Object property encoding and change blindness in multiple object tracking

The paradigm of multiple object tracking (MOT) is an established tool for investigating human performance under conditions of divided attention to several objects. We studied change detection ability for colour and shape information in the setting of MOT. Subjects had to detect colour and shape changes during an MOT task. These changes occurred either openly (with nothing to hide them) or with a mud splash in the background to hide the change transient signal. Our experiment demonstrated that (1) when hidden by mud splashes, we fail to perceive a considerable number of colour changes even in the attended objects (i.e., targets) and (2) the visual system is significantly more likely to miss colour and shape changes in distractors than in target. We conclude that a colour change will be detected a lot more efficiently if attention is drawn to its transient. When a simultaneous mud splash hides the transient signal, subjects are significantly less efficient in detecting the change.