Figure 7.

Spike density functions (σ = 40 ms) illustrate the activity time course of individual neurons (4 each in parietal and prefrontal cortex) exhibiting activity that was significantly influenced (p < 0.05) by the interaction between rule and either horizontal or vertical category in the ANCOVA. A–D, Plots illustrate the activity of four parietal neurons exhibiting rule-dependent category selectivity. Activity on trials when the sample was located in the right (black) and left (gray) spatial categories is plotted separately for neurons with horizontal category preferences (B, D). Activity on trials when the sample was located in the above (gray) and below (black) spatial categories is plotted separately for neurons with vertical category preferences (A, C). In each pair of plots in each panel, activity on compatible rule trials (e.g., the LR rule for neurons preferring horizontal categories, or the AB rule for neurons preferring vertical categories) is plotted on the left, and activity on incompatible rule trials on the right. E–H, Corresponding data for four prefrontal neurons.