Tracking the unconscious: Neural evidence for the retention of unaware information in visual working memory

This study investigates the retention of visual information in visual working memory (VWM)when individuals are unaware of it, aiming to provide clear-cut evidence for an unconsciousVWM effect. To explore the underlying neural mechanisms, we monitored one criticalevent-related potential (ERP) component, i.e., the contralateral delay activity (CDA), whichreflects specifically VWM maintenance. Participants performed a change detection task in whichto-be-memorized Gabor patches were presented at a visibility threshold determined to assesssubjective awareness using the perceptual awareness scale (PAS). Participants performed abovechance level in the change detection task even when the visibility of the Gabor patches wassubthreshold, indicating retention of visual information without conscious awareness. Notably, ina subsample of participants, a reliable CDA amplitude was observed during unaware trials inwhich participants performed correctly compared to trials with incorrect responses, indexingshort active maintenance of unaware visual information in VWM that could be used to performVWM-based tasks. In conclusion, the results of our study support the existence of an activeretention of unaware visual information in VWM. These findings challenge the notion of entirelyactivity-silent working memory by showing that unconscious information is maintained throughactive neural firing (CDA), potentially transitioning to activity-silent mechanisms in later phases.