There is something you likely wouldn’t expect to find in your email inbox: another person’s brain waves. Yet, as an experiment by an international team of scientists shows, transmitting them is actually possible. A study published in the journal *PLOS One* details how the team transmitted words from one person’s brain to another’s by detecting electrical signals in the spine and chest, reports newsweek.com.

For some time, scientists have been working to develop technology capable of capturing and transmitting brain waves. For instance, researchers recently used an electroencephalography (EEG) device to allow users to control flying toy helicopters using only their brains.

These and similar encephalographic processes involve the exchange of information between a human brain and a computer. Electrodes detect the electrical currents generated by the brain when a person performs a deliberate action—such as consciously thinking about bending their arm. A computer then interprets this signal and relays it to a mechanical output, such as a toy aircraft.

In this latest study, however, the scientists replaced the computer with another human brain, adapting the technology to allow two people to exchange information telepathically.

The study involved four participants, aged 28 to 50. Initially, scientists used an electroencephalography device to convert greetings into signals. These were transmitted from a city in India to a city in France. In the French city, a computer interface translated the message from code into words and delivered them to the recipient’s brain via electrical stimulation using light.

During this process, the participants felt nothing; they merely saw flashes of light in their peripheral vision, but they did not hear any message.

Subsequently, the scientists carried out a procedure in which thoughts were successfully transmitted simultaneously to two participants—one located in Spain and the other in France.

The results were not perfect—the error rate in the second experiment was 15 percent—but this represents a significant advancement. Previously, such brain-based signal transmission had only been achieved in rats; this marks the first time it has been accomplished with humans. Scientists believe that, in the near future, computers will be able to interface with the human brain, facilitating both human-computer and human-to-human communication.

In the near future, brain-to-brain information transmission will likely give rise to ethical challenges—for instance, questions regarding who is permitted to use such devices, and what might happen if someone were to choose to enter a dystopian state of mind.