Science helps stroke survivor speak after nearly two decades

A unique brain implant and digital avatar has given a Canadian stroke survivor the ability to speak for the first time in nearly 20 years.

The woman, now 47, was only 30 years old and a mother of two young children when she experienced a stroke that left her paralysed and unable to speak. Her stroke left her with locked-in syndrome (LIS) a neurological disorder that can cause full paralysis except for the muscles that control eye movement.

In 2021 the woman was one of eight participants selected for a unique clinical trial, offered by the departments of neurology and neurosurgery at the University of California, San Francisco.

According to the study, which was published in global science journal Nature, the woman is the first person in the world to speak out loud via decoded brain signals after researchers placed an implant that rests on her brain to record her neurological activity. An artificial intelligence (AI) model translates those signals into words. 
 
 In real time, the decoded text is synthesised into speech at a rate of nearly 80 words per minute, spoken aloud by a digital avatar that can also generate the woman’s facial expressions.

To intercept her brain signals, the research team surgically implanted a paper-thin grid of 253 electrodes onto the surface of the woman’s brain, covering the areas that are important for speech. The researchers then asked her to attempt to silently speak sentences.

The brain signals then get transferred into a port that is attached to the outside of the woman’s head. From there, a cable that plugs into the port can be hooked up to a bank of computers that decode the signals into text and synthesise the text into speech.
 
According to Nature, The AI model doesn’t exactly decode Johnson’s thoughts, but interprets how Johnson’s brain would move her face to make sounds — a process that also allows the AI to generate her facial expressions and emotions.
 
 The next steps for the researchers will be to develop a wireless version of the system that wouldn’t require the woman to be physically hooked up to computers. 
 
 The research team is now hoping it can secure approval from US regulators to make this system accessible to the public.
 

Do you need aged care support for yourself or a loved one? Just Better Care can help people from diverse backgrounds with different lifestyles achieve their goals. Get started by talking to a local team member today.