Neuroscientists have successfully hooked up a three-way brain connection to allow three people share their thoughts – and in this case, play a Tetris-style game. The team thinks this wild experiment could be scaled up to connect whole networks of people, and yes, it's as weird as it sounds.
Source: https://www.sciencealert.com/brain-to-brain-mind-connection-lets-three-people-share-thoughts