1. Chapter 6 Perception

2. Perception
Selective Attention: focus of conscious awareness on a particular stimulus

3. Cocktail party effect
Cocktail party effect explains your ability to keep your attention on only one voice in a room even if there are many other people talking in the room at the same time. This ability to keep your attention can be altered though if someone says your name.

4. This guy

5. Paying attention to only this girl

6. Even though all these people are talking

7. Until this woman(?) says his name

8. Then his attention is on her (?)

9. Awareness Test Video
How many times does the team in white pass the ball?

10. Who Done It?
Let’s test your awareness again

11. Change Blindness

12. Change Blindness video
NOVA video Experiment video

13. Perceptual Illusions
the Müller-Lyer illusion

14. Experiments proved that African tribes who lived in villages composed of only round huts were not fooled by the Müller-Lyer illusion

15. These findings suggest that individuals in the United States are fooled by the Müller-Lyer illusion because we have developed ways of judging depth based on what we are used to seeing.
We are used to seeing outside corners of buildings as near to us with the top and bottom of the corner sloping out and away

16. Perceptual Illusions

17. Perceptual Illusions

18. Perceptual Illusions

19. Perceptual Illusions

20. Perceptual Organization: Gestalt
Visual Capture
tendency for vision to dominate the other senses
Ventriloquist doll

21. Gestalt--an organized whole
tendency to integrate pieces of information into meaningful wholes
S M OTHER I N G

22. Perceptual Organization: Gestalt
Grouping
the perceptual tendency to organize stimuli into coherent groups
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

23. Perceptual Organization: Grouping Principles

24. Perceptual Organization: Closure

25. Perceptual Organization
Figure and Ground--organization of the visual field into objects (figures) that stand out from their surroundings (ground)
Figures = words
Ground = white page

26. Which is the figure and which is the ground?
While the figure continuously reverses between walking people and directional arrows, we will always see those to figures as being separate from the ground (both the black on the bottom and the white on the top.

27. Perceptual Organization: Depth Perception
ability to see objects in three dimensions
allows us to judge distance
Binocular cues- both help with judging distance (depth perception)
retinal disparity
images from the two eyes differ
closer the object, the larger the disparity
convergence
neuromuscular cue
two eyes move inward for near objects
The more your eyes have to move inward towards one another, the closer the object must be to your face

28. Perceptual Organization: Depth Perception
Visual Cliff

29. Retinal disparity You can try this yourself
Because your retinas are separate from one another and about 2 ½ inches apart, they will see images slightly differently, especially when the images are closer to your eyes

30. Perceptual Organization: Depth Perception
Monocular Cues
relative size
smaller image is more distant
interposition
closer object blocks distant object
relative clarity
hazy object seen as more distant
texture coarse --> close fine --> distant

31. Perceptual Organization: Depth Perception
Relative Size

32. Interposition
Which king is closer?
This guy

33. Interposition confusion

34. Relative Clarity
The boat is more clear, so it must be closer

35. Texture gradient
Objects that are further away seem to be much more densely with finer details, while closer objects have much more bold and coarse details.

36. Perceptual Organization: Depth Perception
Monocular Cues (cont.)
relative height
higher objects seen as more distant
relative motion
closer objects seem to move faster
linear perspective
parallel lines converge with distance
relative brightness
closer objects appear brighter

37. Perceptual Organization: Depth Perception
Relative Height- lower buildings seem closer

38. Relative motion
Video- which appears to be moving faster, the batteries or the shoe?

39. Perceptual Organization: Depth Perception
Light and Shadow- used to create the idea of depth

40. Perceptual Organization: Depth Perception
Perspective Techniques-light and shadow are used to create an idea of depth

41. Motion Perception
Phi phenomenon- when two adjacent stationary lights blink on and off in quick succession, we perceive a single light moving back and forth between them.

42. Perceptual Constancy Perceptual Constancy-
perceiving objects as unchanging even as illumination and retinal image change
-The door looks increasingly like a trapezoid, but we still perceive it as a rectangle
color
shape
size

43. Size-Distance Relationships
Ponzo Illusion

44. Perceptual Organization: Muller-Lyer Illusion

45. Perceptual Illusions

47. Perceptual Organization: Size-Distance Relationship

48. The moon illusion
Try this: at what point does the moon seem larger, when it is on the horizon line or when it is high up in the air?
The moon will seem up to 50 percent larger when it is lower in the sky at the horizon. One theory for why this is suggests that the moon seems larger because it is directly behind trees and buildings that you can compare its’ distance with.

49. Lightness constancy
Lightness constancy- we perceive things to have a constant lightness even while it’s illumination varies. Lightness constancy depends on an objects relative luminance, which is the amount of light an object reflects relative to its’ surroundings. Perceived lightness stays roughly constant, given an unchanging context. But when the surrounding context of an object changes, the perceived lightness will change with its’ surroundings. This phenomenon can be used to create illusions.

50. Perceptual Organization-Brightness Contrast
Which square is a lighter color, A or B?
Believe it or not, both squares
are the same exact color!

51. Sensory Deprivation: Blakemore & Cooper, 1970
Kittens raised without exposure to horizontal lines later had difficulty perceiving horizontal bars.

52. Perceptual Interpretation
Perceptual Adaptation-
(vision) ability to adjust to an artificially displaced visual field
prism glasses

53. a mental predisposition to perceive one thing and not another
Perceptual Set-
a mental predisposition to perceive one thing and not another
We see familiar images on Mars because we are used to seeing these images.

54. Perceptual Set: Schemas
What you see in the center is influenced by
the perceptual set
What do you see, a saxophone player or a woman's face?
You will be much more likely to see a woman’s face if first you look at the unambiguous picture of the woman’s face at the bottom.

55. Perceptual Set: Schemas
Flying Saucers or Clouds?

56. Perception and the Human Factor
Human Factors Psychology
explores how people and machines interact
explores how machine and physical environments can be adapted to human behaviors

57. Distance from runway (miles)
Perceptual Set: Human Factors
Actual
descent
path
Pilot’s perceived
descent path
Altitude looks
this much higher
Distance from runway (miles) 10 8 6 4 2
Altitude
(thousands
of feet)

58. Is There Extrasensory Perception?
controversial claim that perception can occur apart from sensory input
Telepathy- communicate thoughts from one mind to another
Clairvoyance- sixth sense of seeing things outside of normal world vision
Precognition- direct knowledge of the future
Parapsychology-
the study of paranormal phenomena
ESP
psychokinesis

59. Telepathy

60. Precognition

61. Clairvoyance

62. Clairvoyance
Are you clairvoyant?