The perception of size in a distorted room

This study was concerned with determining the factors important in the size illusion occurring with respect to extraneous objects introduced into an Ames’ monocular distorted room, It was asserted that the distortion in the room was unnecessary in order for the size illusion to be present, A rectangular room plus the extraneous objects produces the same stimulus conditions found in the Ames’ room and, hence, should produce the same illusion in perceived size, In an experiment using a rectangular room, 24 Os judged the size and distance of objects at the same or different distances behind the windows. As in the case of the Ames’ room it was found that the objects of physically equal size were perceived to be in the plane of the windows with the more distant objects appearing to have the smaller size. These results are explained in terms of the action of the equidistance tendency making the objects appear at the distance of the windows and the concept that objects in the same apparent fronto-parallel plane must have equal values of perceived size per unit of retinal size.