Color Perception

Color Vision at Level of the Receptor:

Trichromatic Theory of Color Vision:

 

 

• each receptor is sensitive to light from a different part of visual spectrum -- based on three different cone photopigments.

  • Blue:

   

  • Green:

   

  • Red:

   

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• Color Blindness results when don't have one type of cone receptor working.

Then we can only use 2 cone receptor types to determine color and it creates confusions.

e.g. red-green color blindness:

from 2 causes

1.

 

 

2.

 

 

e.g. yellow-blue color blindness:

 

 

How visual scenes appear to normal, red/green color blind and yellow/blue color blind people.

examples:

Color Vision at level of the neuron carrying color info to the brain:

Opponent-Process Theory:

 

 

• 3 types

  • Red-Green:

   

   

  • Yellow-Blue:

   

   

  • Black-White:

   

 

• Explains negative afterimages:

Color Vision at Level of the visual cortex in the brain:

• Visual Cortex has neurons that respond to both color and form.

  e.g. McCollough Effect -- orientation contingent color afterimage