Figure 8.

Effect of excitotoxic lesions of the amygdala on stimulus–reward encoding in OFC and MFC during learning. A, Percentage of neurons in OFC and MFC encoding the amount of reward associated with S1 or S2 preoperatively (blue/cyan) and postoperatively (red/orange). B, Time course of encoding: mean (±SEM) percentage explained variance for neurons classified as encoding stimulus–reward associations in OFC (top) and MFC (bottom). For both plots, preoperative S1: dark blue; preoperative S2: cyan; postoperative S1: red; postoperative S2: orange. Data are plotted relative to the onset of S1. C, Mean percentage explained variance for S1 reward (top) and percentage of neurons encoding S2 reward (bottom) for individual monkeys before and after lesions of the amygdala. Inset plots show the percentage change for each subject combined across OFC and MFC. For both plots, preoperative OFC: dark blue; postoperative OFC: cyan; preoperative MFC: red; postoperative MFC: orange. *p < 0.05; # p < 0.1.