A group of neuroscientists claim to have successfully hooked up a machine to allow three people to meld their minds – and play Tetris together.

The University of Washington researchers believe the experiment could eventually be scaled up to connect whole networks of people online.

The researchers have called their system BrainNet, and have said it is ‘to their knowledge’ the first “non-invasive” system for direct brain-to-brain communication between more than two people.

The experiment saw groups of three people sitting in separate rooms and attempting to work together to beat a simplified game of Tetris.

An example of an EEG device in use. Image: Wikipedia

“We present BrainNet which, to our knowledge, is the first multi-person non-invasive direct brain-to-brain interface for collaborative problem solving,” the researchers wrote in the paper.

Two of the subjects are described as ‘senders’ while the third is a ‘receiver.’

All three are hooked up to an electroencephalogram (EEG) device, which records electrical activity in the brain.

The receiver meanwhile is also hooked up to a machine that stimulates brain reactions using short bursts of targeted magnetic energy.

Image: Screens seen by the Receiver and the Senders across Two Rounds. The Receiver sees the examples on the left side while the Senders see the screens on the right.

In the experiment, the two senders were watching the full Tetris screen, while the receiver could only see the blocks falling – but not where they would land.

The senders were asked to communicate to the receiver whether or not to rotate the bloc to allow it to fit into the landing slot.

If the sender wanted the bloc rotated, they were asked to focus their vision on the left hand side of the screen.

Each side of the screen had LED lights flashing at different frequencies – which in turn created different brain waves which were transmitted to the receiver.

The receiver would get a cue – in the form of a phantom ‘phosphene’ flash of light in their mind – and make a decision based on it.

Image: Brain-Computer Interface used by the Senders and the Receiver

Using the technique, the groups of three were able to complete the Tetris puzzle with an accuracy of 81.25%.

In later tests, one of the senders was asked to send the wrong cues – allowing the receiver to decide which of the senders was more accurate.

“We found that Receivers are able to learn which Sender is more reliable based solely on the information transmitted to their brains,” said the researchers.

“Our results raise the possibility of future brain-to-brain interfaces that enable cooperative problem solving by humans using a ‘social network’ of connected brains.”

The same group has previous linked two brain successfully – challenging participants to play a game of 20 questions to transmit ‘yes’ or ‘no’ answers using the same phosphene flashes.