Preserving food, less fighting for food, less roaming to hunt and gather. More stable sense of community. More children. Preserving food, less fighting for food, less roaming to hunt and gather. More stable sense of community. More children.
Contrast sensitivity is the ability of an imaging process to produce an image of objects or tissues in the body that have relatively small physical differences or inherent contrast. The contrast that is to be imaged is in the form of some specific physical characteristic.
With this perception phenomenon, the color with the strongest contrast, the complementary color, is created (by the brain) at the edge. Because the color and its complement are perceived simultaneously, the effect is known as simultaneous contrast.