Exam 1 Grade Distribution

1. Exam 1 Grade Distribution Mean = ~77

2. Exam 1 Grade Distribution Note the “ceiling effect”: these grades would have gone here if the max score was more than 100 Mean = ~77

3. Upcoming: Read article by Gregory for Thursday Read chapter by Pinker for February 28th

4. Seeing Depth • The world is 3D, the retina is 2D !

5. Depth Cues • Four categories: • Pictorial • Physiological • Motion • Stereoscopic

6. Pictorial Depth Cues • Shadows and Shading

7. Pictorial Depth Cues • Retinal image size • far objects smaller than near objects

8. Pictorial Depth Cues • Retinal image size • problem: big far things same as close small things • “solved” by size constancy: Perceived size is adjusted according to perceived distance (based on other cues) • forms the basis for several visual illusions

9. Pictorial Depth Cues • Retinal image size

10. Pictorial Depth Cues • Retinal image size

11. Pictorial Depth Cues • Linear perspective

12. Pictorial Depth Cues • Texture gradient

13. Pictorial Depth Cues • Height in the plane

14. More Depth Cues • Pictorial Depth Cues • Physiological Depth Cues • Motion Parallax • Stereoscopic Depth Cues

15. Physiological Depth Cues • Two Physiological Depth Cues • accommodation • convergence

16. Physiological Depth Cues • Accommodation

17. Physiological Depth Cues • Convergence

18. Physiological Depth Cues • Convergence • small angle of convergence = far away • large angle of convergence = near • What two sensory systems is the brain integrating? • What happens to images closer or farther away from fixation point?

19. Physiological Depth Cues • Convergence and accommodation are reflexively linked Under what circumstances might this be a problem?

20. Motion Depth Cues • Motion • Parallax

21. Motion Depth Cues • Parallax

22. Motion Depth Cues • Parallax • points at different locations in the visual field move at different speeds depending on their distance from fixation

23. Muller - Lyer Illusion

24. Muller - Lyer Illusion