Distinct and overlapping neural representations of refreshing versus refocusing during working memory maintenance

This study investigates how attention modulates internal representations in working memory (WM), focusing on the distinct and overlapping neural effects of retrospective and reflective attention using functional magnetic resonance imaging. Participants performed cue-variant WM tasks with retro-cue, refresh-cue, and no-cue trials. The cues instructed participants to either refocus or refresh one of the memorized stimuli (a face or a scene) during the retention interval. Univariate, multivariate, and functional connectivity analyses revealed that retro and refresh cues engaged overlapping brain regions but also exhibited distinct activation patterns. Whole-brain analyses showed overlapping activations and decoding patterns in the ventral occipitotemporal and posterior brain regions. Region-of-interest analyses confirmed the selective modulation of category-specific visual areas by both cues. Functional connectivity analyses further revealed inter-regional correlations between the prefrontal cortex and visual areas for both cues. Importantly, the multivariate pattern analysis revealed distinct effects in the prefrontal and parietal cortices (PFC and PPC): retro cues exerted a greater influence on representational patterns in the PFC, whereas refresh cues had a greater impact on patterns within the PPC. Taken together, this study provides direct evidence that refocusing and refreshing rely on both distinct and overlapping neural mechanisms to support WM maintenance.