Cognitive Connie
What is consciousness?
Consciousness — the subjective, first-person experience of perceiving, thinking, and feeling — remains one of the most profound and contentious topics in psychology and neuroscience. It is simultaneously the most familiar aspect of mental life (we are conscious right now) and the hardest to explain scientifically.
Key concepts
Global workspace theory
Bernard Baars's (1988) cognitive theory, later elaborated in neuroscientific terms by Dehaene and Changeux, proposes that consciousness arises when information gains access to a "global workspace" — a mental broadcast system that makes information widely available across the brain. Unconscious processing occurs in specialised, encapsulated modules; conscious processing occurs when a "coalition" of neurons ignites and broadcasts information widely. This transition is associated with a late (P300) ERP component and with widespread cortical activation on fMRI.
Default mode network
A set of brain regions (medial PFC, posterior cingulate cortex, precuneus, angular gyrus) that are more active during rest and self-referential thought than during externally focused tasks. The DMN underlies mind-wandering, autobiographical memory, prospective thinking, and the sense of a continuous self across time. Its activity is suppressed when attention is directed outward — suggesting a relationship between external task engagement and self-relevant background cognition.
The hard problem
David Chalmers's (1995) distinction between the "easy problems" of consciousness (explaining cognitive functions, attention, reportability of mental states — tractable to standard scientific methods) and the "hard problem": explaining why any physical brain process is accompanied by subjective experience at all. Even a complete functional account of the brain would leave unanswered the question of why there is "something it is like" to have these processes.
Levels of consciousness
Consciousness is not all-or-nothing. Vegetative state, minimally conscious state, and locked-in syndrome represent different levels of preserved awareness and responsiveness. Neuroimaging (especially fMRI and EEG) has revealed that some patients in apparent vegetative state show brain responses to commands, suggesting covert awareness. These cases have driven development of more refined diagnostic tools and ethical guidelines for disorders of consciousness.
Test your knowledge
Sources
Last reviewed July 2025- 1.
Dehaene, S. (2014). Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts. Viking.
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Accessible and rigorous account of global workspace theory and the neuroscience of conscious access.
- 2.
Crick, F., & Koch, C. (1990). Towards a neurobiological theory of consciousness. Seminars in the Neurosciences, 2, 263–275.
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Influential early paper outlining a scientific approach to consciousness and the search for neural correlates of awareness.
- 3.
Chalmers, D. J. (1995). Facing up to the problem of consciousness. Journal of Consciousness Studies, 2(3), 200–219.
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Defines the hard problem of consciousness — why physical brain processes are accompanied by subjective experience — and distinguishes it from 'easy' problems.
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Baars, B. J. (1988). A Cognitive Theory of Consciousness. Cambridge University Press.
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Original proposal of global workspace theory framing consciousness as information broadcast across a cognitive workspace accessible to diverse processes.