London: Researchers have developed new computer chips that mimic the human brain, which could revolutionise our understanding of how the mind functions.
Attempts to simulate the brain usually involve programming software to behave like groups of neurons. A "neuromorphic" design instead tries to recreate the brain`s hardware, using analogue components last seen in the early days of computing.
"On our system, you can physically point to the neuron," says Karlheinz Meier of the University of Heidelberg in Germany.
The Spikey chip contains 400 "neurons", or printed circuits. Real neurons have a voltage across their outer membrane, which Spikey mimics using capacitors - components that store charge, the `New scientist` reported.
Just as in a real neuron, when the applied voltage reaches a certain level, the capacitor becomes conductive, firing a "nerve signal".
Spikey also mimics synapses - the connections between neurons. In a normal chip, every process is digital and so can only take the value 0 or 1.
Researchers instead used analogue components with variable levels of resistance to simulate the way connections between neurons become stronger or weaker depending on how much they are used.
"Analogue circuits died after digital computers became more powerful," says Meier, but they are now finding new roles.
Researchers modelled six neural networks, including one found in the insect olfactory system. By measuring patterns of activity, they found Spikey`s artificial networks behave much like the real thing.
"This is as good as you can get in simulating neural architecture," says Massimiliano Versace of Boston University.
Neuromorphic chips do already exist, though until now each chip could only mimic one particular brain circuit. Spikey, on the other hand, can recreate any pattern.
Neuromorphics have advantages over conventional chips that makes them useful in certain situations. For Instance, they do not separate memory and computation - information is stored in the synaptic strength - so they can run faster using less power, the report said.
The chips also cope better with damage. Knocking out a few bits of a normal chip often breaks it altogether, but neuromorphics keep working.