Anticipated Relevance Prepares Visual Processing for Efficient Memory-Guided Selection

Finding an object typically involves the use of working memory to prioritize relevant visual information at the right time. For example, successfully detecting a highway exit sign is useless when your announced exit is still ten minutes away, but becomes relevant with only thirty seconds to go. Using EEG, we investigated how predictable changes in stimulus relevance influence top-down (i.e., memory-guided) visual selection. Participants memorized an oriented grating, followed by a cue indicating which of two sequentially presented probes was relevant for a memory-match/-mismatch judgment. Consistent with earlier work, relevant probes evoked stronger univariate responses than irrelevant probes. Furthermore, multivariate responses to (memory-matching and memory-mismatching) probes were more distinct when they were relevant compared to irrelevant. Crucially, using rapid invisible frequency tagging (RIFT), we found that early visual responses to the (empty) probe location were enhanced even before the presentation of relevant (compared to irrelevant) probes. These results demonstrate that predictable changes in stimulus relevance induce both pro-active and re-active changes in visual processing. We conclude that anticipating the (ir)relevance of upcoming visual events enables the visual system to prepare ahead of time, enabling efficient memory-guided visual selection.