The world is divided into objects: things that are distinct from their backgrounds and that can move or be moved. Objects are food and prey and threats, as well as neutral items, and it is critical to be able to see them. How the form of an object is distinguished is one of the most basic, yet least understood, topics of research in vision perception. The object-defining system needs to operate in the real world, where objects and viewers move, and where the scene is cluttered, rarely offering a clear, unobscured view of any object. How are we able to see and define objects using the complex pattern of light falling on the retina? An object becomes visible if it differs sufficiently from its surroundings in its luminance, color, texture, motion, or depth. Although the processes that use these different cues are quite distinct, research has shown that they share some organizational principles. This book, Seeing Spatial Form, is dedicated to David Martin Regan who has made so many contributions to our understanding of how we see objects. Its chapters bring together ideas from some of the world's leading researchers in form vision to explain what we know about distinguishing form. The book includes a CD-ROM, which contains additional demonstrations and color images that considerably enhance the chapter contents. Seeing Spatial Form will be an invaluable resource for student and professional researchers in vision science, cognitive psychology, and neuroscience.