Figure 8.

Principles of the NOW Model in theories of consciousness. The NOW Model provides a framework for comparing theories of consciousness. Purple denotes the primary mechanism by which consciousness is characterized in each theory. (A) The HOT theory describes consciousness as the awareness of mental states. The HOT theory places consciousness primarily in the self-reflection between first-order mental states and higher-order thoughts (purple arrows). Reentrant circuitry is proposed to provide a mechanism for HOT. The concept of mosaic tiling is akin to HOT. (B) Global workspace theory describes the emergence of a single “workspace” as consciousness. Global neuronal workspace posits that highly synchronized neurons create a single theater of consciousness akin to an observer window formed by synchrony. (C) The IIT is an analysis of the interconnectedness of neurons (dashed arrows) with a complexity value, phi, that roughly scales with the degree of connectivity. Consciousness in IIT is akin to a highly coherent network of neurons that create a dynamic observer window. In light grey, a smaller cluster of coherent neurons is depicted that does not create a conscious experience as described by IIT