Students working on an experiment with rats tend to see the following figure as that of a rat, while physicians working on a geriatric ward tend to see the figure as that of an old man with glasses. Primarily what does this difference in perception demonstrate?

A) gestalt principles of organization
B) perceptual constancies
C) bottom-up processing
D) top-down processing

The difference in perception between students and physicians working on different tasks highlights the role of top-down processing in shaping perception. Top-down processing refers to the influence of higher level knowledge, expectations, and context on perception. In this case, the physicians' experience and knowledge about aging and eyeglasses lead them to interpret the visual stimuli as an old man with glasses, whereas the students' focus on rats lead them to see the same stimuli as a rat.