Electrophysiological dynamics reveal distinct processing of stimulus‐stimulus and stimulus‐response conflicts

Abstract The present study examined electroencephalogram profiles on a novel stimulus‐response compatibility ( SRC ) task in order to elucidate the distinct brain mechanisms of stimulus‐stimulus ( S ‐ S ) and stimulus‐response ( S ‐ R ) conflict processing. The results showed that the SRC effects on reaction times ( RT s) and N 2 amplitudes were additive when both S ‐ S and S ‐ R conflicts existed. We also observed that, for both RT s and N 2 amplitudes, the conflict adaptation effects—the reduced SRC effect following an incongruent trial versus a congruent trial—were present only when two consecutive trials involved the same type of conflict. Time‐frequency analysis revealed that both S ‐ S and S ‐ R conflicts modulated power in the theta band, whereas S ‐ S conflict additionally modulated power in the alpha and beta bands. In summary, our findings provide insight into the domain‐specific conflict processing and the modular organization of cognitive control.