SENSING OF RETINAL SIZE

This study examines the interpretation that under reduced conditions of observation the perceived size of an object is the result of a direct response to retinal size. In opposition to this interpretation is the size-distance invariance hypothesis stating that a perceived size results from a retinal size only when an appropriate perceived distance is also present. Four experiments were conducted. The first two experiments indicate that in the absence of distance cues, perceived size is proportional to retinal size. The last two experiments suggest that this result is a consequence of the tendency, under reduced conditions, to perceive the objects at a common (specific) distance. The results support the size-distance invariance hypothesis and are in opposition to the direct perception of retinal size. The possible significance of the specific distance tendency is discussed for binocular as well as monocular conditions of observation. © 1969.