FIGURE 2.

(A) Grid cells in the entorhinal cortex represent locations of a body in an environment. The location representations are updated by movement (Room 1). The path integration property ensures that the representation of location c is independent of the path taken to get there. Locations are unique to each environment such that the representations of locations a, b, and c are distinct from the representations of any point in Room 2. (B) We propose that the neocortex contains grid cell analogs that represent locations relative to an object. The location representations are unique to each object.