It is well-established that neuroelectrophysiological phenotypes, such as EEG, ERPs, and EROs are highly heritable (for reviews, see Begleiter and Porjesz, 2006; Anokhin, 2014). It is suggested that genetic underpinnings of EROs likely stem from regulatory genes that control the neurochemical processes of the brain, thereby influencing neural function (cf. Pandey et al., 2012). Recent genetic studies and the current study have demonstrated associations of KCNJ6 with theta EROs (Kang et al., 2012; Chorlian et al., in press). The current study has indicated that variations in the KCNJ6 SNP (rs702859) influence magnitude of theta ERO power at posterior leads during during the evaluation of loss and gain, reflecting a genetic influence on neuronal circuits involved in reward processing. Higher theta power as a function of minor allele dose suggests more efficient cognitive processing in those carrying the minor allele of the KCNJ6 SNPs, as increased theta activity during cognitive tasks is indicative of efficient processing (Klimesch, 1999; Basar et al., 2001b). On the other hand, lack of frontalization in theta EROs observed in those carrying minor alleles may be suggestive
