The current density (LORETA) maps showed that ORN activity during the loss condition was marked by more activation in frontal/anterior areas than in parietal/posterior areas whereas the reverse (of anterior-posterior source activity) was true for the gain condition (see Fig. 8). The maximal current density (or source) for the loss outcome was found in medial frontal gyrus and anterior cingulate cortex. The gain outcome, on the other hand, showed maximal activity in posterior cingulate cortex and limbic lobe. Although LORETA is not sensitive to amplitude differences, the topography of both LORETA and surface potential has simultaneously confirmed the finding of ‘anterior-loss’ and ‘posterior-gain’. Therefore, as many of the studies have reported, it is possible that ORN is generated in the medial frontal cortex, and probably in the anterior cingulate [44], and that this component has been therefore termed by Gehring & Willoughby [15] as medial frontal negativity or MFN to indicate the brain region associated with this component.
