consciousness · Part 2
The Neural Correlates
What neuroscience has discovered about the brain activity associated with conscious experience.
Searching for Consciousness in the Brain
If consciousness arises from the brain — and most scientists believe it does — then there should be specific patterns of neural activity that correspond to specific conscious experiences. These are called neural correlates of consciousness (NCCs).
Key Discoveries
The Global Workspace
Bernard Baars proposed that consciousness arises when information is broadcast across a “global workspace” — a network connecting many specialized brain regions. Unconscious processing is local; conscious experience is global.
The Thalamocortical Loop
The thalamus and cortex form a loop of reciprocal connections. Giulio Tononi and others have shown that disrupting this loop — through anesthesia or deep sleep — reliably eliminates consciousness.
The Posterior Hot Zone
Recent work by Christof Koch and colleagues has identified a “posterior cortical hot zone” as particularly important for conscious content. Activity in this region more reliably predicts what a person is experiencing than frontal cortex activity.
The Explanatory Gap
Neuroscience can tell us where and when consciousness happens in the brain. But it struggles with why these particular patterns give rise to experience. This is the explanatory gap — the chasm between correlation and explanation.
Knowing that neurons firing at 40 Hz correlate with visual awareness does not explain why 40 Hz firing feels like seeing blue.
What This Means
The neural correlates are essential data. They constrain our theories. But they are not, by themselves, a solution to the hard problem. For that, we need something more — a bridge theory that connects the physical and the experiential.