Fig. 5.

Composite PEHs of normalized firing of all PR, RFe, and RFi cells during water (left)- and food (right)-reinforced responding. Neural activity was normalized relative to the respective overall mean firing rates of each cell here and in Figures 8 and 10. These PEHs therefore reflect the relative increase in firing of each cell type regardless of absolute firing rate. Under both water and food reinforcement conditions, the complementary nature of the relative firing patterns of each cell type is apparent and similar.