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    $\begingroup$ I think your premise is off. If someone recovered from a flat EEG, I think the simpler conclusion to draw is that a flat EEG doesn't equal NO brain activity. The brain was still working; but its activity was not detected. $\endgroup$ – swbarnes2 May 28 '14 at 18:30
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    $\begingroup$ looks like this deals with cryopreservation which is still a field in its infancy $\endgroup$ – The Last Word May 28 '14 at 19:03
  • $\begingroup$ @potterbond007 The actual question (in bold) does not pertain to cryopreservation. I used the premises only to deduce that (long term) memory is indepentent of brain activity, so it should still exist after death (unlike consciousness, which probably depends on the brain's activity). The question is: for how long does memory persist without cryopreservation? $\endgroup$ – user6268 May 28 '14 at 19:11
  • $\begingroup$ Old question, but case 2 (hamsters can be frozen to complete organic inactivity and thawed) doesn't seem to have anything to do with memory. I'd also be interested to see whether this is true of an adult organism, or simply for sperm and/or egg. Hibernation certainly isn't complete organic inactivity, so this must be referring to something else if it is true. $\endgroup$ – De Novo Nov 15 '18 at 18:32
  • $\begingroup$ Note that this point of no return is called information theoretic death. $\endgroup$ – forest Feb 17 at 11:12








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    $\begingroup$ I also fail to see how a tattoo would be relevant to the OP, and consequently do not discuss tattoos in my answer. $\endgroup$ – user 49102 Jun 2 '14 at 6:18
  • $\begingroup$ You have given the OP the answer he wanted. That is what matters. $\endgroup$ – daniel Jun 2 '14 at 9:54





  • $\begingroup$ That frozen hamster, whose btain was "dead" by the definition of human brain death, showed no sign of having lost the memory of his habitat after reanimation. Quite obviously memory is stored physically and independent of brain activity. $\endgroup$ – user6268 May 29 '14 at 18:30
  • $\begingroup$ The brain is unlike a current computer in many ways (e.g. neurons don' t have binary on/off states), and the relevant difference in the context of this question is that the brain stores info in its neuronal structure, i.e. by changing the hardware. $\endgroup$ – user6268 May 29 '14 at 18:48
  • $\begingroup$ Guyton, Arthur C. (1986). "The Cerebral Cortex and Intellectual Functions of the Brain". Textbook of Medical Physiology (7th ed.). W. B. Saunders Company. p. 658. ISBN 0-7216-1260-1. "We know that secondary memory does not depend on continued activity of the nervous system, [contd.] $\endgroup$ – user6268 May 29 '14 at 19:00
  • $\begingroup$ [contd.] because the brain can be totally inactivated by cooling, by general anesthesia, by hypoxia, by ischemia, or by any method, and yet secondary memories that have been previously stored are still retained when the brain becomes active once again. Therefore, secondary memory must result from some actual alterations of the synapses, either physical or chemical." $\endgroup$ – user6268 May 29 '14 at 19:01
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    $\begingroup$ "No activity detectable with this or that instrument" does not equal "no activity", neither is equal to "dead". Your deduction is flawed. $\endgroup$ – swbarnes2 May 29 '14 at 19:58

Technically the main limiting factor for recovery from anoxia is actually that the brain goes into starvation mode and the cells self destruct. There are ways to mitigate this, one idea I had in 2013 is to flood the circulatory system with essentially high concentration glucose and barbiturates mixed with very cold (4C) water and irradiate the brain-to-be-preserved with NIR radiation at two key wavelengths. This is known to improve survival in damaged retinal cells (similar to CNS) and in fact Prof. Canavero (aka the head transplant doctor) is using a very similar method to help spinal neurons reconnect in addition to the use of transverse electrical fields and modulated oxygen flow so as to keep the cells in hibernation but not too high as to damage them. The idea of the barbiturates is to stop the neurons firing out of control therefore "burning out" before the structure can be preserved for later readout.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5820829/ https://link.springer.com/chapter/10.1007/978-3-642-69175-1_17 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5364001/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4768515/

  • $\begingroup$ What size of a machine are we talking, if we wanted this solution as an "emergency pack" to carry around always? $\endgroup$ – user6268 Sep 28 '16 at 7:05
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    $\begingroup$ This answer is pure hypothesis unsupported by evidence. To say what works on retinal cells will work on brain cells is somewhat like saying what works on thyroid cells will work on pancreatic cells (both similar as exocrine gland with an interrelationship.) Hypotheses are not answers. Much better to give a factual answer that only partly supports your hope. $\endgroup$ – anongoodnurse Mar 5 at 16:29

protected by Chris Jan 9 at 15:44


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