Spatial and Temporal Characteristics of Distractor-Induced Repulsion Effect in Visual Working Memory: A Behavioral and ERP Study.

In visual working memory, relation-based distractors can induce a memory repulsion effect, yet its spatial boundary and cognitive stage remain unclear. Across two experiments, we examined the spatial modulation and temporal dynamics of this effect. Experiment 1 presented a central target with peripheral distractors arranged as a regular pentagon and manipulated target-distractor spatial distance. Results showed that the repulsion effect decreased monotonically with increasing distance, supporting an absolute-distance account rather than a strict central attentional window account. Experiment 2 employed EEG and orthogonally manipulated distractor color (identical to vs. different from the target) and spatial distance (small vs. large). Behaviorally, the distance gradient was replicated, and repulsion occurred only for different-color distractors. Critically, the ERP difference between different-color and identical-color conditions emerged as a late positive component (LPC) between 382 and 604 ms post-stimulus, and its amplitude positively correlated with the individual behavioral repulsion effect. Early N1 activity (approximately 96-202 ms) was sensitive to distance but showed no direct correlation with behavioral outcomes. These findings indicate that memory repulsion arises during post-perceptual working memory stages and is modulated by absolute spatial proximity. This work clarifies the spatiotemporal architecture of relational distractor filtering in visual working memory.