Is telepathy just around the corner?

Researchers from Duke University have allowed rats to communicate with each through brain signals.

Placed in separate cages, the rats were able to solve puzzles with the aid of microelectrodes 1/100th the width of a hair implanted into their brains. One rat was able to interpret the other's actions and intentions even when they couldn't see or hear each other.

The same experiment worked when the rats were thousands of miles apart with one in Brazil and another in North Carolina.

'The animal realizes: Oops! The solution is in my head. It's coming to me and he gets it right.'

- Miguel Nicolelis, Neuroscientist

Scientists have so far been able to interpret a rat's thoughts and intentions by downloading those brain waves into a computer, but this is the first time another rat has been able to understand the signals directly.

"Until recently we used to record this brain activity and send it to a computer," said Miguel Nicolelis of Duke's Medical Center in North Carolina. Nicolelis, who led the study, told the BBC's Science in Action program how the the system works. "And the [computer] tells us what the animal is going to do."

"We basically created a computational unit out of two brains," Nicolelis said.

He believes the findings could help shed light on therapy for those dealing with brain injuries and paralysis, such as stroke victims. Any sort of treatment coming to market is still a long way off but that hasn't deterred Nicolelis, who heads one of the leading research teams in the brain space.

They're most well known for one particularly lofty goal: allowing a paralyzed person to kick a ball at the 2014 World Cup in Brazil by developing a brain-controlled robot exoskeleton. The team has already fooled monkey brains into artificially feeling touch and given rats the ability to detect infrared light.

But getting rats to communicate with each other using only their brains was no easy feat. In the experiment, the "encoder" rat had to respond to a visual cue and press a lever to receive its reward. While it's doing this, its brain would send a signal to the "decoder" rat, who then has to interprets this information and also press the right lever to get its prize. If the decoder rat gets it right, the encoder gets an extra reward, creating a feedback loop that encourage cleaner brain signaling. 

It took a month and a half of training before the rats "got it."

"[It] takes about 45 days of training an hour a day," Prof Nicolelis said. "There is a moment in time when ... it clicks. Suddenly the [decoder] animal realizes: 'Oops! The solution is in my head. It's coming to me' and he gets it right."

The team is already developing a version of the experiment that would combine the thoughts of more than one animal. Eventually -- and Nicolelis admits this is many decades away -- we would be able to crowdsource our brainpower.

"You could actually have millions of brains tackling the same problem and sharing a solution" Nicolelis said.