Army of smartphone chips could emulate the human brain

If you have a smartphone, you probably have a slice ofSteve Furber’s brain in your pocket. By the time you read this, his 1-billion-neuron silicon brain will be in production at a microchip plant in Taiwan.

Computer engineers have long wanted to copy the compact power of biological brains. But the best mimics so far have been impractical, being simulations running on supercomputers.

Furber, a computer scientist at the University of Manchester, UK, says that if we want to use computers with even a fraction of a brain’s flexibility, we need to start with affordable, practical, low-power components.

“We’re using bog-standard, off-the-shelf processors of fairly modest performance,” he says.

Furber won’t come close to copying every property of real neurons, says Henry Markram, head of Blue Brain. This is IBM’s attempt to simulate a brain with unsurpassed accuracy on a Blue Gene supercomputer at the Swiss Institute for Technology, Lausanne. “It’s a worthy aim, but brain-inspired chips can only produce brain-like functions,” he says.

That’s good enough for Furber, who wants to start teaching his brain-like computer about the world as soon as possible. His first goal is to teach it how to control a robotic arm, before working towards a design to control a humanoid. A robot controller with even a dash of brain-like properties should be much better at tasks like image recognition, navigation and decision-making, says Furber.

“Robots offer a natural, sensory environment for testing brain-like computers,” says Furber. “You can instantly tell if it is being useful.”

Called Spinnaker – for Spiking Neural Network Architecture – the brain is based on a processor created in 1987 by Furber and colleagues at Acorn Computers in Cambridge, UK, makers of the seminal BBC Microcomputer.

Although the chip was made for a follow-up computer that flopped, the ARM design at its heart lived on, becoming the most common “embedded” processor in devices like e-book readers and smartphones.

But coaxing any computer into behaving like a brain is tough. Both real neurons and computer circuits communicate using electrical signals, but in biology the “wires” carrying them do not have fixed roles as in electronics. The importance of a particular neural connection, or synapse, varies as the network learns by balancing the influence of the different signals being received. This synaptic “weighting” must be dynamic in a silicon brain, too.