28 Feb 07

People's intentions have been read via brain scans by a team of scientists including Professor Dick Passingham from Oxford's Department of Experimental Psychology.

During the study, researchers asked volunteers to decide in advance whether to add or subtract two numbers they were about to be shown on a screen.

Before the numbers appeared, their brains were scanned using functional magnetic resonance imaging. First, the computer program 'learnt' the unique brain patterns relating to the 'add' or 'subtract' intention for each individual volunteer. Afterwards it was able to identify the person's unspoken intentions with 70 per cent accuracy.

The team of scientists from Germany, Japan, London and Oxford published their findings in Current Biology.

It is hoped that the research will advance brain-controlled technology for tools for disabled people, such as thought-controlled prosthetic limbs. However, the ethical implications of reading minds are pressing: could, for example, such a system one day be used to read criminal intentions before any crime has been committed?

Professor Passingham, senior author on the paper, says that such concerns are not a problem at this stage. 'To read your intentions we have to scan you for one hour, and specify in advance that you should decide between adding or subtracting. We could not tell what other intentions you had, only which of two specified intentions - and even then we only get it right 70 per cent of the time. Nor can we use the readings from one person's brain to read another person's - so John Reid can't ask us to find out if someone is going to commit a murder and then lock the person up before they do so.

'However, advances in imaging have come very fast, so I would not be so sure that we won't be able to do better in future. I therefore think that we should be holding ethical discussions now.'