Two dissociable updating processes in working memory
An updating version of a visual change detection paradigm was used to investigate the behavioral outcomes and event-related potential (ERP) correlates of visual working memory updating.In each trial, participants were either presented with a memory array followed by a test probe, or with two successive memory arrays.The participants were instructed to update their WM with the information presented in each trial and then press a key to proceed to the following trial.After a few screens, the participants were probed to recall the most recent digit set that was presented.Selective (item-specific, “local”) updating refers to the idea that each item in WM is gated separately and independently of the others.This is achieved by having multiple parallel gates to WM.
The second array differed from the first one in all, some, or none of the items.
The present study aims to examine how WM representations are affected by repetition and updating of information, and to identify the event-related potential (ERP) correlates of WM updating in the visual domain.
Computational models suggest that maintenance and updating are coordinated by a gate that buffers between perceptual representations and WM (for review see O'Reilly, 2006).
For example, Kessler and Meiran (2008) presented participants with a sequence of digit-sets.
Each set of digits was either identical to the one presented in the previous trial, or different in part or all of the items.