"Perceptual organization" is concerned with how our perceptual system relates the "parts" of an object or a scene to the "entire" object or scene. This process is critical for seeing the world as an interrelated, coherent whole. One of the earliest theoretical battles in experimental psychology revolved around the question of whether we initially perceive "parts" in order to see the whole, or whether perception of one part of the world critically depends on other parts. The study of ambiguous figures has been a major battleground for these two views.