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The dorsal stream (green) and ventral stream (purple) are shown. They originate from a common source in visual cortex. The dorsal stream is responsible for detection of location and motion.
The dorsal stream (green) and ventral stream (purple) are shown. The dorsal stream is a pathway for visual information that flows through the Visual cortex, the part of the Brain which provides visual processing The primate visual system consists of numerous diverse areas of the Cerebral cortex called the Visual cortex. They originate from a common source in visual cortex. The dorsal stream is responsible for detection of location and motion.

Motion perception is the process of inferring the speed and direction of elements in a scene based on visual input. In Psychology, visual perception is the ability to interpret information from Visible light reaching the Eyes The resulting Perception is also Although this process appears straightforward to most observers, it has proven to be a difficult problem from a computational perspective, and extraordinarily difficult to explain in terms of neural processing. The nervous system is a Network of specialized cells that communicate information about an animal's surroundings and itself

Motion perception is studied by many disciplines, including psychology (i. Psychology (from Greek grc ψῡχή psȳkhē, "breath life soul" and grc -λογία -logia) is an Academic and e. visual perception), neurology, neurophysiology, engineering, and computer science. In Psychology, visual perception is the ability to interpret information from Visible light reaching the Eyes The resulting Perception is also Neurophysiology (from Greek grc νεῦρον neuron, "nerve" grc φύσις physis, "nature origin" and grc -λογία Engineering is the Discipline and Profession of applying technical and scientific Knowledge and Computer science (or computing science) is the study and the Science of the theoretical foundations of Information and Computation and their

Contents

Neuropsychology

Area V5 seems to be important to the processing of visual motion and damage to this area can disrupt motion perception. Neuropsychological studies of a patient who could not see motion, seeing the world in a series of static "frames" instead, suggested that visual area V5 in the human is homologous to area MT in the primate. Neuropsychology is the applied scientific discipline that studies the structure and function of the Brain related to specific psychological processes and overt behaviors [1][2]

First-order motion perception

First-order motion perception refers to the perception of the motion of an object that differs in luminance from its background, such as a black bug crawling across a white page. Luminance is a photometric measure of the density of Luminous intensity in a given direction This sort of motion can be detected by a relatively simple motion sensor designed to detect a change in luminance at one point on the retina and correlate it with a change in luminance at a neighbouring point on the retina after a delay. Sensors that work this way have been referred to as Reichardt detectors (after the scientist Werner Reichardt, who first modelled them), [3] motion-energy sensors, [4] or Elaborated Reichardt Detectors. [5] These sensors detect motion by spatio-temporal correlation and are plausible models for how the visual system may detect motion. In Probability theory and Statistics, correlation, (often measured as a correlation coefficient) indicates the strength and direction of a linear Debate still rages about the exact nature of this process. First-order motion sensors suffer from the aperture problem, which means that they can detect motion only perpendicular to the orientation of the contour that is moving. Motion perception is the process of inferring the speed and direction of elements in a scene based on visual, vestibular and proprioceptive inputs Further processing is required to disambiguate true global motion direction. Motion perception is the process of inferring the speed and direction of elements in a scene based on visual, vestibular and proprioceptive inputs

Second-order motion perception

Second-order motion is motion in which the moving contour is defined by contrast, texture, flicker or some other quality that does not result in an increase in luminance or motion energy in the Fourier spectrum of the stimulus. Contrast is the difference in visual properties that makes an object (or its representation in an image distinguishable from other objects and the background Texture refers to the properties held and sensations caused by the external surface of objects received through the sense of touch. This article specifically discusses Fourier transformation of functions on the Real line; for other kinds of Fourier transformation see Fourier analysis and [6][7] There is much evidence to suggest that early processing of first- and second-order motion is carried out by separate pathways. [8] Second-order mechanisms have poorer temporal resolution and are low-pass in terms of the range of spatial frequencies that they respond to. A low-pass filter is a filter that passes low- Frequency signals but Attenuates (reduces the Amplitude of signals with frequencies In Mathematics, Physics, and Engineering, spatial frequency is a characteristic of any structure that is periodic across position in space Second-order motion produces a weaker motion aftereffect unless tested with dynamically flickering stimuli. The motion after-effect (MAE is a Visual illusion experienced after viewing a moving visual stimulus for a time (milliseconds to minutes with stationary eyes and [9] First and second-order signals appear to be fully combined at the level of Area V5/MT of the visual system. The term visual cortex refers to the primary visual cortex (also known as striate cortex or

Motion integration

Having extracted motion signals (first- or second-order) from the retinal image, the visual system must integrate those individual local motion signals at various parts of the visual field into a 2-dimensional or global representation of moving objects and surfaces.

The aperture problem

The Aperture Problem. The grating appears to be moving down and to the right, perpendicular to the orientation of the bars. But it could be moving in many other directions, such as only down, or only to the right. It is impossible to tell unless the ends of the bars become visible in the aperture.
The Aperture Problem. The grating appears to be moving down and to the right, perpendicular to the orientation of the bars. A grating is any regularly spaced collection of essentially identical Parallel, elongated elements In Geometry, two lines or planes (or a line and a plane are considered perpendicular (or orthogonal) to each other if they form congruent But it could be moving in many other directions, such as only down, or only to the right. It is impossible to tell unless the ends of the bars become visible in the aperture.

