You have already died many times over

[Evolver]

You have already "died" many times over...

This thread will be on the topic of self-awareness and what that actually means. To do that we must attempt to look at a few ways in which an entity, such as a human, that considers itself a linear being, can be described:

First off, let's look at it from a physical perspective: The human body is constantly eating, sleeping, regenerating, replacing, etc. When it's doing these things, the cells in the body (which are made up of various arrangements of elements) are taking in new elements, and based on pre-coded information (DNA) are rearranging those elements in a way to suit it's needs. Over the course of time, these cells are merely copies of their former selves, sharing none of the exact subatomic particles of the previous cells. The body that exists now is simply a facsimile of genetic information of the body that existed, say, 10 years ago. So it can be safely stated that there is no linear continuity from a physical perspective.

Now, let's look at the entity from a mental perspective: As the intricate chemical/electrical interactions of the brain progress, any given configuration during any time is completely unique to that of any other configuration. The entity only perceives itself as a linear being because it has amassed a databank of previous states (memory) on which to draw from. If this database should be tampered with, the new state has trouble relating to the old states. Take Alzheimer's for example; a patient with an extreme case has problems with self identification as well as relating to the world around them. This is because with every firing of a neuron's synapse, every replacement of a subatomic particle, every nanosecond that ticks by... "you" are not "you" anymore. You are a unique entity in a unique state that has only perceived itself to have a linear existence, and "you" too will soon be a thing of the past.

Just some food for thought... perhaps it will alleviate the terror of death knowing that by the time you finish reading this "you" will have died and ceased to exist many times over, only to be replaced by an entity that perceives itself and you as the same thing.

Also, feel free to check out my other thread about the nature of the universe as interpreted quantum information: https://www.physicsforums.com/showthread.php?t=368284

 

[ideasrule]

The terror of death comes from the pain usually associated with it, pain caused by disease or injury. It doesn't come from simply ceasing to be a conscious entity. That happens every night, when one sleeps.

 

[Evolver]

A being that thinks itself a linear entity does not fear sleep because it knows it will wake up from it. The fear of death comes from experiencing the unknown (or perhaps losing the ability to experience at all.) Though pain is uncomfortable, I wouldn't say that's the main reason people fear death at all.

That being said, I do not wish to sidetrack on what the actual fear of death is. I am more concerned with the ideas I was relating above, though I do appreciate your response.

 

[disregardthat]

The terror of death comes from the pain usually associated with it, pain caused by disease or injury. It doesn't come from simply ceasing to be a conscious entity. That happens every night, when one sleeps.

I would think that every man who wants to live would choose many times the pain than what a painful death might feel just to live. This is your choice: stabbed once in the back and die - or stabbed ten times and survive?

 

[deian]

Physically we may have died many times over, but there is something else that makes us concious, aware, intelligent and able to perceive reality despite our physical form.

The problem is, we are conscious beings, and being so doesn't mean we know how we work, and that is why we are asking the questions.

I believe physics could hold the answer to the soul, this being an energy that allows conciousness and self-replication until oxidization of the physical material of humans overtakes it's ability to make quality material to hold the soul.

 

[Dembadon]

The terror of death comes from the pain usually associated with it, pain caused by disease or injury. It doesn't come from simply ceasing to be a conscious entity. That happens every night, when one sleeps.

What about the fear of no longer being in contact with one's family/friends; Leaving a child/loved one behind; not getting to be a parent; not accomplishing any (life) goals one may have? Surely the physical ramifications are not the only reason.

Edit: Also, sleep is not usually considered a permanent event; so in this case, fear of going sleep would be illogical. One can be fairly certain that when they go to sleep, they will wake up again.

 

[dacruick]

I would think that every man who wants to live would choose many times the pain than what a painful death might feel just to live. This is your choice: stabbed once in the back and die - or stabbed ten times and survive?

I heard that knives don't hurt that much. my friends friend got a knife thrown at her and she didn't even know until she saw the bleeding

 

[jreelawg]

What about neurons?

 

[disregardthat]

I heard that knives don't hurt that much. my friends friend got a knife thrown at her and she didn't even know until she saw the bleeding

That's not the point. Suppose a person could choose between a painless execution and a painful experience. I believe that one would generally choose the painful experience over a painless execution any day. Pain is not the relevant factor when it comes to fear of death, that is my point.


I believe that fear of death is much more innate to us than fear of what we associate with dying. To cease to exist is frightening in itself regardless of the related consequences.

