Haladjian, Harry Haroutioun. Object-specific priming benefit enhanced during explicit multiple object tracking. Retrieved from https://doi.org/doi:10.7282/T34X5853
DescriptionThe referential link between an external object and its corresponding mental representation has yet to be clearly defined. Visual indexes are primitive mechanisms that act as pointers to objects in a visual scene and can be linked to descriptive mental representations. These representations, or "object files", have been demonstrated by object-specific preview benefits (OSPB), where a priming effect for object identity travels with the object in which information initially appeared. The present study explores OPSB effects during Multiple Object Tracking (MOT) to investigate the formation of object representations in a dynamic environment. All experiments reported used the MOT framework, where four identical circles moved unpredictably and independently on a computer screen. In Experiment 1, either one or two preview letters appeared briefly inside the circles during movement. At the end of the trial, one test letter appeared inside a circle and observers indicated whether or not the test letter matched any of the preview letters. Inter-stimulus intervals (ISI) between the preview and test letters varied at one, two, and four seconds (no tracking was required). Reaction times in the "same-object/same-letter" condition showed significant OSPB effects in both single and dual preview versions, but only during the one-second ISI. This suggests an automatic construction of object files that decay over time. To explore OSPB effects when attention is deployed during tracking, Experiment 2 required observers to track and identify the two objects that displayed preview letters prior to object movement (creating constant four-second ISIs). There was no OSPB effect in the non-tracking condition, which replicated the four-second ISI results in Experiment 1, but there was a significant OSPB effect in the explicit tracking condition. Experiment 3 further tested this effect by using novel symbols from an ancient alphabet (otherwise, the design was identical to Experiment 2). Again, a significant OSPB effect was observed only in the tracking condition. Taken together, these results suggest that feature binding to indexes occurs automatically, but attention is required to extend the persistence of these object representations. Such findings can inform models of referential links between external objects and mental representations.