Complex naturalistic stimuli are prioritized by attention when maintained in visual working memory

Recent studies suggest that a stimulus actively maintained in working memory (WM) automatically captures visual attention when subsequently perceived. Such a WM-guidance effect has been consistently observed for stimuli defined by simple features, such as colour or orientation, but studies using more complex stimuli provide inconclusive results. Therefore, we investigated whether the WM-guidance effect occurs also for naturalistic stimuli, whose identity is defined by multiple features and relations among them, specifically for faces and houses. The experiment consisted of multiple blocks in which participants (N = 28) either memorized or merely saw (WM or exposure condition, respectively) a template stimulus and then performed several dot-probe trials, with pairs of stimuli (template and control) presented laterally as distractors and followed by a target-asterisk. Evidence for attentional prioritization of the memorized stimuli was found in the reaction-times (RT) analysis, but not in the analysis of the N2pc ERP component, which raises questions concerning the attentional mechanism involved. Further, in an exploratory ERP analysis we found evidence for a very early (100-200 ms post-stimulus) prioritization specific to the memorized faces, which is in line with the sensory recruitment theory of WM.