The 2014 Nobel Prize in Physiology or Medicine goes to John O'Keefe, May-Britt Moser and Edvard I. Moser for their discoveries of cells that constitute a positioning system in the brain—an inner GPS. The winning work is explained by Karolinska Institute faculty and Nobel Committee members Göran Hansson, Ole Kiehn, Hans Forssberg and Juleen Zierath