Alisa Brownlee, ATP, CAPS blog offers recent articles and web information on ALS, assistive technology--augmentative alternative communication (AAC), computer access, and other electronic devices that can impact and improve the quality of life for people with ALS.
Any views or opinions presented on this blog are solely those of the author and do not necessarily represent those of the ALS Association.
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Thursday, February 23, 2017
Brain–Computer Interface Allows Speediest Typing to Date
Via Scientific American -- https://www.scientificamerican.com/article/brain-computer-interface-allows-speediest-typing-to-date/
A new interface system allowed three paralyzed individuals to type words up to four times faster than the speed that had been demonstrated in earlier studies
Other methods of interfacing with the brain via electrodes include those put on the scalp for electroencephalography (EEG) and ones placed under the skull on the brain’s surface, known as electrocorticography (ECoG). The advantage of intracortical implants is they can pick out activity from single cells whereas the other methods capture the average activity of thousands of neurons. “This performance is 10 times better than anything you would get from EEG or ECoG, [which don’t] contain enough information to do this kind of task at this level,” says neurobiologist Andrew Schwartz, at Pitt, who was not involved in the study. Movement and scarring reduces signal quality over roughly the first two years after implantation, but what remains is still useful—“much better than you get with any other technique,” he says.
The biggest drawback, currently, is having wires coming out of people's heads and attached to cables, which is cumbersome and carries risks. “The future is making these devices wireless,” Pandarinath says. “We're not there yet with people but we’re probably closer to five than 10 years away, and that’s a critical step [toward] a device that you could send somebody home with and be less worried about potential risks like infection.” The devices would need wireless power but several groups are already working on this. “Most of the technology is basically there,” Schwartz says. “You can do that inductively using coils—like wirelessly charging your cell phone in a cradle with coils on either side.”
The team attributes the improvements to better systems engineering and decoding algorithms. “Performing repeated computations rapidly is critical in a real-time control system,” Pandarinath says. The researchers published a study last year, led by Stanford bioengineer Paul Nuyujukian. In it they trained two macaque monkeys to perform a similar task to the grid exercise used in this study. The animals typed sentences by selecting characters on a screen as they changed color (although they wouldn’t have understood what the words meant). When the team added a separate algorithm to detect the monkeys’ intention to stop, their best speed increased by two words per minute.
This “discrete click decoder” was also used in the current study. “We've basically created a ‘point and click’ interface here, like a mouse. That’s a good interface for things like modern smartphones or tablets,” Pandarinath says, “which would open a whole new realm of function beyond communication: surfing the Web, playing music, all sorts of things able-bodied people take for granted.”
The Stanford team is already investigating wireless technology, and has ambitious long-term goals for the project. “The vision we hope to achieve someday would be to be able to plug a wireless receiver into any computer and use it using your brain,” Henderson says. “One of our main goals is to allow 24 hours a day, seven days a week, 365 days a year control of a standard computer interface using only brain signals.”