Facebook announced in April that it was working on a project to allow people to telepathically text at 100 words per minute, or about five times faster than we can type with our fingers on our smartphones.
Christopher Mims at The Wall Street Journal has followed up to learn more about what the Facebook researchers have in mind. (He spoke with them rather than communicate telepathically.) “Their goal is to update an obscure, largely abandoned technology known as “fast optical scattering,” aka “event-related optical signal,” he writes. “Basically, you shine a light through the head and into the brain, then measure the light reflected back.”
One problem is that not many photons projected at the head will penetrate the skull, bounce of a neuron, and return through the skull to an external sensor. There might be enough to detect, though. Mims explains, “Sensor technology that could in theory accomplish this—developed at the Johns Hopkins University Applied Physics Laboratory and funded almost exclusively by the U.S. Department of Defense—has to date benefited things like sonars, space exploration, and observing the ground from the air through dense foliage.”
Assuming the technology can be adapted to provide a sufficiently detailed picture of neural activity, the problem remains of translating that activity to a specific word. Mims contacted Alexander Huth of the University of California, Berkeley, who isn’t connected to Facebook’s project but has been studying how brains process language.
Mims writes, “His research revealed that words—and the concepts that underlie them—are spread across the surface of our brains. By observing which parts of a brain are active, you might be able to determine the word, or at least concept, that someone is thinking.”
Facebook’s approach will be to deploy machine learning to correlate neural activity with specific words.
Mims quotes Mark Chevillet, a physicist and neuroscientist who is Facebook’s technical lead on the project, as saying, “We accept that this problem is high risk, high reward.”
