ROI volume and food only reward devaluation performance. The y-axes represent the summed difference scores from both testing sessions as the measures of individual performance on the reward devaluation task for the food only condition plotted against volumes on the x-axes for (A) area 11/13 of the OFC, (B) area 14 of OFC, (C) BL nuclei of the amygdala, and (D) CM nuclei of the amygdala for young monkeys (dark gray) and aged monkeys (light gray). There was a significant relationship between area BL volume and reward devaluation performance such that monkeys with a smaller BL volume showed a greater tendency to select the nonsatiated, or higher valued, reward.