Process dynamics of serial biases in visual perception and working memory processes

Serial dependence, a systematic bias in the perceptual decision of current stimuli toward previously encountered ones, has been debated with regard to its locus of processing, with evidence supporting both perceptual processes and post-perceptual working memory (WM) accounts. This study examined the temporal and process-specific dynamics of serial biases across perception and WM processes by analyzing behavioral responses and mouse trajectories. Participants performed two tasks: an immediate perceptual report requiring color matching on a color-wheel with the target color remained visible, and a delayed WM recall consisting of dual responses, a consolidation report immediately after target and mask offset and a retrieval report after a short delay. The results revealed a shift from repulsive biases in immediate perceptual reports to moderate and stronger attraction in WM consolidation and retrieval reports, respectively. Additionally, mouse trajectory analysis further identified a repulsion-to-attraction transition during WM consolidation, suggesting an interplay between sensory adaptation and mnemonic processes. These findings support a mnemonic origin of positive serial dependence, with independent components of perception and WM jointly shaping the output serial bias.