ABSTRACT
One of the most elaborate information-sampling theories of the formation of visual illusions has been provided by Piaget. In general, Piaget looks at the gathering of information from a visual display as an active search involving a series of centrations. An interesting set of implications emanates from Piaget’s notion of an active observer distributing his attention across the visual field. Clearly, anything that would alter the distribution of attention should alter the magnitude of the illusion. Decrement in illusion magnitude following inspection is not confined to the Mueller-Lyer configuration. Many other illusions, including the Poggendorff, the Zoellner, the Wundt-Hering, and the Oppel-Kundt illusions, also show a reduction in strength after periods of prolonged viewing. Although the specific mechanisms involved in illusion decrement are not fully known, there is considerable evidence that they involve changes in information sampling strategies that rely on eye movement information.
