New sensing-technology detects brain signals to move a cursor. Monkeys trained to copy text were able to type at a rate of 12 words per minute.
It does not take an infinite number of monkeys to type a passage of Shakespeare. Instead, it takes a single monkey equipped with brain-sensing technology – and a cheat sheet.
That technology, developed at Stanford University, directly reads brain signals to drive a cursor moving over a keyboard. In an experiment, monkeys were able to transcribe passages from the New York Times and Hamlet at a rate of up to 12 words per minute. It enables a typing rate sufficient for a meaningful conversation.
Earlier versions of the technology have already 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.
New algorithms for brain-sensing technologie
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 have limitations, and can require a degree of muscle control that might be difficult for some people. Directly reading brain signals could overcome some of these challenges and provide a way for people to communicate their thoughts and emotions.
The technology developed by the Stanford team involves a multi-electrode array implanted in the brain to directly read signals from a region that ordinarily directs hand and arm movements used to move a computer mouse.
It’s the algorithms for translating those signals and making letter selections that the team members have been improving. They had tested individual components of the updated technology in prior monkey studies but had never demonstrated the combined improvements in typing speed and accuracy. Using high-performing algorithms, the animals could type more than three times faster than with earlier approaches.
To type or not to type
The monkeys testing the brain-sensing technology had been trained to type letters corresponding to what they see on a screen. For this study, the animals transcribed passages of New York Times articles or, in one example, Hamlet. The results allows a monkey to type with only its thoughts at a rate of up to 12 words per minute.
People using this system would likely type more slowly, 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 cannot be quantified is the cognitive load of figuring out what words you are trying to say. Despite that, 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 kinds of word completion technology used by smartphones or tablets to improve typing speeds. In addition to proving the technology, this study showed that the implanted sensor could be stable for several years. The animals had the implants used to test this and previous iterations of the technology for up to four years prior to this experiment, with no loss of performance or side effects in the animals.
The team is running a clinical trial now to test this latest interface in people. If the group is successful, technologies for directly interpreting brain signals could create a new way for people with paralysis to move and communicate with loved ones.
Learn all about sensor technology in the medical, robotics, aviation and aeronautics, and automobile industries in hall B1 and at the electronica Forum in hall A3 on the day dedicated to “Wearables & Healthcare.”