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Delboeuf Illusion
The Delboeuf illusion is an optical illusion of relative size perception: In the best-known version of the illusion, two discs of identical size have been placed near to each other and one is surrounded by a ring; the surrounded disc then appears larger than the non-surrounded disc if the ring is close, while appearing smaller than the non-surrounded disc if the ring is distant. A 2005 study suggests it is caused by the same visual processes that cause the Ebbinghaus illusion. Eponym The illusion was named for the Belgian philosopher, mathematician, experimental psychologist, hypnotist, and psychophysicist Joseph Remi Leopold Delboeuf (1831–1896), who created it in 1865. Factors According to Girgus and Coren (1982) the Delboeuf illusion uses both assimilation and contrast as elements in its perception distortion. Assimilation is the predominant factor in the disc in the smaller outer ring (the example on the right in the image above). Girgus and Coren mentioned that this i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Delboeuf
Joseph Rémi Léopold Delbœuf (30 September 1831, Liège, Belgium – 14 August 1896, Bonn, Germany) was a Belgian experimental psychologist who studied visual illusions including his work on the Delboeuf illusion. He studied and taught philosophy, mathematics, and psychophysics. He published works across a diverse range of subjects including the curative effects of hypnotism. Early life and education Joseph Delboeuf was born in the French speaking town of Liège, Belgium. His father, a pewter craftsman, died early in Delboeuf’s life. He studied at the University of Liège, earning his PhD in philosophy in 1855, followed by physics and mathematics in 1858. He received a scholarship from the University of Bonn and continued his postdoctoral research under philosopher and mathematician Friedrich Ueberweg. In 1860, he began teaching Greek at l’Ecole Normale des Humanités de Liège. In 1863, he was given the post of Maitre de Conférences, which he only held for a few months b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delboeuf Illusion
The Delboeuf illusion is an optical illusion of relative size perception: In the best-known version of the illusion, two discs of identical size have been placed near to each other and one is surrounded by a ring; the surrounded disc then appears larger than the non-surrounded disc if the ring is close, while appearing smaller than the non-surrounded disc if the ring is distant. A 2005 study suggests it is caused by the same visual processes that cause the Ebbinghaus illusion. Eponym The illusion was named for the Belgian philosopher, mathematician, experimental psychologist, hypnotist, and psychophysicist Joseph Remi Leopold Delboeuf (1831–1896), who created it in 1865. Factors According to Girgus and Coren (1982) the Delboeuf illusion uses both assimilation and contrast as elements in its perception distortion. Assimilation is the predominant factor in the disc in the smaller outer ring (the example on the right in the image above). Girgus and Coren mentioned that this i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 variety; their categorization is difficult because the underlying cause is often not clear but a classification proposed by Richard Gregory is useful as an orientation. According to that, there are three main classes: physical, physiological, and cognitive illusions, and in each class there are four kinds: Ambiguities, distortions, paradoxes, and fictions. A classical example for a physical distortion would be the apparent bending of a stick half immerged in water; an example for a physiological paradox is the motion aftereffect (where, despite movement, position remains unchanged). An example for a physiological fiction is an afterimage. Three typical cognitive distortions are the Ponzo illusion, Ponzo, Poggendorff illusion, Poggendorff, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annulus (mathematics)
In mathematics, an annulus (plural annuli or annuluses) is the region between two concentric circles. Informally, it is shaped like a ring or a hardware washer. The word "annulus" is borrowed from the Latin word ''anulus'' or ''annulus'' meaning 'little ring'. The adjectival form is annular (as in annular eclipse). The open annulus is topologically equivalent to both the open cylinder and the punctured plane. Area The area of an annulus is the difference in the areas of the larger circle of radius and the smaller one of radius : :A = \pi R^2 - \pi r^2 = \pi\left(R^2 - r^2\right). The area of an annulus is determined by the length of the longest line segment within the annulus, which is the chord tangent to the inner circle, in the accompanying diagram. That can be shown using the Pythagorean theorem since this line is tangent to the smaller circle and perpendicular to its radius at that point, so and are sides of a right-angled triangle with hypotenuse , and the ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ebbinghaus Illusion
The Ebbinghaus illusion or Titchener circles is an optical illusion of relative size perception. Named for its discoverer, the German psychologist Hermann Ebbinghaus (1850–1909), the illusion was popularized in the English-speaking world by Edward B. Titchener in a 1901 textbook of experimental psychology, hence its alternative name. In the best-known version of the illusion, two circles of identical size are placed near to each other, and one is surrounded by large circles while the other is surrounded by small circles. As a result of the juxtaposition of circles, the central circle surrounded by large circles appears smaller than the central circle surrounded by small circles. Recent work suggests that two other critical factors involved in the perception of the Ebbinghaus illusion are the distance of the surrounding circles from the central circle and the completeness of the annulus, which makes the illusion comparable in nature to the Delboeuf illusion. Regardless of relati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assimilation And Contrast Effects
The assimilation effect, assimilation bias or biased assimilation is a bias in evaluative judgments towards the position of a context stimulus, while contrast effects describe a negative correlation between a judgment and contextual information. History and definition Francis Bacon (1561 – 1626) is quoted to have written "The human understanding when it has once adopted an opinion ... draws all things else to support and agree with it." In 1979, psychologists speculated about the mechanisms of biased assimilation in that one gives "any information that suggests less damaging ‘alternative interpretations’" such importance to use it as proof for one's belief. The classic Stanford University experiment involved supporters and opponents of the death penalty. After showing participants a study that concluded it deterred crime and another suggesting the opposite, they rated the study contradicting their beliefs as poor quality and not persuasive, so that the information resulted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chimpanzee
