Figure 4.

Grand average population responses. Response efficacy ρ and spike rate υ are plotted against stimulus frequency f for the 23 barrel column neurons (filled squares and black lines), the six septum column neurons (brown triangles and lines), and the total population of barrel cortex neurons (unfilled squares and dashed lines). ρ peaked at 1 apps and then declined continuously (a), although the neural spike rate υ tended to grow logarithmically with increasing f (b). However, plotting υ and f logarithmically reveals that septum column neurons achieve linear growth up to 18 apps (c). The values at f > 9 apps were slightly displaced to dissociate the symbols. The bars through the means represent ±1 SD.