the functional significance of Pe has been explained through several hypotheses (cf. Overbeek et al. [29] and Falkenstein [30]): 1) the affective-processing hypothesis [52], which suggests that the Pe reflects the emotional appraisal of the error or its consequences; 2) the error-awareness hypothesis [32, 48, 53], which proposes that the Pe reflects the conscious recognition of the fact that an error was committed; and 3) the behavior-adaptation hypothesis [32, 53], which suggests that the Pe reflects a process involved in remedial performance adjustments following errors (irrespective of whether such adjustments are driven by affective or cognitive aspects of error processing, or both). In gambling paradigms, the ORP is considered to be the P3 component of the ERPs [22], especially the P3b component with a parietal focus [28]. As in Toyomaki & Murohashi’s [28] study, the finding of our study that the ORP was sensitive to both the quality (loss/gain) and quantity (large/small) of the outcome might reflect that the ORP indexes both the motivational processing for the event of loss/gain (aaha…gain vs. alas…loss) as well as the evaluative processing of amount of loss/gain (larger outcome vs. smaller outcome). This explanation is consistent with the earlier reports that ORP amplitude increased
