Does sensory recruitment support guidance of attention by visual working memory?

Visual working memory (VWM) maintains visual information to support ongoing cognitive processes. This core function requires that VWM resist perceptual interference from intervening sensory events, such as scene or gaze changes. On the other hand, many theories of attention hold that VWM representations interact dynamically with sensory processing to boost the salience of matching items. These two, potentially conflicting, demands could be reconciled if VWM content can be maintained across different brain regions and at different levels of abstraction: Higher-level representations in extra-sensory regions may maintain stable representations, whereas sensory-level representations interact with new perceptual processing. Here, we tested whether sensory recruitment plays a functional role in the guidance of attention. First, we tested whether sensory activation alone is sufficient to guide attention. Participants were exposed to a color before viewing a search array in which either the target (valid) or a distractor (invalid) matched that color. The color was not predictive of the target, and there was no demand to remember it. We observed no evidence of attention guidance from the exposed color (i.e., no validity effect), even at color-array SOAs in the range of iconic persistence, indicating that sensory activation alone is insufficient for attention guidance. We further tested whether VWM-based sensory recruitment is necessary for attention guidance. The basic task was modified so that participants were required to remember the color. In addition, a multi-color mask was or was not presented at variable times during the interval between the color and search array. Robust attention guidance was observed. Critically, the magnitude of attention guidance was unaffected by perceptual masking. The results do not support the hypothesis that VWM-based guidance effects have a specific sensory locus, which is potentially consistent with the claim that sensory recruitment plays a minimal role in functions attributed to VWM.