Electrophysiological correlates of block-wise strategic adaptations to consciously and unconsciously triggered conflict.

The role of consciousness in conflict adaptation has been a topic of much debate. The purpose of the current study was to investigate the neural correlates of block-wise conflict adaptations elicited by conscious and unconscious conflicting stimuli in a meta-contrast masked priming task. Event-related potentials (ERPs) were recorded while individuals responded to prime-target pairs in mostly congruent (80% congruent trials, 20% incongruent trials) and mostly incongruent blocks of trials (20% congruent trials, 80% incongruent trials). Mean response times and error rates revealed that the conflict effect (incongruent trials-congruent trials) was reduced in mostly incongruent blocks relative to mostly congruent blocks. Furthermore, conflict related ERP signals (the amplitude difference between congruent and incongruent trials) for three ERP components (early occipito-parietal negativity, the fronto-central N2 and the centro-parietal P3) were attenuated in mostly incongruent blocks compared to mostly congruent blocks, reflecting block-wise adaptation to the frequency of conflict. The conflict-related frontal N2 component differentiated most strongly between visibility conditions. These results further specify the electrophysiological correlates of block-wise strategic adaptations to consciously and unconsciously elicited conflict.