It might sound rather frightening to have your arm move involuntarily, controlled by some unseen puppet master — but for researchers at the University of Washington, it represented a major breakthrough in human-to-human brain interfaces. Using a non-invasive brain-to-brain setup, a researcher in one lab was able to send a signal from his brain to control the movements of a second researcher in a lab on the other side of campus. It's believed to be the first human brain-to-brain interface; previous demonstrations have featured rat-to-rat and human-to-rat communication.

A Vulcan mind-meld in action

The demonstration focused on a simple computer game: Rajesh Rao, a professor at UW who has worked on brain-computer interfacing for more than a decade, looked at a screen and had to fire a cannon to shoot down an enemy plane while avoiding friendly planes. On the other side of campus, Andrea Stocco had the keyboard to execute those commands, but couldn't see the game itself. But using their brain-to-brain interface, Rao imagined that he was using his right hand to click the space bar on a keyboard — and Stocco's right hand carried out the command without any conscious movement on his part. Stocco likened it to an involuntary twitch or a nervous tic.

"It was both exciting and eerie to watch an imagined action from my brain get translated into actual action by another brain," Rao said. "This was basically a one-way flow of information from my brain to his." The connection was made using two well-known technologies: Rao was hooked up to an EEG brain monitor, while Stocco's brain was activated using transcranial magnetic stimulation (TMS). It's a non-invasive way of stimulating the brain; in this experiment, the "coil" was placed directly over the region of the brain which stimulates right hand movement. While Rao cautioned that this system only reads certain types of relatively simple brain patterns, the team's next step will be to try and transmit more complex information from brain to brain, and then bring those tests to a wider pool of subjects.