Strategies in visual working memory use in healthy and clinical populations

Visual working memory (VWM) allows to temporarily store visual information for imminent goal-directed behavior. It remains unclear, however, if and to what extent VWM is employed strategically in natural behavior, partly because VWM is typically studied through paradigms that enforce one particular behavior, eliminating the possibility of strategic VWM use. Here we employ an unrestricted task which naturally engages VWM: participants reproduce a model (i.e., six colored polygons in a four-by-four grid), in an adjacent ‘workspace’ area, by dragging items from a pool of stimuli (akin to a jigsaw puzzle). While this tasks draws upon VWM (to keep the example image available when not in view), it does not enforce any specific approach to accomplish the overarching goal. Items can be inspected multiple times, memorized simultaneously or consecutively, and in any order. We asked to what extent observers employ specific strategies in unrestricted VWM tasks, and whether strategy use benefits performance. We observed substantial use of two distinct strategies (working systematically and exploiting similarities), and found that strategy use was linked to better performance. Moreover, we found a striking consistency in strategy use between individuals and between settings. We further hypothesized that systematicity may be particularly beneficial when the task demands approach individuals’ memory limits. Reanalysis of copying task data of 24 patients with severe memory impairments (Korsakoff syndrome), revealed strategy use was indeed related to better performance. To obtain a richer understanding of VWM, and to provide applications both for the clinic and for everyday life, we should consider the task-context in which VWM is engaged.