Response relevance modulates visual and frontocentral ERP responses to high-contamination aversive pictures in a...

High-contamination aversive pictures receive preferential attention, but whether their influence on response control depends on action relevance is unclear. Healthy university students completed a counterbalanced picture Go/NoGo task during electroencephalography. Independent ratings showed that the aversive category was more contaminating, unpleasant, and arousing than the neutral category. After excluding two participants with incomplete behavioral records, behavioral analyses included 42 participants, stimulus-locked event-related potential (ERP) analyses included 37, and error-locked analyses included 32. Accuracy was higher for Go than NoGo trials. Correct responses were faster to aversive than neutral Go targets, commission-error responses were slower to aversive than neutral NoGo stimuli, and discriminability was lower in the aversive-target mapping. Posterior P1, N1, and early posterior negativity mean amplitudes varied with stimulus category and response requirement, with the clearest enhancement when aversive pictures were Go targets. The frontocentral N2 showed a reliable Stimulus Category × Response Requirement interaction: aversive Go targets elicited greater negativity, yielding a smaller NoGo-minus-Go difference than in the neutral mapping. Peak-centered analyses retained this N2 interaction. Mean Nogo-P3 and late positive potential amplitudes showed no statistically reliable category effects. Error-locked amplitude contrasts and associations with Padua Inventory contamination/washing scores remained exploratory after correction for multiple testing. These findings indicate that response relevance modulates early visual and frontocentral processing of a bundled high-contamination, unpleasant, high-arousal category. The design does not isolate effects specific to disgust or washing-related symptoms.