Imagine yourself trying to play a video game with your friends, without needing to exchange a single word. That’s essentially what a team of scientists has managed to accomplish. By connecting the brains of three participants, the researchers allowed them to play a Tetris-type game together by sharing their thoughts. BrainNet, a future ‘social brain network’? The technique used to get these results uses a combination of electroencephalograms (EEGs), which are responsible for recording the brain’s electric impulses, and TMS (transcranial magnetic stimulation) which is painless, non-intrusive and capable of stimulating or stopping the activity of groups of neurones with the aid of magnetic fields. The researchers who first conceived of this new system have called it BrainNet. ‘We present BrainNet which, to our knowledge, is the first multi-person non-invasive direct brain-to-brain interface for collaborative problem solving,’ they announce proudly in their study, which was published on the website ArXiv. ‘The interface allows three human subjects to collaborate and solve a task using direct brain-to-brain communication.’ Tetris and telepathy During the course of this experiment, two ‘Senders’ were connected to EEG technology while they were playing a game similar to Tetris. The participants had to decide if each new block had to be rotated or not. To show their decision, they had to look at one of the two LED lights flashing on each side of the screen, one of which flashed at a frequency of 15 HZ (signalling no rotation) and the other at a frequency of 17 Hz (signalling rotation), resulting in distinct neurone signals which were measured by EEG. These choices were then transmitted to a third player via TMS equipment, which is capable of generating ghost flashes of light (called phosphenes) in the third subject’s mind. This third subject then had to either turn the block or refrain from doing so in accordance with the instructions received. Of course, for the duration of this task, the third participant did not have access to the game screen and therefore had to trust his collaborators’ orders. With 5 groups of 3 people in total, the researchers achieved an average score of 81.25%, which was a great result for a first experiment. Their study must now be submitted for re-reading by a validation committee, but if their results are revealed to be viable and reproducible with a greater number of subjects, a whole new means of communication could see the light of day in the near future.