how to telepathically finish each other's… sandwiches?

An experiment to enable humans to exchange thoughts is very underwhelming when you look at the details. But that's only because it barely scratched the surface of what's possible...

Despite what you may have heard, there is no device that allows people to actually share thoughts. In the much publicized experiment is just a novel use of two devices: an electroencephalogram, or an EEG, and a transcranial magnetic stimulator, or TMS. The former read the brain activity of subjects, sent it to a computer which turned them into a binary signal, and transmitted it to other subjects as a magnetic pulse that would cause them to see a bright flash of light as a certain frequency. The researchers then broke down a game of Tetris so enough participants could successfully play using these binary 15 Hz vs. 17 Hz signals.

It's an interesting proof of concept but hardly telepathy, and seems a little simplistic for the kind of information brain-machine interfaces could transmit, especially if they use technologies like brain meshes and neuro-integrated robotic devices. What it had going for it was a splashy, slightly puffed up headline which was eye-catching and clickable, which is why it took off. But it does raise an interesting question. If brain-machine interfaces become more commonplace, especially under our skin and in our skulls, there doesn't seem to be much preventing us from using our thoughts to interact through the internet and cooperate without saying a word.

It's unlikely that humans will ever cease talking to each other in favor of exchanging information digitally, and there will certainly be a lot of questions about security. But it seems like the minute we can create an API to use implants in our speech motor cortices like cell phones, it's inevitable that we'll have private, thought-based exchanges with close friends, loved ones, and, of course, for ethically questionable goals. And just as likely, tools for spies to eavesdrop on these thought-based conversations.

While Tetris played with primitive magnetic stimulation is a far cry from that reality, but only if we ignore the other brain-machine interfaces we've already built and are bound to keep building because they'll have countless applications in medicine, age extension, critical care, and space exploration. Sure, this might sound like a prologue to a dystopian cyberpunk novel, especially considering today's environment in far too many countries, but a lot of technologies we take for granted today started out as, or were inspired by, science fiction. And the tools to turn us into web-enabled cyborgs seem to be taking a similar path to becoming science fact.

See: Linxing J., et al., BrainNet: A Multi-Person Brain-to-Brain Interface for Direct Collaboration Between Brains, arXiv: 1809.08632