ABSTRACT

The ability to localize objects in three-dimensional space is fundamental to many of our interactions with the environment. This ability often depends on visual perception of the size, distance, direction, motion, orientation, and shape of distant objects. Under ordinary circumstances, these visual functions are remarkably efficient. Indeed, naive observers often take them for granted, accepting the “commonsense” view that an object’s shape, size, and position are simply given by the properties of the object itself. As demonstrated by innumerable spatial illusions, however, space perception is not always so accurate. Rather, its accuracy depends heavily on contextual information provided by the object’s surroundings and on the observer’s current condition, actions, and past experiences.