Abstract
How does the cognitive system effectively navigate its limited capacity amidst the overwhelming details of the external world? Accumulating evidence suggests that addressing this longstanding question involves understanding the role of various memory systems in directing visual attention. While prior research has illuminated the enhancement of attention through semantic and working memory, our focus is on how attention adjusts to familiar stimuli. We conducted two tasks exposing participants to displays featuring four items—one familiar and three unfamiliar. The relevance of familiar items for task performance varied between the tasks. In the first task, participants detected a dot on one of the items, making familiarity orthogonal to the task. In the second task, participants memorized the set of four items. Here, familiarity could potentially facilitate item encoding, encouraging the cognitive system to allocate attentional resources to the unfamiliar items. We utilized eye tracking to characterize memory-guided attention patterns in both tasks. Despite familiarity being irrelevant to performance in the dot detection task, participants still exhibited a preference for looking at the familiar item. This preference was also evident in the initial phase of the memory task but shifted towards a preference for unfamiliar items as the trial progressed. Intriguingly, participants could voluntarily attenuate the attentional preference for familiar items but could not eliminate the task-related preference for unfamiliar items. Exploring neurodivergent populations, such as those with congenital prosopagnosia, revealed that the preference for familiar items required explicit knowledge, whereas a preference for unfamiliar items persisted even when these items were not explicitly recognized. Collectively, these results provide compelling evidence that memory-guided attention is a dynamic process that adjusts adaptively to prevailing circumstances and facilitates efficient deployment of visual attention. Understanding these attentional patterns also holds potential practical value, particularly in the context of detecting concealed information in forensic scenarios.