Momentary, Offset-Triggered Dual-Task Interference in Visual Working Memory

There are conflicting views on whether the storage of visual working memory (VWM) involves active maintenance mechanism. If so, it should suffer from secondary tasks that tap into the same mechanisms during the delay. We found that when observers were asked to remember a visual pattern, the interference from a secondary task was only momentary. This suggests that active attentional processing may serves the initial consolidation, rather than maintenance, of information during the delay period. In three experiments, observers remembered a visual grating while having to perform an intervening change detection task on sets of letters presented at various intervals from the to-be-memorized pattern. The secondary task affected memory on the first task, but only for a limited time window post stimulus offset. We furthermore show that this temporary interference is locked to the offset rather than the onset of the to-be-memorized pattern, suggesting that attention may be transiently recruited for consolidation on a just-in-time basis.