In the experiment, each sender was placed in front of a computer game that involved firing a cannon and intercepting rockets to protect a city. The senders, however, were unable to physically interact with the game. They could only defend the city by thinking about moving their hands to fire the cannons and intercept the rockets. Meanwhile, the corresponding receivers sat in a distant, dark room with no ability to see the game and their right hands positioned over touchpads that controlled the game.

The senders were hooked to EEG machines that read brain activity, and their partners wore caps equipped with technology to stimulate the part of the brain that controls hand movements. When the senders thought about moving their hands to shoot the cannon, their partners’ brains received the message to do so via signals sent from their partners’ brains to theirs over the Internet.