How does color vision opponency arise physiologically?

How does color vision opponency arise physiologically?

• A. Color vision opponency arises from color vision being coded only by cones and not by opponent channels
• B. On-center/off-surround ganglion cells feed into red-green and blue-yellow opponent channels; cones feed into bipolar and ganglion cells building opposition
• C. Rods drive color opponency
• D. The retina uses a single channel for color perception

Answer: (B)

Color opponency comes from retinal circuits that convert raw cone signals into opposing hue channels. The retina uses center-surround ganglion cells to compare inputs from different cones, creating antagonistic signals that form red-green and blue-yellow channels. The red-green channel mainly arises from differences between L- and M-cone input carried through the midget pathway to retinal ganglion cells, so one signal excites the channel while the other inhibits it. The blue-yellow channel comes from S-cone input opposing the summed input from L and M cones via the small pathways that relay through distinct ganglion cells. This arrangement means a given retinal ganglion cell responds strongly to a hue (red or blue) and is inhibited by its opponent (green or yellow), laying the groundwork for color perception. Rods contribute to luminance, not color opponency, and the retina uses multiple color-opponent channels rather than a single color channel.

Color opponency comes from retinal circuits that convert raw cone signals into opposing hue channels. The retina uses center-surround ganglion cells to compare inputs from different cones, creating antagonistic signals that form red-green and blue-yellow channels. The red-green channel mainly arises from differences between L- and M-cone input carried through the midget pathway to retinal ganglion cells, so one signal excites the channel while the other inhibits it. The blue-yellow channel comes from S-cone input opposing the summed input from L and M cones via the small pathways that relay through distinct ganglion cells. This arrangement means a given retinal ganglion cell responds strongly to a hue (red or blue) and is inhibited by its opponent (green or yellow), laying the groundwork for color perception. Rods contribute to luminance, not color opponency, and the retina uses multiple color-opponent channels rather than a single color channel.