Paralyzed woman finds her voice through a digital avatar

An innovative leap in brain-computer interface (BCI) technology is opening new vistas of communication for individuals with severe paralysis. A multidisciplinary team from UC San Francisco and UC Berkeley has empowered a woman, unable to speak due to a brainstem stroke, to communicate using a digital avatar. The groundbreaking outcome of this research has been published in the scientific journal Nature.

The researchers have gone beyond their previous work, which allowed decoding of brain signals into text. This time, they have achieved a more comprehensive form of communication, translating brain signals into both synthesized speech and facial expressions. The new BCI system uses artificial intelligence (A.I.) algorithms trained to recognize the patient's unique brain signals for speech.

The woman’s communication journey involved weeks of training with the research team. The process included the implantation of a thin rectangle of 253 electrodes onto her brain's speech-critical areas. These electrodes intercepted brain signals meant for speech and facial expressions, which were then relayed to a suite of computers for data processing.

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One of the key features of the system is its speed. It can decode brain signals into text at an impressive rate of nearly 80 words per minute. This significant improvement over existing technology may soon lead to an FDA-approved system for speech communication.

The creation of a personalized voice for the digital avatar was another crucial achievement of the research. The team used a specially developed algorithm to synthesize speech resembling the woman’s pre-injury voice. They also used software to animate the avatar’s face, mirroring the muscle movements involved in speech and facial expressions.

The project's primary investigator, Dr. Edward Chang, has been at the forefront of BCI technology for over a decade. His team's latest breakthrough could offer individuals with severe paralysis the ability to communicate more naturally and independently. Their next challenge is to devise a wireless version of the system, which would eliminate the physical connection between the user and the BCI.

This research's potential impact is profound, which offers a new frontier to restore full, embodied communication to people living with severe paralysis.