Temporary inhibitory tagging at previously attended locations: evidence from event-related potentials.

Recent studies propose that a mechanism termed "inhibitory tagging" acts upon the processing of the target at the attended location by temporarily blocking the stimulus-response mapping. Here we combined the cue-target paradigm with the Stroop task and measured event-related potential (ERP) responses to the color of a color word presented at the previously attended (cued) or unattended (uncued) location. We found that the conflict-related N450 effect emerged later and had a smaller size at the cued than the uncued location. The overall ERP responses to the target showed lower P1 and N1 amplitude at the cued than the uncued location. Although the P1/N1 effect may reflect deficient perceptual processing of the target, the delay of the N450 suggests that the link between perceptual processing and response activation is temporarily blocked at the previously attended location.