Abstract
The Global Neuronal Workspace (GNW) theory (Baars, 1988; Dehaene et al., 1998) proposes that information must be broadcast across widely distributed networks to enter conscious awareness. But what exactly is the information that is exchanged? I will argue that the GNW provides the substrate for the spread of selection signals and use this perspective to refine the distinction between access and phenomenal consciousness.
Access consciousness corresponds to the information currently circulating within the GNW. In perception, this is the information selected by object-based attention, enabling a degree of representational flexibility that would otherwise not be attainable. In thought, access consciousness corresponds to the attended content of working memory, i.e. the items that can be actively transformed, combined, or used to retrieve associations. Phenomenal consciousness, by contrast, refers to the set of representations that are not yet part of the GNW, but that could be attended next because they are captured by the senses or because they are in an unattended memory form.
I will illustrate these ideas in perception and memory. Perceptual experiments address the construction of coherent object representations through the spread of object-based attention, which at a neuronal level, corresponds to the spread of enhanced activity. In these studies, access consciousness aligns with object-based attention, and the GNW acts as the scaffold that allows selection signals to label all features of a perceptual object. This binding mechanism is incremental, time-consuming and explains why we consciously perceive unified, multi-feature objects.
When considering memory, I will contrast iconic memory, supported by transient activity in early visual cortex, to working memory representations in higher areas that are maintained by persistent firing. Items in access awareness are attended within working memory and show stronger and more stable activity than non-attended items. I will show how the spread of selection signals among attended working memory items through the GNW supports conscious cognitive functions, such as resolving pronouns during reading and the retrieval of associations between concepts.
Together, these findings suggest a revised view of the relationship between attention and consciousness, positioning the GNW as the orchestrator of distributed neuronal representations through the spread of attentional selection signals.
