Working memory may operate on unconscious perceptual contents, though it remains linked to conscious perception. A large, multisite replication (19 labs, 531 participants, 720 trials) of Soto et al. (2011) found above-chance accuracy (.55) on a visual discrimination task when participants reported not seeing the subliminal Gabor grating. Performance correlated positively with cue detection sensitivity (r = .228), and the regression intercept was significantly above chance (β₀ = .521). The study provides an open-access dataset and confirms that measures were reliable and valid, supporting the existence of unconscious working memory.
Noradrenergic activity plays a key role in conscious visuospatial processing, distinct from general arousal effects. Two experiments—one using the sedative Dexmedetomidine (which targets α2A noradrenergic receptors) and another using sleep deprivation—both selectively altered brain activity (fMRI BOLD signal) during conscious processing, unlike the sedative Propofol, which affects both conscious and unconscious processing. However, the two methods produced opposite effects on visuospatial bias: Dexmedetomidine reduced leftward bias, while sleep deprivation increased leftward bias. The sleep deprivation effect was linked to an unexpected increase in sympathetic drive, indicated by heightened central autonomic network activity and heart rate, suggesting increased noradrenaline levels during task performance. These findings highlight noradrenergic activity as a target for studying consciousness.