Multistable perception (or bistable perception) is a

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

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 refl ...

(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, i ...

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 in which a phrase, statement or resolution is not explicitly defined, making several interpretations plausible. A common aspect of ambiguity is uncertainty. It is thus an attribute of any idea or statement ...

for the human

visual system The visual system comprises the sensory organ (the eye) and parts of the central nervous system (the retina containing photoreceptor cells, the optic nerve, the optic tract and the visual cortex) which gives organisms the sense of sight ...

to definitively and uniquely interpret. Familiar examples include the

Necker cube The Necker cube is an optical illusion that was first published as a Rhomboid in 1832 by Swiss crystallographer Louis Albert Necker. It is a simple wire-frame, two dimensional drawing of a cube with no visual cues as to its orientation, so ...

Schroeder staircase Schroeder stairs (Schröder's stairs) is an optical illusion which is a two-dimensional drawing which may be perceived either as a drawing of a staircase leading from left to right downwards or the same staircase only turned upside down, a classic ...

structure from motion Structure from motion (SfM) is a photogrammetric range imaging technique for estimating three-dimensional structures from two-dimensional image sequences that may be coupled with local motion signals. It is studied in the fields of computer vis ...

monocular rivalry Monocular rivalry is a phenomenon of human visual perception that occurs when two different images are optically superimposed. During prolonged viewing, one image becomes clearer than the other for a few moments, then the other image becomes clear ...

, and

binocular rivalry Binocular rivalry is a phenomenon of visual perception in which perception alternates between different images presented to each eye. When one image is presented to one eye and a very different image is presented to the other (also known as dich ...

, 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

ear An ear is the organ that enables hearing and, in mammals, body balance using the vestibular system. In mammals, the ear is usually described as having three parts—the outer ear, the middle ear and the inner ear. The outer ear consists ...

s or two

nostril A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called t ...

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 ...

). 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 themselve ...

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, ...

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 Dutch commonly refers to: * Something of, from, or related to the Netherlands * Dutch people () * Dutch language () Dutch may also refer to: Places * Dutch, West Virginia, a community in the United States * Pennsylvania Dutch Country People E ...

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 ...

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 th ...

, 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 f ...

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 Interdisciplinarity, 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 t ...

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 imagination, imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, Paral ...

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 fic ...

, 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, 1 ...

'', as due to the construction of the Crow T. Robot 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

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