1. Perceptual Organization Module 13

2. Overview Perceptual Organization  Form Perception  Depth Perception  Perceptual Constancy

3. Perception Aoccudrnig to rscheearch at Cmabrigde Uinervtisy, it deosn’t mttaer in what oredr the ltteers in a wrod are, the olny iprmoetnt tihng is that the frist and lsat ltteer be at the rghit pclae. The rset can be a toatl mses and you can still raed it wouthit porbelm. This is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.

9. Perceptual Organization How do we form meaningful perceptions from sensory information? We organize it.

10. Perceptual Organization: Gestalt  Gestalt--an organized whole  tendency to integrate pieces of information into meaningful wholes  a school of psychology founded in Germany in the 1900s that maintained our sensations are processed according to consistent perceptual rules that result in meaningful whole perceptions, or gestalts.

11. Feature Pop Out The slanted line amongst vertical lines Pops Out, but the cross amongst horizontal and vertical lines does not pop out. (a) (b)

12. Organization of the visual field into objects (figures) that stand out from their surroundings (ground). Figure Ground Time Savings Suggestion, © 2003 Roger Sheperd.

13. Laws of Perceptual Organization Figure-Ground Animated necker cube http://dogfeathers.com/java/necker.html

14. From MIND SIGHTS by Shepard © 1990 by Roger N. Shepard. Used with permission by W. H. Freeman and Company. Return Figure 5.7: Reversible Images

15. Faces or Vases?

16. Grouping After distinguishing the figure from the ground, our perception needs to organize the figure into a meaningful form using grouping rules.

17. Grouping demo http://9gag.com/gag/aOqOYv6?ref=9g.m

18. Perceptual Organization: Gestalt  Grouping Principles  proximity--group nearby figures together  similarity--group figures that are similar  continuity--perceive continuous patterns  closure--fill in gaps  connectedness--spots, lines, and areas are seen as unit when connected

19. Laws of Perceptual Organization Law of Continuity Law of Proximity

20. Laws of Perceptual Organization Law of Closure Law of Similarity

21. Law of Proximity

22. The Law of Similarity

23. The Law of Continuity

24. Perceptual Organization: Closure  Gestalt grouping principles are at work here.

25. Reversible Dancer? Note which direction the dancer is rotating. Clockwise or counter? http://www.news.com.au/heraldsun/story/0,21985,22556281-661,00.html

26. Grouping & Reality Although grouping principles usually help us construct reality, they may occasionally lead us astray. Both photos by Walter Wick. Reprinted from GAMES Magazine..© 1983 PCS Games Limited Partnership

27. Depth Perception Visual Cliff Depth perception enables us to judge distances. Gibson and Walk (1960) suggested that human infants (crawling age) have depth perception. Even newborn animals show depth perception. Innervisions

28. Figure 13.7 Relative size Myers: Exploring Psychology, Seventh Edition In Modules Copyright © 2008 by Worth Publishers

29. Binocular Cues Retinal disparity: Images from the two eyes differ.

30. Binocular Cues Convergence: Neuromuscular cues. When two eyes move inward (towards the nose) to see near objects and outward (away from the nose) to see faraway objects.

31. Monocular Cues Relative Size: If two objects are similar in size, we perceive the one that casts a smaller retinal image to be farther away.

32. Perceptual Organization: Depth Perception -- Relative Size

33. Monocular Cues Interposition: Objects that occlude (block) other objects tend to be perceived as closer. Rene Magritte, The Blank Signature, oil on canvas, National Gallery of Art, Washington. Collection of Mr. and Mrs. Paul Mellon. Photo by Richard Carafelli.

34. Interposition

35. Monocular Cues Relative Height: We perceive objects that are higher in our field of vision to be farther away than those that are lower. Image courtesy of Shaun P. Vecera, Ph. D., adapted from stimuli that appered in Vecrera et al., 2002

36. Tall Arch Rick Friedman/ Black Star

37. Monocular Cues Relative motion: Objects closer to a fixation point move faster and in opposing direction to those objects that are farther away from a fixation point, moving slower and in the same direction.

38. Motion Perception Motion Perception: Objects traveling towards us grow in size and those moving away shrink in size. The same is true when the observer moves to or from an object.

39. Apparent Motion Phi Phenomenon: When lights flash at a certain speed they tend to present illusions of motion. Neon signs use this principle to create motion perception. Two lights flashing one after the other. One light jumping from one point to another: Illusion of motion.

40. Monocular Cues Linear Perspective: Parallel lines, such as railroad tracks, appear to converge in the distance. The more the lines converge, the greater their perceived distance. © The New Yorker Collection, 2002, Jack Ziegler from cartoonbank.com. All rights reserved.

41. Perceptual Organization: Linear Perspective

42. Linear Perspective

44. Monocular Cues Light and Shadow: Nearby objects reflect more light into our eyes than more distant objects. Given two identical objects, the dimmer one appears to be farther away. From “Perceiving Shape From Shading” by Vilayaur S. Ramachandran. © 1988 by Scientific American, Inc. All rights reserved.

45. In or Out?

46. Monocular Cues Texture Gradient: Indistinct (fine) texture signals an increasing distance.

47. Perceptual Constancy Perceiving objects as unchanging even as illumination and retinal images change.

48. Figure 13.10 Shape constancy Myers: Exploring Psychology, Seventh Edition In Modules Copyright © 2008 by Worth Publishers

49. Figure 13.9 Perceiving shape Myers: Exploring Psychology, Seventh Edition In Modules Copyright © 2008 by Worth Publishers Link

50. Perceiving familiar objects as having consistent color even when changing illumination filters the light reflected by the object. Color Constancy Link

51. Moon Illusion The moon just above the horizon typically appears to be unusually large because we perceive it as unusually far away from ourselves. This illustrates the importance of context effects.

52. Size-Distance Relationship The distant monster (below, left) and the top red bar (below, right) appear bigger because of distance cues. From Shepard, 1990 Alan Choisnet/ The Image Bank

53. Ponzo Illusion Converging lines indicate that top line is farther away than bottom line

54. From Perplexing Puzzles and Tantalizing Teasers, (p.75), by Martin Gardner, 1988, New York Dover. Figure 5.2: Misperceiving Reality: Which Line Is Longer?

55. Size-Distance Relationship Both girls in the room are of similar height. However, we perceive them to be of different heights as they stand in the two corners of the room. Both photos from S. Schwartzenberg/ The Exploratorium

56. Ames Room The Ames room is designed to demonstrate the size- distance illusion. Ramachandran explains the Ames room http://www.youtube.com/watch?v=Ttd0YjXF0no http://www.youtube.com/watch?v=Ttd0YjXF0no

57. Lightness Constancy The color and brightness of square A and B are the same. Courtesy Edward Adelson

58. Visual Illusions The Ponzo Illusion The Müller - Lyer Illusion

61. EXPLORING PSYCHOLOGY (7th Edition in Modules) David Myers PowerPoint Slides Aneeq Ahmad Henderson State University Worth Publishers, © 2008