Curr. Biol. doi:10.1016/j.cub.2010.01.053 (2010)

By decoding patterns of brain activity, researchers can tell which in a list of events a person is recalling.

Eleanor Maguire and her colleagues at University College London, UK, showed ten volunteers short films depicting three different actions such as drinking coffee. The researchers then asked them to remember each action individually while scanning their brains using functional magnetic resonance imaging (fMRI). They found that unique fMRI patterns in the hippocampus corresponded with the recall of specific memories.

These patterns were stable over 24 hours and allowed the scientists to predict which memory participants chose to recall.