Limited Capacity for the Visual Working Memory-Driven Access to Visual Awareness

Previous studies have shown that sensory information matching the content of visual working memory (VWM) gains prioritized access into awareness. While these studies primarily focused on a single stimulus, it remains unclear whether the prioritization persists when multiple items are memorized. Using a breaking continuous flash suppression paradigm, the current study systematically investigated the time taken to detect a suppressed stimulus when two items were maintained in VWM. The results demonstrated that multiple items stored in VWM did not prioritize the matched stimuli into awareness, regardless of whether the stimuli presented during suppression were partially matched (Experiment 1) or fully matched (Experiment 2) to the memorized items. Furthermore, no prioritization was observed when the memorized items were either integrated into a single object (Experiment 3) or remembered with increased precision (Experiment 4). After confirming the validity of the current experimental paradigm (Experiments 5a and 5b), we found that the item assigned with a higher priority through a retro cue broke into awareness faster than the uncued and the new items (Experiment 6). These findings suggest that when multiple items are retained in VWM, only one single item stored in the active state can facilitate matched stimuli into awareness, indicating a limited capacity for the modulation of VWM on access to visual awareness.