Also, to lose the sense of awareness for limited period is obviously not equivalent to losing it entirely - to the contrary of what ideasrule implies.

 

[AUK 1138]

I completely agree with the OP. it's a fascinating concept. to me however, the most fascinating part is that while you are constantly being torn apart and reconstructed on an atomic level and dying and regenerating on a cellular level you still hold full consciousness of everything that is then added to you. A man doesn't forget how to see when his eyes become replaced through regeneration, and i don't believe there is anything internally you could do to have any inclination that this is happening. it also forces a definition on what it is to be a conscious being. where is the consciousness "stored?" the brain is changing in all these regards, and once a cell dies it has no way of telling it's replacement what it contained. all that information had to be known ahead of time if it was to be transfered. together, i'd say this means that the individual cells have no ramifications on the consciousness. however, i would also wholly disagree with that notion, which leaves me quite confused.

 

[Pythagorean]

This thread will be on the topic of self-awareness and what that actually means. To do that we must attempt to look at a few ways in which an entity, such as a human, that considers itself a linear being, can be described:

Not sure what you mean. Many of the scientific studies on humans (or biological species in general) use predominately nonlinear models. From sociology to psychology to neuroscience, linearity is a neat tool to approximate some cases, but a caveat that's always taught (and practiced in most research) is that the real world is non-linear.

But feel free to extrapolate if I've misinterpreted your use of the word.

First off, let's look at it from a physical perspective: The human body is constantly eating, sleeping, regenerating, replacing, etc. When it's doing these things, the cells in the body (which are made up of various arrangements of elements) are taking in new elements, and based on pre-coded information (DNA) are rearranging those elements in a way to suit it's needs. Over the course of time, these cells are merely copies of their former selves, sharing none of the exact subatomic particles of the previous cells. The body that exists now is simply a facsimile of genetic information of the body that existed, say, 10 years ago. So it can be safely stated that there is no linear continuity from a physical perspective.

I completely disagree. Weather, waves, energy transfer, thermodynamics. All physical studies where the phenomena itself holds importance. The matter through which these properties express these physical phenomena are merely mediums.

Newton's Balls, for instance, are an example of a phenomena (momentum) traveling through a media (usually steel balls). The phenomena doesn't cease to be physical just because it "changes hands". The physics is not the material. The physics is the interactions of the materials.

Also, there is actually a constant material: your DNA. As you get older, mistakes will happen and their will be copy errors, but your cells use copying from the master DNA to make RNA, doing it's best to preserve the DNA.

Now, let's look at the entity from a mental perspective: As the intricate chemical/electrical interactions of the brain progress, any given configuration during any time is completely unique to that of any other configuration.

Agreed. Of course, "mental" is a subset of physical.

The entity only perceives itself as a linear being because it has amassed a databank of previous states (memory) on which to draw from. If this database should be tampered with, the new state has trouble relating to the old states. Take Alzheimer's for example; a patient with an extreme case has problems with self identification as well as relating to the world around them. This is because with every firing of a neuron's synapse, every replacement of a subatomic particle, every nanosecond that ticks by... "you" are not "you" anymore. You are a unique entity in a unique state that has only perceived itself to have a linear existence, and "you" too will soon be a thing of the past.

I don't see how A: Alzheimer's patients have problems with self-identification
leads to B: you are not you from one moment to the next

You'd have to go a lot more in depth into that.

I can say that from a psychological perspective, personality traits of people often stay the same after they've reached a certain point (adulthood) and their brains aren't changing as much anymore (of course, your brain is always changing).

But ultimately my point is that you're growing and developing, not dying over and over again. Of course, we're also decaying and our cells are making errors in copying our genes as we get older. Some things change, but other things remain constant.

There's also more interesting cases than Alzheimer's associated with identity loss. Dissociative Identity Disorder and Depersonalization Disorder to name a few.

 

[brainstorm]

Interesting point, OP. It evokes another question in me.

If neurons can die and regenerate with the soul continuing through the construction and restructuring processes of the cells, does this suggest that soul-transplantation may be possible?

Bracketing the ethical problems with it, you could theoretically link two brains together and allow for neural activity to re-organize so that both brains develop into one.

Then, if you severed them, would you have cloned your soul/self into the other brain/body? Also, I assume that the transfer process would involve actively engaging both bodies simultaneously. So, for example, you would have to shut your eyes on your existing body to practice seeing through the eyes on the new body, etc.

