Masked invisible cue could modulate Stroop effect in spatial cueing paradigm: evidence from an event-related potentials study

We controlled two variations that were cue validity (cued vs. uncued) and Stroop stimuli types (congruent, neutral, incongruent) using to investigate the modulation effect of a masked invisible cue on Stroop interference in a cue-target paradigm with a masked invisible cue. We found that, behaviorally, mean reaction time of the neutral target was longer at previously cued locations, and the Stroop effect was larger in uncued conditions. Electrophysiologically, the conflict related N450 difference negative waveform and N1 component relating to early visual processing were both greater at uncued locations. These results indicated that regardless of awareness, a spatial uninformative cue could induce inhibition of return and affect the Stroop interference.