This new scientific achievement is the first step in the development of a technology that would allow people to speak with their minds.
In an article published in the New England Journal of Medicine, a team of researchers has developed a speech neuroprosthesis that can convert small electrical signals in the brain into understandable words.
A respectable 76% accuracy
This neuroprosthesis was tested on a man who had lost his speech after a severe stroke more than 15 years ago. Before the experiment, he could communicate by writing letters on a screen with a pointer he wears on his head. He agreed to have electrodes implanted outside his brain.
Researchers connected a computer to a group of electrodes for 50 sessions over 81 weeks and recorded his brain’s activity as he saw words on the screen and imagined saying them out loud. They were able to accurately identify the words 47% of the time. They then combined word prediction algorithms similar to automatic suggestions in emails and word processors, for example. They were able to increase the accuracy of the algorithm to a respectable 76%.
The technology is still in the experimental phase
To our knowledge, this is the first successful demonstration of direct decoding of whole words based on brain activity in a paralyzed person who cannot speak, says Dr. Eddie Chang, a neurosurgeon and the lead author of the paper. This method shows great promise for restoring communication by exploiting the brain’s natural speech mechanisms.”
So far, this neuroprosthesis is still in the experimental phase. The system’s high error rate, its limited vocabulary, and the considerable time needed to train it to recognize words are all hurdles that need to be overcome before this device is available on the market. However, this first step offers a glimmer of hope for the thousands of people who lose their speech each year due to disability or illness.