Rats
The training one rat received made it behave in a certain way, and when linked to another rat by electric signals, the second one displayed the same response without any training. A third one linked to second soon learnt to show the same response.Getty Images

The future may not be far off when "organic computers" assembled by animal brains linked together could be used to solve algorithms or predict the weather.

A minor version of such collectives has begun to demonstrate the power of brain to brain interfaces.

Miguel Nicolelis, director of the Centre for Neuroengineering at Duke University has linked the brains of three monkeys and demonstrated a resilient system where they work in collaboration on a task.

So also, four rats whose brains were directly linked to each other showed they could synchronise neuronal activity and pool information to accomplish a job that they struggled to do individually.

From more neurons at work giving better results to more rats working together and then to monkeys was a logical step for Nicolelis.

The four rats were trained by being rewarded for synchronised response to the same signal, acting in the process like a processor. The training one rat received made it behave in a certain way, and when linked to another rat the second one displayed the same response without any training.

The collective brain response was correct 87% of the time and much better compared to individual efforts.

The system was resilient even when one dropped out.

In the case of the monkeys, the computer combined the signals from the monkeys to move the image of the arm on the screen. The monkeys soon learnt to synchronise and move the arm to the ball for the reward.

They even learnt to control the 3D movements of an avatar arm first by imagining and then using joint control.

"Essentially we created a super-brain," Nicolelis said. "A collective brain created from three monkey brains. Nobody has ever done that before."

Brain-machine interfaces that allow amputees and paralysed people to directly control prosthetic limbs have been demonstrated. The next step - brain to brain interfaces - has also been demonstrated by various groups transmitting messages across distances.

Direct transfer or sharing of knowledge from a tutor to a student or between soldiers in combat are some ideas that could come true soon.