Doctor of Philosophy (PhD)



Document Type



The ability to track multiple moving objects (e.g. cars on a roadway, players and/or balls in a sporting event, pedestrians in a crowded space) has been thought to be a parallel process, such that all the objects are tracked simultaneously (Howe et al., 2010). Others have asserted that some serial mechanism is involved in the tracking process, suggesting that there are shifts of attention from object to object in order to successfully track (Oksama & Hyönä, 2008). Subsequent research has demonstrated that changes in trajectory can attract attention (Howard & Holcombe, 2010) and that these localized changes in trajectory negatively affect tracking ability (Ericson & Beck, 2013). However, research has demonstrated that large global scene changes do not have an effect on tracking accuracy (Liu et al., 2005). Therefore, the current research investigated the attentional mechanisms that are used in object tracking. Specifically, this study investigated differences between global and localized changes in trajectory (Experiment 1), determined how long it takes temporally for shifts of attention to occur (Experiment 2), and investigated how parallel and serial mechanisms function together as a cohesive process (Experiment 3). Results from this study indicated that a parallel processing system for multiple object tracking is utilized. However, when two targets sequentially change trajectory abruptly within a specific temporal window tracking accuracy is reduced. This finding suggests that although tracking is primarily parallel, some attentional resources may be devoted or serially transferred towards specific target items. A hybrid resource model that uses both parallel and serial mechanism is discussed.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Beck, Melissa



Included in

Psychology Commons