Abstract
Boundary Extension (BE), the memory distortion whereby viewers remember larger expanses of scenes than they actually saw in photographs, has been attributed to the activation of mental layout representations. However, the effect of viewer's familiarity with the actual scene has never been explored. Three possible outcomes were predicted. First, familiarity with a scene could help viewers memorize the view boundaries, reducing the distortion. In contrast, familiarity could help people build a more expansive mental representation, increasing the distortion. Third, it is possible that boundary extension is linked to low level processes affected by the photograph's spatial layout alone and is not affected by familiarity with the real world scene. In two experiments, participants from two distant colleges viewed a series of pictures (28 Experiment 1; 32 Experiment 2) that included common locations from each campus. Pictures were presented for 15s, during which participants rated their familiarity with the location depicted in the scene. Immediately after the presentation, a forced-choice memory test was administered using four distractor pictures depicting from 20% larger to 20% smaller expanses. In both experiments, participants rated pictures from their own campus as more familiar and significant boundary extension was obtained in all conditions. However, there was no interaction between familiarity and BE scores. One of the campus picture sets seemed to elicit more BE for all viewers, and so an attempt was make to equate the two picture sets in term of the types of scenes used and the layout and crowding within the scenes. With these changes, equivalent levels of BE were obtained for the pictures from both campuses, but again BE did not interact with familiarity. Overall, the results indicate that boundary extension is linked more closely to scene layout than to any familiarity the participant might have with the environment.