Multistable perception (or bistable perception) is a

perceptual Perception () is the organization, identification, and interpretation of sense, sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous ...

phenomenon in which an observer experiences an unpredictable sequence of spontaneous subjective changes. While usually associated with

visual perception Visual perception is the ability to interpret the surrounding environment through photopic vision (daytime vision), color vision, scotopic vision (night vision), and mesopic vision (twilight vision), using light in the visible spectrum reflecte ...

(a form of

optical illusion Within visual perception, an optical illusion (also called a visual illusion) is an illusion caused by the visual system and characterized by a visual perception, percept that arguably appears to differ from reality. Illusions come in a wide v ...

), multistable perception can also be experienced with auditory and

olfactory The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste. In humans, it ...

percepts.

Classification

Perceptual

multistability In a dynamical system, multistability is the property of having multiple stable equilibrium points in the vector space spanned by the states in the system. By mathematical necessity, there must also be unstable equilibrium points between the stable ...

can be evoked by visual patterns that are too

ambiguous Ambiguity is the type of meaning (linguistics), meaning in which a phrase, statement or resolution is not explicitly defined, making several interpretations wikt:plausible#Adjective, plausible. A common aspect of ambiguity is uncertainty. It ...

for the human visual system to definitively and uniquely interpret. Familiar examples include the Necker cube, Schroeder staircase, structure from motion, monocular rivalry, and binocular rivalry, but many more visually ambiguous patterns are known. Because most of these images lead to an alternation between two mutually exclusive perceptual states, they are sometimes also referred to as bistable perception. Auditory and

examples can occur when there are conflicting, and so rival, inputs into the two ears or two nostrils.

Characterization

The transition from one precept (an undefined term) to its alternative (the defined term) is called a perceptual reversal (

Paradigm shift A paradigm shift, a concept brought into the common lexicon by the American physicist and philosopher Thomas Kuhn, is a fundamental change in the basic concepts and experimental practices of a scientific discipline. Even though Kuhn restricted t ...

). They are spontaneous and

stochastic Stochastic (, ) refers to the property of being well described by a random probability distribution. Although stochasticity and randomness are distinct in that the former refers to a modeling approach and the latter refers to phenomena themselv ...

events that cannot be eliminated by intentional efforts, although some control over the alternation process is learnable. Reversal rates vary drastically between stimuli and observers. They are slower for people with

bipolar disorder Bipolar disorder, previously known as manic depression, is a mental disorder characterized by periods of depression and periods of abnormally elevated mood that last from days to weeks each. If the elevated mood is severe or associated with ...

Cultural history

Human interest in these phenomena can be traced back to

antiquity Antiquity or Antiquities may refer to: Historical objects or periods Artifacts *Antiquities, objects or artifacts surviving from ancient cultures Eras Any period before the European Middle Ages (5th to 15th centuries) but still within the histo ...

. The fascination with multistable perception probably comes from the active nature of

endogenous Endogenous substances and processes are those that originate from within a living system such as an organism, tissue, or cell. In contrast, exogenous substances and processes are those that originate from outside of an organism. For example, es ...

perceptual changes or from the dissociation of dynamic perception from constant sensory stimulation. Multistable perception was a common feature in the artwork of the Dutch

lithographer Lithography () is a planographic method of printing originally based on the immiscibility of oil and water. The printing is from a stone (lithographic limestone) or a metal plate with a smooth surface. It was invented in 1796 by the German a ...

M. C. Escher Maurits Cornelis Escher (; 17 June 1898 – 27 March 1972) was a Dutch graphic artist who made mathematically inspired woodcuts, lithographs, and mezzotints. Despite wide popular interest, Escher was for most of his life neglected in t ...

, who was strongly influenced by mathematical physicists such as

Roger Penrose Sir Roger Penrose (born 8 August 1931) is an English mathematician, mathematical physicist, philosopher of science and Nobel Laureate in Physics. He is Emeritus Rouse Ball Professor of Mathematics in the University of Oxford, an emeritus fello ...

Examples

Real-world phenomena

Photographs of craters, from either the moon or other planets including our own, can exhibit this phenomenon. Craters in stereo vision, such as our eyes, normally appear concave. However, in monocular presentations, such as photographs, the elimination of our depth perception causes multistable perception, which can cause the craters to look like plateaus rather than pits. For humans, the "default" interpretation comes from an assumption of

top-left lighting Top-left lighting is an artistic convention in which illustrations are produced so that the light appears to come from the top left of the picture. The vertical element of the convention comes from the human intuition that sunlight comes from a ...

, so that rotating the image by 180 degrees can cause the perception to suddenly switch. This phenomenon is called the concave/convex, or simply up/down, ambiguity, and it confuses

computer vision Computer vision is an interdisciplinary scientific field that deals with how computers can gain high-level understanding from digital images or videos. From the perspective of engineering, it seeks to understand and automate tasks that the hum ...

as well.

In popular culture

In literature, the

science fiction Science fiction (sometimes shortened to Sci-Fi or SF) is a genre of speculative fiction which typically deals with imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, parallel unive ...

novel A novel is a relatively long work of narrative fiction, typically written in prose and published as a book. The present English word for a long work of prose fiction derives from the for "new", "news", or "short story of something new", itsel ...

, ''

Dhalgren ''Dhalgren'' is a 1975 science fiction novel by American writer Samuel R. Delany. It features an extended trip to and through Bellona, a fictional city in the American Midwest cut off from the rest of the world by an unknown catastrophe. Plot o ...

'', by

Samuel R. Delany Samuel R. "Chip" Delany (, ) (born April 1, 1942), is an American author and literary critic. His work includes fiction (especially science fiction), memoir, criticism, and essays (on science fiction, literature, sexuality, and society). His ...

, contains circular text, multistable perception, and multiple entry points. Multistable perception arises with the theater segments of ''

Mystery Science Theater 3000 ''Mystery Science Theater 3000'' (abbreviated as ''MST3K'') is an American science fiction comedy film review television series created by Joel Hodgson. The show premiered on KTMA-TV (now WUCW) in Minneapolis, Minnesota, on November 24, 1988. ...

'', as due to the construction of the

Crow T. Robot Crow T. Robot is a fictional character from the American science fiction comedy television series ''Mystery Science Theater 3000'' (''MST3K''). Crow is a robot, who, along with others, ridicules poor-quality B to Z movies. Overview According ...

puppet, its head can appear to be facing towards the camera rather than towards the film being shown. This was addressed by the creators of the series, even likening Crow to a Necker cube or

The Spinning Dancer The Spinning Dancer, also known as the Silhouette Illusion, is a kinetic, bistable, animated optical illusion originally distributed as a GIF animation showing a silhouette of a pirouetting female dancer. The illusion, created in 2003 by Japan ...

Bibliography

* *

Sources

External links

VisualFunHouse Optical Illusions
Multistable perception Optical Illusions
A collection of visually ambiguous patterns
* {{ cite journal , author1=Miller, S. M. , author2=Liu, G. B. , author3=Ngo, T. T. , author4=Hooper, G. , author5=Riek, S. , author6=Carson, R. G. , author7=Pettigrew, J. D. , url = http://www.uq.edu.au/nuq/jack/HTMLCBpaper.htm , title = Interhemispheric Switching Mediates Perceptual Rivalry , journal = Current Biology , year = 2000 , volume = 10 , issue = 7 , pages = 383–392 , pmid = 10753744 , doi = 10.1016/S0960-9822(00)00416-4 , s2cid=51808719

Ambiguity of spatial perception (fr) Perception Optical illusions