Figure 16.5
Prior knowledge as a guide in visual perception is tested by asking subjects to search for a familiar
object in a photography of an unexceptional scene (top) and in a jumbled photograph of the scene
(bottom). Here, the task is simply to find the bicycle. It tends to take longer in the jumbled image.
The implication is that knowledge of the world (in this case, expectations about the characteristic
locationsofbicyclesinurbanlandscapes)speedsupperceptionandmakesitlesssubjecttoerror.
Certain early aspects of the information processing that underlies visual perception nonethe-
less seem to happen automatically: without the influence of prior knowledge. The illustration
was modeled after experiments done by Irving Biederman of the State University of New York at
Buffalo.
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