Global Neuronal Workspace (GNW)

This theory effectively is a biologically-plausible computational model for human consciousness. It conjectures that signals flow from several perceptual, memory, and attentional regions to a central broadcast medium where certain signals cause a cascade that enters conscious awareness.

Integrated Information Theory (IIT)

Also considering the nature by which brain regions are coordinated, the IIT model proposes that there exists a multivariate information measure that generalizes Shannon’s mutual information which captures the interactivity among various brain regions and therefore measures consciousness. There are many candidate information measures.

See Lav's paper which asks "whether these two theories are in fact two sides of the same coin" -- Towards Information-Theoretic Limits of the Global Neuronal Workspace Architecture


I believe that work studying individuals coming out of anesthesia is a very intriguing means for understanding quantitatively when consciousness comes about. By analyzing the brain during the transition into an unconscious state, these quantitative measures may be elucidated.