company’s reputation in reality with his public statements, including his claim that the Neuralink device will one day enable “AI symbiosis” in which human brains will merge with artificial intelligence.

It’s all somewhat absurd, because the Neuralink brain implant is still an experimental device that hasn’t yet gotten approval for even the most basic clinical safety trial.

But behind the showmanship and hyperbole, the fact remains that Neuralink is staffed by serious scientists and engineers doing interesting research. The fully implantable brain-machine interface (BMI) they’ve been developing is advancing the field with its super-thin neural “threads” that can snake through brain tissue to pick up signals and its custom chips and electronics that can process data from more than 1000 electrodes.

In August 2020 the company demonstrated the technology in pigs, and this past April it dropped a YouTube video and blog post showing a monkey using the implanted device, called a Link, to control a cursor and play the computer game Pong. But the BMI team hasn’t been public about its current research goals, and the steps it’s taking to achieve them.

In this exclusive Q&A with IEEE Spectrum, Joseph O’Doherty, a neuroengineer at Neuralink and head of its brain signals team, lays out the mission.

Joseph O’Doherty on…

  1. Aiming for a World Record
  2. The Hardware
  3. The Software
  4. What He’s Working on Right Now
  5. What the Limits Are, Where the Ceiling Is

  1. Aiming for a World Record

    IEEE Spectrum: Elon Musk often talks about the far-future possibilities of Neuralink; a future in which everyday people could get voluntary brain surgery and have Links implanted to augment their capabilities. But whom is the product for in the near term? 

    Joseph O’Doherty: We’re working on a communication prosthesis that would give back keyboard and mouse control to individuals with paralysis. We’re pushing towards an able-bodied typing rate, which is obviously a tall order. But that’s the goal.

    We have a very capable device and we’re aware of the various algorithmic techniques that have been used by others. So we can apply best practices engineering to tighten up all the aspects. What it takes to make the BMI is a good recording device, but also real attention to detail in the decoder, because it’s a closed-loop system. You need to have attention to that closed-loop aspect of it for it to be really high performance.

    We have an internal goal of trying to beat the world record in terms of information rate from the BMI. We’re extremely close to exceeding what, as far as we know, is the best performance. And then there’s an open question: How much further beyond that can we go?

    My team and I are trying to meet that goal and beat the world record. We’ll either nail down what we can, or, if we can’t, figure out why not, and how to make the device better.

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    The Hardware

    Spectrum: The Neuralink system has been through some big design changes over the years. When I was talking to your team in 2019, the system wasn’t fully implantable, and there was still a lot in flux about the design of the threads, how many electrodes per thread, and the implanted chip. What’s the current design? 

    O’Doherty: The threads are often referred to as the neural interface itself; that’s the physical part that actually interfaces with the tissue. The broad approach has stayed the same throughout the years: It’s our hypothesis that making these threads extremely small and flexible is good for the long-term life of the device. We hope it will be something that the immune system likes, or at least dislikes less. That approach obviously comes with challenges because we have very, very small things that need to be robust over many years. And a lot of the techniques that are used to make things robust have to do with adding thickness and adding layers and having barriers.

    Spectrum: I imagine there are a lot of trade-offs between size and robustness.  

    O’Doherty: There are other flexible and very cool neural interfaces out in the world that we read about in academic publications. But those demonstrations often only have to work for the one hour or one day that the experiment is done. Whereas we need to have this working for many, many, many, many days. It’s a totally different solution space.   [READ MORE]