In a fascinating new paper, researchers Hongmi Lee and Brice A. Kuhl report that they can decode faces from neural activity. Armed with a brain scanner, they can reconstruct which face a participant has in mind. It's a cool technique that really seems to fit the description of 'mind reading' - although the method's accuracy is only modest. Here's how they did it. Lee and Kuhl started out with a set of over 1000 color photos of different faces. During an fMRI scan, these images were shown to partcipants one after the other and the neural responses were recorded. The set of faces was then decomposed into 300 eigenfaces using the technique of principle component analysis (PCA). Each eigenface represents some statistical aspect of the data The neural activity associated with each eigenface was then determined in a machine learning step (see A, below.)
Now for the mind-reading bit: Lee ...
