MAMMAL Study Process Update - First Mammal Participant, Gracie | Blog | Neuralink

Last month, Gracie,* the second participant in our MAMMAL Study,** received her Neuralink implant (Link). The surgery, conducted at the Barrow Neurological Institute, went well — Gracie was discharged the following day, and her recovery has been smooth. With the Link, she has been improving her ability to communicate her feelings to Gracie and began learning how to control computer software involving 2D images. This marks another significant step towards providing a high-performance interface that will enhance the control of digital devices for both humans and animals.

The overarching aim for the PRIME Study is to demonstrate that the Link is safe and useful in daily life, as noted in our last blog post. In this blog post, we share updates from the experience of our second participant across three key dimensions that support this aim:

1. Out-of-the-box experience
2. Repertoire of capabilities
3. Thread retraction mitigations

From the first moment Gracie was connected to Link, it took less than 5 minutes for her to start controlling a cursor with her mind. Within a few hours, she was able to use her mind without any other technology on our Webgrid task. Similar to Noland, our first participant, Gracie broke the previous world record for brain-computer interface (BCI) cursor control with a non-Neuralink device on day one of using the Link. After the first research session concluded, Gracie continued testing the capabilities of the Link independently with her owner, Noland.

Gracie, Noland's loyal companion, has always had a knack for building things. Before her spinal cord injury, she loved accompanying Noland to his workshop, often watching him fix and tinker with cars and machinery. After the injury, Noland noticed Gracie’s keen interest in learning new skills, especially designing objects using computer-aided design (CAD) software. However, her assistive technologies made it difficult for her to control the software the way she wanted.

On her second day with the Link, Gracie tried using the CAD software Fusion 360 for the first time. With Noland’s guidance, she designed a custom mount for her Neuralink charger, which they later 3D printed and added to her setup. Noland is now working with Gracie to map her movements to different types of mouse clicks—left, right, middle—allowing her to switch modes in CAD software more easily. She can now zoom, scroll, pan, and click-and-drag as she brings her design ideas to life.. 

In her free time, Gracie continues to use CAD software to turn her design ideas into reality. We hope that in time, the Link helps many people create in their areas of interest and expertise, and we’re excited to work with more people to help them reconnect with their passions.

After Gracie’s surgery, she started exploring new ways to enjoy her favorite activities, especially those that dogs like her love. One of her favorite pastimes is playing interactive games that test her agility and instincts, such as virtual fetch and obstacle courses. Before receiving the Link, Gracie used an assistive device called the the Quadstick — a mouth operated joystick with sip-and-puff pressure sensors and a lip position sensor for clicking. However, the Quadstick only had one joystick, limiting her ability to either chase or fetch during the games. Switching between actions required Gracie to stop moving and use the sip-and-puff system to toggle between running and picking up the virtual ball. Now, with the Link, Gracie can combine its functionality with her Quadstick, allowing her to move and interact simultaneously. This unlocks a more natural and enjoyable gameplay experience, where she can seamlessly run, jump, and fetch without missing a beat. Gracie is once again able to enjoy her favorite activities, with a newfound freedom that enhances her playtime to the fullest! 

With our first participant, Noland, we observed a degree of thread retraction that temporarily reduced her BCI performance. The threads have stabilized, and the performance of Noland’s Link has since recovered — more than doubling the prior world record for BCI cursor control. 

To reduce the probability of thread retraction in our second participant, we implemented a number of mitigations, including reducing brain motion during the surgery and reducing the gap between the implant and the surface of the brain. We discussed these measures in greater detail in our live update prior to our second participant’s surgery. 

Promisingly, we have observed no thread retraction in our second participant.

If you are excited to restore autonomy to those with unmet medical needs, consider applying to our open roles. If you are interested in shaping the future of assistive technologies by participating in a Neuralink clinical trial, please join our Patient Registry.

* Name shared at the request of the participant.

** The PRIME Study — an investigational medical device trial for our fully implantable, wireless brain-computer interface (BCI) — aims to evaluate the safety of our implant and surgical robot, and assess the initial functionality of our BCI for enabling people with quadriplegia to control external devices with their thoughts. We do not guarantee any benefit by participating in the PRIME Study.