Doradzinska, L. | Search bioRxiv

bioRxiv2020

Complex naturalistic stimuli capture attention automatically when maintained in 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.

neuroscience↗

bioRxiv2020

The self-face automatically captures attention without consciousness

It is well established that stimuli representing or associated with ourselves, like our own name or an image of our own face, benefit from preferential processing. However, two key questions concerning the self-prioritization mechanism remain to be addressed. First, does it operate in an automatic manner during the early processing, or rather in a more controlled fashion at later processing stages? Second, is it specific to the self-related stimuli, or can it be activated also by other stimuli that are familiar or salient? We conducted a dot-probe experiment to investigate the mechanism behind attentional prioritization of the selfface image and to tackle both questions. The former, by employing a backwards masking procedure to isolate the early and preconscious processing stages. The latter, by investigating whether a face that becomes visually familiar due to repeated presentations is able to capture attention in a similar manner as the self-face. Analysis of the N2pc ERP component revealed that the self-face image automatically captures attention, both when processed consciously and unconsciously. In contrast, the visually familiar face did not attract attention, neither in the conscious, nor in the unconscious condition. We conclude that the selfprioritization mechanism is early and automatic, and is not triggered by a mere visual familiarity. More generally, our results provide further evidence for efficient unconscious processing of faces, and for a dissociation between attention and consciousness.

neuroscience↗