"The fMRI technique is a relatively new way to measure changes in the brain's blood oxygen levels, which have strong links to neural activity.

The collected data were used to "teach" a computer program to associate certain blood flow patterns with particular kinds of images.

Participants were then asked to look at a second set of images they had never encountered before.

The model was programmed to take what it had learned from the previous pairings and figure out what was being shown in the new set of images.

For a collection of 120 images, the model correctly identified what a person was looking at 90 percent of the time. When the set was enlarged to a thousand images, accuracy was about 80 percent.

Continued at: http://news.nationalgeographic.com/news/2008/03/080305-brain-scan_2.html