Rubin's vase (sometimes known as the Rubin face or the Figure-ground vase) is a famous set of cognitive optical illusions developed around 1915 by the Danish psychologist Edgar Rubin. They were first introduced at large in Rubin's two-volume work, the Danish-language Synsoplevede Figurer ("Visual Figures"), which was very well-received; Rubin included a number of examples, like a Maltese cross figure in black and white, but the one that became the most famous was his vase example, perhaps because the Maltese cross one could also be easily interpreted as a black and white beachball. An optical illusion is characterized by visually perceived images that, at least in common sense terms, are deceptive or misleading. ... 1915 (MCMXV) was a common year starting on Friday (see link for calendar). ... A psychologist is a scientist and/or clinician who studies psychology, the systematic investigation of the human mind, including behavior and cognition. ... Edgar John Rubin (September 6, 1886 - May 3, 1951) was a Danish psychologist/phenomenologist, remembered for his work on figure-ground perception as seen in such optical illusions like the Rubin vase. ... Maltese Cross The Maltese cross is identified as the symbol of the Christian warrior. ... A beach ball is a large inflatable ball used in various games and other recreational activities traditionally conducted on the beach. ...

The illusion

The illusion generally presents the viewer with a mental choice of two interpretations, each of which is valid. Often, the viewer sees only one of them, and only realizes the second, valid, interpretation after some time or prompting. When they attempt to simultaneously see the second and first interpretations, they suddenly cannot see the first interpretation anymore, and no matter how they try, they simply cannot encompass both interpretations simultaneously- one occludes the other.

A classic Rubin vase. The faces can be seen in blue, and the vase in white.

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Explanation

The illusions are useful because they are an excellent and intuitive demonstration of the figure-ground distinction the brain makes during visual perception. Rubin's figure-ground distinction, since it involved higher-level cognitive pattern matching, in which the overall picture determines its mental interpretation, rather than the net effect of the individual pieces, influenced the Gestalt psychologists, who discovered many similar illusions themselves. In visual perception, figure-ground refers to humans ability to separate elements based upon contrast. ... This article or section does not cite its references or sources. ... Gestalt is a German word whose meaning is only roughly approximated by the English words shape or form. ...

Normally the brain classifies images by what surrounds what- establishing depth and relationships. If something surrounds another thing, the surrounded object is seen as figure, and the presumably further away (and hence background) object is the ground, and vice versa. This makes sense, since if a piece of fruit is lying on the ground, one would want to pay attention to the "figure" and not the "ground". However, when the contours are not so unequal, ambiguity starts to creep into the previously simple inequality, and the brain must begin "shaping" what it sees; it can be shown that this shaping overrides and is at a higher level than feature recognition processes that pull together the face and the vase images- one can think of the lower levels putting together distinct regions of the picture (each region of which makes sense in isolation), but when the brain takes to make sense of it as a whole, contradictions ensue, and patterns must be discarded. Distance is a numerical description of how far apart things lie. ...

Construction

The distinction is exploited by devising an ambiguous picture, whose contours match seamlessly the contours of another picture (sometimes the same picture; a practice M. C. Escher used on occasion) or more often another picture. The picture should be "flat" and have little (if any) texture to it. The stereotypical example has a vase in the center, and a face matching its contour (since it is symmetrical, there is a matching face on the other side). Elevation contour map A contour line (also level set, isopleth, isogram or isarithm) for a function of two variables is a curve connecting points where the function has a same particular value. ... Hand with Reflecting Sphere (Self-Portrait in Spherical Mirror), 1935. ...

Sex

References

A painting of a Rubin vase.

• A Psychology of Picture Perception, John M. Kennedy. 1974, Jossey-Bass Publishers, ISBN 0-87589-204-3

The same vase, but with the colors swapped. Can you see how your perception switches between face and vase?

• The art and science of visual illusions, Nicholas Wade. 1982 Routledge & Kegan Paul Ltd. ISBN 0-7100-0868-6
• Visual Space Perception, William H. Ittelson. 1969, Springer Publishing Company, LOCCCN 60-15818
• "Vase or face? A neural correlates of shape-selective grouping processes in the human brain." Uri Hasson, Talma Hendler, Dafna Ben Bashat, Rafael Malach.

Journal of Cognitive Neuroscience, Vol 13(6), Aug 2001. pp. 744-753. ISSN: 0898-929X (Print) Image File history File links Rubin1. ... Image File history File links Rubin1. ... Image File history File links Rubin2. ... Image File history File links Rubin2. ...

External links

• Illusionworks.com article