Abstract
Whereas memory obviously affects preference, how precisely is yet unknown. Shimojo et al. (VSS '07) reported a segregation of the two principles, novelty and familiarity, across object categories: familiarity preference for faces and novelty preference for natural scenes. However, the results are partly inconsistent with the “mere exposure” effect (Zajonc, '68), i.e., repeated exposure to a visual object, regardless of the object category, leads to an increase in preference. The inconsistency may be partly due to what exact task was repeatedly performed during the experience phase: preference decision, selection of any kind, or mere exposure. To address this issue in relation to object category, we conducted the same two-alternative force-choice preference judgment as Shimojo et al. (VSS '07) in which the same old stimulus was presented always with a new stimulus following either kinds of experience phases: passively viewing all the paired pictures, or performing an objective judgment on the paired stimuli (on roundness of face, color temperature of natural scene, or complexity of geometric figure). The results showed that after passive viewing the old stimulus was preferred significantly more frequently in faces, i.e., mere exposure effect, but not in natural scenes or geometric figures. In the objective judgment task during the experience phase, the novel stimulus was chosen significantly more frequently in both geometric figures and natural scenes, but not in faces, even though the old stimulus was the median in pre-rating of color temperature or complexity. It possibly indicates a habituation at the selection level for certain object categories. The overall results further confirm the segregation of novelty and familiarity principles across object categories, indicate uniqueness of face as a special kind of stimulus, and suggest that different tasks lead to memory effects at different levels such as perception and selection.