Each neuron in the visual system is sensitive to visual input in a small part of the visual field, as if each neuron is looking at the visual field through a small window or aperture. Neurons (ˈnjuːɹɒn also known as neurones and nerve cells) are responsive cells in the Nervous system that process and transmit information The term visual field is sometimes used as a Synonym to Field of view, though they do not designate the same thing The motion direction of a contour is ambiguous, because the motion component parallel to the line cannot be inferred based on the visual input. This means that a variety of contours of different orientations moving at different speeds can cause identical responses in a motion sensitive neuron in the visual system.

Individual neurons early in the visual system (LGN or V1) respond to motion that occurs locally within their receptive field. The lateral geniculate nucleus ( LGN) of the Thalamus is a part of the Brain, which is the primary processor of visual information received from the The term visual cortex refers to the primary visual cortex (also known as striate cortex or Because each local motion-detecting neuron will suffer from the aperture problem, the estimates from many neurons need to be integrated into a global motion estimate. This appears to occur in Area MT/V5 in human visual cortex. The term visual cortex refers to the primary visual cortex (also known as striate cortex or The term visual cortex refers to the primary visual cortex (also known as striate cortex or

See also the barberpole illusion. The barberpole illusion is a Visual illusion that reveals biases in the processing of visual motion in the human brain

Motion in depth

As in other aspects of vision, the observer's visual input is generally insufficient to determine the true nature of stimulus sources, in this case their velocity in the real world. In monocular vision for example, the visual input will be a 2D projection of a 3D scene. The motion cues present in the 2D projection will by default be insufficient to reconstruct the motion present in the 3D scene. Put differently, many 3D scenes will be compatible with a single 2D projection. The problem of motion estimation generalizes to binocular vision when we consider occlusion or motion perception at relatively large distances, where binocular disparity is a poor cue to depth. Binocular vision is vision in which both Eyes are used together This fundamental difficulty is referred to as the inverse problem. An inverse problem is the task that often occurs in many branches of Science and Mathematics where the values of some model parameter(s must be obtained from the

References

  1. ^ Hess, Baker, Zihl (1989). "The" motion-blind" patient: low-level spatial and temporal filters". Journal of Neuroscience 9 (5): 1628-1640.  
  2. ^ Baker, Hess, Zihl (1991). "Residual motion perception in a" motion-blind" patient, assessed with limited-lifetime random dot stimuli". Journal of Neuroscience 11 (2): 454-461.  
  3. ^ Reichardt, W. (1961). "Autocorrelation, a principle for the evaluation of sensory information by the central nervous system. ". W. A. Rosenblith (Ed. ) Sensory communication (: 303-317. MIT Press.  
  4. ^ Adelson, E. H. , & Bergen, J. R. (1985). "Spatiotemporal energy models for the perception of motion. ". J Opt Soc Am A, 2 (2): 284-299.  
  5. ^ van Santen, J. P. , & Sperling, G. (1985). "Elaborated Reichardt detectors. ". J Opt Soc Am A, 2 (2): 300-321.  
  6. ^ Cavanagh, P & Mather, G (1989). "Motion: the long and short of it. ". Spatial vision 4: 103-129. doi:10.1163/156856889X00077. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
  7. ^ Chubb, C & Sperling, G (1988). "Drift-balanced random stimuli: A general basis for studying non-Fourier motion perception. ". J Opt Soc Amer A, 5: 1986-2007.  
  8. ^ Nishida, S. , Ledgeway, T. & Edwards, M. (1997). "Dual multiple-scale processing for motion in the human visual system. ". Vision Research 37: 2685-2698. doi:10.1016/S0042-6989(97)00092-8. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
  9. ^ Ledgeway, T. & Smith, A. T. (1994). "The duration of the motion aftereffect following adaptation to first- and second-order motion. ". Perception 23: 1211-1219. doi:10.1068/p231211. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  

See also

External links

Labs specialising in motion research

Beta movement is a perceptual Illusion, described by Max Wertheimer in his 1912 Experimental Studies on the Seeing of Motion, Induced movement or induced motion is an Illusion of Visual perception in which a stationary or a moving object appears to move or to move differently because Lilac chaser is a Visual illusion, also known as the Pac-Man illusion. Max Wertheimer (April 15 1880 – October 12 1943 was a Czech -born Jewish teacher who was one of the three founders of Gestalt psychology, The motion after-effect (MAE is a Visual illusion experienced after viewing a moving visual stimulus for a time (milliseconds to minutes with stationary eyes and Optic flow is the perceived visual motion of objects as the observer moves relative to them Persistence of vision is the phenomenon of the eye by which even nanoseconds of exposure to an image result in milliseconds of reaction (sight from the retina to the optic nerves The phi phenomenon is a perceptual Illusion described by Max Wertheimer in his 1912 Experimental Studies on the Seeing of Motion, The Pulfrich effect is a psychophysical phenomenon wherein lateral motion of an object in the field of view is interpreted by the Visual cortex as having a depth component due Rudolf Arnheim ( July 15, 1904 &ndash June 9, 2007) was a German -born author art and Film theorist and perceptual psychologist Temporal aliasing is the term applied to a visual Phenomenon also known as the stroboscopic effect. The term visual cortex refers to the primary visual cortex (also known as striate cortex or In Psychology, visual perception is the ability to interpret information from Visible light reaching the Eyes The resulting Perception is also The wagon-wheel effect (alternatively or stagecoach-wheel effect, stroboscopic effect) is an Optical illusion in which a Spoked Wheel In Physics, motion means a constant change in the location of a body
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