Latent Memory Traces for Prospective Items in Visual Working Memory

Abstract

Visual working memory is a capacity-limited cognitive system that is utilized for enabling goal-directed actions. When sampling items for visual working memory storage, however, observers are often exposed to other items that are not selected for imminent action (hereafter: ‘prospective items’). Here, we asked whether such exposure leads to memory buildup of these prospective items, facilitating subsequentvisual working memory encoding for imminent action. In a series of experiments, weaddressed this question using a copying task, in which participants attempted toreproduce a model display by placing items in an adjacent empty grid. To investigatewhether a memory is formed for prospective items, we swapped the position ofunplaced items in the model and compared copying task performance to a condition inwhich items remained stable. The results show that, when prospective items remainedstable, participants took less time inspecting the model when encoding these items later(compared to when they were swapped). This reduced inspection duration was notaccompanied by a higher number of inspections or an increase in errors. We concludethat the memory system gradually builds up latent memory traces of items that are notselected for imminent action, thus increasing the efficiency of subsequent visualworking memory encoding.