University Building Human Brain Model

A human brain simulator based on a million ARM processors is in development at the University of Manchester.

Chips loaded with 18 processors each will form the system architecture of a supercomputer called SpiNNaker (Spiking Neural Network Architecture), which aims to map the brain’s individual functions.

Computer scientists say the huge volume of processors will enable them to model just one percent of brain functionality, which operates based on billions of interacting neurons.

The chips were delivered last month and have passed functionality testing.

It is hoped SpiNNaker can eventually help neuroscientists, doctors, and psychologists to understand complex brain injuries, diseases and conditions to identify the most effective therapies.

Learning how the brain works

Professor Steve Furber, from the university’s School of Computer Science, said: “We don’t know how the brain works as an information-processing system, and we do need to find out. We hope that our machine will enable significant progress towards achieving this understanding.”

He added: “This could ultimately be of great help for patients, for example, who have presented with reading problems caused by strokes or similar brain injuries. Psychologists have already developed neural networks on which they can reproduce the clinical pathologies.”

There are 100 billion neurons with 1,000 trillion connections in the human brain. The neurons emit spikes which are relayed as tiny electrical signals.

SpiNNaker models these impulses as a ‘packet’ of data, in what the university described as a scaled down version of the way the Internet carries information.

This packet is then sent to all connected neurons, represented by small simple equations solved in real-time by software on the ARM processors.

Because the electronic connections in SpiNNaker convey these spikes much quicker than the brain’s biological connections, SpiNNaker can work just as effectively and quickly with many fewer connections.

Bespoke package

The bespoke microchips, designed in Manchester and manufactured in Taiwan, are integrated in a single 19mm square package.

A second microchip provides substantial memory using 3D System-in-Package technology from Unisem Europe, who have packaging facilities in south Wales.

It is claimed this package delivers the computing power of a PC in a tiny space and for around one watt of electrical power.

Mike Muller, chief technical officer at ARM said: “SpiNNaker seeks to create a working model of the ultimate smart system, the human brain. Steve is part of the ARM family, so this project was a perfect way to partner with him and Manchester University, and for ARM to encourage leading research in the UK.”

The University of Manchester was selected to design the system architecture for the project, and received half of a £5 million engineering and physical sciences research council grant to support the work.

The universities of Southampton, Cambridge and Sheffield are sharing the rest to work on other parts of the project.