Tracking attentional states: Assessing the relationship between sustained and selective focused attention in visual working memory.

Attention has multiple influences on visual working memory (VWM). Fluctuations in sustained attention predict VWM performance. Furthermore, focusing selective attention in VWM by retro-cuing the to-be-tested item during maintenance boosts retrieval. So far, we lack knowledge how the ability to focus selective attention relates to the state of sustained attention during the VWM trial. Here, we combined a retro-cue task and a self-rated attention protocol to test whether focusing selective attention via retro-cues: (1) mitigates spontaneous attention fluctuations, in which case retro-cues should be more helpful under low levels of self-rated attention; (2) depends on an optimal state of sustained attention, in which case retro-cue benefits should be largest under high levels of self-rated attention; or (3) is independent of sustained attention, in which case retro-cue benefits and self-rated attention effects should be additive. Our data supported the additive hypothesis. Across four experiments, self-rated attention levels predicted continuous reproduction of colors. Retro-cue trials produced better recall and higher rated attention. Critically, retro-cues improved recall to a similar extent across all levels of self-rated attention. This indicates that attention has multi-faceted and independent contributions to VWM.