IS THE RICHNESS OF OUR VISUAL WORLD AN ILLUSION - TRANSSACCADIC MEMORY FOR COMPLEX SCENES

Our construction of a stable visual world, despite the presence of sac cades, is discussed. A computer-graphics method was used to explore tr anssaccadic memory for complex images. Images of real-life scenes were presented under four conditions: they stayed still or moved in an unp redictable direction (forcing an eye movement), while simultaneously c hanging or staying the same. Changes were the appearance, disappearanc e, or rotation of an object in the scene. Subjects detected the change s easily when the image did not move but when it moved their performan ce fell to chance. A grey-out period was introduced to mimic that whic h occurs during a saccade. This also reduced performance but not to ch ance levels. These results reveal the poverty of transsaccadic memory for real-life complex scenes. They are discussed with respect to Denne tt's view that much less information is available in vision than our s ubjective impression leads us to believe. Our stable visual world may be constructed out of a brief retinal image and a very sketchy, higher -level representation along with a pop-out mechanism to redirect atten tion. The richness of our visual world is, to this extent, an illusion .