Visual Crowding

Crowding is ubiquitous: When objects are surrounded by other elements, their perception may be impaired depending on factors such as the proximity of the surrounding elements and the grouping of elements and targets. Crowding research aims to identify these factors, for instance, which elements interfere with one another and how close they need to be to cause crowding. Traditionally, crowding was thought to occur only within narrow temporal and spatial limits around the target. Recent studies, however, indicate that crowding may involve both low- and high-level processes, such as perceptual grouping, timing, and complex visual arrangements. This review highlights these new insights, suggesting that overall organization, as well as both feedforward and feedback processes, play a role. Crowding emerges as a highly complex and dynamic phenomenon, underscoring the need for a more integrated approach to fully capture its intricacies, which may carry broader implications not only for crowding but also for vision science as a whole.