Stage-specific priming of pop-out effects in the target-feature memory encoding and retrieval

Priming of Pop-out (PoP), when a target-defining feature repeats, accelerates visual search. While previous studies highlight the influence of display density-sparse versus dense arrays-on PoP, how display density interacts with memory encoding and retrieval stages remains unresolved. The present study disentangled the contributions of encoding (trial n-1) from retrieval (trial n) and tracked their influence on early orienting (pre-selective) versus late identification (post-selective) processes. Participants searched for a uniquely colored target under blocked and interleaved density regimes, with eye movements and manual responses recorded. By crossing sparse and dense displays across consecutive trials, four transition types were probed to determine where density exerts its effect. Color repetition reduced reaction times and first saccadic latency, and boosted first-saccade accuracy, but only when the current (i.e., the retrieval) display remained sparse. In contrast, dense displays showed fast responses, with the absence of PoP, due to saliency-driven guidance. Pre-selective eye-movement metrics showed robust PoP in sparse retrieval arrays, whereas dense retrieval arrays defaulted to saliency-driven guidance. Post-selective decision times were comparable across conditions, indicating that PoP drives only the early attentional guidance. These results indicate that while encoding reliably forms target templates, it is the retrieval context that switches feature-biasing mechanisms on or off, highlighting a dynamic interplay between memory and bottom-up salience in adaptive search.