Now, here's the big problem: If this worked and you successfully cloned your consciousness, once you sever the connection between the two yous, the old you goes back to being itself the same as if it had never connected with the new body for soul-transfer. Plus, the new you becomes alienated from your old body when you sever - i.e. it just becomes like a twin sibling who shares the exact same memories, knowledge, etc.

You would end up as two people who know each other's most intimate details from personal experience, but futher you would just be two separate people, both with an individual will, rights, etc. E.g. you would not be able to eliminate either you ethically.

If you had a terminal disease, you could theoretically transplant your soul into a new body but the problem is that your old body/soul would still have to endure death. You could euthanize your old body, but it's not as if the experience of euthanasia wouldn't be the same for you because you had transferred consciousness into the new body.

Even if you were somehow able to perform the euthanasia at precisely the same moment as the soul/consciousness transfer takes place, you couldn't somehow ensure that your soul completely exits the old body for the new one, could you? It comes down to the fact that death is always experienced as loss of one's host body.

 

[Greg Bernhardt]

I would recommend watching these videos for solid arguments on the existence of a soul and the origins of personal identity:
http://oyc.yale.edu/philosophy/death/content/class-sessions

 

[Evo]

This is going off into science fiction.

Our rules are that threads in philosophy must remain within the bounds of known science.

Remember, also, that our policies for discussion of science and mathematics hold just as strongly in the Philosophy Forums as anywhere else on the site. Overly speculative or incorrect statements within the domains of science and math may be moved, locked, or deleted at the mentors' discretion, and warnings may be issued. In general, there is more legroom for speculation in philosophical discussion, but it must be in the form of a well motivated question or argument, as described above. In particular, even a 'speculative' argument should be logically consistent with well established scientific knowledge and theory.

https://www.physicsforums.com/showthread.php?t=47294

Edit: I see Greg got here first.

 

[apeiron]

The issue of molecular turnover is a real issue for material reductionism. Fortunately the answer does not invove souls, reincarnation, or other mystical beliefs.

Here is a column I wrote for Lancet Neurology a few years back...

++++++

How do you persist when your molecules don’t? Holism says the whole shapes the parts. And here is how the mind does indeed act to form the brain, reversing the usual reductionist story.

Do you know the half-life of a microtubule, the protein filaments that form the internal scaffolding of a cell? Just ten minutes. That’s an average of ten minutes between assembly and destruction.

Now the brain is supposed to be some sort of computer. It is an intricate network of some 1,000 trillion synaptic connections, each of these synapses having been lovingly crafted by experience to have a particular shape, a particular neurochemistry. It is of course the information represented at these junctions that makes us who we are. But how the heck do these synapses retain a stable identity when the chemistry of cells is almost on the boil, with large molecules falling apart nearly as soon as they are made?

The issue of molecular turnover is starting to hit home in neuroscience, especially now that the latest research techniques such as fluorescent tagging are revealing a far more frantic pace of activity than ever suspected. For instance, the actin filaments in dendrites can need replacing within 40 seconds, making microtubules look like positive greybeards (Star et al, 2002).

A turnover time of five days for NMDA receptors seemed pretty steep when it was reported a few years back. (Shimizu et al, 2000). But recently Michael Ehlers at Duke University Medical Center in Durham, North Carolina, reported that the entire post-synaptic density (PSD) - the protein-packed zone that powers synaptic activity - is replaced, molecule for molecule, almost by the hour. Ehlers had expected the turnover to take days and when he found no labelled protein on his first 24 hour assay, he thought he must have mucked up the experiment

Myelin and RNA molecules seem to last months. And DNA is of course fairly hardy, though it still needs continual repair. But on the kinds of figures that are coming out now, it seems like the whole brain must get recycled about every other month. And certainly everything points to the synapses as being about the most dynamic part of the whole system.

Clearly the shape of the synapses IS somehow maintained despite the molecular turmoil. But there is an issue here that demands some specific theory. The stability of brain circuits cannot simply be taken for granted.

Princeton University's Joe Tsien – famous for making mice smarter by splicing in slower-closing NMDA receptors – is one of a number of researchers pursuing the idea that synaptic structure may be stabilised by pressure from both above and below.

