Orch-OR: Difference between revisions

From Citizendium
Jump to navigation Jump to search
imported>Gareth Leng
No edit summary
imported>Peter Schmitt
(all sources have been moved to Bibliography subpage)
 
(11 intermediate revisions by 4 users not shown)
Line 1: Line 1:
{{subpages}}
{{subpages}}
'''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 [[Roger Penrose|Sir Roger Penrose]] and American anesthesiologist [[Stuart Hameroff]].  
'''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 proteins within [[microtubule]]s. The proposal was put forward in the mid-1990s by British theoretical physicist [[Roger Penrose|Sir Roger Penrose]] and American anesthesiologist [[Stuart Hameroff]]. A few papers have been published criticising specific features of the theory, but
 
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'' <ref>Hameroff SR, Penrose R (1996) [http://www.quantumconsciousness.org/penrose-hameroff/orchOR.html ''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</ref><ref>Hagan S ''et al.'' (2002) [http://arxiv.org/abs/quant-ph/0005025 ''Quantum Computation in Brain Microtubules? Decoherence and Biological Feasibility''.] ''Physical Rev E'' 65: 061901</ref>
 
<ref>Hameroff SR, Penrose R (1996) [http://www.quantumconsciousness.org/penrose-hameroff/consciousevents.html ''Conscious events as orchestrated spacetime selections''.] ''J Consciousness Studies'' 3:36-53</ref>
<ref>Hameroff S (1998) [http://www.quantumconsciousness.org/penrose-hameroff/quantumcomputation.html ''Quantum computation in brain microtubules? The Penrose-Hameroff "Orch OR" model of consciousness''.] ''Philos. Trans. R. Soc. London Ser. A'' 356:1869-96</ref>
<ref>Hameroff S (1998b) [http://www.quantumconsciousness.org/penrose-hameroff/fundamentality.html ''"Funda-mentality": is the conscious mind subtly linked to a basic level of the universe?''] ''Trends Cognitive Sci'' 2:119-27</ref>.
<ref>Hameroff S (1998d) [http://www.quantumconsciousness.org/penrose-hameroff/cambrian.html ''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</ref>
<ref>Hameroff SR, Watt RC (1982) [http://www.quantumconsciousness.org/documents/informationprocessing_hameroff_000.pdf ''Information processing in microtubules''.] Journal of Theoretical Biology 98: 549-561</ref>
<ref>Hameroff SR ''et al.'' (2002) [http://www.quantumconsciousness.org/pdfs/conduction%20pathways_hamerof.pdf ''Conduction pathways in microtubules, biological quantum computation and microtubules''.] ''Biosystems'' 64:149-68.</ref>
<ref>
{{cite journal
| author =  Hameroff SR
| title = Quantum computation in brain microtubules? The Penrose-Hameroff "Orch OR" model of consciousness
| journal = Philosophical Transactions Royal Society London (A)
| volume = 356
| pages = 1869–1896
| year = 1998
| url = http://www.quantumconsciousness.org/penrose-hameroff/quantumcomputation.html
| doi =
}}</ref>
 
A few papers have been published criticising specific features of the theory, but
largely it has been ignored by academic neuroscientists.
largely it has been ignored by academic neuroscientists.


<ref>
Microtubules are cylindrical lattices of tubulin proteins that serve as structural elements inside a cell and can act like "highways" for the movement of [[vesicles]], [[granules]], organelles like [[mitochondria]], and [[chromosomes]] to different locations in the cell via special motor proteins; they are also important components of [[cilia]] and [[flagella]] in motile cells, and are important for [[mitosis]] in all cells. Structurally, microtubules are linear polymers of a globular protein, [[tubulin]] - these linear polymers are called [[protofilaments]].
{{cite journal
  | author = Grush, R., Churchland, P.S.
| title = Gaps in Penrose's toilings
| journal = Journal of Consciousness Studies
| volume = 2
| issue = 1
| pages = 10–29
| year = 1995
| url = http://mind.ucsd.edu/papers/penrose/penrose.pdf
| doi =
}}</ref>
<ref>Penrose R, Hameroff SR (1995) [http://www.quantumconsciousness.org/penrose-hameroff/whatgaps.html ''What gaps? Reply to Grush and Churchland''.] J Consciousness Studies 2:98-112</ref>
<ref>[http://psyche.cs.monash.edu.au/v2/psyche-2-17-mcdermott.html Penrose is Wrong] Drew McDermott, PSYCHE, 2), October, 1995</ref>, <ref>[http://psyche.cs.monash.edu.au/v2/psyche-2-09-chalmers.html Minds, Machines, And Mathematics - A Review of Shadows of the Mind by Roger Penrose] David J. Chalmers, ''[[Psyche (journal)|PSYCHE]]'' 2 June 1995</ref>
</ref>
<ref>
{{cite journal
| author = Reimers JR ''et al.''  | title = Weak, strong, and coherent regimes of Fröhlich condensation and their applications to terahertz medicine and quantum consciousness
| journal = Proc Nat Acad Sci USA
| volume = 106
| pages = 4219–24
| year = 2009
}}</ref>
<ref>
{{cite journal
| author = Georgiev DD
| title = Falsifications of Hameroff-Penrose Orch OR model of consciousness and novel avenues for development of quantum mind theory
| journal = NeuroQuantology
| volume = 5
| pages = 145–74
| year = 2007
}}
</ref>
<ref>
{{cite journal
| author = Georgiev DD
| title = Remarks on the number of tubulin dimers per neuron and implications for Hameroff-Penrose Orch
| journal = NeuroQuantology
| volume = 7
| pages = 677–9
| year = 2009
| url = http://precedings.nature.com/documents/3860/version/1
| doi =
}}
<ref name="Georgiev2009b">
{{cite journal
| author = Georgiev DD
| title = Tubulin-bound GTP cannot pump microtubule coherence in stable microtubules. Towards a revision of microtubule based quantum models of mind
| journal = NeuroQuantology
| volume = 7
| pages = 538–47
| year = 2009
}}
</ref><ref>
{{cite journal
| author = McKemmish LK ''et al.''  | title = Penrose-Hameroff orchestrated objective-reduction proposal for human consciousness is not biologically feasible
| journal = Physical Review E
| volume = 80
| pages = 021912–6
| year = 2009
}}
</ref>
<ref>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</ref>
<ref>{{citation  | last = Tegmark | first =  M  | year = 2000  | title = Importance of quantum decoherence in brain processes  | journal = Phys Rev E  | volume = 61  | pages = 4194–206  }}</ref>
 
== References ==


<references/>
Penrose 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 called ''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''.

Latest revision as of 17:18, 14 May 2010

This article is a stub and thus not approved.
Main Article
Discussion
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
 
This editable Main Article is under development and subject to a disclaimer.

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 proteins within microtubules. The proposal was put forward in the mid-1990s by British theoretical physicist Sir Roger Penrose and American anesthesiologist Stuart Hameroff. A few papers have been published criticising specific features of the theory, but largely it has been ignored by academic neuroscientists.

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

Penrose 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 called 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.