Using the device, the man was able to speak at a rate of 15 words per minute. Researchers say this could be a major breakthrough for computer-mediated communication. (Image credit: UCSF)
I love developments like this. What a step forward.
People who have lost the ability to speak using their vocal cords often rely on devices that use eye or head movements to spell out words one letter at a time. There are even devices that let them control a computer cursor with their thoughts. Now, researchers from The University of California, San Francisco, are working on a device that allows you to generate words and sentences on a computer using only your thoughts.
The team developed an experimental implant device that decodes signals in the brain that usually control your vocal tract. Researchers tested the device on a man who has been unable to move or speak for the past 15 years. Using the device, he was able to communicate with his thoughts with a limited vocabulary of only 50 words at a rate of 15 words per minute – much slower than natural speech.
So, how does it work? The device was implanted on the surface of the man's brain. A computer then studied the patterns of electrical activity produced when the man, known as BRAVO1, attempted to speak 50 different words. The process took months until BRAVO1 could reliably generate words on a computer screen. Once that happened, researchers had him form sentences using a program that analyzed the context of each word as it was added to help improve accuracy. It's similar to texting software on most smartphones.
It took several more months of adjustments before the man was able to generate a word reliably every four seconds, or 15 words per minute. Since normal speech happens at a rate of 120 – 150 words per minute, there's still a lot of work to be done. But so far, the results are promising. With further development, the device could help people who have suffered from strokes or traumatic brain injury. It may even help those with ALS, a disease that eventually makes it difficult to speak.
These implants could be life-changing, but there are some privacy concerns. Because these devices are implanted directly into the brain, it could be difficult for people to separate private thoughts from public ones. "We want to make sure the devices we create allow that separation, allow people to be able to think their private thoughts without anything just being broadcast to the world," says Chethan Pandarinath, an assistant professor in the Department of Biomedical Engineering at Emory University and Georgia Tech.
Still, this device shows that using this method makes communicating via thoughts possible. Edward Chang, a neurosurgeon at the University of California, San Francisco, says "I think there's a huge runway to make this better over time."
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