Gaze coherence reveals distinct tracking strategies in multiple object and multiple identity tracking

In dynamic environments, a central task of the attentional system is to keep track of objects changing their spatial location over time. In some instances, it is sufficient to track only the spatial locations of moving objects (i.e., multiple object tracking; MOT). In other instances, however, it is also important to maintain distinct identities of moving objects (i.e., multiple identity tracking; MIT). Despite previous research, it is not clear whether MOT and MIT performance emerge from the same tracking mechanism. In the present report, we study gaze coherence (i.e., the extent to which participants repeat their gaze behaviour when tracking the same object locations twice) across repeated MOT and MIT trials. We observed more substantial gaze coherence in repeated MOT trials compared to the repeated MIT trials or mixed MOT-MIT trial pairs. A subsequent simulation study suggests that MOT is based more on a grouping mechanism than MIT, whereas MIT is based more on a target-jumping mechanism than MOT. It thus appears unlikely that MOT and MIT emerge from the same basic tracking mechanism.

Automated summary

In dynamic environments, the attentional system is responsible for tracking objects' changing spatial location over time. This study found that there was greater coherence in gaze behavior in repeated multiple object tracking (MOT) trials compared to repeated multiple identity tracking (MIT) trials or mixed MOT-MIT trial pairs. A simulation study also suggested that MOT is based more on a grouping mechanism, while MIT is based more on a target-jumping mechanism. These findings suggest that MOT and MIT may not emerge from the same basic tracking mechanism.