Abstract
Scene images are complex arrangements of multiple items, yet we can have memory for them. However, not all scene images can be remembered with equal performance; it is possible to have outstanding memory for some scenes, but poor for others. This characteristic is called memorability. This study examined the hypothesis that scenes with high memorability are more salient, thus attracting attention more quickly and difficult to disengage, resulting in the scene being remembered. To investigate this, we conducted a visual search task using the search asymmetry paradigm with natural scenes as the search item. Search asymmetry is the dramatic change in search efficiency when the roles of target and distractor are interchanged, and can be explained by the difference in the speed of disengaging from distractors. In Experiment 1, participants searched for a scene that was instructed every trial. There were two conditions: one in which the high memorability scene was among various low memorability scenes, and vice versa. The result showed that a high memorability scene among low memorability scenes could be found more efficiently than vice versa, suggesting that search asymmetry was observed. In Experiment 2, scene color was removed and gray scale images were presented, but we replicated the results of Experiment 1. To exclude the possibility that the high memorability scenes were found earlier because participants easily learned them when they were the target, in Experiment 3, the number of times that each scene was presented as a target increased and participants could train the low memorability scenes as well as the high memorability scenes. The results again showed the search asymmetry as Experiments 1 and 2. These results suggest that attention was less likely to disengage from high memorability scenes when searching for low memorability scenes, resulting in less search efficiency for low memorability targets.