Resting posterior minus frontal EEG slow oscillations is associated with extraversion and DRD2 genotype

The agency facet of extraversion has been hypothesized to be based on individual differences in dopamine activity. Recent work suggests that resting posterior minus frontal electroencephalographic (EEG) slow oscillations (delta, theta) is both consistently associated with extraversion and sensitive to dopamine D2 receptor antagonist-induced changes in dopaminergic activity. Here we examine for the first time the interrelations between polymorphisms of the dopamine D2 receptor (DRD2) gene (rs1800497 [previously termed TAQ1A], rs1076560, rs1799732 [−141C Ins/Del]), extraversion and resting posterior minus frontal (Pz–Fz) slow oscillations. As predicted, we found an association between DRD2 and resting Pz–Fz slow oscillations in a sample of 141 individuals participating in an eyes-closed resting EEG session. Moreover, we replicated the association between extraversion and Pz–Fz slow oscillations. Our findings strongly suggest that the posterior–frontal distribution of slow oscillations constitutes a useful brain-based intermediate phenotype for investigating the dopaminergic basis of extraversion.