PARK, H.-B. | bioRxiv Science

bioRxiv2026

Distinct Control States Underlie Voluntary Task Switching: Evidence for Capacity-Dependent Control Modes

People often switch tasks when attention wanes or an alternative task becomes more appealing. Such choices may reflect different control modes that may vary with working memory (WM) capacity. This study tested whether momentary attentional lapses prospectively predict voluntary task switching and whether this relationship depends on WM capacity. Participants performed a continuous performance task involving face and scene images, with blocks in which they either freely chose the next task or followed an externally imposed sequence. The results suggested a capacity-dependent pattern in which individuals with lower WM capacity were more likely to switch following lapse-prone blocks, whereas higher-capacity individuals tended to switch from relatively well-focused states. Eye-tracking revealed greater bias toward the competing irrelevant category before switches in lower-capacity individuals, accompanied by early conflict-related pupil dilation. Externally imposed task sequencing selectively reduced lapses in the lower-capacity group without affecting higher-capacity performance, suggesting that external structure can scaffold weaker internal goal maintenance. These findings suggest that the relationship between lapses and voluntary switching varies with WM capacity rather than being uniform across individuals. This pattern is consistent with a goal-competition account in which lapses reflect shifts in the balance between competing task goals, and voluntary switches may be preceded by different control states.

neuroscience↗

bioRxiv2025

Contributions from Long-Term Memory Explain Superior Visual Working Memory Performance with Meaningful Objects

Visual working memory (WM) capacity has been claimed to be larger for meaningful objects than for simple features, possibly because richer semantic representations enhance the distinctiveness of stored items. However, prior demonstrations typically compared trial-unique meaningful objects with a small set of repeated simple features. This design confounds meaningfulness with proactive interference (PI), such that PI is minimal for trial-unique objects but substantial for repeated features. As a result, superior performance for meaningful objects may reflect contributions from episodic long-term memory (LTM) rather than expanded WM capacity. To test this, Experiment 1 measured WM for repeated colors, repeated meaningful objects, and trial-unique meaningful objects. The advantage for objects over colors was replicated in the trial-unique condition, but eliminated for repeated objects that equated PI across stimulus types. Hierarchical Bayesian dual-process modeling revealed that the trial-unique advantage reflected stronger familiarity signals, whereas recollection remained stable across stimulus types. Experiment 2 assessed WM storage directly using contralateral delay activity (CDA), an electrophysiological marker of the number of items stored. Although trial-unique objects again yielded behavioral advantages, CDA activity across increasing set sizes revealed a common slope and plateau for trial-unique meaningful objects and repeated colors. The CDA difference between stimulus types was additive and did not vary with set size, providing no evidence for an increased number of stored items. These findings demonstrate that previously reported advantages for meaningful objects primarily reflect reduced PI and enhanced LTM familiarity. When PI is equated, WM storage limits for simple and meaningful stimuli are equivalent. Significance StatementWorking memory provides the mental workspace that underlies reasoning, learning, and everyday decision making, yet its capacity is sharply limited. Previous studies suggested that meaningful, real-world objects are remembered better, raising the possibility that knowledge can expand this known capacity limit. However, many designs confound working memory with long-term familiarity. Here, equating proactive interference removed the behavioral advantage for meaningful items. A neural marker of active storage showed additive differences between stimulus types that did not vary with load, indicating no increase in the number of stored items. These findings identify interference, rather than expanded storage, as the source of the reported advantage and offer practical guidance for future experimental design and theories of memory limits.

neuroscience↗