Orch-OR

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Orch OR (Orchestrated Objective Reduction) is the proposal that information processing in the brain involves complex computational processes within every neuron, that involve co-ordinated changes in the conformational states of tubulin proteins within microtubules. The proposal was put forward in the mid-1990s by British theoretical physicist Sir Roger Penrose and American anesthesiologist Stuart Hameroff.

Microtubules are cylindrical lattices of tubulin proteins that can act like "conveyer belts" inside cells to move vesicles, granules, organelles like mitochondria, and chromosomes to different locations in the cell via special attachment proteins; they are also important components of cilia and flagella in motile cells, and are importany for mitosis in all cells. Structurally, microtubules are linear polymers of a globular protein, tubulin - these linear polymers are called protofilaments.

Roger Penrose had argued in his 1989 book The Emperor's New Mind that human consciousness and understanding required a factor outside algorithmic computation, and that the missing “non-computable” factor was related to a type of quantum computation involving what he termed objective reduction (OR). Hameroff suggested to Penrose that microtubules within neurons might be involved in such quantum computation, and together they developed the theory of Orch OR [1][2]

[3] [4] [5]. [6] [7] [8] [9]

A few papers have been published criticising specific features of the theory, but largely it has been ignored by academic neuroscientists.

[10] [11] [12], [13] </ref> [14] [15] Cite error: Closing </ref> missing for <ref> tag McKemmish LK et al. (2009). "Penrose-Hameroff orchestrated objective-reduction proposal for human consciousness is not biologically feasible". Physical Review E 80: 021912–6.

</ref> [16] [17]

References

  1. ↑ Hameroff SR, Penrose R (1996) Orchestrated reduction of quantum coherence in brain microtubules: A model for consciousness. In: Toward a Science of Consciousness - The First Tucson Discussions and Debates. (Hameroff, S.R., Kaszniak, and Scott, A.C., eds.), pp. 507-540, MIT Press. Also published in Mathematics and Computers in Simulation (1996) 40:453-480
  2. ↑ Hagan S et al. (2002) Quantum Computation in Brain Microtubules? Decoherence and Biological Feasibility. Physical Rev E 65: 061901
  3. ↑ Hameroff SR, Penrose R (1996) Conscious events as orchestrated spacetime selections. J Consciousness Studies 3:36-53
  4. ↑ Hameroff S (1998) Quantum computation in brain microtubules? The Penrose-Hameroff "Orch OR" model of consciousness. Philos. Trans. R. Soc. London Ser. A 356:1869-96
  5. ↑ Hameroff S (1998b) "Funda-mentality": is the conscious mind subtly linked to a basic level of the universe? Trends Cognitive Sci 2:119-27
  6. ↑ Hameroff S (1998d) Did consciousness cause the Cambrian evolutionary explosion? In: Toward a Science of Consciousness II: The Second Tucson Discussions and Debates. Eds. Hameroff, S.R., Kaszniak, A.W., & Scott, A.C., Cambridge, MA: MIT Press, pp.421-37
  7. ↑ Hameroff SR, Watt RC (1982) Information processing in microtubules. Journal of Theoretical Biology 98: 549-561
  8. ↑ Hameroff SR et al. (2002) Conduction pathways in microtubules, biological quantum computation and microtubules. Biosystems 64:149-68.
  9. ↑ Hameroff SR (1998). "Quantum computation in brain microtubules? The Penrose-Hameroff "Orch OR" model of consciousness". Philosophical Transactions Royal Society London (A) 356: 1869–1896. [e]
  10. ↑ Grush, R., Churchland, P.S. (1995). "Gaps in Penrose's toilings". Journal of Consciousness Studies 2 (1): 10–29. [e]
  11. ↑ Penrose R, Hameroff SR (1995) What gaps? Reply to Grush and Churchland. J Consciousness Studies 2:98-112
  12. ↑ Penrose is Wrong Drew McDermott, PSYCHE, 2), October, 1995
  13. ↑ Minds, Machines, And Mathematics - A Review of Shadows of the Mind by Roger Penrose David J. Chalmers, PSYCHE 2 June 1995
  14. ↑ Reimers JR et al. (2009). "Weak, strong, and coherent regimes of Fröhlich condensation and their applications to terahertz medicine and quantum consciousness". Proc Nat Acad Sci USA 106: 4219–24.
  15. ↑ Georgiev, D.D. (2007). "Falsifications of Hameroff-Penrose Orch OR model of consciousness and novel avenues for development of quantum mind theory". NeuroQuantology 5: 145–174.
  16. ↑ Spier E, Thomas A (1998)A Quantum of Consciousness? A glance at a physical theory for a mind Trends in Cognitive Sciences 2:124-5
  17. ↑ Tegmark, M (2000), "Importance of quantum decoherence in brain processes", Phys Rev E 61: 4194–206
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