amount(s) [21]. For example, when 10 is chosen (between 10 and 50) and the Chosen Outcome Stimuli (COS) is +10 (a gain of 10), and the outcome of the unchosen Alternative Outcome Stimuli (AOS) is +50 (a gain of 50), the relative or ‘net’ outcome is −40 (a loss of 40); on the other hand, if the COS is −10 and the AOS is −50, then the net outcome is +40 (a gain of 40). This phenomenon of ‘net-loss’ and ‘net-gain’ was evident even for the neutral (no loss and no gain) COS which could elicit an ORN as large as that elicited by a negative COS, and thus the ORN was thought to reflect the binary evaluation of resultant good versus bad outcomes [16, 17]. Yeung & Sanfey [22] reported that the ORN was found to be greater after losses than after gains but it was not significantly different between higher and lower amounts. Toyomaki & Murohashi [23] made an observation that the ORN elicited for the loss and neutral was larger than that of the gain condition, and the ORN was not affected by the magnitude of the bet. Interestingly, Yeung et al. [24] elicited ORNs in simple
