The dynamics of attentional guidance by working memory contents.

Working memory (WM) contents can guide attention toward matching sensory information in the environment, but there are mixed findings regarding whether only a single prioritized item or multiple items held in WM can guide attention. The present study examines the limit of WM-guided attention with a novel task procedure and mouse trajectory analysis. Specifically, we introduced a perceptual-matching task utilizing the continuous estimation procedure within the maintenance interval of a WM task for one or two colors. We found that the overall perceptual matching mouse trajectory were robustly biased toward the location of WM-match color on the color-wheel (i.e., attraction bias), but only at memory set size one. However, the analysis of circular mouse trajectory distributions, through hierarchical Bayesian modeling, revealed two separable central peaks at both memory set sizes. Furthermore, model-free analysis demonstrated that the perceptual matching mouse trajectory patterns were similar regardless of memory set sizes. Together, these results support the single-item account and highlight the utility of mouse trajectory analyses in hypothesis testing in experimental psychology.