Understanding Vision

Vision can be thought of in two fundamentally different ways: 1) that what we see is determined by visual system circuitry evolved to detect and represent object features and conditions in the physical world; or 2) that what we see is determined empirically by neural associations based on the relative success of trial and error behavior accumulated over evolutionary and individual time. The evidence reviewed here is indicates that the qualities we perceive are based on the frequency of occurrence of stimuli. How and why this empirical scheme underlies vision is discussed.