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Chubb Illusion
The Chubb illusion is an optical illusion or error in visual perception in which the apparent contrast of an object varies substantially to most viewers depending on its relative contrast to the field on which it is displayed. These visual illusions are of particular interest to researchers because they may provide valuable insights in regard to the workings of human visual systems. An object of low-contrast visual texture surrounded by a field of uniform visual texture appears to have higher contrast than when presented on a field of high-contrast texture. This illusion was observed by Charles Chubb and colleagues and published in 1989. An empirical explanation of the Chubb illusion was published by Lotto and Purves in 2001. Discovery Chubb and his colleagues researched this illusion by showing various combinations of foreground objects and background fields to human test subjects and asking them to rate the sharpness of the visual contrast in each foreground object. They found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is equal to one event per second. The period is the interval of time between events, so the period is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times a minute (2 hertz), the period, —the interval at which the beats repeat—is half a second (60 seconds divided by 120 beats). Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. Definitions and units For cyclical phenomena such as oscillations, waves, or for examples of simple harmonic motion, the term ''frequency'' is defined as the number of cycles or vibrations per unit of time. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spatial Frequency
In mathematics, physics, and engineering, spatial frequency is a characteristic of any structure that is periodic across position in space. The spatial frequency is a measure of how often sinusoidal components (as determined by the Fourier transform) of the structure repeat per unit of distance. The SI unit of spatial frequency is cycles per meter (m). In image-processing applications, spatial frequency is often expressed in units of cycles per millimeter (mm) or equivalently line pairs per mm. In wave propagation, the spatial frequency is also known as ''wavenumber''. Ordinary wavenumber is defined as the reciprocal of wavelength \lambda and is commonly denoted by \xi or sometimes \nu: :\xi = \frac. Angular wavenumber k, expressed in rad per m, is related to ordinary wavenumber and wavelength by :k = 2 \pi \xi = \frac. Visual perception In the study of visual perception, sinusoidal gratings are frequently used to probe the capabilities of the visual system. In these stimu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Checker Shadow Illusion
The checker shadow illusion is an optical illusion published by Edward H. Adelson, professor of vision science at MIT in 1995. Description The image depicts a checkerboard with light and dark squares, partly shadowed by another object. The optical illusion is that the area labeled A appears to be a darker color than the area labeled B. However, within the context of the two-dimensional image, they are of identical brightness, ''i.e.'', they would be printed with identical mixtures of ink, or displayed on a screen with pixels of identical color. Related illusions Whilst being one of the most well-known contrast illusions, there are similar effects which cause two regions of identical color to appear differently depending on context: * The Cornsweet illusion creates a boundary between two identically-shaded regions with a discontinuous gradient, resulting in the opposing sides appearing to be different. * The Chubb illusion evokes this effect by surrounding zones with others ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contrast Effect
A contrast effect is the enhancement or diminishment, relative to normal, of perception, cognition or related performance as a result of successive (immediately previous) or simultaneous exposure to a stimulus of lesser or greater value in the same dimension. (Here, normal perception, cognition or performance is that which would be obtained in the absence of the comparison stimulus—i.e., one based on all previous experience.) Perception example: A neutral gray target will appear lighter or darker than it does in isolation when immediately preceded by, or simultaneously compared to, respectively, a dark gray or light gray target. Cognition example: A person will appear more or less attractive than that person does in isolation when immediately preceded by, or simultaneously compared to, respectively, a less or more attractive person. Performance example: A laboratory rat will work faster, or slower, during a stimulus predicting a given amount of reward when that stimulus and re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schizophrenia
Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social withdrawal, decreased emotional expression, and apathy. Symptoms typically develop gradually, begin during young adulthood, and in many cases never become resolved. There is no objective diagnostic test; diagnosis is based on observed behavior, a history that includes the person's reported experiences, and reports of others familiar with the person. To be diagnosed with schizophrenia, symptoms and functional impairment need to be present for six months (DSM-5) or one month (ICD-11). Many people with schizophrenia have other mental disorders, especially substance use disorders, depressive disorders, anxiety disorders, and obsessive–compulsive disorder. About 0.3% to 0.7% of people are diagnosed with schizophrenia during their lifetime. In 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contour Junctions , a type of Brit ...
