A team of engineers, neuroscientists, and neurosurgeons at UC Davis and UC Davis Health has achieved a significant advancement in brain-computer interface (BCI) technology. Their research, published in the Journal of Neuroengineering, shows that BCIs developed for translating brain signals into speech can also be used to control a computer cursor. The project received support from the National Science Foundation and the National Institutes of Health.
The research team’s work aims to restore more functions for people with paralysis, increasing their autonomy. Tyler Singer-Clark, a biomedical engineering Ph.D. student and first author on the paper, said, “Future steps in multimodal BCIs could include gesture decoding for all sorts of different things, enriching the types of interactions someone with paralysis can have with their environment beyond speech.”
Singer-Clark is part of the UC Davis Neuroprosthetics Lab, which is led by neuroscientist Sergey Stavisky and neurosurgeon David Brandman. The lab previously developed a highly accurate BCI for speech, which provided the foundation for this new project. Their BCI is implanted in the speech motor cortex and interprets electrical activity from thoughts, converting it into recognizable words on a computer.
During their research, the team noticed that the area of the brain used for speech could also support cursor control, a function usually linked to a different brain region. Based on this observation, Singer-Clark began developing software to allow cursor control through the speech BCI. He utilized previous research on cursor control from other brain areas and adapted the lab’s existing code.
“We didn’t have to reinvent the pre-processing of the neural data,” Singer-Clark said. “For cursor control, it’s actually the same pre-processing steps the speech BCI uses to get the neural features that are going to be useful for decoding the intention of the participant.”
Singer-Clark then personalized the software for a participant in the BrainGate clinical trial. The participant, who has amyotrophic lateral sclerosis (ALS), is unable to move. Singer-Clark observed the participant’s neural activity as he watched and thought about moving a cursor on a screen. This data was used to adapt the software to the participant’s BCI implant.
Once the software was ready, the participant quickly adapted to using the cursor. He was able to move the cursor and click on applications by thinking about the movement. Singer-Clark explained that the system does not translate abstract thoughts but works more like intuition. “That’s his word, intuition,” Singer-Clark said. “I’ll say, ‘What motor imagery are you using?’ And he says, ‘Intuition.’”
David Brandman, co-director of the UC Davis Neuroprosthetics Lab, commented on the importance of the work. “Singer-Clark’s work is incredibly important for the field. His work has not only empowered our BrainGate2 participant to use a computer cursor with his thoughts but has also led the way for multiple companies in this space to design their clinical trials.”
Singer-Clark noted the broader impact of the project. “It hammers home a growing viewpoint that different body parts and their movements are represented in multiple areas of the motor cortex, as opposed to being all siloed in their own areas.” He also highlighted the personal significance: “There’s a man with ALS who can control his computer independently without someone else helping him for hours and hours every day. It’s like this great event, and we might not have tried if we didn’t have that prior research encouraging us to do that.”
The UC Davis team continues to advance BCI technology with the goal of increasing independence for people with paralysis.
