The visual perception of natural scenes is a dynamic process during which local objects are selected by movements of the eyes and attention. The selective nature of scene perception paces strong constraints on the construction of a visual representation of a scene, as previously selected items must be retained in memory and integrated to form a representation of the scene as a whole. The goal of the proposed research is to investigate the nature of the visual representation constructed during the viewing of natural scenes. Change detection and forced-choice discrimination procedures will be used to investigate four primary questions. First, do visual representations decay upon the withdrawal of attention from an object, and is attending to an object a necessary condition for detecting change to that object? Second, do limitations on change detection (i.e. change blindness) derive solely from constraints on visual memory or do retrieval and comparison constraints play a role in change detection failure? Third, to what extent is the retrieval of object information mediated by spatial position. Fourth, how quickly does visual memory for a local object decay during the viewing of a natural scene? This research will help to determine the specificity of visual memory for natural scenes, the relationship between visual memory attention, and the mechanisms of visual memory encoding and retrieval.
