As the waveforms in Fig. 4 indicate, the ORN components in the current study have followed the same order as shown by Gehring & Willoughby [15] and by Nieuwenhuis et al [19] and the morphology of ORN and ORP components in our study matched Toyomaki & Murohashi’s [28] study. Although many studies that have used gambling tasks measured/reported the negativity at FCZ [15, 19] and the positivity at PZ [22, 28], we found that both ORN and ORP were maximal at the CZ electrode. The topography of ORN and ORP components (see Fig. 7) has shown interesting differences. The finding that loss conditions were more anteriorized than gain conditions suggests that the loss-related processing may be more involved with the frontal lobe (especially anterior cingulate cortex) functioning than the gain processing. This is consistent with the findings from source modeling, fMRI, and single-unit recording studies that the ORN (or feedback negativity) is generated in the medial frontal cortex, and probably in the anterior cingulate cortex [cf. 44]. While the gender difference in the outcome processing is explained separately in the
