In a new study, Northwestern University neurobiologists have found that the brain’s internal GPS changes each time we navigate a familiar, static environment.

This means that if someone walks the same path every day—and the path and surrounding conditions remain identical—each walk still activates different “map-making” brain cells (neurons). Not only does this discovery shed light on the fundamental mystery of how the brain processes and stores spatial memories, but it could also have profound implications for scientists’ understanding of memory, learning and even aging.

The study appears in Nature.