The Perception of Transient Structures

Abstract

The phenomenon studied is the perception of well known structures, the elements of which are moving in the visual field and only briefly join together. Consider a horizontal bar traveling along the equator of the screen, and a capital letter F placed in the middle of the screen, with its foot in contact with the trajectory of the bar. There is a moment when the left end of the bar comes in contact with the foot of the F, producing a capital letter E. Preliminary observations show that an E is perceived only if the bar stops its motion for a considerable amount of time, some 120 – 150 ms. In this case a significant structure (the F) is transformed into another significant structure (the E). Other cases are under observation: a meaningless structure that becomes a significant one (an F completed by a bar that is traveling on its top), and a meaningless structure that remains meaningless (an upside down T constituted by a stationary vertical bar with its foot in contact with the trajectory of a moving horizontal bar). The phenomenon shows strong relations with other findings regarding the perception of a stop in the movement of an object, and the perception of a transition between two levels of brightness of the same object.