Figure 9. Tonic changes in firing rate. A, Single neuron example. Histogram shows firing rate of a neuron in C→X blocks. Gray shading indicates duration of cue. “X” indicates that no solenoid activation occurs at this time in this context. B, Histogram for the same cell as in A from the C→R context. Solenoid activation (“R,” arrow) occurred 0.5 s after cue offset. C, Red line shows population average normalized modulation index (initial bin width, 1 ms smoothed with 25 bin running average) calculated from all cells with tonic elevation in the C→X context. Vertical axis has been scaled to the tonic component, severely truncating the phasic response. Blue line shows the average calculated for the same cells in the C→R context. D, As for C, but for cells with tonic inhibition in C→X. E, As for C, but for cells with excitation in C→R context. F, As for E, but for inhibitions. G, Population average baseline-normalized lick rates averaged across all recording blocks from which neural data were obtained. Dark blue and red lines show lick data from C→R and C→X blocks in graph C, respectively, and light blue and red lines show data from blocks in E. Note that red lines from C→X blocks are barely visible because they run along baseline. H, Lick data associated with neural data in D and F (conventions as in G).