Induced movement or induced motion is an
illusion
An illusion is a distortion of the senses, which can reveal how the mind normally organizes and interprets sensory stimulation. Although illusions distort the human perception of reality, they are generally shared by most people.
Illusions may oc ...
of
visual perception
Visual perception is the ability to interpret the surrounding Biophysical environment, environment through photopic vision (daytime vision), color vision, scotopic vision (night vision), and mesopic vision (twilight vision), using light in the ...
in which a stationary or a moving object appears to move or to move differently because of other moving objects nearby in the
visual field
The visual field is the "spatial array of visual sensations available to observation in introspectionist psychological experiments". Or simply, visual field can be defined as the entire area that can be seen when an eye is fixed straight at a point ...
. It is interpreted in terms of the change in the location of an object due to the movement in the space around it. The object affected by the illusion is called the ''target'', and the other moving objects are called the ''background'' or the ''context'' (Duncker, 1929).
Induced movement with stationary target
A stationary object appears to move in the opposite direction to the background. For example, the moon on a cloudy, windy night appears to be racing through the sky opposite to the direction of the clouds, though the moon is essentially stationary in the sky and only appears to be moving due to the movement of the clouds. For an illustration, see http://psychlab1.hanover.edu/Classes/Sensation/induced/
Induced movement with a moving target
A moving object appears to be moving faster when it is moving in the opposite direction to the background; it appears to be moving slower when it is moving in the same direction as the background.
History of induced movement
Induced motion has more continuous history than does apparent motion.
Induced movement was reported by
Ptolemy
Claudius Ptolemy (; grc-gre, Πτολεμαῖος, ; la, Claudius Ptolemaeus; AD) was a mathematician, astronomer, astrologer, geographer, and music theorist, who wrote about a dozen scientific treatises, three of which were of importance ...
(ca. 90 – ca. 168 AD) (see Smith, 1996). It was researched extensively by Duncker (1929).
See also
*
Autokinetic effect
The autokinetic effect (also referred to as autokinesis and the autokinetic illusion) is a phenomenon of visual perception in which a stationary, small point of light in an otherwise dark or featureless environment appears to move. It was first re ...
*
Motion aftereffect
The motion aftereffect (MAE) is a visual illusion experienced after viewing a moving visual stimulation, stimulus for a time (tens of milliseconds to minutes) with stationary eyes, and then fixating a stationary stimulus. The stationary stimulus ...
*
Motion induced blindness
Motion Induced Blindness (MIB) is a phenomenon of visual disappearance or perceptual illusions observed in the lab, in which stationary visual stimuli disappear as if erased in front of an observer's eyes when masked with a moving background. Mo ...
*
Motion perception
References
{{reflist
Duncker, K. (1929). Über induzierte Bewegung (Ein Beitrag zur Theorie optisch wahrgenommener Bewegung). ''Psychologische Forschung, 12,'' 180-259.
Smith, A. M. (1996). Ptolemy's theory of visual perception: An English translation of the Optics with introduction and commentary. ''Transactions of the American Philosophical Society, 86''(2).
Hae-Won Shin; Mi J. Kim; Jong S. Kim; Myoung C. Lee; Sun J. Chung (2009). Levosulpiride-induced movement disorders . "Movement Disorders",24 (15), pg. 2249-2253 .
Illusions
Perception