1. PSYCHOLOGY (8th Edition) David Myers PowerPoint Slides Aneeq Ahmad Henderson State University Worth Publishers, © 2006 1

2. Perception Chapter 6 2

3. Perception Group Experiment Selective Attention Perceptual Illusions Perceptual Organization  Form Perception  Motion Perception  Perceptual Constancy 3

4. Perception Perceptual Interpretation  Sensory Deprivation and Restored Vision  Perceptual Adaptation  Perceptual Set  Perception and Human Factor 4

5. Perception Is there Extrasensory Perception?  Claims of ESP  Premonitions or Pretensions  Putting ESP to Experimental Test 5

6. Perception The process of selecting, organizing, and interpreting sensory information, which enables us to recognize meaningful objects and events (Top down processing). 6

7. ACTIVITY DO NOT LOOK AT THE PRINTED WORDS!! Fold your paper vertically so the left side is visible and the right side is not Select the five words that BEST describe YOU by placing a check to the left of the word What does the activity show about perception? 7

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9. Selective Attention Perceptions about objects change from moment to moment. We can perceive different forms of the Necker cube (below); however, we can only pay attention to one aspect of the object at a time. Other examples: the Stroop Task, dichotic listening) 9 Necker Cube

10. Stroop Task 10

11. GREENYELLOWBLUE YELLOWGREEN BLUE RED

12. STROOP TASK Green Red Blue Purple Blue Purple Blue Purple Red Green Purple Green 12

13. SELECTIVE ATTENTION Stress narrows attention OTHER EXAMPLES: –Cell phones in car –? 13

14. How many times is the ball passed? http://www.youtube.com/watch?v=vJG6 98U2Mvohttp://www.youtube.com/watch?v=vJG6 98U2Mvo 14

15. Inattentional Blindness Inattentional blindness refers to the inability to see an object or a person in our midst. Simmons & Chabris (1999) showed that half of the observers failed to see the gorilla-suited assistant in a ball passing game.. 15 Daniel Simons, University of Illinois

16. Change Blindness http://www.youtube.com/watch?v=- HVw9kWkPX0http://www.youtube.com/watch?v=- HVw9kWkPX0 16

17. Change Blindness Change blindness is a form of inattentional blindness in which two-thirds of individuals giving directions failed to notice a change in the individual asking for directions. 17 © 1998 Psychonomic Society Inc. Image provided courtesy of Daniel J. Simmons.

18. INATTENTIONAL BLINDNESS CHANGE DEAFNESS CHOICE BLINDNESS CHOICE BLINDNESS BLINDNESS 18

19. POP-OUT, opposite of inattentional blindness A STRIKINGLY DISTINCT STIMULUS AUTOMATICALLY DRAWS OUR EYE: accomplished by parallel processing 19

20. ATTENTION – Give an example of each Attentional resources are limited Attention can be divided Attention requires effort. Attention improves mental processing Control of attention can be voluntary or involuntary 20

21. ATTENTION Overt vs covert orienting –Overt: pointing sensory systems at a particular stimulus Example? –Covert: Shifting attention without the appearance of shifting the sensory system Example? 21

22. Perceptual Illusions 22 Illusions provide good examples in understanding how perception is organized. Studying faulty perception is as important as studying other perceptual phenomena. Muller- Lyer Illusion: Line AB is longer than line BC.

23. Tall Arch 23 In this picture, the vertical dimension of the arch looks longer than the horizontal dimension. However, both are equal. Rick Friedman/ Black Star

24. Illusion of a Worm 24 The figure on the right gives the illusion of a blue hazy “worm” when it is nothing else but blue lines identical to the figure on the left. © 1981, by permission of Christoph Redies and Lothar Spillmann and Pion Limited, London

25. 3-D Illusion 25 It takes a great deal of effort to perceive this figure in two dimensions. Reprinted with kind permission of Elsevier Science-NL. Adapted from Hoffman, D. & Richards, W. Parts of recognition. Cognition, 63, 29-78

