Effects of stimulus duration and spatial distance on serial dependence

Serial dependence is such a phenomenon that the current processes of human brain, such as perception, decisions, and memory, are systematically biased by the recent past. While serial dependence effects have been extensively found, the roles of stimulus duration and spatial distance in serial dependence remain unclear. Here, we investigated how spatiotemporal factors jointly influenced serial dependence effects by manipulating stimulus durations and spatial locations in three independent experiments, in which participants were required to report perceived orientations of grating stimuli via an adjustment task. When the grating stimuli were presented at the center, increasing stimulus durations weakened serial dependence effects (Experiments 1A and 1B). Furthermore, when introducing spatial distance, in Experiment 2 we found that shorter durations induced serial dependence only in close spatial proximity while longer durations yielded serial dependence effects across a broader spatial field. These results reveal that serial dependence dynamically integrates temporal and spatial information under varying environmental demands.