Visual perception-illusions-paradoxes
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This document discusses visual perception and illusions. It begins by explaining that visual perception involves both biological determinism and learned experiences. It then discusses several concepts related to visual perception, including the Panopticon, emotions communicated through visuals, and how perception involves both sensation and interpretation. The document goes on to explore various visual illusions and paradoxes, how the brain makes inferences to resolve ambiguities, and discusses concepts like attention, filtering, and Gestalt principles of form perception. It analyzes works by several artists and concludes by mentioning references for further information.
Visual perception-illusions-paradoxes
- 1. Visual Perception Illusions & Paradoxes d Priyadarshi Patnaik Associate Professor Department of Humanities & Social S i D fH ii S i l Sciences IIT Kharagpur
- 2. What about visuals? Many things which are visually communicated or perceived are biologically determined But many other things are learnt Visuals communicate power Visuals communicate emotions Visuals communicate culture
- 3. The Panopticon Jeremy Bentham (1785) Discipline and Punish Paranoia Control Fear Close circuit EPR
- 4. Visuals and the Communication of Emotions
- 6. What is perception? Sensation + Interpretation
- 7. In philosophy psychology and the cognitive philosophy, psychology, sciences, perception is the process of attaining awareness or understanding of sensory information. The word "perception" comes from the Latin words perceptio percipio and means perceptio, percipio, "receiving, collecting, action of taking possession, possession apprehension with the mind or senses."
- 8. When external stimuli is transmitted to our brain through our senses – sensation Devoid of any definition, any interpretation, meaning The simplest building block But then it is taken up by the mind and analyzed Memory is stirred up remembering used up, Sensation identified, matched, given a name, defined, defined interpreted and remembered for future use
- 9. Part of what we perceive comes through the senses from the objects before us; another part always comes out of our own head William J Willi James
- 10. Subjective perception Image credit: Mark R. Homes @ National Geographic Society
- 11. To resolve ambiguities and make sense of the world, the brain also creates shapes from incomplete data. data The i l Th triangle you saw was d l d b I li developed by Italian psychologist Gaetano Kanizsa.
- 12. Illusion Image credit: Mark R. Homes @ National Geographic Society
- 13. Illusion created because of “size constancy size constancy” effect to be discussed a little later.
- 14. Orientation Image credit: Mark R. Homes @ National Geographic Society
- 15. According to noted neuroscientist V. V Ramachandran of University of California, San Diego, Diego the brain can make guesses based on information available and some simple assumptions Pattern of shadows Light Li h usually from top ll f
- 16. Which are the concaves now?
- 17. Orientation
- 18. From the eye to the mind Retina 1 2 brain eye 1: R l t ti 1 Relay station - LGN 2: Primary and more advanced area of visual cortex
- 19. Rods: Monochrome and in low light Cones: colour vision
- 20. Attention The perceptual process of selecting certain inputs for inclusion in our conscious experience or awareness at any given time
- 21. Flash animation Image taken Flash Animation Software demo movie
- 22. Filtering Why does focus shift? We filter, partly bl ki certain i W fil l blocking i inputs Limited Mental Capacity
- 23. Perception is taking in, filtering and interpretation to make sense of the world. Memory and learning play an important part, but so do certain innate organizational abilities of the mind, highlighted by Gestalt psychologists. The limits of my perception are the limits of my world The word is the world (since it takes us a step further and helps us cognize what we have perceived)
- 24. What we shall do next Form perception Colour perception Depth D h perception i These will give us some idea of how and why we visually perceive the many things that we do. yp y g
- 25. Form Perception and Gestalt G l
- 26. Gestalt (German) used to indicate the form- form- forming capabilities of the mind (Whole form approach) and the belief that this holistic perception is innate to the mind
- 27. Figure-g ou d Figure-ground gu e M.C. Escher: Moebious with Birds
- 28. The visual system uses an innate binary division – the figure we look at and the ground which is everything else and forms the background This relation is reversible But B we cannot perceive the same thing as fi i h hi figure and ground at the same time – it requires a mental switching l i hi
- 29. Gestalt Max Wertheimer Kurt Koffka Wolfgang K hl W lf Kohler We are surrounded by sounds and forms that do not have a sole meaning. At any moment, our g y , perception is what gives it form and meaning.
