MOVEMENT ILLUSION: A REVIEW
Movement illusion is a phenomenon in which a stationary stimulus appears to move. It has been studied extensively in the fields of psychology, neuroscience, and visual perception. This review provides an overview of the history and current research on movement illusion, including the different types of illusions and the underlying mechanisms.
History
The first documented instance of a movement illusion is attributed to the Greek philosopher Aristotle, who described an illusion in which a still object appears to move in response to a viewer’s gaze. This phenomenon has since been referred to as the “Aristotle illusion”(Franz, 1990). In the 19th century, German physicist Hermann von Helmholtz coined the term “optical illusion” to describe the phenomenon of visually induced movement (Helmholtz, 1867). Since then, the study of movement illusion has become an important area of research in visual perception and neuroscience.
Types of Movement Illusions
Movement illusions can be categorized into three main types: self-motion illusions, apparent motion illusions, and relative motion illusions (Freyd & Finke, 1984).
Self-motion illusions involve the perception of self-motion when a stationary stimulus is presented. Examples include the “waterfall illusion” and the “directional aftereffect” (Kanizsa, 1979).
Apparent motion illusions involve the perception of an illusory motion path when two stationary stimuli are presented sequentially. Examples include the “phi phenomenon” and the “stroboscopic effect” (Kanizsa, 1979).
Relative motion illusions involve the perception of motion when two different motion stimuli are presented simultaneously. Examples include the “kinetic depth effect” and the “dynamic brightness effect” (Kanizsa, 1979).
Underlying Mechanisms
The underlying mechanisms of movement illusion are still largely unknown. However, some research suggests that the perception of movement may be due to the activation of motion-sensitive neurons in the visual cortex (Sugita, 1998). Additionally, there is evidence that different types of movement illusions may be mediated by different neuronal mechanisms. For example, self-motion illusions may be mediated by neurons that respond to motion signals, while relative motion illusions may be mediated by neurons that respond to the relative motion between two stimuli (Sugita, 1998).
Conclusion
Movement illusion is a fascinating phenomenon that has been studied for centuries. This review provides an overview of the history and current research on movement illusion, including the different types of illusions and the underlying mechanisms. While the exact mechanisms of movement illusion are still unknown, research suggests that different types of illusions may be mediated by different neuronal mechanisms.
References
Franz, V. H. (1990). Visual illusions and neurobiology. Scientific American, 262(6), 78-85.
Helmholtz, H. von. (1867). Handbook of physiological optics. Leipzig: Voss.
Freyd, J. J., & Finke, R. A. (1984). Representational momentum. Journal of Experimental Psychology: Learning, Memory, and Cognition, 10(2), 126-132.
Kanizsa, G. (1979). Organization in vision: Essays on gestalt perception. New York: Praeger.
Sugita, Y. (1998). Neural mechanisms of motion illusions. Trends in Neurosciences, 21(4), 156-162.