Abstract
Lowering observer's view-height may result in an increase of overlaps among objects in the visual field, making it difficult to identify those objects. Based on this possibility, this study presented an array of colored squares constructed according to its expected view from different heights, and examined visual short-term memory (VSTM) performance for those squares. In Experiment 1, the array was presented on the floor of a grid-patterned background providing a view of linear perspective. The size of each stimulus in the array was adjusted with respect to depth position of each square on the floor. In the three view-height conditions (high, middle, and low), lines of the background grids were arranged according to the view of linear perspective expected from each different view-height. Participants were asked to remember both colors and positions of the squares, and performed change detection of both features in two setsize conditions (3 vs. 6 items). We found an evident drop of change detection performance when the view-height condition was lowest in the setsize 6 condition. In Experiment 2, we ran the same change detection task with the same view-height manipulation as Experiment 1 except that the setsize was fixed to 6 items, and that the background grids were manipulated to be present or removed. While the removal of background did not influence change detection performance, overall performance dropped as the view-height became lower. The results demonstrate that lowering view-height of an observer can increase the amount of overlaps across objects in the visual field, and sensory interference arising from the increased overlaps can impair VSTM performance for the objects.