The author argues that access consciousness and phenomenal consciousness, though conceptually distinct, might refer to the same brain process, similar to how water and H2O are different concepts of the same substance. However, recent work by Crick and Koch suggests that these two forms of consciousness may have distinct, albeit overlapping, neural correlates, even though Crick and Koch themselves implicitly reject this possibility.
Functionalists define consciousness by its role, while physicalists define it as the biological mechanism that performs that role. Global workspace theory aligns with functionalism, treating consciousness as a functional process. Physicalists, however, view consciousness as a biological phenomenon that implements global accessibility, meaning it is the physical brain's activity that realizes the functional role.