A paralyzed woman couldn't speak for more than 20 years. With AI, now she can — just by thinking.

• A development in neurotechnology has given a stroke survivor her voice back after nearly 20 years.
• The woman had a brain stem stroke that left her paralyzed and unable to speak at age 30.

Nearly two decades ago, then-30-year-old Ann Johnson had a brain stem stroke, and though she survived, she was left paralyzed and unable to speak with a condition known as locked-in syndrome.

Johnson slowly regained the ability to breathe independently, move her neck, and wink, but after 18 years, her brain hasn't recovered its ability to move the muscles required for her to speak more than a few words.

With the help of a new AI-driven brain implant, she has become the first patient to successfully use a groundbreaking neurotechnology that synthesizes speech and facial expressions from brain signals, the researchers behind the project claim.

In a study published in Nature late last month, researchers at the University of California San Francisco and the University of California Berkeley detailed their findings after implanting a thin layer of 253 electrodes on Johnson's brain and customizing the technology to read her brain signals.

The neurotechnology uses artificial intelligence to decode the woman's brain signals while she tries to speak. Though her muscles don't move, her brain sends a signal perceptible to the electrodes, which decode what she is trying to say, and then synthesizes speech and facial expressions using a computer-generated avatar.

Johnson, who doesn't have cognitive or sensory impairment after the stroke, could previously communicate at roughly 14 words per minute using her old typing method involving a device that responds to small head movements, per a University of California San Francisco news article about the breakthrough. With her new implant, her digital avatar speaks almost 80.

"Our goal is to restore a full, embodied way of communicating, which is the most natural way for us to talk with others," Dr. Edward Chang, chair of neurological surgery at the University of California San Francisco, said in the UCSF publication about the research. "These advancements bring us much closer to making this a real solution for patients."

Chang did not immediately respond to Insider's request for comment.

While the UCSF and UCB researchers claim Johnson's case is a scientific first for allowing people with locked-in syndrome to communicate using neurotechnology, two researchers from Austria's Wyss Center for Bio and Neuroengineering claimed last year they had achieved a similar feat.

Though their results working with a 34-year-old man to regain his ability to speak after being paralyzed were promising, the Austrian researchers previously had a paper on the subject retracted, and "several cases of scientific misconduct" were identified in a 2019 investigation conducted by the German Research Foundation (DFG), which funded some of the work.

Despite neurotechnology facing controversy and ethics concerns, developments in the public and private sectors have been identified by groups like the United Nations as among the fastest-growing fields with the possibility to improve human lives.

As for Johnson, the benefits of being involved in the UCSF project are far more expansive than just offering her the opportunity to speak again after all these years.

"When I was at the rehab hospital, the speech therapist didn't know what to do with me," Johnson said, per the UCSF publication. "Being a part of this study has given me a sense of purpose, I feel like I am contributing to society. It feels like I have a job again. It's amazing I have lived this long; this study has allowed me to really live while I'm still alive!"