New research shows that a part of the brain called the hippocampus stores memories by their "temporal context" -- what happened before, and what came after -- and not by content. From brain scans of the hippocampus as the volunteers were answering questions in this study, researchers could identify patterns of activity specific to each image. But when they showed the volunteers the same images in a different sequence, they got different patterns of activity. In other words, the coding of the memory in the hippocampus was dependent on its context, not just on content.