PT  - JOURNAL ARTICLE
AU  - Martin Stemmler
AU  - Alexander Mathis
AU  - Andreas V. M. Herz
TI  - Decoding the Population Activity of Grid Cells for Spatial Localization and Goal-Directed Navigation
AID  - 10.1101/021204
DP  - 2015 Jan 01
TA  - bioRxiv
PG  - 021204
4099  - http://biorxiv.org/content/early/2015/06/21/021204.short
4100  - http://biorxiv.org/content/early/2015/06/21/021204.full
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.