The role of motion in visual working memory for dynamic stimuli: More lagged but more precise representations of moving objects

While most visual working memory studies use static stimuli with unchanging features, objects in the real world are often dynamic, introducing significant differences in the surface feature information hitting the retina from the same object over time (e.g., changes in orientation, lighting, shadows). Previous research on dynamic stimuli has shown that change detection is improved if objects obey rules of physical motion, but it is unclear how memory for visual features interacts with object motion. In the current study, we investigated whether object motion facilitates greater temporal integration of continuously changing surface feature information. In a series of experiments, participants were asked to report the final color of continuously changing colored dots that were either moving or stationary on the screen. We found that the reported colors “lagged behind” the physical states of the dots when they were in motion. We also observed that the precision of memory responses was significantly higher for stimuli in the moving condition compared to the stationary condition. Together, these findings suggest that memory representation is improved – but lagged – for moving objects, consistent with the idea that object motion may facilitate integration of object information over longer intervals.