fMRI 'mind reading' data set available.
Quantitative receptive-field models that characterize the relationship between visual stimuli and fMRI activity in early visual areas make it possible to identify, from a large set of completely novel natural images, which specific image was seen by an observer.
Data set contributed by Jack Gallant Lab, UC Berkeley, available here.
From the abstract: "Our results suggest that it may soon be possible to reconstruct a picture of a person's visual experience from measurements of brain activity alone."