Previous research has revealed that a supine body posture, as compared to a sitting upright posture, decreases approach motivation and cognitive dissonance reduction. The present research was designed to test whether a supine body posture would decrease cognitive conflict processing, the process that occurs prior to cognitive dissonance reduction. Previous research using the Stroop task has found event-related potentials (N450, error-related negativity [ERN]) that are associated with cognitive conflict processing. In the current experiment, participants (N = 35) completed a color-naming Stroop task while sitting upright or supine (within-subjects, counterbalanced). Results revealed that as compared to the upright posture, the supine posture reduced the N450 Stroop interference effect but not the ERN. 10 of 12 | SUN aNd HaRMON-JONES Price, et al., 2015), and suggests that a supine posture has an early influence on cognitive conflict and dissonance. The present research thus suggests that being in a supine body posture may have a real "laid-back" effect, which decreases cognitive conflict processes. CONFLICTS OF INTEREST No conflicts of interest occurred with regard to this research.