Neuroboffins at Duke University in Durham, North Carolina, have managed to link the brains of two rats on different continents in an experiment they claim could pave the way for organic supercomputers built from networked animal brains.
In a paper published in the journal Scientific Reports on Thursday, Duke researcher Miguel Nicolelis explains how he and his team managed to connect the motor portions of the rodents' brains using what he describes as a brain-to-brain interface (BTBI).
"The present study demonstrates for the first time that tactile and motor information, extracted in real time from simultaneously recorded populations of cortical neurons from a rat's brain, can be transmitted directly into another subject's cortex through the utilization of a real-time BTBI," Nicolelis writes.
In the experiment, Nicolelis designated one rat as the "encoder" and fitted it with a device that could transmit signals from the part of its brain that controls its movements to the other rat, dubbed the "decoder". Nicolelis's team then trained the encoder rat to press either of two levers, as indicated by a visual stimulus (a light).
Nicolelis found that with the BTBI activated, the decoder rat would press the same lever as the encoder rat 64 per cent of the time, even though it wasn't receiving the same visual stimulus as the encoder rat.
Nicolelis admits that this isn't exactly a stellar success rate, but he argues that it's significantly higher than if the decoder rat simply chose which lever to push by chance.
When the BTBI was deactivated, he says, the decoder rat's success rate plummeted back to chance-like levels, indicating that signals from the encoder rat's brain had been affecting the decoder rat's decision-making.
Nicolelis says the BTBI worked even when one of the rats was moved to a lab in Natal, Brazil, some 4,034 miles distant from Nicolelis's lab at Duke.
"It's not telepathy," Nicolelis told the journal Nature. "It's not the Borg. But we created a new central nervous system made of two brains."
Two rats getting on each other's nerves
Nicolelis says his next step will be to move up the evolutionary ladder from rats to monkeys, to see if two monkeys connected via BTBI can play a game together using virtual avatars controlled directly by each other's brains.
"Rats don't have a sense of self, so it's hard to say what the effect on the animals are, but monkeys can collaborate in a much more complex way," he says.
Nicolelis's paper goes on to postulate that if a synthetic nervous system based on BTBIs was expanded to include multiple brains, it could form the basis of a new kind of organic computer that could draw on the unique abilities of living brains to solve problems that would be considered non-computable using traditional Turing-machine computers.
"Future works will elucidate in detail the characteristics of this multi-brain system, its computational capabilities, and how it compares to other non-Turing computational architectures," Nicolelis writes.
Of course, similar ideas have long been staples of science fiction. In David Cronenberg's 1981 film Scanners, super-evolved humans could form direct links with each others' brains, and even with computer networks – although the results weren't always desirable.
But some of Nicolelis's colleagues believe he's nowhere near achieving the kind of inter-brain links he envisages. According to Andrew Schwartz, a neurobiologist at the University of Pittsburgh in Pennsylvania, the BTBI Nicolelis demonstrated in his experiment with the rats was really nothing special.
"Although this may sound like 'mental telemetry', it was a very simple demonstration of binary detection and binary decision-making," Schwartz told Nature. "To be of real interest, some sort of continuous spectrum of values should be decoded, transmitted and received."
Physiologist Lee Miller of Northwestern University in Evanston, Illinois, was even more critical. Describing Nicolelis's paper and its conclusions as reading like something out of a "poor Hollywood science-fiction script," he questioned whether the experiments had any validity at all.
"It is not clear to what end the effort is really being made," Miller said. ®
Sponsored: Webcast: Ransomware has gone nuclear