1. Depth Perception Kimberley A. Clow kclow2@uwo.ca

2. Outline Oculomotor Cues Pictorial Cues Motion Based Cues Stereopsis
Development of Depth Perception
Effects of Experience

3. Types

4. Importance
Recognition of location in space is essential for almost all activities
navigating/avoiding objects
jumping
catching/throwing
reaching/grasping
size judgements and recognition
As a result, many redundant systems available for assessing depth and distance

5. How Do We Perceive Depth?

6. Oculomotor Cues

7. Accomodation

8. Convergence

9. Pictorial Cues

10. Occlusion

11. Height in Visual Field

12. Moon Illusion

13. Possibility

14. Relative Size

15. How it works

16. Can Create Illusions...

17. “Excuse me for shouting – I thought you were farther away.”

18. Which is Bigger?

19. Familiar Size

20. Effects of Familiar Size
Size Constancy
Shape Constancy

21. Atmospheric Haze

22. Linear Perspective

23. Which Line is Longer?

24. Which pair of white dots has the greatest vertical separation ?

25. Texture Gradient

26. Texture Discontinuities

27. An Example

28. Another Example

29. Shading
Original
Reversed

30. Pictorial Cues Together
Pictorial Cues work together to give 2D pictures and art a 3D feel

32. Illusion

33. Explanation

34. Motion Based Cues These cues depend on Geometric changes in the scene
Effects of self-motion
Movement through the visual field

35. Motion Parallax

36. Biological Motion

37. Optic Flow

38. Binocular Cues Two eyes Slightly displaced images in each eye
Info about relative depth
Based on the geometry of the images reaching the eye

39. Important Terms

40. Retinal Disparity

41. Example

42. Crossed & Uncrossed

43. Diplopia

44. Stereopsis

48. Physiological Basis
How can cortical neurons process disparity information?
Cortical neurons that code retinal disparity
Respond based on the positions of the images on the two retinae

49. Example

50. Motion Illusion

51. Size Constancy
Why does someone walking away NOT appear to shrink?

52. The Holway-Boring Experiment

53. Which Line is Longer?
#1?
#2?
Muller-Lyer Illusion:

54. Explanation #1 #2

55. Development

56. The Effects of Experience