RT Journal Article SR Electronic T1 Decoding the Population Activity of Grid Cell for Spatial Localization and Goal-Directed Navigation JF bioRxiv FD Cold Spring Harbor Laboratory SP 021204 DO 10.1101/021204 A1 Martin Stemmler A1 Alexander Mathis A1 Andreas V. M. Herz YR 2015 UL http://biorxiv.org/content/early/2015/06/18/021204.abstract AB Mammalian grid cells fire whenever an animal crosses the points of an imaginary, hexagonal grid tessellating the environment. Here, we show how animals can localize themselves and navigate by reading-out a simple population vector of grid cell activity across multiple scales, even though this activity is intrinsically stochastic. This theory of dead reckoning explains why grid cells are organized into modules with equal lattice scale and orientation. Computing the homing vector is least error-prone when the ratio of successive grid scales is around 3/2. Silencing intermediate-scale modules should cause systematic errors in navigation, while knocking out the module at the smallest scale will only affect navigational precision. Read-out neurons should behave like goal-vector cells subject to nonlinear gain fields.