The chimpanzee (''Pan troglodytes''), also known as simply the chimp, is a species of great ape native to the forest and savannah of tropical Africa. It has four confirmed subspecies and a fifth proposed subspecies. When its close relative the bonobo was more commonly known as the pygmy chimpanzee, this species was often called the common chimpanzee or the robust chimpanzee. The chimpanzee and the bonobo are the only species in the genus ''Pan''. Evidence from fossils and DNA sequencing shows that ''Pan'' is a sister taxon to the human lineage and is humans' closest living relative. The chimpanzee is covered in coarse black hair, but has a bare face, fingers, toes, palms of the hands, and soles of the feet. It is larger and more robust than the bonobo, weighing for males and for females and standing . The chimpanzee lives in groups that range in size from 15 to 150 members, although individuals travel and forage in much smaller groups during the day. The species lives in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capuchin Monkey
The capuchin monkeys () are New World monkeys of the subfamily Cebinae. They are readily identified as the " organ grinder" monkey, and have been used in many movies and television shows. The range of capuchin monkeys includes some tropical forests in Central America and South America as far south as northern Argentina. In Central America, where they are called white-faced monkeys ("carablanca"), they usually occupy the wet lowland forests on the Caribbean coast of Costa Rica and Panama and deciduous dry forest on the Pacific coast. Etymology The word "capuchin" derives from a group of friars named the Order of Friars Minor Capuchin, an offshoot from the Franciscans, who wear brown robes with large hoods. When Portuguese explorers reached the Americas in the 15th century, they found small monkeys whose coloring resembled these friars, especially when in their robes with hoods down, and named them capuchins. When the scientists described a specimen (thought to be a golden-bel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhesus Macaque
The rhesus macaque (''Macaca mulatta''), colloquially rhesus monkey, is a species of Old World monkey. There are between six and nine recognised subspecies that are split between two groups, the Chinese-derived and the Indian-derived. Generally brown or grey in colour, it is in length with a tail and weighs . It is native to South, Central, and Southeast Asia and has the widest geographic range of all non-human primates, occupying a great diversity of altitudes and a great variety of habitats, from grasslands to arid and forested areas, but also close to human settlements. Feral colonies are found in the United States, thought to be either released by humans or escapees after hurricanes destroyed zoo and wildlife park facilities. The rhesus macaque is diurnal, arboreal, and terrestrial. It is mostly herbivorous, mainly eating fruit, but will also consume seeds, roots, buds, bark, and cereals. Studies show almost 100 different plant species in its diet. Rhesus macaques are gener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring-tailed Lemur
The ring-tailed lemur (''Lemur catta'') is a large strepsirrhine primate and the most recognized lemur due to its long, black and white ringed tail. It belongs to Lemuridae, one of five lemur families, and is the only member of the ''Lemur'' genus. Like all lemurs it is endemic to the island of Madagascar and endangered. Known locally in Malagasy as ' (, spelled ' in French) or ', it inhabits gallery forests to spiny scrub in the southern regions of the island. It is omnivorous and the most terrestrial of extant lemurs. The animal is diurnal, being active exclusively in daylight hours. The ring-tailed lemur is highly social, living in groups of up to 30 individuals. It is also female dominant, a trait common among lemurs. To keep warm and reaffirm social bonds, groups will huddle together. The ring-tailed lemur will also sunbathe, sitting upright facing its underside, with its thinner white fur towards the sun. Like other lemurs, this species relies strongly on its sense of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Damselfish
Damselfish are those within the subfamilies Abudefdufinae, Chrominae, Lepidozyginae, Pomacentrinae, and Stegastenae within the family Pomacentridae. Most species within this group are relatively small, with the largest species being about 30cm (12 in) in length. Most damselfish species exist only in marine environments, but a few inhabit brackish or fresh water. These fish are found globally in tropical, subtropical, and temperate waters. Habitat in tropical rocky or coral reefs, and many of those are kept as marine aquarium pets. Their diets include small crustaceans, plankton, and algae. However, a few live in fresh and brackish waters, such as the freshwater damselfish, or in warm subtropical climates, such as the large orange Garibaldi, which inhabits the coast of southern California and the Pacific Mexican coast. Foraging The domino damselfish '' D. albisella'' spends the majority (greater than 85%) of its daytime hours foraging. Larger individuals typically fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guppy
The guppy (), also known as millionfish and rainbow fish, is one of the world's most widely distributed tropical fish and one of the most popular freshwater aquarium fish species. It is a member of the family Poeciliidae and, like almost all American members of the family, is live-bearing. Guppies originate from northeast South America, but have been introduced to many environments and are now found all over the world. They are highly adaptable and thrive in many different environmental and ecological conditions. Male guppies, which are smaller than females, have ornamental caudal and dorsal fins. Wild guppies generally feed on a variety of food sources, including benthic algae and aquatic insect larvae. Guppies are used as a model organism in the fields of ecology, evolution, and behavioural studies. Taxonomy Guppies were first described in Venezuela as ''Poecilia reticulata'' by Wilhelm Peters in 1859 and as ''Lebistes poecilioides'' in Barbados by De Filippi in 1861. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
