Figure 3.

Reward modality and magnitude effect in a priori regions of interest. (A) Regions of interest (ROIs) and main effect of reward anticipation. The existing literature on reward anticipation and anticipatory affect implicated the NAcc and the aINS as potential contributors to motivation. Using predefined ROIs, we found that both money (green) and candy (blue) reward conditions (with our control condition as a baseline) led to increased activation in both NAcc and aINS. Error bars represent SE of the mean (SEM). Stars represent significant paired comparisons (p < 0.05). (B) Repeated-measures 2 × 2 ANOVA of reward anticipation. To determine whether there was a significant modality (money, candy) by magnitude (big, small) interaction in our fMRI data, a 2 × 2 repeated-measures ANOVA of the same anticipation contrasts was run. The statistical map here displays the z-scored F statistics for that interaction. There were significant clusters in both NAcc and aINS.