Working memory and conscious perception are often thought to rely on the same brain mechanisms, but recent evidence suggests non-conscious working memory exists. Using visual masking and magnetoencephalography in a spatial delayed-response task, participants reported the location of a subjectively unseen target above chance after a long delay. Conscious perception and conscious working memory showed sustained alpha/beta desynchronization over frontal cortex and decodable target location in posterior sensors. During non-conscious working memory, these signals vanished, contradicting models equating working memory with sustained neural firing. The findings support 'activity-silent' working memory, where slowly decaying synaptic changes allow cell assemblies to go dormant during the delay yet be retrieved above chance after seconds.
The scope of unconscious processing remains hotly debated, driven by diverse methods for manipulating and measuring perceptual awareness. Through dialogue among researchers with varied theoretical backgrounds, ten recommendations and nine outstanding issues are provided for designing experimental paradigms, analyzing data, and reporting results. These guidelines aim to evoke discussion about norms in studying unconscious processes and help researchers make informed decisions. While some recommendations may not align with existing approaches and will likely evolve, they are intended to foster a more convergent understanding of the extent and limits of unconscious processing.