Analyses of PFC-STR synchrony in error trials of SR Learning and Category Learning stages. A. Average (±SEM) PLV in error trials: In contrast to the increase of beta-band synchrony observed in correct trials (Fig. 2), synchrony between PFC and STR did not increase across learning stages; rather, it decreased significantly at least during the exemplar epoch. B. The average (±SEM) z-transformed difference (d’) between error- and correct-trial PLV. During both trial epochs, error trials displayed stronger PFC-STR synchrony than did correct trials in the SR Learning stage, but, in the Category Learning stage, this difference was either eliminated (decision epoch) or reversed (exemplar epoch).