BrainNet, an interface between brains to play Tetris

BrainNet, an interface between brains to play Tetris

Researchers at the University of Washington created the first brain-to-brain interface that allowed three people to collaborate through brain waves to play Tetris.

A world premiere

In the future, the term “brainstorming” may have a completely different, rather literal, meaning. Building on the work on brain-to-brain interfaces in recent years, researchers at the University of Washington have just taken a big leap forward by creating a network that has allowed three people to transmit information directly to their brains.

This “social network of connected brains” called BrainNet was successfully used by this trio to play Tetris collaboratively. The device based on an electroencephalogram records the electrical activity of the “emitting” brain through electrodes distributed through the head. The signal is decoded and transmitted to the “receiving” brain through a transcranial magnetic stimulation (TMS) receiver. The latter sends pulses to the visual cortex to create a phosphene, a luminous illusion that gives the impression the subject sees a light from its visual field.

This noninvasive process had already been used in the past by the University of Washington team (see initial article below) in 2013 and then by another group of researchers to carry out transmission of thought. But it is the first time that more than two people can communicate with each other in this way.

A high success rate

For this experiment, three volunteers had to play Tetris in separate rooms without seeing what the others were doing. Two people with EEG headphones were responsible for issuing the commands for the third. On one screen, they observed the falling bricks and had to decide whether or not to rotate them to insert them correctly into the lower block. To tell the third player what action to perform, the two “transmitters” had to set the LEDs located on the side of the screen, one operating at 15 Hz and the other at 17 Hz.

The idea is that by perceiving these flashes of light, the brain produces waves corresponding to these frequencies. The electroencephalograph can then pick them up and interpret the command. In this case, the 15 Hz LED was used to turn the brick, and 17 Hz was used to do nothing. If the system picked up the signal at 15 Hz, it transmitted it to the TMS equipment, which generated a pulse in the brain of the “receiver” that perceived a phosphene, indicating that it had to turn the brick.

The experiment was conducted with five groups of three people. The average success rate is slightly above 81%, which is quite impressive. On this basis, the researchers believe that it would be entirely possible to increase the number of people participating in this network through an Internet connection. They imagine a “brain-to-brain interface hosted on a cloud server” that would serve as a transmission node for a network of people all over the world. Human communication has probably not exhausted all its possibilities.