The Knierim lab reports in the current issue of Nature Neuroscience. The Knierim lab demonstrates that new spatial firing fields (place fields) in the hippocampus can be created almost instantaneously when a rat pauses to investigate its environment. This finding may lend physiological support to current ideas about the role of the hippocampus as serving as a memory index that rapidly stores information about attended experience onto the rat’s mental map of its environment.