Spatial and feature-based suppression in working memory

Working memory (WM) can guide attention towards items similar to its content, both based on features and locations maintained in WM. So far, however, this has only been demonstrated with memory items that are relevant and thus maintained with a positive weight. The finding that negative attention templates can support the suppression of upcoming distractors raises the question whether items can also be stored with a negative priority in WM. We let participants memorize the exact hue of a memory target that was presented among not-to-be-encoded memory distractors. Before their WM was probed, they performed a visual search task in which they had to find a target among distractors. When the search target was presented in the same color as an item suppressed from WM, response times (RTs) were longer than for a target presented in the same color as the memory target. Similarly, when the search target was presented at the same location as an items suppressed from WM, RTs were longer than for a target presented at the same location as the memory target. Our results suggest that items can be maintained in WM with a negative priority and then support the suppression of subsequent similar stimuli. Such items with negative priority in WM may be what constitutes negative attentional templates.