London - A new electronic circuit can mimic the activity of the brain and may one day be used to create computers that think more like humans, scientists said on Wednesday.
The cerebral cortex of the brain, the centre of human intelligence, is an intricate network of neurons that contain unusual feedback loops.
Scientists at the Massachusetts Institute of Technology (MIT), Lucent Technologies' Bell Labs in New Jersey and the Institute of Neuroinformatics in Zurich have created an electronic circuit similar to the brain's neural system.
It consists of artificial neurons that communicate with each other via synapses, or junctions where they connect, in a system that could lead to the development of computers that could perform perceptual tasks such as sight recognition.
"The neural circuits of the cortex contain many feedback loops," said H Sebastian Seung, of MIT. "Neuroscientists have found that cortical feedback seems to operate in a way unfamiliar to today's electronic designers. We set out to mimic this novel mode of operation in an unconventional way."
The brain processes both analogue and digital signals.
When a car approaches, for example, the brain receives and processes information about its colour, size and distance. The digital component is still there because the brain makes an either-or decision as to whether or not it is a car.
In a report in the science journal, Nature, the researchers explained that when multiple signals are fed to two artificial neurons, the circuit responds to one stimulus and suppresses its response to the other.
The scientists also added an inhibitory neuron in their circuit, which controls the signals and keeps feedback in check.
"The electronic world is evolving more and more towards mixed analogue-digital computation as the brain has already done.
"However, the brain's mixed-signal circuits combine analogue and digital functions in a much more intimate way than is done in the electronic world," said MIT's Rahul Sarpeshkar, who worked on the project. - Reuters