The Psychophysical Study of Visual Motion Aftereffect Rate in Monkeys

Abstract

Visual aftereffect of motion is the apparent motion of an objectively stationary stimulus pattern induced by prior viewing of a moving pattern. The aftereffect is probably always in a direction opposite to that of the eliciting motion. Aristotle was the first to describe the phenomenon (see Hutchins, 1952). His example was the apparent motion of stationary objects observed after steady fixation of a swiftly flowing stream. Purkinje (1825) described the aftereffect, which he observed after viewing a cavalry procession, and suggested that habitual eye movements learned during the eliciting period continued during the viewing of the stationary object. Helmholtz (1867) and Wundt (1874) were among those who supported this explanation of aftereffect. Plateau (1850) introduced the rotating spiral as an eliciting stimulus. The rotating spiral appears to move in toward the center or out away from it, depending upon the direction of rotation. The aftereffect is one of expansion in the former case and contraction in the latter. Plateau’s observation defeated Purkinje’s theory since the eyes cannot move in all directions at once. There is a voluminous 19th century literature, which includes attempts to illustrate analogous effects in other senses, e. g., Dvorak (1871). Mach (1875) was the first to propose a retinal locus for the physiologic processes involved in the aftereffect. Several ingenious retinal theories were subsequently devised to account for the aftereffect (e. g., Exner, 1876). A good review of the older literature is to be found in Wohlgemuth (1911) who suggested that the aftereffect might be a useful index to central nervous system function. A more recent summary is given in an excellent book by Holland (1965).