Attention and the representation of serial order in verbal working memory

A recent study by Guitard et al. (2021) suggests that representation of serial order in verbal working memory may require greater attentional control than representation of item information. The present study examined this hypothesis by manipulating attentional load in a WM task via a dual-task paradigm. Participants conducted item and serial order short-term probe recognition tasks while also performing a sound detection task with two levels of attentional load. In the first two experiments, we observed a similar impact of secondary task attentional load on item and serial order WM performance. When using in a further experiment an immediate serial recall task challenging item memory to a higher extent, we observed an enhanced impact of attentional load on item memory as opposed to order memory. In a final experiment, we increased the difficulty of the serial order condition in a probe recognition task, but item memory remained more impacted by secondary task attentional load, either during encoding, or during an additional retention phase. Our results rule out increased attentional demands as a fundamental property of encoding and maintaining serial order information in WM.