Dual Pathways of Category-Guided Attentional Selection: Task- Relevance Modulates Hierarchical Integration of Top-Down Control and Salience

Category-guided attentional selection (CAS) enables efficient information filtering in complex environments through cognitive category formation. However, systematic comparisons between semantic and prototype-based CAS mechanisms are critically lacking, particularly in how they dynamically integrate top-down control and salience processing. Combining a hybrid experimental design (4 experiments, N = 80) manipulating cognitive load (high vs. low), stimulus salience (oddball vs. standard) and salience relevance (task-related vs. task-irrelevant), we dissected CAS dynamics across semantic (numbers/letters) and prototype-based ("O"/"X" shapes) categories. High cognitive load consistently impaired performance, demonstrating working memory-dependent top-down modulation. Salience effects emerged exclusively under task-relevant conditions, with oddball stimuli eliciting slower RTs and reduced accuracy, indicating goal-contingent weighting. Critically, cognitive load and task-relevant salience interacted during late decision stages, suggesting dynamic resource competition between control processes. Notably, prototype-based categories outperformed semantic categories in oddball trials, likely driven by perceptual similarity-mediated bottom-up integration. These findings extends a refinement to theories of category-guided attention into a dual-pathway model, where semantic categories rely on conceptual templates in working memory, while prototype-based categories leverage perceptual feature binding.