Revisiting the attentional demands of rehearsal in working-memory tasks

There is a recent surge of interest in maintenance processes in working memory, such as articulatory rehearsal, elaboration, and attentional refreshing. Yet, we know little about the central attentional demand of these processes. It has been assumed that articulatory rehearsal does not require central attention at all (Vergauwe, Camos, & Barrouillet, 2014), being in essence a cost-free strategy. In contrast, elaboration and attentional refreshing are assumed to incur large and continuous costs on central attention. We tested these assumptions in three experiments in which participants were presented with a varying number of words to rehearse. Participants were instructed to rehearse the words aloud, or to elaborate them by creating interactive images. Attentional refreshing was examined in a condition in which words were to be maintained during articulatory suppression. During retention participants carried out a series of choice reaction tasks, which were used to measure central attentional demands of the maintenance strategies. Articulatory rehearsal had costs on processing RTs that lasted for 10 s. Maintenance of words during articulatory suppression did not yield persistent costs on central attention, implying that participants did not continuously refresh the words. Finally, the current results cast doubt on the idea that elaboration requires central attention for an extended period of time. All experimental scripts and data sets reported here are available online (https://osf.io/69p8j/).