(Image: Duke University)

( Duke University)

The old proverb, “two heads are better than one,” was put to the test recently when researchers electronically linked the brains of two rats, prompting the animals to work together to accomplish a common goal.

The researchers fitted each rat with a device that allowed one rat to send brain waves to the other, even when separated by long distances.  The rat that received the transmitted information used it to help perform a simple task, which earned both rats a reward.

When the rats’ joint efforts were unsuccessful, the animals used the device as a two-way communicator, to mentally collaborate with each other until they performed the task properly.

“These experiments demonstrated the ability to establish a sophisticated, direct communication linkage between rat brains, and that the decoder brain is working as a pattern-recognition device,” said Miguel Nicolelis from Duke University’s School of Medicine. “So basically, we are creating an organic computer that solves a puzzle.”

Microscopic electrodes were inserted into the brains of the two lab rats, into an area of the cerebral cortex which processes motor information, forming what researchers called an “organic computer.”

One of the rats, considered to be the encoder, transmitted brain wave information to the other rat, known as the decoder.

Screen capture of a video demonstrating behavior of the encoder rat (left) transmitting brain waves to the decoder rat (right) who is receiving the information with an electronic device (Photo: Duke University)

Screen capture of a video showing the encoder rat (left) transmitting brain waves to the decoder rat (right), which is receiving the information via an electronic device (Duke University)

The encoder rat received a visual cue, such as a light, indicating which lever to press in order to be rewarded with a sip of water.

When the encoder rat pressed the correct lever, brain activity indicating its  decision was translated into signals of electrical stimulation and transmitted directly to the brain of the decoder rat.

The encoder rat, unlike his partner, wasn’t given the same kind of visual cue to indicate which lever to press to obtain the reward.

So, in order to get the sip of water, the decoder rat had to rely strictly on the information transmitted by the encoder rat via the brain-to-brain electronic interface.

Researchers found the decoder rat responded to the electronic cues about 70 percent of the time.

The researchers also learned that the brain-to-brain interface provided two-way communications between the two rats which allowed them to help each other.

An encoder rat fitted with a brain-to-brain interface from video capture (Image: Duke University)

An encoder rat fitted with a brain-to-brain interface (Duke University)

“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,” Nicolelis said. “The encoder improved the signal-to-noise ratio of its brain activity that represented the decision, so the signal became cleaner and easier to detect.”

The researchers even took an encoder to Brazil while the decoder rat remained in a North Carolina lab. Despite the distance, scientists were able to send brain wave signals between the rats via the internet and found that they were still able to work together.

“So, even though the animals were on different continents, with the resulting noisy transmission and signal delays, they could still communicate,” said Miguel Pais-Vieira, a postdoctoral fellow and author of the study. “This tells us that it could be possible to create a workable, network of animal brains distributed in many different locations.”

The study with the details of the research and findings were published recently in  Scientific Reports.