Signal processing in the mammalian retina.

Visual information contains many different elements, such as contrast, color, brightness, and movement. Each element is extracted from visual information in a specialized neural circuit of the retina. Finally, the extracted signals are reconstructed into coded signals at the retinal ganglion cells and sent to the higher visual center in parallel for further processing. Each specialized neural circuit has both ON- and OFF-pathways, and the signal processing in the ON-pathway is a mirror image of that in the OFF-pathway. This review focuses on the dichotomy of neural circuits in the mammalian retina.