Object-based perception mediates the effect of exogenous attention on temporal resolution

The effects of target distinctiveness, target placeholders, and target spatial separation on the relation between exogenous attention and temporal resolution were examined in a visual temporal order judgement (TOJ) task. When identical targets were presented at different locations within a cued or uncued placeholder, attention degraded temporal resolution (Experiment 1), but when distinct targets were presented at different locations that cueing effect disappeared (Experiment 2), and when the target placeholders were not used, attention enhanced temporal resolution for distinct targets presented at different locations (Experiment 3). Attention also degraded temporal resolution when distinct targets were presented at the same location (Experiment 4). The latter two results were then replicated in a task in which distinct targets appeared randomly at the same or different locations (Experiment 5). Clearly, the nature of the relation between exogenous attention and temporal resolution is not a straightforward one—the relative location of targets, the similarity of targets, and the presence of placeholders all qualitatively affect the cueing relation. We hypothesize a mediating role for object-related processes. Specifically, exogenous attention enhances feature binding and related object representations, which subsequently degrade temporal resolution.