Beta movement

from Wikipedia, the free encyclopedia
Flip book with scene of a soccer game (video, 10 seconds)

As beta movement (also Stroboscopic movement ) is the perception of an apparent movement referred to by a series of closely spaced, actually static optical stimuli is caused. In his experiments carried out in 1912, Max Wertheimer showed that, under certain conditions, the perception of such a sequence cannot be differentiated from the perception of real movement. This is the reason why, for example, in flip books or television pictures, the movements shown are perceived as natural.

Recent research has shown that when a realistic pseudo movement is perceived, a distinction can be made between short ( short-range ) and long ( long-range ) distances of movement jumps. With small viewing angle distances of the representation of the moving object, the perception according to current knowledge actually corresponds in every respect to the perception of real movements, so it is a purely sensory perception. In contrast, at greater distances, higher cognitive processes appear to be involved.

Experimental investigation

Illustration of the beta movement using a ball bouncing back and forth. The impression is created that the ball is temporarily between the two end positions, although no intermediate position is shown.

In the experiments, which are mostly carried out on beta movement, two optical stimuli are generated one after the other, not too far apart, usually in the form of two stripes on a screen. Such a beta movement can be perceived at certain frequencies of the stimulus generation, also depending on distance and viewing angle. With a viewing angle of approximately one degree, most test subjects perceive a movement of the displayed objects from one position to another from a period of approximately 250 milliseconds between the stimulus changes ( stimulus onset asynchrony , SOA). If the time span is shorter, partial movements of the objects are initially perceived. If the time spans are still shorter, a shadow moving back and forth is perceived, which alternately obscures the no longer moving objects. The latter is also known as the Phi phenomenon .

The experiments are usually carried out with an immediate stimulus change, i.e. the so-called interstimulus interval (ISI) is 0. If the time between the stimulus changes is increased, the movement perception disappears with pauses of more than 300 milliseconds. Even if the stimuli begin to overlap in time, i.e. a negative interstimulus interval is used, the perception of movement is impaired and a moving object is no longer perceived, but one that disappears and another that appears.

Research history

Siegfried Exner first described in 1875 that a sequence of optical stimuli generated by actually stationary objects creates the impression of movement . He had achieved the effect, among other things, by successively lighting up two sparks.

At the beginning of the 20th century, Max Wertheimer analyzed movement perception in detail based on two stimuli presented one after the other and in his influential post-doctoral thesis from 1912 ( Experimental Studies on Seeing Movement ) he documented the conditions under which “optimal movement” can be perceived. Kurt Koffka , who, together with Wolfgang Köhler , had participated as a test person in Wertheimer's experiments, published several studies in the following year, which included further variants of Wertheimer's experiments. One of them dealt with whether and how optical illusions can influence the movement perceptions described by Wertheimer. In this work written by Friedrich Kenkel , a colleague of Koffka, he introduced the term "α-movement". He used this to describe the variants of Wertheimer's experiments in which an optical illusion was also involved, such as the Müller-Lyer illusion . The normal case, described by Wertheimer as “optimal movement”, he called “β-movement” to distinguish it. For other very special test arrangements, the Greek letters gamma (γ), delta (δ) and epsilon (ε) were introduced later. Only the term “beta movement” has gained greater importance and has survived to this day.

Classification of the perception of apparent movement

In the 1970s it turned out that there was a difference in the perception of short ( short-range ) and long ( long-range ) jumps in movement. Movement distances under a viewing angle of 0.25 degrees create a movement perception analogous to real movement. This is also expressed in the fact that, as with real movement, secondary effects of movement are possible. In contrast, these do not appear to occur with the long-range apparent movement. In addition, the processing process for the latter is relatively slow, and the latter also seems to be dependent on attention. In contrast to the short-range apparent movement, which only seems to react to relative elementary stimuli such as intensity and contrast, the stimuli in the long-range apparent movement can be of many forms. It is assumed that the latter has a parallel to pattern recognition .

The classification by means of short and long range apparent movement has been criticized, in particular because it is based exclusively on the stimulus itself and not on the processes that process the stimulus. Newer classifications have been drawn up, one of which has become relatively well known in three stages:

  • first-order : The movement can be derived directly from changes in luminance .
  • second-order : The movement can be derived from changes in structure or contrast.
  • third-order : The movement is derived from the change in any features.

