How does the human brain run itself without any software? Find that out, say European researchers, and a whole new field of neural computing will open up. A prototype ‘brain on a chip’ is already working. The EU-supported FACETS project brings together scientists from 15 institutions in seven countries to do just that. Inspired by research in neuroscience, they are building a ‘neural’ computer that will work just like the brain but on a much smaller scale.The human brain is often likened to a computer, but it differs from everyday computers in three important ways: it consumes very little power, it works well even if components fail, and it seems to work without any software. A team within FACETS is completing an exhaustive study of brain cells – neurons – to find out exactly how they work, how they connect to each other and how the network can ‘learn’ to do new things. Meanwhile, another FACETS group is developing simplified mathematical models that will accurately describe the complex behaviour that is being uncovered. Although the neurons could be modelled in detail, they would be far too complicated to implement either in software or hardware.
The goal is to use these models to build a ‘neural computer’ which emulates the brain. The first effort is a network of 300 neurons and half a million synapses on a single chip. The team used analogue electronics to represent the neurons and digital electronics to represent communications between them. It’s a unique combination. Since the neurons are so small, the system runs 100,000 times faster than the biological equivalent and 10 million times faster than a software simulation. The network is already being used by FACETS researchers to do experiments over the internet without needing to travel to Heidelberg. But this ‘stage 1’ network was designed before the results came in from the mapping and modelling work. Now the team are working on stage 2, a network of 200,000 neurons and 50 million synapses that will incorporate all the neuroscience discoveries made so far. To build it, the team is creating its network on a single 20cm silicon disk, a ‘wafer’, of the type normally used to mass-produce chips before they are cut out of the wafer and packaged. This approach will make for a more compact device. So called ‘wafer-scale integration’ has not been used much before for this, as such a large circuit will certainly have manufacturing flaws.More information:
http://cordis.europa.eu/ictresults/index.cfm/section/news/tpl/article/BrowsingType/Features/ID/90451