Fw: [virtropy] Consciousness: Hameroff and Penrose
Jim Shaffer, Jr. ( (no email) )
Fri, 5 Mar 1999 19:16:20 -0500
>From: "J. R. Molloy" <jr@shasta.com>
>
>
>From:
>
>http://www.u.arizona.edu/~hameroff/hardfina.html
>
>
>ABSTRACT
>
>
>What is consciousness? Some philosophers have contended that "qualia," o=
r an
>experiential medium from which consciousness is derived, exists as a
>fundamental component of reality. Whitehead, for example, described the
>universe as being comprised of "occasions of experience." To examine thi=
s
>possibility scientifically, the very nature of physical reality must be
>re-examined. We must come to terms with the physics of space-time--as is
>described by Einstein's general theory of relativity--and its relation t=
o
>the fundamental theory of matter--as described by quantum theory. This l=
eads
>us to employ a new physics of objective reduction: " OR" which appeals t=
o a
>form of quantum gravity to provide a useful description of fundamental
>processes at the quantum/classical borderline (Penrose, 1994; 1996). Wit=
hin
>the OR scheme, we consider that consciousness occurs if an appropriately
>organized system is able to develop and maintain quantum coherent
>superposition until a specific "objective" criterion (a threshold relate=
d to
>quantum gravity) is reached; the coherent system then self-reduces
>(objective reduction: OR). We contend that this type of objective
>self-collapse introduces non-computability, an essential feature of
>consciousness. OR is taken as an instantaneous event--the climax of a
>self-organizing process in fundamental space-time--and a candidate for a
>conscious Whitehead "occasion" of experience. How could an OR process oc=
cur
>in the brain, be coupled to neural activities, and account for other
>features of consciousness? We nominate an OR process with the requisite
>characteristics to be occurring in cytoskeletal microtubules within the
>brain's neurons (Penrose and Hameroff, 1995; Hameroff and Penrose, 1995;
>1996).
>In this model, quantum-superposed states develop in microtubule subunit
>proteins ("tubulins"), remain coherent and recruit more superposed tubul=
ins
>until a mass-time-energy threshold (related to quantum gravity) is reach=
ed.
>At that point, self-collapse, or objective reduction (OR) abruptly occur=
s.
>We equate the pre-reduction, coherent superposition ("quantum computing"=
)
>phase with pre-conscious processes, and each instantaneous (and
>non-computable) OR, or self-collapse, with a discrete conscious event.
>Sequences of OR events give rise to a "stream" of consciousness.
>Microtubule-associated-proteins can "tune" the quantum oscillations of t=
he
>coherent superposed states; the OR is thus self-organized, or "orchestra=
ted"
>("Orch OR"). Each Orch OR event selects (non-computably) microtubule sub=
unit
>states which regulate synaptic/neural functions using classical signalin=
g.
>
>The quantum gravity threshold for self-collapse is relevant to
>consciousness, according to our arguments, because macroscopic superpose=
d
>quantum states each have their own space-time geometries (Penrose, 1994;
>1996). These geometries are also superposed, and in some way "separated,=
"
>but when sufficiently separated, the superposition of space-time geometr=
ies
>becomes significantly unstable, and reduce to a single universe state.
>Quantum gravity determines the limits of the instability; we contend tha=
t
>the actual choice of state made by Nature is non-computable. Thus each O=
rch
>OR event is a self-selection of space-time geometry, coupled to the brai=
n
>through microtubules and other biomolecules.
>
>If conscious experience is intimately connected with the very physics
>underlying space-time structure, then Orch OR in microtubules indeed
>provides us with a completely new and uniquely promising perspective on =
the
>hard problem of consciousness.
>
>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D
>
>Conclusion: What is it like to be a worm?
