Computer scientists and brain specialists have been discussing how they could work together to speed progress towards computers that show human intelligence and improve understanding of the human brain. Both goals are some way off but areas where the two fields might help each other have been identified.
Forty computer scientists and brain scientists met at a BCS debate, organised as part of the national Foresight Programme, last month. The meeting was held under a rule of anonymity.
One issue is that much of the computer science work on cognitive systems has little to do with biology. Models are devised by computer scientists but there is no reason to believe the brain works in the same way: the fact that a system gets the same result as a human is not proof.
The debate asked whether it was possible to build a computer model of the brain, and what use it would be. If a machine that matched a brain was built, mapping 10,000 billion neurons, each with about 1,000 connections, and assumed that the function of each connection could be represented by one bit, it would need 10 square metres of silicon at today's electronics density rates.
Much existing work on artificial neural networks is on a small scale and it would be hard for humans to get to grips with such a huge machine, the debate heard. Even with a big enough machine, it would still not reveal how the brain works. It would, however, enable theories and models to be tested.
Considering how neuroscience could help computer science, the debate heard that one area already seeing progress is that of technology interfaces with humans. Interfaces between a machine and the brain or nervous system involve implanted devices controlling artificial limbs or stimulating muscles affected by damage such as spinal lesions.
Another interesting area is systems that understand speech, or intuitively search databases, working much like human memory. Humans currently have to adapt to systems to use them; life would be easier if machines had to adapt to human foibles instead, the debate heard. Understanding the brain could also help in the design of database systems handling large numbers of queries.
Computer scientists at the debate said they had been disappointed to find that neuroscientists were unable to explain how human memory works - they had hoped to apply it to computer memory design. Such comments, along with the need for common terminology, highlighted the problems of bringing the two disciplines together.
However, there is middle ground where practical work is being conducted on robots and other devices that help elderly and housebound people. These show some human characteristics but do not involve an understanding of how the brain works.
The debate concluded that computer cognition could take a decade, a century or a millennium, but the potential rewards for success were great.
This was first published in September 2005