I focus only when I see your fear—fearful faces are not prioritized by attention when processed outside of awareness

Abstract The defensive reaction to threats consists of two components: non-specific physiological arousal and specific attentional prioritization of the threatening stimulus, both of which are assumed by the so-called “low-road” hypothesis to be induced automatically and unconsciously. Although ample evidence indicates that non-specific arousal can indeed be caused by unconscious threatening stimuli, data regarding the involvement of the attentional selection mechanism remain inconclusive. Therefore, in the present study we used ERPs to compare the potential engagement of attention in the perception of subliminal and supraliminal fearful facial expressions to that of neutral ones. In the conscious condition, fearful faces were preferentially encoded (as indicated by the N170 component) and prioritized by bottom-up (EPN) and spatial attention (N2pc) in an automatic, task-independent manner. Furthermore, consciously perceived fearful expressions engaged cognitive resources (SPCN, P3) when face stimuli were task-relevant. In the unconscious condition, fearful faces were still preferentially encoded (N170), but we found no evidence for any type of attentional prioritization. Therefore, by showing that threatening stimuli engage attention only when perceived consciously, our findings challenge the “low road” hypothesis and point to the limits of unconscious attentional selection.