Are Irrelevant Items Actively Deleted from Visual Working Memory?: No Evidence from Repulsion Effects in Dual-Retrocue Tasks

In addition to processes associated with maintaining, manipulating, and updating to-be-remembered information for ongoing cognition, some theories suggest that working memory (WM) also involves the active deletion of irrelevant information, including items that were retained in WM, but are no longer relevant for ongoing cognition. Considerable evidence provides support for an active deletion mechanism, particularly for categorical representations (Rose et al., 2016; Fulvio & Postle, 2020; but see Bae & Luck, 2017 for contradictory evidence with line orientations). On each trial of the current task, healthy young adults maintained two line orientations in visual WM, switched attention to maintaining and recalling the orientation cued first, and then switched to recall the item cued second, at which point the uncued orientation was no-longer-relevant on the trial. The results showed that the no-longer-relevant items exerted the strongest “repulsive” bias on participants’ recall of to-be-remembered items, directly contradicting the active deletion hypothesis. We suggest that visual WM binds features like line orientations into ensemble representations, and an irrelevant feature of a bound object cannot be actively deleted--it biases recall of the target feature via repulsion. Models of WM will need to be updated to explain this dynamic phenomenon.