Figure 3. Physical space projects onto log firing rate space.

A four-cell simulation with normalized inputs was run during simulated movements among the corners of a box. a. Successive paths of the simulated movement in physical space. b. The activity of the simulated neurons projected into log space for the sequences corresponding to a. The x axis in these plots is log(t_E/t_W ), where t_E is the firing rate of the first unit, with preferred direction pointing toward the east. When the animal moves north/south, logt_E/t_W is unchanged, despite the fact that both t_E and t_W are subject to exponential decay.