They get a person with ALS unable to speak to communicate through a brain implant

A team of scientists has managed to get a totally paralyzed person unable to speak to communicate through a brain-computer interface (BCI) device, according to a study published Tuesday in ‘Nature’. The research, led by the Wyss Center for Neuroengineering (Switzerland) and the University of Tübingen (Germany), developed this method in an individual with amyotrophic lateral sclerosis (ALS) advanced.

The patient, a 34-year-old male in a state of “total lockdown”, sends brain signals to the BCI, and the BCI decodes them to form letters, in a process experts call the “auditory neurofeedback system.” Previous work has already developed similar tools to allow people with ALS to “speak” through the movement of their eyes or facial muscles, but once the disease degenerates and they lose muscle control they are no longer able to communicate in this way.

To overcome this problem, the team led by Jonas Zimmermann, a neuroscientist at the Wyss Center in Geneva, turned to this type of auditory feedback (neurofeedback) BCI, which consists of two intracortical microelectrodes surgically implanted in the motor cortex.

The patient is affected by the so-called total captivity syndrome (CLIS, its acronym in English) -by which the paralysis is absolute-, but it was unknown until now if he has also “lost the ability of his brain to generate commands for communication,” explains the expert in a statement.

During two years of work, this individual learned to generate brain activity by testing different movements, brain signals that are detected by microelectrodes and then decoded by a real-time machine learning model. This artificial intelligence tool “maps” the signals to attribute a “yes” or “no” meaning to them and, to decipher what the participant wants to communicate, a spelling program calls out the letters of the alphabet.

And here “auditory neurofeedback” comes into play, since the subject is capable of choosing, after identifying the pitch and frequency of the “feedback”enter “yes” or “no” to confirm or discard a letter, up to complete words and sentences at a rate of about one character per minute.

“Previously, successful communication has been achieved via BCIs in people with paralysis. But we believe that our study is the first to achieve communication in subjects who have lost all ability to move, and therefore this BCI is their only means of communication,” Zimmermann says.