Opponent Process
Transduction involves chemical messages sent from the photoreceptors to the bipolar cells to the ganglion cells. Several photoreceptors may send their information to one ganglion cell. There are two types of ganglion cells: red/green and yellow/blue. These neuron cells consistently fire—even when not stimulated. The brain interprets different colours (and with a lot of information, an image) when the rate of firing of these neurons alters. Red light stimulates the red cone, which in turn stimulates the red/green ganglion cell. Likewise, green light stimulates the green cone, which stimulates the red/green ganglion cell and blue light stimulates the blue cone which stimulates the yellow/blue ganglion cell. The rate of firing of the ganglion cells is increased when it is signalled by one cone and decreased (inhibited) when it is signalled by the other cone. The first colour in the name if the ganglion cell is the colour that excites it and the second is the colour that inhibits it. I.e.: A red cone would excite the red/green ganglion cell and the green cone would inhibit the red/green ganglion cell. This is an opponent process. If the rate of firing of a red/green ganglion cell is increased, the brain would know that the light was red, if the rate was decreased, the brain would know that the colour of the light was green.
Read more about this topic: Visual Perception
Famous quotes containing the words opponent and/or process:
“An avant-garde man is like an enemy inside a city he is bent on destroying, against which he rebels; for like any system of government, an established form of expression is also a form of oppression. The avant-garde man is the opponent of an existing system.”
—Eugène Ionesco (b. 1912)
“Thinking is seeing.... Every human science is based on deduction, which is a slow process of seeing by which we work up from the effect to the cause; or, in a wider sense, all poetry like every work of art proceeds from a swift vision of things.”
—Honoré De Balzac (1799–1850)