Comparison Unpleasant vs. Neutral Stimuli. Brain maps showing significant condition differences with respect to cortical source activation towards unpleasant and neutral picture content. Depicted are the significant differences in the average over the whole stimulation interval as calculated in the permutation analysis. The left panel shows the areas, where unpleasant stimuli lead to higher activation, the right panel shows the areas where neutral stimuli lead to higher activation and the center panel shows the difference of activation that was fed to the permutation analysis.