A hexagonal Fourier model of grid cells.Grid cells in rat medial entorhinal cortex are widely thought to play a major role in spatial behavior.  In sum, this hexagonal Fourier model suggests how the entire population of grid cells may be modeled in a principled way, incorporates biologically feasible mechanisms and provides a potentially powerful interpretation of the relationship between grid-cell activity and contextual information beyond spatial knowledge. 
hexagonal Fourier model