Neural Correlates of Unconscious Visual Stimuli in Working Memory: EEG Evidence from a Binocular Rivalry Paradigm

Within consciousness research, great effort has been devoted to identifying the neural correlates of visual awareness, defined as the “minimum neural mechanisms jointly sufficient for any one conscious experience” (Koch et al., 2016). More recently, with the advent of no-report paradigms (Tsuchiya et al., 2015), researchers have begun to disentangle neural processes related to visual phenomenology from those underlying cognitive operations required to report the experience, such as attention, decision making, and visual working memory (VWM). While a large body of evidence points to a dissociation between attention and consciousness (Tsuchiya & Koch, 2007; Nani et al., 2019), the relationship between consciousness and visual working memory remains unclear (Velichkovsky, 2017), although previous findings suggests that VWM can operate even on unconscious stimuli (Gambarota et al., 2022). The study presented in this thesis aim to investigate the relationship between these two processes using binocular rivalry to induce alternations in the contents of (visual) consciousness while tracking the Contralateral Delay Activity (CDA), an ERP marker of VWM processing (Luria et al., 2016). The results suggest that a CDA component recorded approximately 600 ms before the participant’s response may guide the process of report. Moreover, prior findings suggest that the CDA can be recorded even when the stored representation is unconscious (Gambarota et al., 2025), indicating that the CDA may index representational availability for report regardless of subjective visibility. Taken together, these results suggest a dissociation between VWM and consciousness, consistent with theoretical frameworks that separate cognition from conscious experience (Block, 1995, 2011; Huan & Tononi, 2025).