Learning influences the attentional capture and suppression of abrupt onset and color singletons: Evidence from...

While most prior research has emphasized the role of saliency in attentional capture and suppression, it has largely overlooked learning experience-an equally critical factor. Yet, the relative contributions of saliency and learning experience may jointly shape attentional priority. In this study, we investigate whether the learning experience can enable suppression of attentional capture by abrupt onsets, thereby testing the applicability of Signal Suppression Theory to such stimuli. To this end, event-related potential (ERP) techniques were employed to examine changes in N2pc (indicating attentional capture) and P_D (reflecting suppression) across the learning process. Participants completed four repeated visual search tasks over three days to establish implicit learning. Behaviorally, the interference effect caused by abrupt onsets persisted both before and after learning, although it was significantly reduced with increased learning experience. In contrast, color singletons were suppressed to baseline levels pre-learning and below baseline post-learning. Electrophysiological results revealed that the N2pc amplitude elicited by targets increased after learning, whereas the N2pc to distractors remained unchanged. Furthermore, the late P_D elicited by abrupt onsets decreased following learning, while the P_D associated with color singletons was unaffected by learning. Taken together, these findings suggest that top-down implicit learning does not fully eliminate but attenuates the processing of highly salient distractors, indicating that Signal Suppression Theory is not applicable to abrupt onsets. This study demonstrates that suppression through implicit learning primarily arises from enhanced target-related attentional capture and reduced late-stage suppression of distractors.