January 17, 2022

Researchers discover how to help paralysed patients with brain to text communication

It may be possible to type without using hands

F. Willett et al./Nature 2021/Erika Woodrum

Scientists are exploring a number of ways for people who are unable to speak or move to communicate with their thoughts. The newest and fastest turns back to a vintage means for communication: handwriting.

For the first time, researchers have deciphered the brain activity associated with trying to write letters by hand. Working with a participant with paralysis who has sensors implanted in his brain, the team used an algorithm to identify letters as he attempted to write them. Then, the system displayed the text on a screen — in real time.

The innovation could, with further development, let people with paralysis rapidly type without using their hands, says study co-author Krishna Shenoy, of Stanford University.

By attempting handwriting, the study participant typed 90 characters per minute – more than double the previous record for typing with such a “brain-computer interface,” Shenoy and his colleagues report in Nature.

This technology and others like it have the potential to help people with all sorts of disabilities – 90 characters a minute is a world record!

The participant, who was 65 years old at the time of the research, had a spinal cord injury that left him paralysed from the neck down. Using signals, the sensors picked up from individual neurons when the man imagined writing, while a machine learning algorithm recognized the patterns his brain produced with each letter.

Using this system, the man could copy sentences and answer questions at a rate similar to that of someone his age typing on a smartphone.

This so-called “Brain-to-Text” BCI is so fast because each letter elicits a highly distinctive activity pattern, making it relatively easy for the algorithm to distinguish one from another.

Michael Cook is editor of BioEdge  

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