>
>The Orch OR model has the implication that an organism able to sustain
>quantum coherence among, for example, 109 tubulins for 500 msec might be
>capable of having a conscious experience. More tubulins coherent for a
>briefer period, or fewer for a longer period (E =3Dh/T) will also have
>conscious events. Human brains appear capable of, for example, 1011 tubu=
lin,
>5 msec "bengal tiger experiences," but what about simpler organisms?
>
>>From an evolutionary standpoint, introduction of a dynamically function=
al
>cytoskeleton (perhaps symbiotically from spirochetes, e.g. Margulis, 197=
5)
>greatly enhanced eukaryotic cells by providing cell movement, internal
>organization, separation of chromosomes and numerous other functions. As
>cells became more specialized with extensions like axopods and eventuall=
y
>neural processes, increasingly larger cytoskeletal arrays providing
>transport and motility may have developed quantum coherence via the Fr=F6=
hlich
>mechanism as a by-product of their functional coordination.
>
>Another possible scenario for emergence of quantum coherence leading to =
Orch
>OR and conscious events is "cellular vision." Albrecht-Buehler (1992) ha=
s
>observed that single cells utilize their cytoskeletons in "cellular
>vision" - detection, orientation and directional response to beams of
>red/infra-red light. Jibu et al (1995) argue that this process requires
>quantum coherence in microtubules and ordered water, and Hagan (1995)
>suggests the quantum effects/cellular vision provided an evolutionary
>advantage for cytoskeletal arrays capable of quantum coherence. For what=
ever
>reason quantum coherence emerged, one could then suppose that, one day, =
an
>organism achieved sufficient microtubule quantum coherence to elicit Orc=
h
>OR, and had a "conscious" experience.
>
>At what level of evolutionary development might this primitive conscious=
ness
>have emerged? A single cell organism like Paramecium is extremely clever=
,
>and utilizes its cytoskeleton extensively. Could a paramecium be conscio=
us?
>Assuming a single paramecium contains, like each neuronal cell, 107
>tubulins, then for a paramecium to elicit Orch OR, 100% of its tubulins
>would need to remain in quantum coherent superposition for nearly a minu=
te.
>This seems unlikely.
>
>Consider the nematode worm C elegans. It's 302 neuron nervous system is
>completely mapped. Could C elegans support Orch OR? With 3 x 109 tubulin=
s, C
>elegans would require one third of its tubulins to sustain quantum coher=
ent
>superposition for 500 msec. This seems unlikely, but not altogether
>impossible. If not C elegans, then perhaps Aplysia with a thousand neuro=
ns,
>or some higher organism. Orch OR provides a theoretical framework to
>entertain such possibilities.
>
>Would a primitive Orch OR experience be anything like ours? If C elegans
>were able to self-collapse, what would it be like to be a worm? (Nagel,
>1974) A single, 109 tubulin, 500 msec Orch OR in C elegans should be equ=
al
>in gravitational self-energy (and thus perhaps, experiential intensity) =
to
>one of our "everyday experiences." A major difference is that we would h=
ave
>many Orch OR events sequentially (up to, say, 109 per second) whereas C
>elegans could generate, at most, 2 per second. C elegans would also
>presumably lack extensive memory and associations, and have poor sensory
>data, but nonetheless, by our criteria a 109 tubulin, 500 msec Orch OR i=
n C
>elegans would be a conscious experience: a mere smudge of known reality,=
the
>next space-time move.
>
>Consciousness has an important place in the universe. Orch OR in
>microtubules is a model depicting consciousness as sequences of
>non-computable self-selections in fundamental space-time geometry. If
>experience is a quality of space-time, then Orch OR indeed begins to add=
ress
>the "hard problem" of consciousness in a serious way.
>
>
>
>
>------------------------------------------------------------------------
>We are proud as punch of our new web site!
>http://www.onelist.com
>Onelist: The leading provider of free email community services
>------------------------------------------------------------------------
>Virtropy:
>Movement toward virtuality.
>
>In the event of virtual disconnect, contact the list owner at:
>Afterglow
>PO Box 333
>Palo Cedro, California 96073
>