We are legion: Pairs of humans communicate brain-to-brain

In a continuation of earlier research, University of Washington scientists have demonstrated human brain-to-brain communication with multiple pairs of people.

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Michelle Starr
3 min read

Sender Darby Losey, left, and receiver Jose Ceballos participating in the experiment. Mary Levin, University of Washington

Researchers at the University of Washington have proved the efficacy of their human brain-to-brain communication system. Last year, Rajesh Rao and Andrea Stucco demonstrated a system that lets one brain remotely send signals to another brain, moving the receiver's hand.

Now the experiment has been successfully replicated with three pairs of students. With each pair, signals were transmitted from the sender's brain to the receiver's via the Internet, moving the receiver's hand within a split second of the signal being sent.

"The new study brings our brain-to-brain interfacing paradigm from an initial demonstration to something that is closer to a deliverable technology," said co-author Stocco, a research assistant professor of psychology and a researcher at UW's Institute for Learning & Brain Sciences. "Now we have replicated our methods and know that they can work reliably with walk-in participants."

The setup uses a collection of noninvasive technologies. The sender wore an EEG cap, which recorded brain activity while the two participants collaborated on playing a simple video game. When the game reached a point where a cannon had to be fired, the sender thought about moving his right hand to press the fire button, while being careful to not actually move it. The sender had no way to manually control the game -- no keyboard, mouse, controller or other physical interface.

This signal was recognised and captured by the EEG, and sent via Internet to the receiver, where it was transmitted to his brain using transcranial magnetic stimulation, with a coil placed near the part of the brain that controls hand movements. The signal caused the receiver -- sitting in a darkened room with no screen -- to hit the touchpad with his right hand, firing the cannon.

In the first study, Rao and Stocco tested the setup themselves, sitting in the same room. In the more comprehensive study, each pair of participants was seated in buildings about half a mile apart, and was unable to communicate with each other in any way other than the experimental setup.

The accuracy of the signals varied, from 25 percent to 83 percent -- most of the misses were attributed to the sender failing to send the "fire" command accurately. The research team was also able to quantify the amount of information being sent from one brain to another.

With a $1 million grant from the WM Keck Foundation, the team's next course of action is to widen the range of information that can be transmitted brain-to-brain, including thoughts, concepts and rules. They hope one day to explore the idea of brain-to-brain tutoring.

"Imagine someone who's a brilliant scientist but not a brilliant teacher. Complex knowledge is hard to explain -- we're limited by language," said co-author Chantel Prat, a faculty member at the Institute for Learning & Brain Sciences and a UW assistant professor of psychology.

The team will also be exploring fatigue, and the types of brain waves associated with alertness and sleepiness. This could be used, for example, between two co-pilots -- stimulating one to become more alert when the other starts to grow sleepy.

The full study, "A Direct Brain-to-Brain Interface in Humans", can be found online in the journal PLOS One.