Advancements in Brain-Computer Interfaces
In 2024, a year after significant strides from the team at Stanford, Stavisky and her colleagues released their findings regarding a brain-to-text system that achieved an impressive accuracy rate of 97.5 percent. “Almost every word was correct, but communicating solely through text can present limitations,” Stavisky noted. “There are times when expressing oneself vocally is preferable. It enables interjections, mitigates interruptions from others, and allows for singing or the use of non-standard vocabulary.” However, the predominant method for generating spoken language involved synthesizing it from written text, a process that introduced its own complications, notably high latency in BCI systems.
Most BCI speech assistance technologies feature noticeable delays, displaying sentences on screens long after a user has formed the thoughts in their mind. This issue arises because the speech synthesis process only initiates after the text generation completes, contributing to extended lag. Furthermore, existing brain-to-text solutions are limited by their vocabulary size, with the most advanced systems accommodating roughly 1,300 words. Consequently, attempts to articulate phrases in different languages, utilize complex vocabulary, or even specify obscure local references often result in system failures.
In response to these challenges, Wairagkar innovated a prosthesis designed to convert brain signals into sounds directly, bypassing the need for textual translation and enabling real-time communication.
Participant Profile
T15, a 46-year-old man diagnosed with ALS, volunteered for Wairagkar’s study. “He is severely paralyzed, and his speech is often very difficult to comprehend. Having known him for several years, I understand roughly 5 percent of what he manages to say,” explained David M. Brandman, a neurosurgeon and co-author of the research. Prior to his involvement with the UC Davis team, T15 relied on a gyroscopic head mouse to maneuver a cursor on a computer screen for communication.
