Harvard University researchers have also shown that a human could move a rat's tail with their minds, translating the person's neural signals to excite the motor area of a rat that had a motor sensor on it. This study was published in the journal PLOS One earlier this year.
A true brain-to-brain interface would involve the ability for choice, and for feedback, Nicolelis said. In other words, the receiver would have the ability to send signals back to the sender.
Nicolelis' own research has shown this more complicated technique is possible, at least in rodents. In an experiment described in a study in the journal Scientific Reports, two rats were placed in separate chambers with several levers. The brains of these rats were connected through arrays of tiny electrodes. One rat got a visual cue about which lever would lead to a reward of a drink of water. When this rat pressed the correct lever, the second rat received brain activity from the first rat corresponding to that decision.
The researchers believe that the receiving rats were actively using and interpreting this information, not just pressing a lever involuntarily, because the receiving rat pressed the correct lever about 70% of the time. That is still fairly high, but not 100%.
Here's the more impressive part: The rats appeared to demonstrate two-way collaboration in their brain network -- the rat sending the signal changed its brain function and behavior when the receiving rat did not press the correct lever. The researchers incentivized this by not giving a full reward to the sending rat if the receiving rat messed up.
This kind of two-way brain communication between humans has yet to be demonstrated. But that doesn't mean it isn't possible.
For now, the University of Washington scientists can show off their technique using simple brain signals, but their technology doesn't allow people to read each other's thoughts.
And don't worry -- it was done in a laboratory setting in accordance with a strict human-testing protocol, so it would not be used to control people's behavior without their consent, they say.
The technology is still in its early stages, but Stocco imagines many practical applications: For instance, a senior surgeon could control the hands of another surgeon in training during an operation. Stocco also told the University of Washington's news office that a person with disabilities could signal that he or she would like food or water, or a pilot who becomes incapacitated could be assisted from the ground.
"It was both exciting and eerie to watch an imagined action from my brain get translated into actual action by another brain," Rao told the University of Washington's news office. "This was basically a one-way flow of information from my brain to his. The next step is having a more equitable two-way conversation directly between the two brains."
The researchers said they intend to conduct another experiment involving more complex information from one brain to another. They will try the technique on more people if that is successful, and if approved by the ethics board.
If they can pump up the technology to do what Nicolelis has demonstrated in rats, this would be, quite literally, a meeting of minds.
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