Figure 3.

Gradient of response magnitude within the receptive field of projection cells. A, PSTHs show the total number of spikes (sum of all directions) evoked in a projection cell by deflection of each of the vibrissae tested in the E row. B, Three-dimensional bar graphs of normalized response magnitudes within the receptive field of two projection cells. For each vibrissa, response magnitudes were summed across all directions. Bars with zero magnitude (D6 and E6 in the top graph, for example) indicate vibrissae of a threshold too high to be tested with the piezo stimulator. C, Histogram shows how response magnitude, as measured in B, diminishes as distance from the dominant vibrissa increases. Error bars indicate 1 SD. D, Relationship between magnitude and onset latency of vibrissa-evoked responses in three projection cells. Dots, open circles, and stars are values obtained for three different cells.