26. Sidewalk Art http://www.youtube.com/watch?v=fKJ0KY nB5R8 26

27. Perceptual Organization When vision competes with our other senses, vision usually wins – a phenomena called visual capture. How do we form meaningful perceptions from sensory information? We organize it. Gestalt psychologists showed that a figure formed a “ whole ” different than its surroundings: ” the whole is greater than the sum of its parts ”. 27

28. PERCEPTUAL ORGANIZATION Sensation (bottom up processing) and Perception (top down processing) blend into one continuous process Fundamental point: We constantly filter sensory information and infer perceptions in ways that make sense to us. Mind matters. 28

29. Form Perception Organization of the visual field into objects (figures) that stand out from their surroundings (ground). Another example: cocktail party phenomena 29 Time Savings Suggestion, © 2003 Roger Sheperd.

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33. REVERSIBLE FIGURE GROUND Reversible figure- ground illusions demonstrate that the same stimulus can trigger more than one perception. 33

34. Grouping 34 After distinguishing the figure from the ground, our perception needs to organize the figure into a meaningful form using grouping rules.

35. GESTALT GROUPING PRINCIPLES graphicdesign.spokanefalls.edu/tutorials/p rocess/gestaltprinciples/gestaltprinc.htm 35

36. GROUPING FIRST IMPRESSIONS _____1. Sometimes interviewers focus on one trait to the A. gestalt exclusion of others; this one trait, good or bad, is dominant against the background of other traits. _____2. “The purpose of this interview, “ Sarah was told, “isB. similarity to gather bits and pieces of information about you so that I might form an overall, meaningful ‘picture’ of you.” _____3. Sometimes applicants are compared to other C. proximity applicants who are the same age, gender, race, education, and so on. Interviewers have to avoid this tendency because it prevents their seeing the person as an individual. _____4. John sees the whole interview process as one, long continuousD. continuity stream of asking questions and gathering information. _____5. Mrs. Thatcher tends to group interviewees together into her E figure-ground morning” applicants, afternoon” applicants, and “drop-in’s”, depending on who comes in with whom during the course of a day’s appointments. 36

37. Grouping & Reality Although grouping principles usually help us construct reality, they may occasionally lead us astray. 37 Both photos by Walter Wick. Reprinted from GAMES Magazine..© 1983 PCS Games Limited Partnership

38. OTHER GROUPING PRINCIPLES LIKLIHOOD PRINCIPLE: we tend to perceive objects in the way that experience tells us is the most likely physical arrangement Auditory scene analysis –Sound localization –Visual capture 38

39. Depth Perception Depth perception enables us to judge distances. Gibson and Walk (1960) suggested that human infants (crawling age) have depth perception. Depth perception appears to be innate, amplified by experience 39 Visual Cliff Innervisions

40. DEPTH PERCEPTION Two dimensional images fall on our retina, how do we see three dimensionally? Depth perception (seeing objects in three dimensions) allows us to judge distance 40

41. RETINAL DISPARITY Note on the diagram how each eye sees the object from a different angle Retinal disparity = binocular disparity 41

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43. Binocular Cues Retinal disparity: Images from the two eyes differ. Brain compares these images, their differences provide cues to relative distance of different objects Try looking at your two index fingers when pointing them towards each other half an inch apart and about 5 inches directly in front of your eyes. You will see a “ finger sausage ” as shown in the inset. 43

44. 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. Accomodation – muscles surrounding the lens tightening 44

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46. BINOCULUAR CUES Hole in the Hand – roll a sheet of paper into a tube and raise it to your right eye like a telescope. Look through it, focusing on a blank wall in front of you. Hold open left hand beside the tube and continue to focus ahead The images received by the two eyes will fuse and the hole in the tube will appear to be in your hand! 46

47. MONOCULAR CUES: RETINAL SIZE Go to the classroom window and estimate the size of a distant object, say a car. Return to your seat and draw a line the length of which produces the same-size retinal image that the object did. Then, go to the window, hold up a thumb to measure the object. Next return to your seat and measure your line with your thumb 47

48. WINDOW EXERCISE ON RETINAL How did your first estimate compare to the actual size? 48

49. 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. 49

50. Monocular Cues Interposition: Objects that occlude (block) other objects tend to be perceived as closer. 50 Rene Magritte, The Blank Signature, oil on canvas, National Gallery of Art, Washington. Collection of Mr. and Mrs. Paul Mellon. Photo by Richard Carafelli.

