Unit of attentional refreshing in multiple identity tracking: Object and Boolean map

Abstract

Abstract Tracking multiple distinct moving objects requires periodically refreshing the objects’ identity-location bindings. Classic theories assume that individual object is the unit of refreshing. Considering that features and locations can be represented as Boolean maps, in the present study we investigated whether Boolean map can also serve as the unit of refreshing in multiple identity tracking (MIT). We used an adapted MIT paradigm, in which every two targets shared the same identity and thus could be represented in one Boolean map. A cue was used to guide the refreshing when tracking was about to end. We examined whether only the cued target was refreshed (i.e., object-based refreshing) or the other target sharing the same identity was also refreshed (i.e., Boolean-map-based refreshing). In Experiment 1, all objects moved randomly. The results showed that while the cued target showed significantly better performance than uncued targets, no significant advantage was observed for the other same-identity target relative to other targets, revealing no Boolean-map-based refreshing. In Experiment 2, same-identity targets moved along parallel trajectories, so that the spatial relationship within each Boolean map remain unchanged during motion. The results showed that the same-identity target, as well as the cued target, was tracked better than other targets, revealing a same-Boolean-map advantage. Taken together, the results indicate that Boolean map can be used as the unit for attentional refreshing in MIT, but only in the circumstance where spatial relationship within each Boolean map remain unchanged as objects move, otherwise the refreshing is based on individual object.