- 30. What do we have here? Twelve lines 4 vertical 4 horizontal 4 oblong
- 31. The vase and the two faces A demonstration of multi-stability: popping back and forth between two or more unstable perceptions
- 32. Organization in form perception The whole is more than the sum of its h h fi parts
- 33. A Poem A Black Coat It was a dark evening d k i Simple Life
- 35. Subjective Contour/Reification Image credit: Mark R. Homes @ National Geographic Society
- 36. Proximity
- 37. Similarity
- 38. The law of good figure
- 39. Continuity
- 41. Closure
- 42. Emergence
- 43. Shape constancy or invariance
- 44. Analysis
- 45. Analyze these Dali images Salvador Dali: Mae West
- 47. Salvador Dali: The Phantom Cart
- 48. Salvador Dali: Galatea of Spheres
- 49. Depth Perception
- 50. Depth Perception D th P ti Monocular Binocular
- 51. Binocular
- 53. Linear perspective Vanishing i t V i hi point Horizon Road
- 54. Dali: Vertigo
- 55. Interposition
- 56. Relative Size The farther an object is from the eye, the smaller eye it looks The episode of the buffalos
- 58. Size Constancy
- 59. Illusion room Source: Blog site: MirageStudio7
- 60. Perceptual assumption Source: Encyclopedia Britannica Deluxe Edition 2007
- 62. Source: Encyclopedia Britannica 2007 Deluxe Edition
- 63. Colour wheel Website of “The Joy of Perception”
- 64. Simultaneous Contrast Website of “The Joy of Perception”
- 65. Source: “Color in Mind: Adobe Magazine, November 1996
- 66. Size Source: “Color in Mind: Adobe Magazine, November 1996
- 67. Brightness, colour and depth Website of “The Joy of Perception”
- 68. The light coloured dot seems to pop out while the dark coloured dot seems to sit further back Source: “Color in Mind: Adobe Magazine, November 1996
- 69. Analysis
- 71. De Chirico: The Nostalgia of Infinite
- 74. Van Gogh: Cypress in Starry Night
- 75. Van Gogh: Wheatfield under threatening skies
- 76. Tibetan Buddhist Tanka painting
- 77. Colour symbolism Cultural differences Age difference Class difference Cl diff Gender difference Trend or current fashion
- 82. Illusion There is an innate ambiguity in retinal input. For a g y p given retinal image, there are infinite number of three dimensional images available for interpretation. Usually we get the interpretation right. When we don’t, we have t th i t rpr t ti ri ht Wh d ’t h an illusion. Some illusions arise because there are more than one possible interpretations. An illusion is a distortion of the senses, revealing how the brain normally organizes and interprets sensory stimulation.
- 83. Types of Ambiguous illusions are pictures or objects that g p j elicit a perceptual 'switch' between the alternative interpretations. Distorting illusions are characterized by distortions of size, length, or curvature. Paradox illusions are generated by objects that are paradoxical or impossible. d i l i ibl Fictional illusions (Hallucinations) are defined as the perception of objects that are g p p bj genuinely not there y to all but a single observer, such as those induced by schizophrenia or a hallucinogen.
- 84. Image source: Encyclopedia Britannica 2007 deluxe edition
- 85. Image source: Encyclopedia Britannica 2007 deluxe edition
- 89. Shape contrast: context Image source: www.colorcube.com
- 90. Simultaneous contrast/spreading Image source: www.colorcube.com
- 92. Escher: Birds & fish
- 93. Escher on Escher "In the horizontal center strip there are birds and fish In equivalent to each other. We associate flying with sky, and so for each of the black birds the sky in which it is flying is formed by the four white fish which encircle it. Similarly swimming makes us think of water, and water therefore the four black birds that surround a fish become the water in which it swims." swims
- 94. Escher: Bond of union
- 95. Escher: Day & night
- 96. Escher: Mobius strip II
- 97. Magritte: Call of the Peaks
- 98. Magritte: the blank cheque
- 101. Pieter Bruegel the Elder (1525-1559), Netherlands
- 102. Jos de Mey (1928 - 2007) Belgian Artist
- 103. Rob Gonsalves (1959-) Canadian Painter
- 109. References and images Doors of Perception http://www.doorsofperception.com/doors The Joy of Perception http://www.yorku.ca/eye Perception Online http://www.pion.co.uk/perception “Perception.” E l p di Britannica 2007 Deluxe Edition. “P ti ” Encyclopedia B it i D l Editi Art and Visual Perception. Rudolf Arnheim, University of California Press, 1984. Mark Hardin’s A hi (www.artchive.com) M k H di ’ Artchive (www.artchive.com) hi Colour. Bettey Edwards, Tarcher/Penguin, 2004. Perception, Gestalt, Panopticon, etc ( p p (Wikipedia) p )