Using a brain implant, Stanford researchers have developed a mind-machine interface that allows monkeys to text at the very reasonable rate of 12 words per minute. Eventually, the system could be used to help people with movement disorders to communicate more efficiently.
The new technology, developed by Stanford researchers Krishna Shenoy and Paul Nuyujukian, allowed monkeys to move a cursor across a keyboard and select letters without having to lift a finger. The animals transcribed passages from the New York Times and Hamlet at a rate of 12 words per minute.
This isn’t the first time that scientists have used a brain-computer interface (BCI) to enable thought-controlled typing, but the new technique, described in the latest edition of the Proceedings of the IEEE, improves upon earlier techniques more than three fold.
Other techniques, which rely on eye tracking or facial movements, tend to be tedious (just ask Stephen Hawking), while previous versions of BCIs have resulted in slow and imprecise typing among paralysed human test subjects. The new system improves upon these earlier efforts, enabling “a typing rate sufficient for a meaningful conversation,” in the words of the researchers.
For the experiment, the researchers implanted a multi-electrode array into the brains of two rhesus macaques. The device reads signals from a brain region that normally controls hand and arm movements. “The interface we tested is exactly what a human would use,” noted Nuyujukian in a statement. “What we had never quantified before was the typing rate that could be achieved.”
Importantly, the monkeys were tested in ideal conditions — and with “cheat sheets” (the monkeys were simply copying the text being shown to them — there’s no actual comprehension). The researchers expect that human subjects will likely text a bit slower than the monkeys, but not by much. That said, this system doesn’t have auto-complete functionality which would most assuredly be used in a human version.
Encouragingly, multi-electrode arrays, though invasive (they have to be surgically implanted), are proving safe and durable in both non-human and human test subjects. It won’t be long before this technology enters into the real world. And who knows, it may eventually be used by anyone who wants to text with their brains instead of their thumbs.