Scientists from the University of Washington have proven it’s possible for people to communicate using only their brains. Specifically, they showed that a player of a shooter-style video game could trigger another player to fire a cannon just by thinking “fire.”

The study, “A Direct Brain-to-Brain Interface in Humans,” was published Wednesday in the journal PLOS One.

The researchers had help from some fancy but non-invasive electronics. A “brain-to-brain interface” was created by attaching electrodes that recorded brain signals in one person and a transcranial magnetic stimulation coil that stimulated the brain of another. It was the first time humans have communicated using only their brains and this sort of computer setup.

Here’s how the experiment worked: Six people were paired up to play a video game in which they had to defend a city by firing a cannon and intercepting rockets launched from a pirate ship. One person, the sender, sat in front of a gaming console with an EEG device attached to her head. Just by thinking “fire,” she could make her partner a mile away press a touchpad to fire a cannon.

The receiver was wearing a cap with a coil near the part of the brain that controls hand movements. He was in a dark room and couldn’t see what was happening in the game. If he received his partner’s brain signal, his hand would jerk upward, pressing a touchpad that fired a cannon.

The whole thing – from the time the sender thought “fire” to the time the receiver hit the touchpad – took about 627 milliseconds.

Some teams were better at the game than others – they fired the cannon accurately between 25 and 83 percent of the time. However, the researchers said the problem wasn’t due to a breakdown in brain signals, but simply the sender thinking the “fire” command at the wrong time.

The results were compared to a control group where the receiver’s TMS cap wasn’t positioned to trigger hand movements.

Future experiments could go beyond transmission of visual, auditory or motor information to explore brain-to-brain communication of abstract thoughts, the researchers said in the study.

The experiment, the researchers wrote, show that “current technology is sufficient to develop devices for rudimentary brain-to-brain information transmission in humans. Such devices (which have been long cherished by science fiction writers) have the potential to not only revolutionize how humans communicate and collaborate, but also open a new avenue for investigating brain function.”

The authors were led by Rajesh P. N. Rao.

Correction: The study author’s name was previously misspelled in this story.