Detecting Changes in Scenes

Abstract

Introduction Contrary to popular belief, the ability of people to detect single changes in a scene can be very poor, even when all the information is visibly available to them (Grimes, 1996). Some types of changes are more easily detected than others; however, what constitutes a change sufficiently significant to be detected is unclear (O'Regan, 1992). Changes usually made to images are the removal of an object, the change in location or structure of an object, or the change of the color of an object. In a recent experiment, Rensink et al. (1997) showed that subjects are faster at determining the exact change if it is a color change than if it is a disappearance change, and in turn subjects are faster at determining an object disappearance change than an object location change. The poor ability of people to detect changes in visual scenes has been shown in experiments in which images are altered during saccades (Grimes, 1996), and in experiments in which the original image and its alte