Chris Newmarker

September 13, 2016

3 Min Read
How to Type With Only Your Brain

Revamped technology out of Stanford University could help people with movement disorders to communicate.

Nancy Crotti

Stanford Brain TypingMonkeys really can type Shakespeare, at 12 words per minute, with the help of brain-sensing technology developed at Stanford University.

That technology directly reads brain signals to drive a cursor moving over a keyboard. In a pilot experiment conducted with monkeys, the animals were able to transcribe passages from The New York Times and "Hamlet" at a rate of 12 words per minute.

Earlier versions of the technology have been tested successfully in people with paralysis, but the typing was slow and imprecise. This latest work tests improvements to the speed and accuracy of the technology that interprets brain signals and drives the cursor, according to the university.

"Our results demonstrate that this interface may have great promise for use in people," said postdoctoral fellow Paul Nuyujukian, who will join Stanford faculty as an assistant professor of bioengineering in 2017. "It enables a typing rate sufficient for a meaningful conversation."

Other approaches for helping people with movement disorders type involve tracking eye movements or, as in the case of Stephen Hawking, tracking movements of individual muscles in the face. However, these can require a degree of muscle control that might be difficult for some people. For example, Hawking wasn't able to use eye-tracking software due to drooping eyelids, and other people find eye-tracking technology tiring. Directly reading brain signals could overcome some of these challenges and provide a way for people to communicate their thoughts and emotions.

The Stanford team had previously developed a multi-electrode array that, when implanted in the brain, can read signals from a region that ordinarily directs the hand and arm movements used to move a computer mouse. They recently improved upon the algorithms for translating those signals and making letter selections, and found that the animals could type more than three times faster and more accurately than with earlier approaches.

"The interface we tested is exactly what a human would use," Nuyujukian said. "What we had never quantified before was the typing rate that could be achieved."

To type or not to type

The monkeys testing the technology had been trained to type letters corresponding to what they see on a screen. For this study, the animals transcribed passages ofNew York Times articles or, in one example, Hamlet. The results, which were published in IEEE, show that the technology allows a monkey to type with only its thoughts at a rate of up to 12 words per minute. The animals had the implants for up to four years prior to this experiment, with no loss of performance or side effects in the animals, according to the university.

People using this system would likely type more slowly, the researchers said, while they think about what they want to communicate or how to spell words. People might also be in more distracting environments and in some cases could have additional impairments that slow the ultimate communication rate.

"What we cannot quantify is the cognitive load of figuring out what words you are trying to say," Nuyujukian said.

Despite that, Nuyujukian said even a rate lower than the 12 words per minute achieved by monkeys would be a significant advance for people who aren't otherwise able to communicate effectively or reliably. Eventually the technology could be paired with the kinds of world completion technology used by smartphones or tablets to improve typing speeds.

The team is running a clinical trial to test this latest interface in people.

Nancy Crotti is a contributor to Qmed.

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