Figure 2.

PEHs showing three types of neuronal firing patterns observed within seconds of the lever-press response (FR1) for water reinforcement. Top, Example of an Acb neuron displaying increased firing rates within seconds preceding the reinforced response (PR). Middle, Another neuron showing increased firing immediately after response completion (RFe). Bottom, A third Acb cell displaying a marked inhibition in background firing rates within seconds before and after the response (RFi). R, Reinforced responses. Each PEH contains 250 bins here and in subsequent figures.