51. Monocular Cues 51 Relative Clarity: Because light from distant objects passes through more light than closer objects, we perceive hazy objects to be farther away than those objects that appear sharp and clear.

52. Monocular Cues Texture Gradient: Indistinct (fine) texture signals an increasing distance. 52 © Eric Lessing/ Art Resource, NY

53. Monocular Cues Relative Height: We perceive objects that are higher in our field of vision to be farther away than those that are lower. 53 Image courtesy of Shaun P. Vecera, Ph. D., adapted from stimuli that appered in Vecrera et al., 2002

54. 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. 54

55. 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. 55 © The New Yorker Collection, 2002, Jack Ziegler from cartoonbank.com. All rights reserved.

56. 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. 56 From “Perceiving Shape From Shading” by Vilayaur S. Ramachandran. © 1988 by Scientific American, Inc. All rights reserved.

57. Motion Perception Motion Perception: Objects traveling towards us grow in size (looming) and those moving away shrink in size. The same is true when the observer moves to or from an object. Evolutionary importance of detecting movement: wiggle your finger demo 57

58. 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. 58 Two lights flashing one after the other. One light jumping from one point to another: Illusion of motion.

59. Perceptual Constancy Perceiving objects as unchanging even as illumination and retinal images change. Brain needs to recognize the object without being deceived by changes. Perceptual constancies include constancies of shape and size. 59 Shape Constancy

60. Perceptual Constancy Hold a hand in front of you at arm’s length and move it toward your head, then away; there will be no perceived change in size. However, retinal image size is changing. How can we detect? Hold forefinger of left hand about 8 inches in front of your face and focus on it Now position your right hand at arm’s length past your left forefinger. While maintaining fixation on left fingertip, move your right hand toward and away from your face.’ Focus on finger, but also notice image of the hand as it moves. It will change dramatically in size 60

61. Size Constancy Stable size perception amid changing size of the stimuli. 61 Size Constancy

62. Size-Distance Relationship The distant monster (below, left) and the top red bar (below, right) appear bigger because of distance cues. Cultural experience also influences. 62 From Shepard, 1990 Alan Choisnet/ The Image Bank

63. Size-Distance Relationship 63 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

64. Ames Room 64 The Ames room is designed to demonstrate the size- distance illusion.

65. Lightness Constancy 65 The color and brightness of square A and B are the same. Depends on relative luminance - the amount of light an object reflects relative to its surroundings. Courtesy Edward Adelson

66. Color Constancy Perceiving familiar objects as having consistent color even when changing illumination filters the light reflected by the object. 66 Color Constancy

67. COLOR CONSTANCY http://www.cnn.com/2009/OPINION/10/ 26/lotto.optical.illusions/index.htmlhttp://www.cnn.com/2009/OPINION/10/ 26/lotto.optical.illusions/index.html 67

68. Perceptual Interpretation Immanuel Kant (1724-1804) maintained that knowledge comes from our inborn ways of organizing sensory experiences. John Locke (1632-1704) argued that we learn to perceive the world through our experiences. 68 How important is experience in shaping our perceptual interpretation?

69. Restored Vision After cataract surgery, blind adults were able to regain sight. These individuals could differentiate figure and ground relationships, yet they had difficulty distinguishing a circle and a triangle. (Von Senden, 1932). 69

70. Facial Recognition After blind adults regained sight, they were able to recognize distinct features, but were unable to recognize faces. Normal observers also show difficulty in facial recognition when the lower half of the pictures are changed. 70 Courtesy of Richard LeGrand

71. Sensory Deprivation Kittens raised without exposure to horizontal lines later had difficulty perceiving horizontal bars. Influence of critical periods shown. 71 Blakemore & Cooper (1970)

72. Perceptual Adaptation Visual ability to adjust to an artificially displaced visual field, e.g., prism glasses. Stratton experiment with optical headgear. 72 Courtesy of Hubert Dolezal