The first two correspond to the short-range apparent movement, the last case to the long-range apparent movement. Furthermore, the perception of the first two can be simulated by analyzing the kinetic energy ( Motion Energy Analysis , MEA). However, this method based on a Fourier analysis can not be used to explain biological perception, since it is unclear how this should be mapped on the neuronal level. Approximately similar results can be achieved using an improved Reichardt detector ( Elaborated Reichardt Detector ), which is more suitable as a reflection of reality.

See also

literature

  • Walter S. Neff: A Critical Investigation of the Visual Apprehension of Movement. In: The American Journal of Psychology. University of Illinois Press, Volume 48, Number 1, 1936, pp. 1-42 ( online ).

Web links

Commons : Beta phenomenon  - collection of images, videos, and audio files

Individual evidence

  1. ^ A b Christian Becker-Carus, Mike Wendt: General Psychology: An Introduction. Springer Verlag, Berlin / Heidelberg 2017, ISBN 978-3-662-53005-4 , p. 137 ( Google books ).
  2. ↑ a b Max Wertheimer: Experimental studies on seeing movement. Zeitschrift für Psychologie, Volume 61, 1912, pp. 161-265; gestalttheory.net (PDF).
  3. ↑ Martha Blassnigg: Time, Memory, Consciousness and the Cinema Experience: Revisiting Ideas on Matter and Spirit. Edision Rodopi, Amsterdam / New York 2009, ISBN 90-420-2640-5 , p. 126 ( Google books ).
  4. ↑ a b c Axel Larsen, Joyce E. Farrell, Claus Bundesen: Short- and long-range processes in visual apparent movement. In: Psychological Research. Volume 45, Number 1, 1983, pp. 11-18 ( researchgate.net ).
  5. ^ A b c Axel Larsen, Claus Bundesen: Common mechanisms in apparent motion perception and visual pattern matching. In: Cognition and Neurosciences. Volume 50, 2009, pp. 526-534, doi: 10.1111 / j.1467-9450.2009.00782.x .
  6. ↑ a b c Vebjørn Ekroll, Franz Faul, Jürgen Golz: Classification of apparent motion percepts based on temporal factors. In: Journal of Vision. Volume 8, 2008, No. 31, pp. 1-22 ( jov.arvojournals.org ).
  7. ^ Walter S. Neff: A Critical Investigation of the Visual Apprehension of Movement. In: The American Journal of Psychology. University of Illinois Press, Volume 48, Number 1, 1936, pp. 1-42, JSTOR 1415551 .
  8. ↑ Siegmund Exner: About seeing movements and the theory of the compound eye. In: Session reports of the mathematical and natural science class of the Imperial Academy of Sciences, III. Department: Physiology, Anatomy and Theoretical Medicine. Volume 72, pp. 156-190., 1875, hdl: 2027 / coo.31924063807345 .
  9. ↑ Friedrich Kenkel: Investigations into the connection between appearance size and appearance movement in some so-called optical illusions. In: F. Schumann (Ed.): Journal for Psychology. Volume 67, Leipzig 1913, p. 363.
  10. ^ Howard C. Warren: Dictionary of Psychology. Routledge Revivals. New York 2018, ISBN 1-138-61628-1 , p. 54 ( Google books ). First published in 1935 by George Allen & Unwin.
  11. ^ Robert M. Steinman, Zygmunt Pizlob, Filip J. Pizlob: Phi is not beta, and why Wertheimer's discovery launched the Gestalt revolution. In: Vision Research. Volume 40, 2000, pp. 2257-2264, PMID 10927113 .
  12. ↑ Joseph and Barbara Anderson: The Myth of Persistence of Vision Revisited. In: Journal of Film and Video. Volume 45, Number 1, 1993, pp. 3-12, JSTOR 20687993 .
  13. ^ P. Cavanagh: Short-range vs long-range motion: not a valid distinction. In: Spatial Vision. Vol. 5, 1991, pp. 303-309; cavlab.net (PDF).
  14. ^ ZL Lu ,, G. Sperling: The functional architecture of human visual motion perception. In: Vision Research. Volume 35, No. 19, 1995, pp. 2697-2722 ( sciencedirect.com ).
  15. ^ Joseph Norman: A Theory for the Visual Perception of Object Motion. Dissertation, 2014 ( researchgate.net ).