Using electrical brain recordings and a form of magnetic stimulation, University of Washington researcher Rajesh Rao sent a brain signal to fellow scientist Andrea Stocco on the other side of the university campus, causing Stocco's finger to move on a keyboard.
Rao and Stocco said they believe this is the first demonstration of human-to-human brain interfacing.
"The Internet was a way to connect computers, and now it can be a way to connect brains," Stocco said. "We want to take the knowledge of a brain and transmit it directly from brain to brain."
Rao sat in his lab wearing a cap with electrodes hooked up to an electroencephalography machine, which reads electrical activity in the brain. Stocco was in his lab across campus wearing a swim cap marked with the stimulation site for the transcranial magnetic stimulation coil that was placed directly over his left motor cortex, which controls hand movement.
Rao looked at a computer screen displaying a simple video game. When he was supposed to fire a cannon at a target, he imagined moving his right hand -- being careful not to actually move his hand -- and his brain signals caused a cursor on his computer screen to hit the "fire" button.
Almost instantaneously, Stocco, who wore noise-canceling ear buds and wasn't looking at a computer screen, involuntarily moved his right index finger to push the space bar on the keyboard in front of him, as if firing the cannon.
Stocco said the feeling of his hand moving involuntarily was comparable to 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 next step is having a more equitable two-way conversation directly between the two brains."
The technology only reads certain kinds of simple brain signals, not a person's thoughts, Rao said, emphasizing it doesn't give anyone the ability to control your actions against your will.
"I think some people will be unnerved by this because they will overestimate the technology," UW researcher Chantel Prat, who helped conduct the experiment, said. "There's no possible way the technology that we have could be used on a person unknowingly or without their willing participation."