Materialism › Neurobiological
Gray’s Brain-Built World-Model: Qualia, Comparators, Late-Error Detection
Consciousness as a Display for Late Error Detection
Jeffrey Gray argues that phenomenal consciousness is a slow, brain-built multimodal display of the organism and its world, produced by unconscious systems and consulted by other unconscious systems. It arrives too late to steer most behavior, so its job is late error detection: a stable model against which a comparator checks outcomes against predictions. Gray openly denied that this explains why any of it is felt.
Jeffrey Alan Gray
What consciousness is
Consciousness is a brain-constructed simulated world, and qualia are the felt properties of that construction, presented as a unified model for comparison against prediction.
Mind and body
Gray rejected dualism and held experience to be generated by brain processes, but denied that identifying neural correlates or functions explains why those processes are felt.
Mechanism
Late error detection: the conscious display gives a comparator a stable, integrated, cross-modal model in which mismatches between outcome and prediction show up, so unconscious servomechanisms can be adjusted next time.
Core claims
- Conscious percepts form too slowly to control fast actions such as returning a tennis serve, and the dorsal action stream is dissociable from the ventral stream that yields visual qualia.
- In colored-hearing synesthesia, spoken words activate color area V4 without earlier visual-pathway involvement.
- The alien color effect, where synesthetic color opposes the real color, separates qualia from function.
- Gray rejected Penrose-Hameroff quantum proposals because wave-function collapse does not explain why one quale rather than another occurs.
Criticisms
The benefits Gray credits to consciousness would accrue equally to an unconscious mechanism doing the same operations. Gray also held some non-linguistic animals to be conscious, though they lack the distinctive functions he names. Kriegel and Biggs note that a display seems to need an audience, bringing back a homunculus.
Implications
- AI consciousness: Uncertain
- Gray's synesthesia argument holds that qualia are not fixed by function, so reproducing a brain's functions in a machine would not guarantee experience.
- Survival beyond death: No
- Since Gray rejected dualism and takes experience to be constructed by the brain, it ends with the brain.
- Meaning and purpose: Humanistic only
- Consciousness is explained by an adaptive biological function.
- Virtual immortality: Unlikely
- If qualia do not follow from function, a functional simulation of a person would not reliably carry their experience.
Related theories
- Functionalism (Critique)
- Penrose-Hameroff's Orchestrated Objective Reduction (Critique)
- Predictive Theories (Top-Down) (Overlap)
- Epiphenomenalism (Materialism) (Contrast)
Sources
- Consciousness: Creeping Up on the Hard Problem, Jeffrey Alan Gray (2004)
- How are qualia coupled to functions?, Jeffrey Alan Gray (2003)
- Implications of synaesthesia for functionalism: Theory and experiments, J. A. Gray, S. Chopping, J. Nunn et al. (2002)
- Evidence against functionalism from neuroimaging of the alien colour effect in synaesthesia, J. A. Gray, D. M. Parslow, M. J. Brammer et al. (2006)
- The Neuropsychology of Anxiety, J. A. Gray and N. McNaughton (2000)
- Functional magnetic resonance imaging of synesthesia: Activation of V4/V8 by spoken words, J. A. Nunn et al. (2002)
- The Visual Brain in Action, A. D. Milner and M. A. Goodale (1995)
- Review of Consciousness: Creeping Up on the Hard Problem, U. Kriegel (2005)