An upgraded brain-to-brain interface has allowed researchers to transmit signals from one person's brain over the internet and use those signals to control the hand motions of another person. Remarkably, the system allowed the participants to collaborate on a computer game.


Photo: Mary Levin, U of Wash.

This latest experiment by University of Washington researchers is an extension of one they did back in August 2013. The newer, more comprehensive study, which now appears in PLOS One, brings their brain-to-brain interface (BBI) from the demo stage to something more like a tangible, deliverable technology.


The technique is similar to one developed earlier this year by a separate team of researchers. But unlike that BBI experiment, this one tested different pairs of study participants and was conducted in real time over the Web.

Combining EEG and TMS

To make it work, the research team combined two kinds of non-invasive instruments. One participant (the "sender") was hooked-up to an electroencephalography machine, which recorded brain signals and sent electrical pulses through the Web to the second participant (the "receiver") who was wearing a swim cap with a transcranial magnetic stimulation (TMS) coil placed near the part of the brain that controls hand movements.


During the experiment, the sender issued a command to move the hand of the receiver by simply thinking about that hand movement. Three different pairs of participants were used for the experiment, each confronted with different roles and constraints. The volunteers worked in separate buildings about a half-mile apart, and they were unable to interact or communicate with each other in any way. Well, except for that mind-to-mind interface strapped to their heads.


Shall We Play A Game — With Our Thoughts?

Now here comes the fun part. The senders were tasked with playing a computer game in which he or she had to defend a city by firing a cannon and intercepting rockets launched by a pirate ship. But the senders weren't given any kind of controller or joystick — the only way they could defend the city was by thinking about moving their hand to fire the cannon.


In the other building across campus, the receivers meanwhile sat wearing headphones in a dark room with no ability to see the computer game. Their right hand was positioned over a touchpad that could actually fire the cannon. If the interface was successful, the receiver's hand would twitch, firing the cannon displayed on the sender's computer screen.

Results showed that the accuracy varied among the pairs, ranging from 25% to 83%. Misses were mostly on account of the senders failing to execute the "fire" command with their thoughts.


Future Potential

Excitingly, the research team was just awarded a $1 million grant from the W. M. Keck Foundation. From here, they'd like to take the work further and attempt to decode and transmit more complex brain processes, including complex visual and psychological phenomena such as concepts, thoughts, and rules.


They also want to explore how brain waves can influence alertness or sleepiness. So, for example, the brain of a sleepy airplane pilot dozing off at the controls could stimulate the copilot's brain to become more alert.

The work could also lead to "brain tutoring," where knowledge is sent directly from the brain of a teacher to a student.


"Imagine someone who's a brilliant scientist but not a brilliant teacher. Complex knowledge is hard to explain – we're limited by language," noted co-author Chantel Prat, a faculty member at the Institute for Learning & Brain Sciences and a UW assistant professor of psychology.

Read the entire study at PLOS One: "A Direct Brain-to-Brain Interface in Humans". Supplementary information via UW.


Images: Rajesj Rao et al./PLOS One.