73. PECEPTUAL ADAPTATION Form groups of four or five. Pick up a set of goggles and a ball. Assign roles: catcher, pitcher, subject (rotate roles) 73

74. Problems with Schemas 74 (Allport & Postman, 1947)

75. PERCEPTUAL SET Our Whisper Down the Lane example was based on Allport and Postman’s 1947 study Story was altered to fit the social expectations and stereotypes of the subjects. Three major perceptual distortions in transmission of information: 75

76. Allport and Postman LEVELING - perceiver drops certain details because they don’t “fit” SHARPENING - details consistent with values and interests are emphasized ASSIMILATION - padding and organization used to make central theme fit subject’s expectations 76

77. Perceptual Set A mental predisposition to perceive one thing and not another. What you see in the center picture is influenced by flanking pictures. Whisper Down the Lane example. 77 From Shepard, 1990.

78. Perceptual Set 78 (a) Loch ness monster or a tree trunk; (b) Flying saucers or clouds? Other examples of perceptual set. Frank Searle, photo Adams/ Corbis-Sygma Dick Ruhl

79. Other Examples of Perceptual Set Provide punctuation that will make the words meaningful: “TIME FLIES I CANT THEYRE TOO FAST!” 79

80. EXPLANATION Apostrophes come easily, but the rest is difficult. We’re too familiar with the slogan. Think of time as a verb rather than a noun. Now it makes sense! 80

81. PERCEPTUAL SET What determines perceptual set? Through experience we form concepts, or schemas, that organize and interpret unfamiliar information. –Example: a child ’ s simplified drawing of people Our innate schemas for faces primes us; we are especially attuned to the eyes and mouth 81

82. Schemas 82 Children's schemas represent reality as well as their abilities to represent what they see. Schemas are concepts that organize and interpret unfamiliar information. Courtesy of Anna Elizabeth Voskuil

83. Features on a Face 83 Students recognized a caricature of Arnold Schwarzenegger faster than his actual photo. Face schemas are accentuated by specific features on the face. Kieran Lee/ FaceLab, Department of Psychology, University of Western Australia

84. Eye & Mouth 84 Eyes and mouth play a dominant role in face recognition. Courtesy of Christopher Tyler

85. Cultural Context 85 To an East African, the woman sitting is balancing a metal box on her head, while the family is sitting under a tree. Context instilled by culture also alters perception.

86. Perception Revisited 86 Is perception innate or acquired?

87. Perception & Human Factors Human Factor Psychologists design machines that assist our natural perceptions. 87 The knobs for the stove burners on the right are easier to understand than those on the left. Photodisc/ Punchstock Courtesy of General Electric

88. Human Factors & Misperceptions Understanding human factors enables us to design equipment to prevent disasters. 88 Two-thirds of airline crashes caused by human error are largely due to errors of perception.

89. Human Factors in Space To combat conditions of monotony, stress, and weightlessness when traveling to Mars, NASA engages Human Factor Psychologists. 89 Transit Habituation (Transhab), NASA

90. HUMAN FACTORS PSYCHOLOGY Examples of poor design? Why do experts often come up with poor solutions? “ Curse of knowledge ” – the mistaken assumption that others share our expertise and will behave as we would Fail to schedule user-testing to reveal perception-based problems prior to production and distribution Why is this topic important? 90

91. Is There Extrasensory Perception? Perception without sensory input is called extrasensory perception (ESP). A large percentage of scientists do not believe in ESP. PARAPSYCHOLOGY: THE STUDY OF PARANORMAL PHENOMENON. 91

92. Claims of ESP Paranormal phenomena include astrological predictions, psychic healing, communication with the dead, and out-of-body experiences, but most relevant are telepathy, clairvoyance, and precognition. 92

93. Claims of ESP 1. Telepathy: Mind-to-mind communication. One person sending thoughts and the other receiving them. 2. Clairvoyance: Perception of remote events, such as sensing a friend ’ s house on fire. 3. Precognition: Perceiving future events, such as a political leader ’ s death. 93

