Recently, two human brains have communicated via the Internet without any spoken or written words. This astonishing breakthrough was made by scientists from the University of Washington and is published in Plos One.

The researchers used Transcranial Magnetic Stimulation (TMS) devices to allow participants to transmit bits of information through electric pulses. Wearing an electroencephalography (EEG) cap, the participants had to concentrate hard to change the shape of their brain waves.

Two brains so linked were able to guess what the other was thinking about- while in two complete different cities.

“This is the most complex brain-to-brain experiment, I think, that’s been done to date in humans,” said lead-author Andrea Stocco, an assistant professor of psychology and a researcher at UW’s Institute for Learning & Brain Sciences.

The two linked brains were first asked to play a simple video game that required cooperation to win. They then asked each other yes-or-no questions. A yes answer would send a mild stimulation to the visual cortex, causing the questioner to see a phosphine- a optical disturbance similar to spots from looking into a light.

“They have to interpret something they’re seeing with their brains,” said co-author Chantel Prat, a faculty member at the Institute for Learning & Brain Sciences and a UW associate professor of psychology. “It’s not something they’ve ever seen before.”

Research into brain-to-brain communication could be an invaluable medical advancement. If the technology was perfected, patients with brain damage to communicate with the outside world.

“Imagine having someone with ADHD and a neurotypical student,” said Prat. “When the non-ADHD student is paying attention, the ADHD student’s brain gets put into a state of greater attention automatically.”