Scientists report today that they can identify what a person is observing just by measuring his or her brain activity with a functional magnetic resonance imaging (fMRI) brain scan. Two groups of researchers published results of their groundbreaking studies in the new issue of Nature Neuroscience. From New Scientist:
(Yukiasu Kamitani of Kyoto's ATR Computational Neuroscience Laboratories and Vanderbilt University's Frank Tong) showed patterns of parallel lines in 1 of 8 orientations to four volunteers. By focussing on brain regions involved in visual perception they were able to recognise which orientation the subjects were observing. Each line orientation corresponded to a different pattern of brain activity, although the patterns were different in each person. What is more, when two sets of lines were superimposed and the subjects were asked to focus on one set, the researchers could work out which one they were thinking of from the brain images.Link to New Scientist, Link to New York Times article
In a separate study, also published in Nature Neuroscience, John-Dylan Haynes and Geraint Rees at University College London, UK, showed two patterns in quick succession to 6 volunteers. The first appeared for just 15 milliseconds - too quick to be consciously perceived by the viewer.
But by viewing fMRI images of the brain, the researchers were able to say which image had been flashed in front of the subjects. The information was perceived in the brain even if the volunteers were not consciously aware of it.