And they’re not stopping there.

• Brain-to-brain verbal communication in humans was first accomplished in 2014 when brain-computer interfaces helped transmit a message from India to France.
• Since then, some progress has been made on technology that could make so-called mind-reading possible, including a device that would allow at least three people to share thoughts.
• While communication using only thoughts shows promise in the medical field for patients who are unable to speak, when it comes to other uses, there are still many ethical implications that need to be navigated.

Mind reading has long existed in science fiction—Vulcan mind meld, anyone?—and those carnivals where alleged mind readers try to part you from your last $10 bill with a promise that they know exactly what you’re thinking. But thanks to some recent scientific developments, it is now no longer the stuff of cyberpunk and magic.

Back in 2014, two words were heard halfway around the world. Those words were ciao and hola. The only people who heard them were two subjects, one in India and one in France, both of whom were willing subjects for an experiment that wanted to probe into whether it was possible for one person to find out what another was thinking from 5,000 miles away.

The non-invasive research merged brain-computer interfaces and computer-brain interfaces. Brain-computer interfaces allow the brain to control a device or application by analyzing and translating brain signals into digital commands, while computer-brain interfaces use a computer to influence brain activity. Wireless EEG recorded brain activity through electrodes on the subjects’ heads. When the subject in India sent the message, the letters of the two words were then converted to binary code. The code was transferred to another computer before being sent to the subject in France via internet.

Transmission of thoughts from one brain to another succeeded. Because the computer-brain interface used transcranial magnetic stimulation to prepare the receiver by using magnetic fields to boost electrical signals in neurons, the receiver found out when there was a message on the way. This experiment marked the first brain-to-brain verbal communication in humans and opened up a new frontier.

“We speculate that future research could explore the use of closed mind-loops in which information associated to voluntary activity from a brain area or network is captured and, after adequate external processing, used to control other brain elements in the same subject,” the researchers who ran the experiment said at the time in a study published in PLOS One.

How far have we come since then? In 2019, another research team invented BrainNet, a non-invasive system that also uses EEG and transcranial magnetic stimulation and became the first multi-person brain-to-brain interface. Meant for problem-solving applications, it can accommodate three people at a time, decoding the brain signals of the two message senders with EEG before transmitting them to the receiver through an internet connection. BrainNet originally demonstrated how three people could silently work together to tackle a computer game similar to Tetris. The researchers predicted that the system could eventually be scaled to accommodate larger groups.

The mechanism behind direct brain-to-brain communication, or neural interfacing, in both humans and animals was elucidated in 2021, when veterinary physiologist Ehsan Hosseini hypothesized that the weak magnetic field in one animal’s brain was capable of transmitting information to another. He also suggested that cryptochromes, proteins that act as photoreceptors which help regulate circadian rhythm, can actually perceive these magnetic fields and convert them to action potentials, or ultrafast zaps of voltage across the membrane of a neuron. Other studies even claimed that the ability to pick up on weak magnetic field energy may explain telepathy and other paranormal phenomena.

More recently, the neurotechnology startup Neuroba is exploring ways to integrate human consciousness with not only brain-computer interfaces, but AI and even quantum communication. They are currently trying to develop algorithms that will allow messages to be delivered more accurately. This could be a breakthrough in the medical field, with patients who are otherwise unable to speak still having the ability to communicate by using just their brains, whose messages will be analyzed and translated by a computer.

Beyond medical use, ethical implications for this technology remain unclear. Neuroba also mentions that a device like an updated version of BrainNet could revolutionize the workplace by connecting thoughts during meetings and other collaborative efforts. While some are convinced that hooking up everyone’s brains in a conference room would be revolutionary, there are concerns. Everyone reading each other’s thoughts and thinking alike, possibly being pressured to think alike, ventures on the robotic and could possibly (brace for another Star Trek reference incoming) create another Borg.

There is also the possibility of misusing neural interfacing to invade others’ privacy. Ultimately, much of the field still remains unexplored, and a code of ethics will have to be established if it is to be used regularly in the future.