Beta movement

Lights blink in sequence, giving the appearance of movement.

Beta movement is a perceptual illusion whereby two or more still images are combined by the brain into surmised motion. Beta movement is one of two illusions referred to as "phi phenomena." (Confusingly, the other illusion is referred to as the phi phenomenon).

Discovery

Beta movement was first discovered by Max Wertheimer, who noticed that the light appeared to jump from one lamp to another when he turned them on and off in quick succession. Wertheimer published his findings in his 1912 paper Experimental Studies on the Seeing of Motion.

Description

The classic beta phenomenon experiment involves a viewer or audience watching a screen, upon which the experimenter projects two images in succession. The first image depicts a ball on the left side of the frame. The second image depicts a ball on the right side of the frame. The images may be shown quickly, in rapid succession, or each frame may be given several seconds of viewing time. Viewers generally claim to see one ball move from left to right, not two balls flashing in succession.

The beta phenomenon can also create the illusion of motion toward and away from an audience. When the first image is of a large object, and the second is of a small object (or vice-versa), viewers generally report that the object moved away from them. Additionally, if the first frame depicts a brightly-colored object against a solid background, and the second depicts the same object but in colors similar to the background, viewers report that the object moved away from them.

Beta movement is commonly found in computer generated examples as a circle of dots that disappear in a clockwise or counterclockwise sequence, making it seem as though dots are jumping into the empty space next to them. A similar image is used to show the related illusion of phi phenomenon, the only difference being the speed of the sequence of disappearing circles.

Explanation

Scientists do not yet fully understand what causes the illusion of apparent motion with beta movement. Most theories involve a physiological, rather than psychological explanation, and have to do with the various ways the brain and optic nerves communicate.

Applications

Beta movement is often seen in strings of decorative holiday lights, which sometimes blink on and off in sequence. It can also be found on old theater marquees or other such signs, where individual lights appear to travel around the perimeter of the sign. Beta movement can also be found in neon signs, where a figure or object appears to change position.

External links

• Phi is not Beta – An explanation of the difference between the beta and phi phenomena. Retrieved October 4, 2007.
• The Myth of Persistence of Vision Revisited – A detailed explanation of how the perception of motion in film and video differs from the simplest notions of "persistence of vision". Retrieved October 4, 2007.

References

ISBN links support NWE through referral fees

• Chang, Freddy., Daniel Gerstman., P.A. Pietsch and Linda Locke. MEPC: Optometry: Examination Review. March, 1994. McGraw-Hill Medical. Publishing. ISBN 0838574491
• Hartmann, George Wilfried. 2006. "Gestalt Psychology: A Survey of Facts and Principles". Kessinger Publishing. ISBN 142545285X
• Schwartz, Steven H. 2004. "Visual Perception". McGraw-Hill Medical. ISBN 0071411879

Credits

New World Encyclopedia writers and editors rewrote and completed the Wikipedia article in accordance with New World Encyclopedia standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License (CC-by-sa), which may be used and disseminated with proper attribution. Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here:

• Beta_movement  ^history

The history of this article since it was imported to New World Encyclopedia:

• History of "Beta movement"

Note: Some restrictions may apply to use of individual images which are separately licensed.