Decoding the population activity of grid cells for spatial localization and goal-directed navigation
Mammalian grid cells discharge when an animal crosses the points of an imaginary hexagonal grid tessellating the environment. In this talk, I will show how animals can navigate by reading out the population activity of grid cells across multiple spatial scales. The theory explains key experimental results, makes testable predictions for future physiological and behavioral experiments, and provides a mathematical foundation of the concept of a "neural metric" for space. For goal-directed navigation, the proposed allocentric grid cell representation can be readily transformed into the egocentric goal coordinates needed for planning movements. These results show that the grid-cell code provides a powerful and highly flexible neural substrate to solve various cognitive tasks.