By Steve Connor, Science Editor, The Independent
Thursday, 6 March 2008
The ability to read someone's mind and even to visualise their dreams has come a step closer with a study showing that it is possible to predict accurately what someone is seeing by analysing their brain activity with a medical scanner.
Scientists have built a computer that can "decode" the brain activity signals from a scanner and match them to photographs of what a person has seen. In the future, they believe the technology will be able to reconstruct scenes being visualised in a person's head – whether real or imaginary. Tests of the decoder show that it can predict which photograph someone is looking at with an accuracy of up to 90 per cent, although the success rate falls as the total number of photographs being assessed increases.
The scientists believe that it might be possible in the near future to adopt the same approach in making a device that can read someone's thoughts, although they warn against doing this surreptitiously or against someone's will.
"It is possible that decoding brain activity could have serious ethical and privacy implications downstream in, say, the 30 to 50-year time frame. It is something I do care about," said Professor Jack Gallant of the University of California, Berkeley, who led the study published in the journal Nature.