Size effects in visual recognition memory are determined by perceived size.

Recognition memory for shapes has been shown to depend on differences between the size of shapes at the time of encoding and at the time of the memory test (Jolicoeur, 1987). Experiment 1 of the present paper replicates this effect and establishes a set of parameters used in the subsequent experiments. Experiment 2 considers the results of Experiment 1 in light of the distinction between "perceived" size, which, under normal viewing conditions, varies minimally with changes in distance between the observer and object, and "retinal" size, which varies proportionally with viewing distance as an object is moved closer to or farther from an observer. Subjects studied novel shapes and performed a recognition memory test in which the distance from the subject to the viewing screen at the time of testing was different from that at the time of encoding. The viewing distance and the size of the shapes were manipulated such that perceived and retinal sizes were dissociated. The results suggest that the size-congruency effect in memory for visual shape occurs as a result of changes in the perceived size of shapes between the encoding and the testing phases, with little or no contribution of retinal size per se.