94. Premonitions or Pretensions? Can psychics see the future? Can psychics aid police in identifying locations of dead bodies? What about psychic predictions of the famous Nostradamus? The answers to these questions are NO! Nostradamus ’ predictions are “ retrofitted ” to events that took place after his predictions. 94

95. Putting ESP to Experimental Test In an experiment with 28,000 individuals, Wiseman attempted to prove whether or not one can psychically influence or predict a coin toss. People were able to correctly influence or predict a coin toss 49.8% of the time. 95

96. ESP CLAIMS To give ESP credibility, you would need: A reproducible phenomenon and a theory to explain it 96

97. 97 Population Representative Sample ( larger the better) Experimental Group Control Group Apply Methods of control Apply methods of control Independent Variable Placebo Measure Dependent Variable Is the difference statistically significant? Random Assignment Everyone has equal chance. Random Sampling (aka Random Selection) This is the goal! EXPERIMENTAL DESIGN =

98. QUASI EXPERIMENT: Not a true experiment No random assignment The independent variable already exists in the population (age, gender, etc) IV could be continuous (e.g. age) or categorical (e.g. gender) We can never be sure the quasi iv is causing the change in the dv or if another third factor can explain the difference 98

99. PERCEPTION EXPERIMENT Step One: Brainstorm ideas for an experiment. Remember: develop an idea based on a perceptual concept. Develop a hypothesis, with an independent variable and dependent variable. A good format for your hypothesis: If ________, then _____. Operationally define variables. 99

100. INTRODUCTION – Why Am I Doing This Study? You will need to research your topic for the Introduction (review of past research, justify the logic of the study, and presenting your hypothesis) Check your textbook for background information. You need to cite two additional sources in your Introduction. Introduction: two pages double spaced; all sources must be cited using APA style Hypothesis with iv, dv, and operational definitions 100

101. METHOD – What Did I Do? All ethical guidelines must be followed! Based on your description of the apparatus and procedures could someone replicate your experiment? Have separate sections labeled: Subjects (include description of population and method of selection), Procedures (you may number this), Materials and Apparatus 101

102. CONSENT FORM..\AP Notes\Perception\Consent Form for Experiment.doc..\AP Notes\Perception\Consent Form for Experiment.doc Fill the consent form out as a group to insure uniformity. Make enough copies to give each subject a copy and to keep a copy for yourself. Be prepared to hand these in if I request you to do so. 102

103. RESULTS – What Did I Find? Graphs, charts, tables that present an analysis of your findings. You do NOT interpret the results in this section. You do not present the raw data here, but you should include it in an Appendix if required. 103

104. DISCUSSION - What is the Significance of My Findings? You relate your findings to your hypothesis and the theories you investigated. Did you support your hypothesis? A null hypothesis is one where no effect is expected. You may need to explain why you did not get the results you expected. Were there confounding variables, experimenter bias, etc.? Identify new or additional questions raised by your study. 104

105. REFERENCES – How Do I Give Credit Where Credit Is Due? Requirement: two sources in addition to textbook You need to use the APA style for your citations and reference page Place appropriate citations in the paper as well as including a reference page. It is better to overcite than to undercite. 105

106. APA STYLE CITATION EXAMPLES: – the effects of unchecked infections accumulate (Neese, 1991) –Carrie Armel and Vilayanur Ramachandran (2003) cleverly illustrated…. 106

107. APA STYLE Reference Page Examples: Journal: Murzynski, J. (1996). Body language of women. Journal of Applied Social Psychology, 26, 1617 – 1626. Book: Paloutzian, R. F. (1996). Invitation to the psychology of religion. (2 nd ed.). Boston: Allyn and Bacon. Online: Nielsen, M.E. Notable people in psychology. Retrieved August 3, 2005, from http://www. psywww.comhttp://www Encyclopedia Shea, J.D. (2004) Depression and Adjustment. In J.F. Schumaker (Ed), Encyclopedia of Mental Health (pp. 70-84). New York: Oxford /University Press. 107

108. APPENDIX If necessary, this might include: –Copies of surveys, pictures, etc used as materials –Raw data 108

109. ABSTRACT Complete last, but place first. Single spaced Short summary; include one or two sentences from each section: Introduction, Methodology, Results, Discussion 109