Panoramic search: the interaction of memory and vision in search through a familiar scene

How do observers search through familiar scenes? A novel panoramic search method is used to study the interaction of memory and vision in natural search behavior. In panoramic search, observers see part of an unchanging scene larger than their current field of view. A target object can be visible, present in the display but hidden from view, or absent. Visual search efficiency does not change after hundreds of trials through an unchanging scene (Experiment 1). Memory search, in contrast, begins inefficiently but becomes efficient with practice. Given a choice between vision and memory, observers choose vision (Experiments 2 and 3). However, if forced to use their memory on some trials, they learn to use memory on all trials, even when reliable visual information remains available (Experiment 4). The results suggest that observers make a pragmatic choice between vision and memory, with a strong bias toward visual search even for memorized stimuli.