Fig. 3.

Parametric maps of simple effects of reward (contrast high vs. low reward) in the baseline (A) and treatment conditions (B), and of the interaction high vs. low reward in baseline vs. treatment conditions (C) overlaid on a template brain. The red ovals highlight the effect tested in the region of interest analysis. For display purposes, the maps were thresholded at p < 0.005, uncorrected. In D, estimated effects of the contrast high vs. low reward in the baseline and administration conditions (percent signal change). In E, individual effect estimates are shown (high, low: high and low reward trials; baseline, treatment: first and second scan). One can see that the interaction reward levels x treatment was driven by the high reward trials in the baseline scan.