The Cumulative Influence of Depth and Flatness Information on the Perception of Size in Pictorial Representations

Abstract

It long has been recognized that depth and flatness information influence the perception of size in pictures. However, never has their combined influence been factorially examined and quantified. Using the Ponzo illusion as a model, three experiments, using young adult observers, explored this combined influence. Results showed that the salience of depth information and the salience of flatness information had a cumulative impact on size perception such that, for example, the combined effects of higher depth salience and lower flatness salience produced responses more closely approaching size constancy than did other combinations of depth and flatness salience. Furthermore, females' size perception more closely approached size constancy than did that of males, although this difference disappeared in conditions where depth salience was particularly low. The three experiments are discussed in terms of the interaction between depth and flatness and its implications for perceiving size in pictures, and possible implications of this interaction with gender, including the possibility that females may process depth information in a manner different from males.