Issue 28

25 June - 22 July 1996

Science insight

Mind over matter

For years it has been known that people could modify the rhythm of their brain waves through relaxation techniques. In recent years researchers at the University of Tübingen, Germany were able to assist epileptics to control their fits by teaching them to alter their brain waves; while Austrian scientists at Graz University of Technology achieved a 80 per cent success rate in training subjects to move an on-screen cursor with their thoughts.

Both of these projects involved defining and detecting human brain waves. Here at IC, Dr Steve Roberts, Department of Electrical and Electronic Engineering, is involved in parallel research. "We're working with the waves that are created a second or so before the brain tells a part of the body to move rather than the signal that is actually sent" said Steve. Detecting, recording and classifying these waves so they may be accurately differentiated from one another and translated into 'intelligent' brain mimicking software, is Steve's current research project.

The applications of this work may have far reaching consequences for the severely disabled. While injured bodies may not be capable of movement, the brain waves which precede human movement are still produced, even though the message is never sent. These are the impulses which Steve is currently classifying and which he hopes will eventually direct electronic devices such as wheelchairs and word processors.

Controlling such devices with the mind is dependent, however, on improving the accuracy with which brain waves are currently classified. "If we can get a high accuracy rate we might be able to put a computer underneath an electric wheelchair" said Steve. The computer program of which Steve speaks is known as a connectionist system or artificial neural network. Able to learn, recognise and interpret complex patterns, the neural network behaves something like human nerve cells which can relate information from one channel to another, or in this case, brain waves into directions for movement.