Unconscious conflict adaptation without feature-repetitions and response time carry-over

Leading theories of cognition linked executive control to consciousness or awareness. Evidence from masked priming experiments questioned this link, but without addressing possible confounds. Responding to a target after a masked prime, participants are slower if prime and target present conflicting (incongruent) than nonconflicting (congruent) information. Crucially, congruence in the previous trial modulates this congruence effect, presenting a congruence-sequence effect. This has been interpreted as conflict adaptation by executive control processes, but alternative explanations through trial-to-trial feature-repetitions and response-time (RT) carry-over are possible. Here, we ruled out these alternative explanations by a mixed-model analysis of trials without trial-to-trial feature-repetitions and still found a congruence-sequence effect-that is, evidence for conflict adaptation, in the absence of conflict awareness. There was also no evidence that the participants' awareness of their RTs played a role. These findings suggest that executive control can indeed operate in an awareness-independent fashion.