Abstract
Items in visual working memory (VWM) are susceptible to visual interference. As such, mechanisms exist to protect high priority representations. When an item in VWM is retroactively cued during retention, it can be shielded from perceptual interference, enhancing task performance. Classically, the literature focuses on shielding static VWM representations not currently in use. Is retro-cue shielding effective when the VWM representation needs to be actively manipulated? We employed a behavioral paradigm in which participants remembered the orientations of two colored bars appearing briefly at the start of each trial. Subsequently, a colored retro-cue identified one bar as the target. At the end of each trial, participants reported the target bar orientation from memory using a continuous report probe bar. On a subset of trials (mental rotation trials; intermixed), participants were asked to mentally manipulate the target orientation during the delay period: either one or two sequential rotation cue(s) appeared above fixation, indicating the degree and direction to mentally rotate. Critically, on some trials, a perceptual distractor (a starburst of four overlapping colored bars angled in 45 degree increments) appeared during the retention interval. On rotation trials, the distractor was shown at different points during the retention interval (before, between, or after the rotation cue(s)). Behavioral performance (average error in orientation reports) on no-rotation trials was comparable across distractor and no-distractor trials, indicating effective shielding. However, on mental rotation trials, we observed a robust distractor cost: Average error was greater on trials when the distractor appeared during a mental rotation relative to rotation trials with no distractor. As such, although a retro-cue can be effective at shielding a static mental representation from perceptual interference, our results suggest that it may not be possible to retroactively protect and effectively shield an in-use working memory item from distraction.