The working memory advantage for meaningful stimuli persists under high levels of proactive interference

Previous work has shown that visual working memory performance is higher for recognizable and meaningful stimuli relative to meaningless, but physically matched, stimuli (e.g., Asp et al., 2021). Here, we test whether the benefit for meaningful stimuli arises due to active storage in working memory or can, at least in part, be explained by reliance on other more durable memory traces, such as long-term memory. We manipulated meaningfulness using ambiguous Mooney faces (Exp. 1) and objects (Exp. 2) vs. scrambled versions of the same stimuli. Although items were repeated 10x more often in the high interference condition than the low interference condition, we found equivalent objective and subjective effects of meaningfulness at high levels of proactive interference, suggesting that persistent passive long-term memory traces do not play a critical role for the meaningfulness advantage in working memory tasks.