Amazing World

Researchers have electronically linked the brains of pairs of rats, enabling the animals to communicate directly via implanted microelectrode arrays to solve simple behavioral problems, according to a study published today (February 28) in Scientific Reports.

The authors of the study claim the achievement is the first of its kind, and could lead to the linking of multiple animal brains to form the first “organic computer” through which multiple animals could exchange, store, and process sensory and motor information.

But neuroscientists in the field of brain-machine interfaces (BMIs) told The Scientist that the study is actually a combination two methods demonstrated several times before—namely, recording and decoding information from neural networks and using extracted neural firing patterns to stimulate external devices or muscles of the body.

Critics also pointed out several methodological flaws, including the lack of adequate controls, and cautioned that claims about enabling “organic computing” are far-fetched at best.

“[The researchers] have made numerous important contributions to the field of neural interfaces,” said Lee Miller, a neuroscientist at Northwestern University in Evanston, Illinois, who was not involved in the study, in an email to The Scientist. The group, led by Duke University neuroengineer Miguel Nicolelis, has made critical advancements in the development of BMIs that extract motor signals from an animal’s brain and/or provide it with somatosensory feedback, Miller added. “However, I'm afraid one would have to be forgiven, on reading the current account, with its references to, a ‘grid of multiple reciprocally interconnected brains . . . solving heuristic problems deemed non-computable by a general Turing-machine,’ for mistaking it for a poor Hollywood science fiction script. It is not clear to what end the effort is really being made.”

Several studies in the past few years have demonstrated that brain-derived motor signals, recorded through implanted microelectrodes, can be decoded and utilized to control the movement of mechanical or electrical devices. Some groups have also shown that behaviorally relevant information can be extracted in real-time and fed back into the same brain. Building on that research, Nicolelis and his colleagues wanted to see if a brain could assimilate and use electrical stimulation patterns transferred directly from sensory and motor neural networks of a different brain. In other words, they wanted to build a brain-to-brain interface (BTBI).

To test the idea, the researchers conducted experiments with rats containing brain microelectrode implants capable both of recording electrical activity from neural networks and stimulating neurons. Simply put, patterns of cortical signals were recorded in one rat—the encoder—and transmitted directly into the brains of another rat—the decoder.

In the first experiment, the researchers trained pairs of rats to press one of two levers, with the correct one indicated by a flashing light above, to get a drink of water. When the encoder rat pressed the right lever and got its reward, a sample of the brain activity that coded for that behavior was translated into a pattern of electrical stimulation and delivered directly to the brain of the decoder rat. The decoder faced the same lever setup, but got no visual clues, so had to rely on cues transmitted from the encoder to guide it to the correct lever and the reward.

In trials, the decoder rats picked the right lever 70 percent of the time, a performance significantly better than chance, suggesting that the information was successfully transferred and understood.

The rats performed similarly well on a comparable test using tactile information—distinguishing between a narrow and wide opening using their whiskers. In these trials, the decoder followed the actions of the encoder 65 percent of the time; again, with accuracy better than chance.

The findings demonstrate that implanted microelectrodes and decoding methods can be used to directly channel behavioral information between two animal brains. This, the authors speculate, indicates that brain networks could allow multiple animals to synchronize their behaviors in response to directly transferred electrical cues. “So basically, we are creating what I call an organic computer,” Nicolelis said in a press release. “Such a computer solves a puzzle in a ‘non-Turing’ way.”

The researchers also attempted to train the encoder rats to give better signals to improve the performance of the decoder rats. By providing the encoder with an extra reward every time the decoder performed a trial correctly, the encoder appeared to improve the signal-to-noise ratio of its brain activity that represented the decision, making the information easier for the decoder rat to detect.

Nicolelis also said that, in theory, BTBIs could be used be used to link a network of brains. “We cannot even predict what kinds of emergent properties would appear when animals begin interacting as part of a brain-net. In theory, you could imagine that a combination of brains could provide solutions that individual brains cannot achieve by themselves.”

“It’s possible, or at least plausible, that two brains work better than one, or at least differently,” agreed Kevin Otto, a neuroengineer at Purdue University in Indiana. “They may be able to interact to change behaviors in ways that we can’t envisage in a natural environment, and this could be a step toward understanding that.”

And though Otto cited “limitations in the design and execution of the experiments,” he praised the paper for drawing attention to BTBIs as a way of exploring how neural systems work to govern behaviors that are rewarded. “The study helps to promote the role of BMIs not only in prosthetic applications, but also as scientific tools. It’s a contribution to that.” 

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It's no secret that tortoises are among the most resilient animals on Earth, perfectly adapted for life in natural environments that others would find inhospitable. But for one particularly tenacious pet tortoise, that hardy sense of survival allowed it to endure for decades in the most unnatural of places.

Back in 1982, the Almeida Family was saddened to learn that their beloved pet, Manuela, a young red-footed tortoise, had gone missing. Their house was under renovation at the time, so the family just assumed that the slow-moving animal had slipped out through a gate left open by the construction crew -- disappearing into the forest near their home in Realengo, Brazil. But they couldn't have been more wrong.

The true fate of their lost pet remained a mystery for the next 30 years, that is, until recently.

Earlier last month, after their father Leonel passed away, the Almeida children returned to help clean out his cluttered storage room upstairs. As it turns out, Leonel was somewhat of a horder, so the room was jam-packed with things that he had found on the street, like broken televisions and furniture. Deciding it was mostly junk, the family set about moving it to the trash out front.

But while son Leandro Almeida was making a trip to the dumpster with a box of broken records, a neighbor asked him if he was intending to throw out the tortoise that was holed up inside.

"At that moment I was white and did not believe,

Flickr/CC BY-SA 2.0

That's when the Almeidas learned that, amazingly, the hardy turtle had managed to survive three decades in storage.

The family suspects she had been able to sustain herself grubbing on termites which, thanks to all that unwanted furniture, was likely in abundance. And although she seemed to be surviving just fine in the dank confines of the storage room, Manuela is no doubt pleased (in her own tortoisey way) to be reunited with the family that had so long thought her gone forever.

But in the end, it's hard not to be impressed with the resiliency of life and the slow-and-steady approach to survival taken by tortoises -- both in living with us, and perhaps sometimes in spite of it.

Please note, the photos show a red-footed tortoise, though not the actual one from the story, as that image was not available to us.