Scientists have designed ways to "read" words directly from brains. Brain implants (植入物) can translate internal speech into external signals, allowing communication from people with paralysis (瘫痪) or diseases that steal their ability to talk or type. New results from two studies, presented on November 14 provide additional evidence of the extraordinary potential that brain implants have for restoring lost communication, says Leigh Hochberg, a physician at Massachusetts General Hospital in Boston.
"The new studies targeted internal speech, which requires that a person only think. Our device predicts internal speech directly, allowing the patient to just focus on saying a word inside his head and transform it into text," says Sarah Wandelt.
Neural signals associated with words are detected by electrodes (电极) implanted in the brain. The signals can then be translated into text, which can be made an oral speech by computer programs.
Another approach presented at the meeting, led by neuroscientist Sean Metzger of the University of California, San Francisco and his colleagues, relied on spelling. The participant was a man called Pancho who hadn't been able to speak for more than 15 years because of a disease. In this study, Pancho attempted to silently think code (代码) words, such as "alpha" for A and "echo" for E. By stringing these letters into words, he produced sentences such as "I do not want that" and "You have got to be kidding." Each session would end when Pancho attempted to squeeze his hand thereby creating a movement-related brain signal that refused the decoding (解码).
With this system, Pancho produced about seven words per minute. That's faster than the five words per minute his usual communication device makes, but much slower than normal speech, typically about 150 words per minute. The techniques will need to ger faster and more accurate to be useful. It's also unclear whether the technologies will work for people with more serious speech disorders. "These are still early days," Hochberg says.