In the Ponzo illusion, cues to size and distance conflict. The fact that an illusion of size is created suggests that:
A) monocular depth cues cannot operate correctly with conflicting cues to size
B) the cues to distance are more accurate here than the cues to size
C) perceived size is computed from perceived distance
D) perceived distance is computed from perceived size

Question

Quizplus · Accepted Answer

The fact that the illusion of size is created suggests that perceived size is computed from perceived distance. In the Ponzo illusion, the converging lines suggest that the top horizontal line is farther away than the bottom one, which creates a perceptual illusion of size. This illusion shows that perceived size is influenced by perceived distance, and that our visual system uses depth cues to compute size perception.

In the Ponzo Illusion, Cues to Size and Distance Conflict