ABSTRACT
One of the most obvious yet significant features of our perceptual experience is that it is organized and meaningful. That is, rather than experiencing a world consisting of fleeting, elementary units of sensation, we perceive a coherent world of integrated, three-dimensional objects and of unified temporal events, This observation becomes even more challenging when we realize that, in our ordinary perceptual encounters with the world, we generally operate on the basis of incomplete information concerning the layout and the structure of objects and events. The information acquired in a single glance or even in multiple samples involving eye fixations and observer movement rarely provides projections of either all surfaces of objects in the environment or the relationships among the surfaces of one or many such objects. Nonetheless, behavior proceeds in a relatively uninterrupted fashion; rarely do we collide with the hidden surfaces of three-dimensional objects or register surprise as previously concealed aspects of object structure are revealed. Clearly, the partial information available for object structure effectively specifies the important properties of hidden surfaces, and/or this partial information is used as a basis for the ongoing construction of a mental model of the objects and their relationships in the immediate environment.
