Retinal and assumed size cues as determinants of size and distance perception.

Abstract

Three experiments were conducted to determine the importance of the retinal image in perception of size and distance. Os. [Observers] were given 2 different types of instructions. One set of instructions (objective) emphasized judging physical size while the other set (analytic) required size judgments in terms of the retinal image. When other visual cues were eliminated, it was found that the assumed size of an object was an important determiner of its estimated size and distance under objective instructions but not under analytic instructions. When objective instructions were given, size and distance estimates were positively correlated but when analytic instructions were given no significant relationship was found between judgements of size and distance.