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Undid revision 721682403 by Jytdog (talk) Redirect to "legal death" is nonsensical and was not discussed in Talk. |
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#REDIRECT [[Legal death]] |
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The term '''Information-theoretic death''' relates to a definition of [[death]] articulated by computer scientist [[Ralph Merkle]] that is concerned with the question of when, in the process of death, the "information" (as the term is considered in [[information theory]]) stored in the brain can no longer be retrieved; the definition arises in the context of asking at what point during the dying process someone can no longer be preserved with [[cyronics]] such that they could be revived again as themselves.<ref name=MerkleFeas/> |
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An unreviewed paper ''Molecular Repair of the Brain'' by Merkle defined "information-theoretic death":<ref>{{citation|first=Ralph |last=Merkle | url=http://www.alcor.org/Library/html/MolecularRepairOfTheBrain.htm | title=Molecular Repair of the Brain |journal=Cryonics |date=January–April 1994|via=Alcor library online|accessdate=2014-12-27}}</ref> |
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{{quote|A person is dead according to the information-theoretic criterion if their memories, personality, hopes, dreams, etc. have been destroyed in the information-theoretic sense. That is, if the structures in the brain that encode memory and personality have been so disrupted that it is no longer possible in principle to restore them to an appropriate functional state, then the person is dead. If the structures that encode memory and personality are sufficiently intact that inference of the memory and personality are feasible in principle, and therefore restoration to an appropriate functional state is likewise feasible in principle, then the person is not dead.}} |
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Merkle further suggested, in another unreviewed paper, that at room temperature information-theoretic death occurs gradually after many hours of clinical death as the brain undergoes [[autolysis (biology)|autolysis]].<ref name=MerkleFeas>{{cite journal |
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| last = Merkle |
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| title = The technical feasibility of cryonics |
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| journal = Medical Hypotheses |
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| volume = 39 |
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| pages = 6–16 |
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| year = 1992 |
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| publisher = Elsevier |
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| pmid=1435395 |
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| doi = 10.1016/0306-9877(92)90133-W |
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| first1 = R |
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| issue = 1}}</ref><ref>{{cite journal |
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| last = Wowk |
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| title = The future of death |
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| journal = Journal of Critical Care |
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| volume = 29 |
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| pages = 1111–1113 |
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| year = 2014 |
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| publisher = Elsevier |
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| pmid=25194588 |
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| doi = 10.1016/j.jcrc.2014.08.006 |
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| first1 = B |
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| issue = 6}}</ref> |
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Because of the brain's high metabolism rate, low energy stores, and dependence of aerobic metabolism of glucose, it is exquisitely sensitive to loss of oxygen at normal temperatures; within minutes of the onset of ischemia, [[ATP]] levels fall, leading to the failure of ATP-dependent [[ion transporter]]s and collapse of [[membrane potential]] differentials, which causes neurons to initiate [[apoptosis|programmed cell death]].<ref name=Dugan>Dugan LL, Kim-Han JS. Hypoxic-Ischemic Brain Injury and Oxidative Stress. Chapter 32 in Basic Neurochemistry: Molecular, Cellular and Medical Aspects. Eds. Brady S, et al. Academic Press, 2005. ISBN 9780080472072</ref>{{rp|559-560}} Additionally, as neurons go into crisis, they fall into a feedback loop of glutaminergic [[excitotoxicity]], overwhelming and disrupting [[synapses]],<ref name=Dugan/>{{rp|563-565}} among which information is stored in the brain.<ref name=Tsien>Tsien JZ. Learning and Memory. Chapter 53 in Basic Neurochemistry: Molecular, Cellular and Medical Aspects. Eds. Brady S, et al. Academic Press, 2005. ISBN 9780080472072</ref>{{rp|861-871}} |
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==References== |
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{{reflist}} |
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==External links== |
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*[http://www.timeoutintensiva.it/archivio/cc3894.pdf?PHPSESSID=79a9b2cb47d09efdc8081c2f4e75ed07 Pro/con ethics debate: When is dead really dead?] |
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*[http://nereja.free.fr/files/DarkAngels.pdf Ethics review: Dark angels-- the problem of death in intensive care] |
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*[http://www.evidencebasedcryonics.org/2008/06/01/albert-einsteins-brain-and-information-theoretic-death/ Albert Einstein’s brain and information-theoretic death] |
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*[http://www.alcor.org/Library/html/medicaltimetravel.htm Medical Time Travel] by Brian Wowk |
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{{Cryonics}} |
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{{Death}} |
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[[Category:Death]] |
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[[Category:Cryonics]] |
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[[Category:Information theory]] |
Revision as of 14:00, 23 May 2016
The term Information-theoretic death relates to a definition of death articulated by computer scientist Ralph Merkle that is concerned with the question of when, in the process of death, the "information" (as the term is considered in information theory) stored in the brain can no longer be retrieved; the definition arises in the context of asking at what point during the dying process someone can no longer be preserved with cyronics such that they could be revived again as themselves.[1]
An unreviewed paper Molecular Repair of the Brain by Merkle defined "information-theoretic death":[2]
A person is dead according to the information-theoretic criterion if their memories, personality, hopes, dreams, etc. have been destroyed in the information-theoretic sense. That is, if the structures in the brain that encode memory and personality have been so disrupted that it is no longer possible in principle to restore them to an appropriate functional state, then the person is dead. If the structures that encode memory and personality are sufficiently intact that inference of the memory and personality are feasible in principle, and therefore restoration to an appropriate functional state is likewise feasible in principle, then the person is not dead.
Merkle further suggested, in another unreviewed paper, that at room temperature information-theoretic death occurs gradually after many hours of clinical death as the brain undergoes autolysis.[1][3]
Because of the brain's high metabolism rate, low energy stores, and dependence of aerobic metabolism of glucose, it is exquisitely sensitive to loss of oxygen at normal temperatures; within minutes of the onset of ischemia, ATP levels fall, leading to the failure of ATP-dependent ion transporters and collapse of membrane potential differentials, which causes neurons to initiate programmed cell death.[4]: 559–560 Additionally, as neurons go into crisis, they fall into a feedback loop of glutaminergic excitotoxicity, overwhelming and disrupting synapses,[4]: 563–565 among which information is stored in the brain.[5]: 861–871
References
- ^ a b Merkle, R (1992). "The technical feasibility of cryonics". Medical Hypotheses. 39 (1). Elsevier: 6–16. doi:10.1016/0306-9877(92)90133-W. PMID 1435395.
- ^ Merkle, Ralph (January–April 1994), "Molecular Repair of the Brain", Cryonics, retrieved 2014-12-27 – via Alcor library online
- ^ Wowk, B (2014). "The future of death". Journal of Critical Care. 29 (6). Elsevier: 1111–1113. doi:10.1016/j.jcrc.2014.08.006. PMID 25194588.
- ^ a b Dugan LL, Kim-Han JS. Hypoxic-Ischemic Brain Injury and Oxidative Stress. Chapter 32 in Basic Neurochemistry: Molecular, Cellular and Medical Aspects. Eds. Brady S, et al. Academic Press, 2005. ISBN 9780080472072
- ^ Tsien JZ. Learning and Memory. Chapter 53 in Basic Neurochemistry: Molecular, Cellular and Medical Aspects. Eds. Brady S, et al. Academic Press, 2005. ISBN 9780080472072