5.7 From Sensation to Perception

Question 1

Color-blinds
Dichromats vs Anomalous trichromats

Answer 1

people with only two photopigments can be classified as red-green color-blind if they are missingthe photopigment sensitive for either medium or long wavelengths, or blue-yellow color-blind if they are missing the short-wavelength photopigment.
vs
have all three photopigments, but one of the photopigments exhibits abnormal sensitivity

Question 2

achromatopisa

Answer 2

A rare disorder of color perception is a disorder that arises from disturbances of the central nervous system. Individuals with these disorders are able to see and recognize objects color is not a necessary cue for shape perception. But, despite their relatively good visual recognition, achromatiopsia patients are likely to have some impairments in their ability to perceive shape, given that color-sensitive neurons show tuning for other properties as well, such as orientation. Lesions to areas in and around V4 can result in achromatopsia.

Question 3

akinetopsia

Answer 3

Another rare disorder has to do with a selective loss of motion perception. viewing the world as a series of snapshots, rather than seeing things move continuously in space, the patient saw moving objects appear in one position and then another. The impairment can be very dramatic when V5 is damaged in both left and right hemispheres.