Image memorability facilitates visual working memory formation: Evidence from contralateral delay activity

Human observers remember some images more reliably than others, a phenomenon known as image memorability, a stimulus-driven property that predicts relatively consistent memory outcomes across individuals. Although memorability has been studied primarily in long-term memory, recent evidence suggests that it also benefits visual working memory (VWM). However, this behavioral advantage could reflect differences in formation processes or in stimulus comparison at test, rather than processes specific to VWM, and behavioral measures alone cannot resolve this distinction because performance in change-detection tasks is influenced by both test-phase comparison and decision-related factors. To determine when memorability influences VWM, we combined a lateralized change-detection task with time-resolved electrophysiological measures indexing memory-related activity during the retention interval, relatively independent of test-related processing. Participants remembered faces with high or low image memorability while scalp EEG was recorded. Behaviorally, we replicated the memorability benefit in VWM performance. Neurally, we examined contralateral delay activity (CDA) over posterior electrodes as an index of VWM retention. Memorability modulated CDA amplitude during an early retention period (i.e., the rising phase of the CDA), with weak or no reliable differences later in the delay interval. Importantly, variation in early CDA amplitude directly predicted improved task performance, and this pattern held even though memorability was defined using a predominantly White-face database and tested in Chinese-speaking participants, providing converging electrophysiological evidence for cross-cultural generalizability. Together, these findings suggest that image memorability strengthens the transformation of perceptual inputs into durable VWM representations before stable retention is established. Yet, this transient advantage during the early formation stage does not appear to significantly change the total amount of information maintained at a fixed set size. Thus, memorability likely shapes how VWM is formed, rather than how much is ultimately retained.