So accustomed are we to reject what the eye sees in nature, so dull and dead have we become as a result of visual experience, that to appreciate the wonder and wealth of color around us we must be shown our surroundings in some novel or unusual manner—in a picture, for instance, or as they appear when we stand on our heads, or when seen inverted in the focusing screen of a camera. Indeed, so largely does experience enter into and modify our perception of objects, that many people are quite unable to accept what the eye gives them, but only what they have learned to expect it is giving them: they see only what they know. They have lost that power which artists by patient striving have recovered, and which Ruskin calls the "innocence of the eye." (p. 2)
I wonder if Cott was aware of the research of American artist and optical physiologist Adelbert Ames II (1880-1955), who also focused on the role of past experience in human perception, which he explored through a series of "laboratory set-ups," now called the Ames Demonstrations.