Supine body posture reduces cognitive conflict processing: Evidence from N450 Stroop interference.

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.