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Saccadic Suppression Of Image Displacement
Saccadic suppression of image displacement (SSID) is the phenomenon in visual perception where the brain selectively blocks visual processing during eye movements in such a way that large changes in object location in the visual scene during a saccade or blink are not detected. The phenomenon described by Bridgeman et al. (Bridgeman, G., Hendry, D., & Stark, L., 1975) is characterized by the inability to detect changes in the location of a target when the change occurs immediately before, during, or shortly after the saccade, following a time course very similar to that of the suppression of visual sensitivity, with a magnitude perhaps even more striking than that of visual sensitivity (4 log units vs. 0.5–0.7 log units (Bridgeman et al., 1975; Volkmann, 1986)). These results indicate that the human perceptual system neglects many useful pieces of information when it comes to spatially localizing target displacements occurring during a saccade. Surprisingly, in contrast to the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 reflected by objects in the environment. This is different from visual acuity, which refers to how clearly a person sees (for example "20/20 vision"). A person can have problems with visual perceptual processing even if they have 20/20 vision. The resulting perception is also known as vision, sight, or eyesight (adjectives ''visual'', ''optical'', and ''ocular'', respectively). The various physiological components involved in vision are referred to collectively as the visual system, and are the focus of much research in linguistics, psychology, cognitive science, neuroscience, and molecular biology, collectively referred to as vision science. Visual system In humans and a number of other mammals, light enters the eye through the cornea and is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eye Movement (sensory)
Eye movement includes the voluntary or involuntary movement of the eyes. Eye movements are used by a number of organisms (e.g. primates, rodents, flies, birds, fish, cats, crabs, octopus) to fixate, inspect and track visual objects of interests. A special type of eye movement, rapid eye movement, occurs during REM sleep. The eyes are the visual organs of the human body, and move using a system of six muscles. The retina, a specialised type of tissue containing photoreceptors, senses light. These specialised cells convert light into electrochemical signals. These signals travel along the optic nerve fibers to the brain, where they are interpreted as vision in the visual cortex. Primates and many other vertebrates use three types of voluntary eye movement to track objects of interest: smooth pursuit, vergence shifts and saccades. These types of movements appear to be initiated by a small cortical region in the brain's frontal lobe. This is corroborated by removal of the fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saccade
A saccade ( , French for ''jerk'') is a quick, simultaneous movement of both eyes between two or more phases of fixation in the same direction.Cassin, B. and Solomon, S. ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing Company, 1990. In contrast, in smooth pursuit movements, the eyes move smoothly instead of in jumps. The phenomenon can be associated with a shift in frequency of an emitted signal or a movement of a body part or device. Controlled cortically by the frontal eye fields (FEF), or subcortically by the superior colliculus, saccades serve as a mechanism for fixation, rapid eye movement, and the fast phase of optokinetic nystagmus. The word appears to have been coined in the 1880s by French ophthalmologist Émile Javal, who used a mirror on one side of a page to observe eye movement in silent reading, and found that it involves a succession of discontinuous individual movements. Function Humans and many animals do not look at a scene in f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blink
Blinking is a bodily function; it is a semi-autonomic rapid closing of the eyelid. A single blink is determined by the forceful closing of the eyelid or inactivation of the levator palpebrae superioris and the activation of the palpebral portion of the orbicularis oculi, not the full open and close. It is an essential function of the eye that helps spread tears across and remove irritants from the surface of the cornea and conjunctiva. Blinking may have other functions since it occurs more often than necessary just to keep the eye lubricated. Researchers think blinking may help with disengagement of attention; following blink onset, cortical activity decreases in the dorsal network and increases in the default-mode network, associated with internal processing. Blink speed can be affected by elements such as fatigue, eye injury, medication, and disease. The blinking rate is determined by the "blinking center", but it can also be affected by external stimulus. Some animals, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chronostasis
Chronostasis (from Greek χρόνος, chrónos, "time" and στάσις, stásis, "standing") is a type of temporal illusion in which the first impression following the introduction of a new event or task-demand to the brain can appear to be extended in time. For example, chronostasis temporarily occurs when fixating on a target stimulus, immediately following a saccade (i.e., quick eye movement). This elicits an overestimation in the temporal duration for which that target stimulus (i.e., postsaccadic stimulus) was perceived. This effect can extend apparent durations by up to half a second and is consistent with the idea that the visual system models events prior to perception. A common occurrence of this illusion is known as the stopped-clock illusion, where the second hand of an analog clock appears to stay still for longer than normal when looking at it for the first time. This illusion can also occur in the auditory and tactile domain. For instance, a study suggests that wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frame Rate
