Ten years ago,  Professor Miguel Nicolelis and his team at Duke University made history.  They implanted electrodes — sensors — into a monkey’s brain and trained her to control a robotic arm with her thoughts. That may sound like the stuff of science-fiction, but his latest work is even more incredible.  In a paper recently published in Scientific Reports, Professor Nicolelis and his team used similar technology to enable a pair of rats to communicate — one brain to another — even when they were a continent apart.  If you’ve read some of the news coverage of this story, you may have gotten the idea that it’s some kind of telepathy, mind control or mind meld. It’s not, but the truth, though more down-to-earth, is no less exciting.

Nicolelis and his team implanted up to 30 tiny electrodes in rats’ brains to record their neural activity.  The rats were trained to press one of two levers whenever an indicator light in their cage went on. Once they had learned to pick the correct lever, the rats were separated into two groups, “encoders” and “decoders”. An encoder rat then repeated the lever-pressing test ten times during which the team then recorded its neural activity.  They used a computer to analyze patterns in the readings and build an average profile from the ten sessions.  Meanwhile, the decoder rats received further training.  They were taught to respond to electric pulses from the implants in their brain; many pulses meant to press the “correct” lever (the same one as in the light tests) while just a single pulse meant to press the other lever — the “wrong” one.

During the experiment itself, the encoder and decoder rats were in separate cages.  When the light went on in the encoder rat’s cage, the decoder rat couldn’t see it.  The well-trained encoder rat would press the correct lever and, as it did, its brain activity was fed into a computer which was connected to the implants in the decoder rat.  The computer calculated how similar the encoder’s brain pattern was to the average profile from earlier and used this to decide how many pulses the decoder rat received.  The more similar the profile was, the more pulses the decoder rat received.  If everything went smoothly, the encoder rat’s profile brain activity would match up with the average from the correct tests, so the decoder rat would get many pulses into its brain and would also make the right choice.  Things went that way in seven out of every ten trials — even though the decoder rat couldn’t see the light, it picked the correct lever because it was getting information from the encoder rat’s brain!

To make things more interesting, the researchers also included a connection back to the encoder rat: if the decoder rat pressed the right lever, the encoder got an extra reward.  The effect was amazing.  If the decoder made a mistake, the encoder not only made a decision more quickly the next time, but also increased the clarity of the signal from its brain so it would be easier to detect!  “We saw that when the decoder rat committed an error, the encoder basically changed both its brain function and behavior to make it easier for its partner to get it right,” said Nicolelis. “Invariably, when the encoder made those adaptations, the decoder got the right decision more often, so they both got a better reward.”  Thanks to the feedback, the encoder rat’s brain was learning to improve its new-found ability to communicate!

The researchers also succeeded in making rats communicate about what they were sensing instead of what they were doing.  To do this, they recorded the activity from an encoder rat’s brain as it went through a gap rather than when it pressed a lever.  The rat’s whiskers would bend as it passed through the gap and, in a similar experiment, a decoder rat could receive information about how wide the gap was from the encoder’s brain.  In one experiment, encoder rats in Natal, Brazil communicated over the internet with decoders at Duke University in North Carolina.

So is this telepathy?  I don’t think so.  At the moment, the rats aren’t actually communicating directly, brain-to-brain.  There’s a computer in between them, interpreting the signal from the encoder’s brain and passing information to the decoder.  The computer judges whether the encoder’s brain activity looks right and informs the decoder, so the rats can only communicate about one thing.  The communication is also limited to a single binary signal for now — a left/right choice — but it’s not hard to imagine improving the translation program to include more information.  Semantic quibbles aside, though, this is exciting and amazing research!  Even if it’s just one bit of information about one fact, it’s communication from one brain to another.  This may not be a mind-meld yet, but it’s a first step…and I can’t wait to see where it leads!

Ref
Pais-Vieira, M., Lebedev, M., Kunicki, C., Wang, J., & Nicolelis, M. (2013). A Brain-to-Brain Interface for Real-Time Sharing of Sensorimotor Information Scientific Reports, 3 DOI: 10.1038/srep01319
(Scientific Reports is an open-access journal, so the original article is freely available to everyone!)