Main effect of task instructions. A & C: statistical maps showing a main effect of task in the left orbitofrontal cortex (A) and left fusiform gyrus (C). Color scale indicates F score on two-way ANOVA, threshold: p < 0.005, minimum cluster size = 662 (estimated false positive rate α = 0.05). L: left. R: right. Z: position of axial slice in Talairach space. B & D: BOLD responses in the left orbitofrontal cortex (B) and left fusiform gyrus (D). Error bars show standard error. Vertical dotted lines show beginning and end of trial. EP: emotion rating on pleasant pictures, EU: emotion rating on unpleasant pictures, FP: frequency rating on pleasant pictures, FU: frequency rating on unpleasant pictures.