Contour may refer to: * Contour (linguistics), a phonetic sound * Pitch contour * Contour (camera system), a 3D digital camera system * Contour, the KDE Plasma 4 interface for tablet devices * Contour line, a curve along which the function has a constant value * Contour drawing, an artistic technique * A closed path in the mathematical method of contour integration * Boundary (topology) of a set Contours may refer to: * ''Contours'' (album), by Sam Rivers * The Contours, a soul music group Contouring may refer to: * The makeup technique contouring Other uses * Ford Contour, a motor car * CONTOUR, a failed NASA space probe * Contour, a North Wing Apache ultralight aircraft variant See also * Contour fort Hillforts in Britain refers to the various hillforts within the island of Great Britain. Although the earliest such constructs fitting this description come from the Neolithic British Isles, with a few also dating to later Bronze Age Britain, Britis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motion (physics)
In physics, motion is the phenomenon in which an object changes its position with respect to time. Motion is mathematically described in terms of displacement, distance, velocity, acceleration, speed and frame of reference to an observer and measuring the change in position of the body relative to that frame with change in time. The branch of physics describing the motion of objects without reference to its cause is called kinematics, while the branch studying forces and their effect on motion is called dynamics. If an object is not changing relative to a given frame of reference, the object is said to be ''at rest'', ''motionless'', ''immobile'', '' stationary'', or to have a constant or time-invariant position with reference to its surroundings. Modern physics holds that, as there is no absolute frame of reference, Newton's concept of '' absolute motion'' cannot be determined. As such, everything in the universe can be considered to be in motion. Motion applies to various p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Inhibition
In neurobiology, lateral inhibition is the capacity of an excited neuron to reduce the activity of its neighbors. Lateral inhibition disables the spreading of action potentials from excited neurons to neighboring neurons in the lateral direction. This creates a contrast in stimulation that allows increased sensory perception. It is also referred to as lateral antagonism and occurs primarily in visual processes, but also in tactile, auditory, and even olfactory processing. Cells that utilize lateral inhibition appear primarily in the cerebral cortex and thalamus and make up lateral inhibitory networks (LINs). Artificial lateral inhibition has been incorporated into artificial sensory systems, such as vision chips, hearing systems, and optical mice. An often under-appreciated point is that although lateral inhibition is visualised in a spatial sense, it is also thought to exist in what is known as "lateral inhibition across abstract dimensions." This refers to lateral inhibition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Empirical
Empirical evidence for a proposition is evidence, i.e. what supports or counters this proposition, that is constituted by or accessible to sense experience or experimental procedure. Empirical evidence is of central importance to the sciences and plays a role in various other fields, like epistemology and law. There is no general agreement on how the terms ''evidence'' and ''empirical'' are to be defined. Often different fields work with quite different conceptions. In epistemology, evidence is what justifies beliefs or what determines whether holding a certain belief is rational. This is only possible if the evidence is possessed by the person, which has prompted various epistemologists to conceive evidence as private mental states like experiences or other beliefs. In philosophy of science, on the other hand, evidence is understood as that which ''Scientific method#Confirmation, confirms'' or ''disconfirms'' Hypothesis#Scientific hypothesis, scientific hypotheses and arbitrates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmittance
Transmittance of the surface of a material is its effectiveness in transmitting radiant energy. It is the fraction of incident electromagnetic power that is transmitted through a sample, in contrast to the transmission coefficient, which is the ratio of the transmitted to incident electric field. Internal transmittance refers to energy loss by absorption, whereas (total) transmittance is that due to absorption, scattering, reflection, etc. Mathematical definitions Hemispherical transmittance Hemispherical transmittance of a surface, denoted ''T'', is defined as :T = \frac, where *Φet is the radiant flux ''transmitted'' by that surface; *Φei is the radiant flux received by that surface. Spectral hemispherical transmittance Spectral hemispherical transmittance in frequency and spectral hemispherical transmittance in wavelength of a surface, denoted ''T''ν and ''T''λ respectively, are defined as :T_\nu = \frac, :T_\lambda = \frac, where *Φe,νt is the spectral radiant flux ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lotto And Purves
Lotto may refer to: * Lotto, original, 15th century name of the Italian lottery * Lotto (Milan Metro), a railway station in Milan, Italy * Lotto carpet, a carpet having a lacy arabesque pattern * Lotto Sport Italia, an Italian sports apparel manufacturer * Lotto–Soudal, a Belgian cycling team * "Lotto" (''The Office''), a 2011 episode of the US television series * Lotto (band), a Polish alternative rock trio * ''Lotto'' (album), by EXO * "Lotto" (song), by EXO * "Lotto", a song by Joyner Lucas from the 2020 album ''ADHD'' * Lorenzo Lotto (c. 1480–1556/57), Italian painter, draughtsman and illustrator * Myron P. Lotto (1925-2017), American politician See also *Lotta (other) *Lotte (other) *Lotti (given name) *Lotty Lotty is an English feminine given name that is a diminutive form of Charlotte or Lieselotte, an alternate form of Lotte, and that is also related to Lisa, Elisa and Elisabeth. Notable people with the name include the following: Given name * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
