Describe how colors are detected and processed in the retina before being sent to the brain.

Question

What will be an ideal response?

Answer 1

There are three types of cone receptors, each of which are responsive to either the short (blue), medium (green), or long (red) wavelengths of light. It is the differential patterns of responding among the three types of cone receptors that influences our perception of different colors. This provides evidence for the trichromatic theory, which states that three color processes account for all the color we are able to distinguish. The cone receptors relay information about color to the ganglion cells, which in turn process color in an opponent way. Stimulation of the red cone receptors with long wavelengths of light causes activation of the red/green ganglion cell, giving us the perception of the color red. Stimulation of the green cone receptors with medium wavelengths of light causes inhibition of the red/green ganglion cells, giving us the perception of the color green. Stimulation of the blue cone receptors with short wavelengths of light causes inhibition of the yellow/blue ganglion cells, giving us the perception of the color blue. Equal stimulation of the red and green cone receptors causes excitation of the yellow/blue ganglion cells, giving us the perception of the color yellow.