Is search over time functionally equivalent to search over space?
36.433, Sunday, May 12, 2:45 - 6:45 pm, Orchid Ballroom
Nicole L. Jardine1, Cathleen M. Moore1; 1Department of Psychology, University of Iowa
Most visual search experiments use static scenes, but most visual search involves scenes that change over time. We have investigated the consequences of dynamics on the ability to perform orientation search (e.g., VSS 2011). Search for a tilted bar among non-tilted bars displayed for 200 ms is highly accurate when this display is presented in isolation, but extremely difficult when the same display is part of a 3-frame movie of rotating bars (Exp. 1). A 3-frame movie has three times the number of distractors, and we know that increased target-distractor similarity in static displays can cause search inefficiency. Is search over time analogous to searching the same stimuli over space? Exp. 2a and 2b showed that when all stimuli from the dynamic display were presented in the same frame (removing temporal aspects), search was as difficult as when the stimuli were presented in the dynamic series of frames. This suggests that the representations of features from the changing scenes remain active for some time within the representation used in temporal search. Dynamic search can, however, benefit from spatial consistency and motion coherence. When the stimuli were presented over time as in the original dynamic displays, but the stimuli were repositioned in each frame, search was more difficult than with the original dynamic displays in which stimuli were in the same locations across frames (Exp. 3). And when spatial consistency was maintained but the order of frames was shuffled, performance was worse than with the original coherently changing dynamic displays (Exp. 4). Thus although dynamic search appears to be similar to search within a static ensemble that contains all of the information from across the dynamic display, dynamic search nonetheless benefits from spatial consistency and motion coherence.