Working Memory Guides Perceptual Decisions Through Fast Capture and Slow Drift

The top-down influence of working memory (WM) can manifest as both attentional capture and small systematic biases in perceptual judgement (i.e., "tinted lens" effect). Yet it remains unclear whether these influences arise from a single mechanism or reflect functionally distinct processes operating over different timescales. Across two experiments, we embedded a perceptual estimation task during the delay interval of a WM task and tracked continuous mouse trajectories during both perceptual matching and subsequent WM tests. Hierarchical Bayesian mixture modeling revealed robust bidirectional attraction between memory and perception. Time-resolved analyses of mouse trajectories further revealed two distinct components: an early, endpoint-inconsistent deviation that varied with movement onset latency, whereas a slower, endpoint-consistent drift that closely tracked biases in the final report. This pattern is consistent with a fast, capture-like influence of the WM template, and a sustained bias in the evolving decision, respectively. Notably, the prospective influence of WM on perception expressed both early deviation and sustained drift, whereas the retrospective influence of perception on WM primarily involved the sustained component. These findings indicate that WM shapes perceptual decisions through at least two temporally distinct contributions, and illustrate how continuous trajectories can reveal the dynamic structure of top-down influences within single trials.