Researchers say they have used brain waves of a paralyzed man who cannot speak to produce words from his thoughts onto a computer. A team led by Dr. Edward Chang at the University of California, San Francisco, carried out the experiment.
"Most of us take for granted how easily we communicate through speech," Chang told The Associated Press. "It's exciting to think we're at the very beginning of a new chapter, a new field to ease the difficulties of patients who lost that ability. " The researchers admit that such communication methods for paralysis victims will require years of additional research. But, they say the new study marks an important step forward.
Today, paralysis victims who cannot speak or write have very limited ways of communicating. For example, a victim can use a pointer attached to a hat that lets him move his head to touch words or letters on a screen. Other devices can pick up a person's eye movements. But such methods are slow and a very limited replacement for speech.
Using brain signals to work around disabilities is currently a hot field of study. Chang's team built their experiment on earlier work. The process uses brain waves that normally control the voice system. The researchers implanted electrodes on the surface of the man's brain, over the area that controls speech. A computer observed the patterns when he attempted to say common words such as "water" or "good. " Over time, the computer became able to differentiate between 50 words that could form more than 1,000 sentences. Repeatedly given questions such as "How are you today?" or "Are you thirsty," the device enabled the man to answer "I am very good" or "No, I am not thirsty. "The words were not voiced, but were turned into text on the computer.
In an opinion article published with the study, Harvard brain doctors Leigh Hochberg and Sydney Cash called the work a "pioneering study." The two doctors said the technology might one day help people with injuries, strokes or diseases like Lou Gehrig's. People with such diseases have brains that "prepare messages for delivery, but those messages are trapped," they wrote.