Adaptation for Discrimination

4. Adaptation for Discrimination

5. Light reflected = r * I Light reflected = r * I Adaptation for Discrimination

6. Adaptation for Discrimination

7. Adaptation for Discrimination

8. Adaptation for Discrimination

14. DIT1

20. DIT1 DIT2

21. Discrimination Thresholds

22. DIT1 DIT2 Response Function Pedestal Contrast

23. Discrimination Thresholds See Hillis and Brainard (2005; under review)

24. Boynton et al., 1999

27. Discrimination Thresholds See Hillis and Brainard (2005; under review)

28. Discrimination Thresholds See Hillis and Brainard (2005; under review)

30. Light reflected = r * I Light reflected = r * I Adaptation for Appearance

31. Adaptation for Appearance

32. Adaptation for Appearance

33. Adaptation for Appearance

38. See Hillis and Brainard (2005; under review)

39. Discrimination Thresholds See Hillis and Brainard (2005; under review)

40. Discrimination Thresholds See Hillis and Brainard (2005; under review)

41. Thresholds & Appearance See Hillis and Brainard (2005; under review)

42. See Hillis and Brainard (2005; under review)

43. Summary • Both threshold and appearance measurements can be linked (by hypothesis) to an underlying response function. • Studying change in response function with viewing context is one way to characterize adaptation. • For simple context changes (intensity of uniform backgrounds, unstructured contrast), both threshold and appearance data are consistent with a common mechanism of adaptation. [This is not true in general.]

44. “PAINT” x x “SHADOW” x x (Adopted, with permission, from Adelson’s checkerboard illusion)

45. “Shadow” “Paint”

46. “Shadow” “Paint”