Abstract
The object file framework of Kahneman et al. (1992) holds that representations of an object's properties (e.g., visual form or identity) are indexed to a spatial location, which is updated with changes in object position. The primary evidence supporting these claims came from position-specific priming effects in letter naming. The timecourse of priming, the maintenance of object-file representations across saccades, and position effects in visual short-term memory (VSTM) raise the possibility that object-file representations and VSTM object representations might be one and the same. However, traditional object-file experiments did not require memory to perform the task and thus cannot speak to this possibility. In the present study, we examined the updating of object-position binding in a change-detection paradigm that required VSTM. Participants saw a set of empty boxes. The boxes were filled by objects (either color patches or real-world objects). The objects were removed, and the boxes moved to trade positions (yielding the same spatial configuration before and after movement). The objects reappeared, and memory was tested by change detection. At test, the objects either appeared in the updated positions, in their original positions, or in positions corresponding to neither of these (no correspondence). Change detection was faster and more accurate in the updated-positions condition than in the no-correspondence condition, providing initial evidence that object files and VSTM are indeed the same system. Intriguingly, performance in the original-positions condition was also superior to that in the no-correspondence condition, suggesting multiple position-bound representations per object or severe capacity limits on updating.