>>11620589In the past ten years, such demonstrations of subliminal perception have been replicated hundreds of times—not just for written words but also for faces, pictures, and drawings. They led to the conclusion that what we experience as a conscious visual scene is a highly processed image, quite different from the raw input that we receive from the eyes. We never see the world as our retina sees it. In fact, it would be a pretty horrible sight: a highly distorted set of light and dark pixels, blown up toward the center of the retina, masked by blood vessels, with a massive hole at the location of the “blind spot” where cables leave for the brain; the image would constantly blur and change as our gaze moved around. What we see, instead, is a three-dimensional scene, corrected for retinal defects, mended at the blind spot, stabilized for our eye and head movements, and massively reinterpreted based on our previous experience of similar visual scenes. All these operations unfold unconsciously —although many of them are so complicated that they resist computer modeling. For instance, our visual system detects the presence of shadows in the image and removes them (figure 10). At a glance, our brain unconsciously infers the sources of lights and deduces the shape, opacity, reflectance, and luminance of the objects.
Whenever we open our eyes, a massively parallel operation takes place in our visual cortex—but we are unaware of it. Uninformed of the inner workings of our vision, we believe that the brain works hard only when we feel that we are working hard—for instance, when we’re doing math or playing chess. We have no idea how hard it is also working behind the scenes to create this simple impression of a seamless visual world."
