A principle of economy predicts the functional architecture of grid cells

Elife. 2015 Sep 3:4:e08362. doi: 10.7554/eLife.08362.


Grid cells in the brain respond when an animal occupies a periodic lattice of 'grid fields' during navigation. Grids are organized in modules with different periodicity. We propose that the grid system implements a hierarchical code for space that economizes the number of neurons required to encode location with a given resolution across a range equal to the largest period. This theory predicts that (i) grid fields should lie on a triangular lattice, (ii) grid scales should follow a geometric progression, (iii) the ratio between adjacent grid scales should be √e for idealized neurons, and lie between 1.4 and 1.7 for realistic neurons, (iv) the scale ratio should vary modestly within and between animals. These results explain the measured grid structure in rodents. We also predict optimal organization in one and three dimensions, the number of modules, and, with added assumptions, the ratio between grid periods and field widths.

Keywords: efficient coding; grid cells; neuroscience; rat; spatial cognition; theoretical neuroscience.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Humans
  • Models, Neurological*
  • Neurons / physiology*
  • Space Perception*

Grants and funding

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.