There are two possible approaches to the investigation of visual processing, a bottom-up approach that begins with neurophysiology and the behavior of the single cell, and a top-down approach that begins with the subjective experience of visual consciousness. Both approaches are essential to the investigation of visual processing, for each offers a view of the visual mechanism from its own unique perspective. A perceptual modeling approach is proposed to demonstrate how the properties of visual experience can be expressed in a quantitative model independent of any neurocomputational assumptions. This approach reveals a wide gap between our understanding of neurocomputation as suggested by neurophysiology, and the properties of the subjective experience of perception.