unconscious inference theory
the hypothesis that perception is indirectly influenced by inferences about current sensory input that make use of the perceiver’s knowledge of the world and prior experience with similar input. For example, consider two trees of the same height but different distances from the perceiver. The images of the trees that appear on the retina are of different sizes, but the knowledge that one tree is farther away than the other leads the perceiver to infer, without conscious effort, that in actuality the two trees are the same size. [proposed by Hermann von Helmholtz]