Adaptation for Discrimination

Light reflected = r * I Adaptation for Discrimination

 I T1

 I T2

Discrimination Thresholds

Pedestal Contrast Response Function  I T1  I T2

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

Boynton et al., 1999

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

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

Light reflected = r * I Adaptation for Appearance

See Hillis and Brainard (2005; under review)

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

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

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

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.]

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

“Paint” “Shadow”

“Paint” “Shadow”