1. Perception The process of organizing and interpreting information, enabling us to recognize meaningful objects and events.

2. 184-186 Visual Capture – the tendency for vision to dominate the other senses

3. Gestalt Psychology Gestalt means “an organized whole” These psychologists emphasize our tendency to integrate pieces of information into meaningful wholes

4. Figure-Ground Relationship The organization of the visual field into objects (figures) that stand out from their surroundings (ground)

5. Figure – Ground Example

6. Grouping The perceptual tendency to organize stimuli into groups that we understand

7. Gestalt Principals of Grouping

8. Gestalts (cont’d)

10. Localization = Depth Perception. 186-190 Perceiving distance – babies can do it from the time they are able to crawl 3-D characteristics Visual Cliff

11. How do we transform two-dimensional objects to three-dimensional perception? Accomodation – lens of eye flat = distant object. Lens thickens = nearby object Binocular Cues: depth cues that depend on two eyes Monocular Cues: depth cues that depend on one eye

12. Binocular Cues Binocular Disparity – Slightly different image is cast on the retina of each eye. 2 images different – close to us.

13. Finger Sausage Illusion Stand or sit still and extend your arms out in front, with your index fingers pointed at each other in front of your face at eye-level. Finger tips should be about 1-inch apart. Now focus your attention beyond your fingers into the distance. Between your fingers you will see a floating finger form in the overlapping region, as illustrated by the image at the left.

14. Binocular Cues Convergence – the more the eyeballs rotate inwards, closer object perceived to be

15. Stereogram – uses binocular disparity

16. Monocular Cues - requires the use of one eye Relative size – 2 objects assumed similar, object that is smaller is farther away

17. Monocular Cues Relative Height – Something above the horizon line in your line of vision is assumed to be further away.

18. Monocular Cues Interposition – closer object blocks a distant object

19. Monocular Cues Relative Clarity/Aerial Perspective – hazy object seen as more distant

20. Monocular Cues Texture Gradient – coarse texture = close. Fine texture = faraway

21. Monocular Cues Linear Perspective – parallel lines seem to meet in the distance. Closer the lines are, farther it appears to be

22. Last Supper Perfect example of Linear Perspective

23. Monocular Cues Relative Motion – closer objects seem to move faster.

24. Monocular Cues Relative Brightness – closer objects appear brighter

25. Motion Perception and Constancies 190-194

26. Motion Perception – how fast is it? Judged by change in size of retinal image Relative size Stroboscopic movement – animation Rapid series of slightly varying images

27. Phi Phenomenon An illusion of movement created when two or more adjacent lights blink on and off in succession.

28. Perceptual Constancy  Perceptual Constancy  perceiving objects as unchanging even as illumination and retinal image change  Lightness/Brightness  shape  size

29. Lightness/Brightness Constancy

30. Size Constancy

31. Perceptual Organization – Ponzo Illusion

32. Moon Illusion Environmental cues make moon appear larger at horizon than when it is at your zenith. What monocular cues make moon at horizon seem farther away?

33. Muller Lyer Effect - Two lines are the same size, but humans have tendency to assume that line pointed away from us is longer. We assume object further away is larger.

35. Perceptual Interpretation  Perceptual Adaptation  (vision) ability to adjust to an artificially displaced visual field  Perceptual Set  a mental predisposition to perceive one thing and not another

36. Perceptual Set: Schemas  Schemas – a mental web of associations  What you see in the center is influenced byperceptual set

37. What is this?

38. 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

39. Monocular Cues You really only need one eye to use these (used in art classes to show depth).

40. Relative size if we know that two objects are similar in size, the one that looks smaller is farther away.

41. Interposition: if something is blocking our view, we perceive it as closer. A.K.A: Overlap

42. Relative Clarity: we assume hazy objects are farther away.

43. Texture gradient: distinct texture to fine indistinct texture (far=densely packed)

44. Relative height: below the horizon =higher is farther Above horizon: reverse!

45. Relative motion: closer objects seem to move faster.

46. Linear Perspective:

47. Relative brightness:

48. Perceived Motion 190-194 Stroboscopic effect (flip book effect) Phi phenomenon: holiday lights Autokinetic Effect (if people stare at a white spotlight in a dark room, it appears to move.)

49. Perceptual Constancy Objects change in our eyes constantly as we or they move….but we are able to maintain content perception Shape Constancy Size Constancy Brightness Constancy

50. Size Constancy/Shape constancy

51. Size-distance relationship

52. Illusions Moon Illusion: Ponzo illusion: Muller-Lyer