Abstract
Updating memorized information is important for cognition, for example when mentally resorting a list. Is this process object-specific in visual short-term memory (VSTM)? Kessler and Meiran (2006, JEP:HPP, 32(3):570–585) suggested that updating an element in verbal short-term memory refreshes all elements in memory. The current study investigated whether this finding could be replicated in VSTM. If updating the memory of one object refreshes all of VSTM, performance across conditions with the same number of updates should be equal, regardless of how updates are distributed across objects. Conversely, if updating objects in VSTM requires attention that would otherwise be allocated to the maintenance of non-updated objects, performance should be better when updates are distributed equally across all objects, compared to when they are restricted to one. Participants (n=14) memorized colors and locations of three briefly presented dots. Participants then either maintained this information, or updated VSTM to match recurrences of the dots. During recurrences, one dot briefly re-appeared at its original location in a new color. Each dot recurred either zero, one, two or three times. At test, all dots were presented in their most recent colors either at the correct locations, or with the locations of two dots swapped. Participants reported whether or not the test matched their updated memory representation. Accuracy did not differ with the number of recurring objects when the number of total recurrences per trial was equal (e.g., one object with three recurrences versus three objects with one recurrence each). Results are consistent with the theory that all information in VSTM is refreshed when a subset is updated. These preliminary findings suggest that the process of updating objects in VSTM operates under similar principles as in verbal STM. This provides an initial step in understanding updating processes in multi-element VSTM.