Frame rate (expressed in or FPS) is the frequency (rate) at which consecutive images (frames) are captured or displayed. The term applies equally to film and video cameras, computer graphics, and motion capture systems. Frame rate may also be called the , and be expressed in hertz. Frame rate in electronic camera specifications may refer to the maximal possible rate, where, in practice, other settings (such as exposure time) may reduce the frequency to a lower number. Human vision The temporal sensitivity and resolution of human vision varies depending on the type and characteristics of visual stimulus, and it differs between individuals. The human visual system can process 10 to 12 images per second and perceive them individually, while higher rates are perceived as motion. Modulated light (such as a computer display) is perceived as stable by the majority of participants in studies when the rate is higher than 50 Hz. This perception of modulated light as steady is known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Cognitive Biases
Cognitive biases are systematic patterns of deviation from norm and/or rationality in judgment. They are often studied in psychology, sociology and behavioral economics. Although the reality of most of these biases is confirmed by reproducible research, there are often controversies about how to classify these biases or how to explain them. Several theoretical causes are known for some cognitive biases, which provides a classification of biases by their common generative mechanism (such as noisy information-processingMartin Hilbert (2012) "Toward a synthesis of cognitive biases: How noisy information processing can bias human decision making"'. Psychological Bulletin, 138(2), 211–237; free access to the study here: https://www.martinhilbert.net/toward-a-synthesis-of-cognitive-biases/). Gerd Gigerenzer has criticized the framing of cognitive biases as errors in judgment, and favors interpreting them as arising from rational deviations from logical thought. Explanations include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raster Scan
A raster scan, or raster scanning, is the rectangular pattern of image capture and reconstruction in television. By analogy, the term is used for raster graphics, the pattern of image storage and transmission used in most computer bitmap image systems. The word ''wiktionary:raster, raster'' comes from the Latin word ''wiktionary:rastrum, rastrum'' (a rake), which is derived from ''wiktionary:radere, radere'' (to scrape); see also rastrum, an instrument for drawing musical staff lines. The pattern left by the lines of a rake, when drawn straight, resembles the parallel lines of a raster: this line-by-line scanning is what creates a raster. It is a systematic process of covering the area progressively, one line at a time. Although often a great deal faster, it is similar in the most general sense to how one's gaze travels when one reads lines of text. The data to be drawn is stored in an area of memory called the Framebuffer. This memory area holds the values for each pixel on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saccadic Masking
Saccadic masking, also known as (visual) saccadic suppression, is the phenomenon in visual perception where the brain selectively blocks visual processing during eye movements in such a way that neither the motion of the eye (and subsequent motion blur of the image) nor the gap in visual perception is noticeable to the viewer. The phenomenon was first described by Erdmann and Dodge in 1898, when it was noticed during unrelated experiments that an observer could never see the motion of their own eyes. This can easily be duplicated by looking into a mirror, and looking from one eye to another. The eyes can never be observed in motion, yet an external observer clearly sees the motion of the eyes. The phenomenon is often used to help explain a temporal illusion by the name of chronostasis, which momentarily occurs following a rapid eye-movement. Mechanism A saccade is a fast eye motion, and because it is a motion that is optimised for speed, there is inevitable blurring of the im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transsaccadic Memory
Transsaccadic memory is the neural process that allows humans to perceive their surroundings as a seamless, unified image despite rapid changes in fixation points. Transsaccadic memory is a relatively new topic of interest in the field of psychology. Conflicting views and theories have spurred several types of experiments intended to explain transsaccadic memory and the neural mechanisms involved. In many situations, human eyes move repeatedly in rapid, discontinuous steps, focusing on a single point for only a short period of time before moving abruptly to the next point. Rapid eye movements of this type are called saccades. If a video camera were to perform such high speed changes in focal points, the image on screen would be disorienting for a human viewer. In contrast, despite the rapidly changing sensory input to the visual system, the normal experience is of a stable visual world; this is an example of perceptual constancy. Transsaccadic memory is a system that helps maintain t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 (the ability to perception, detect and process visible light) as well as enabling the formation of several non-image photo response functions. It detects and interprets information from the optical spectrum perceptible to that species to "build a representation" of the surrounding environment. The visual system carries out a number of complex tasks, including the reception of light and the formation of monocular neural representations, colour vision, the neural mechanisms underlying stereopsis and assessment of distances to and between objects, the identification of a particular object of interest, motion perception, the analysis and integration of visual information, pattern recognition, accurate motor coordination under visual guidance, and mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
