Notwithstanding the power of the cell assembly concept, which holds that specific patterns of neuronal
activity constitute the substrate of perceptual awareness that rises into consciousness, a explanatory gap
remains between the phenomenological experience of consciousness and the brain processes from which
that experience arises. A number of compelling and insightful theories have been offered that attempt
to bridge that gap, but most of them fall short by failing to [a] specify which of many options other
than hard-wired cell assemblies carry the information that becomes conscious, or [b] identify the brain
mechanism for monitoring the functional events that become conscious. This Viewpoint article points
to a number of possibilities that could be considered for both the substrate and monitor that give rise to
consciousness.
