Susceptibility to attentional capture by target-matching distractors predicts high visual working memory capacity

Introduction: It is well known that the ability of distractor suppression has a close relation to visual working memory (VWM). Recent event-related potential (ERP) studies (e.g., Gaspar et al., 2016) showed that individuals with high working memory capacity could call on an early suppression (indexed by Pd component) to salient-but-irrelevant distractors whereas those low-capacity ones could not. However, it remains unclear whether such an early suppression mechanism applies to nonsalient distractors that possess the target-defining feature. The main purpose of the present study is to investigate the relation between the VWM capacity and the attentional process of feature-matched distractors. Methods: Fifty-one healthy young adults participated in this study. Like previous studies (e.g., Gaspar et al., 2016), individual VWM capacity was measured by the K-score of change detection task. In the ERP experiment, we adopted a central rapid serial visual presentation (RSVP) task in which distractors with or without the target-defining feature were presented peripherally. Participants were informed to identify a digit of a specified color in the central RSVP stream. We focus on two distractor-elicited ERP components (i.e., N2pc and Pd) that would reflect two distractor-related attentional processes (i.e., attentional capture and attentional suppression), respectively. Results: Surprisingly, we revealed that high-capacity individuals would be captured more attention (reflected by a larger distractor-N2pc emerging in less than 200 ms) compared to low-capacity ones, meaning that they are less able to ignore such distractors in early visual processing. Although feature-matched distractors captured more attention for high-capacity individuals, they received stronger suppression soon afterwards, indexed by a larger distractor-Pd. Conclusion: Compared to low-capacity individuals, high-capacity ones would first be captured more attention by feature-matched distractors, then enact more inhibition to those distractors. Our findings support that, high-capacity individuals could exhibit more flexible ways of attentional processing when dealing with different kinds of distractors.