The Surprising Relativism of the Brain’s GPS
The first pieces of the brain’s “inner GPS” started coming to light in 1970. In the laboratories of University College London, John O’Keefe and his student Jonathan Dostrovsky recorded the electrical activity of neurons in the hippocampus of freely moving rats. They found a group of neurons that increased their activity only when a rat found itself in a particular location.1 They called them “place cells.”
Building on these early findings, O’Keefe and his colleague Lynn Nadel proposed that the hippocampus contains an invariant representation of space that does not depend on mood or desire. They called this representation the “cognitive map.” In their view, all of the brain’s place cells together represent the entirety of an animal’s environment, and whichever place cell is active indicates its current location. In other words, the hippocampus is like a GPS. It tells you where you are on a map and that map remains the same whether you are hungry and looking for food or sleepy and looking for a bed. O’Keefe and Nadel suggested that the absolute position represented in the hippocampal place cells provides a mental framework that can be used by