Many people know about the emerging "below" picture of how shifts in gene expression patterns could be necessary to underpin neural learning. Put simply, the genes remember what kind of state a junction ought to be in and so keep rebuilding the same old structure. As a relative oasis of calm in the thermodynamic bustle of a cell, the genes could anchor the homeostatic network needed to allow a given synaptic pattern to persist.

Of course, this story is complicated by evidence that RNA actually in the dendrites may do the same job. But it seems to be a "loops within loops" mechanism with short-loop local feedback nested in long-loop feedback between synapses and genes (Lisman and Fallon, 1999).

But Tsien says that as well as this shape-maintaining pressure from within, synapses may be just as dependent on pressures from without - the old "jangling trace" hypothesis. Back in the early 1990s it was discovered that there is a kind of compressed replay of the day's accumulated memories during slow wave sleep. The networks of cells active during learning would burst to life again. This led to the theory that the hippocampus consolidates new learning to the cortex when the brain is off-line.

But Tsien feels this spontaneous jangling of neural traces is probably a much more general homeostatic mechanism that helps to keep labile synapses stabilised. And the jangling probably goes on around the clock, in all areas of the brain, at regular intervals to remind each synaptic connection of its place in the great scheme of things (Wittenberg et al, 2002).

All this Byzantine complexity does matter. To make sense of the brain as an information processing system, clearly we must be physically able to locate its information. And it’s long been an almost unquestioned tenet of neuroscience that neurons with their weighted junctions and crisp connection patterns are devices for trapping information. The hardwired network is the solid foundation for all the pretty patterns that play across it.

Yet when we zero in on these synapses, suddenly their “information” appears to scatter. The synapses turn out to be merely reflecting a living confluence of top-down and bottom-up pressures. The information is now out there in the system and it is making the synaptic patterns we observe.

This kind of topsy-turvey picture can only be resolved by taking a more holistic view of the brain as the organ of consciousness. The whole shapes the parts as much as the parts shape the whole. No component of the system is itself stable but the entire production locks together to have stable existence. This is how you can manage to persist even though much of you is being recycled by day if not the hour.

References

Star EN, Kwiatkowski DJ and Murthy VN. Rapid turnover of actin in dendritic
spines and its regulation by activity, Nature Neuroscience 5:239-246 (2002)

Ehlers MD. Activity-dependent regulation of postsynaptic composition and signaling by the ubiquitin-proteasome system. Nature Neuroscience 6:231-242 (2003)

Shimizu E, Tang YP, Rampon C and Tsien JZ. NMDA receptor dependent synaptic reinforcement as a crucial process for memory consolidation. Science 290:1170–1174 (2000)

Lisman JE and Fallon JR. What maintains memories? Science 283:339-340 (1999)

Wittenberg GM, Sullivan MR and Tsien JZ. Synaptic Reentry Reinforcement Based Network Model for Long-Term Memory Consolidation Hippocampus 12:637–647 (2002)

 

[brainstorm]

This is going off into science fiction.

Our rules are that threads in philosophy must remain within the bounds of known science.
https://www.physicsforums.com/showthread.php?t=47294

Edit: I see Greg got here first.

My post wasn't really intended as scifi as much as I was just trying to use a concrete example to visualize the issue of death and consciousness/soul transfer. (I was just using "soul" as a short-hand for consciousness and because it seems awkward to call it "consciousness" when you're asleep, even though it's still there)

The OP was about cellular regeneration and death, and the fact that one's body may die and be "reborn" in a decentralized way many times during a "lifetime." I was trying to expand on this foundation for contemplating body/soul life/death by hypothesizing about neural "melding" and separation because it demonstrates by example that consciousness may be able to re-situate itself in a dynamic medium of living/dying cells, but it still identifies individual bodies as its host and perceives itself as continuous as long as an individual body continues regenerating its cells.

I was trying to point out that cellular regeneration of an existing body in the same individual is very similar to, for example, generating a new body to takes its place. However, because of the fact that the new body (a child or clone, for example) is perceived by the old consciousness as separate from the old body, it cannot be accepted/perceived as continuity of consciousness/soul by the old consciousness because the old consciousness perceives the old body as dying.

This is contrasted with the situation of cellular regeneration/death in that the old body dies without any perceivable discontinuity with the new body.

Who knows, though, maybe it is possible that each time you sleep and wake up, your body generates a new consciousness that gains access to the same mind, memories, etc. In that case you would be new person each morning you wake up and literally die each time you fall asleep. Dreaming might be the nascent state of "fetal" consciousness preparing for birth at the moment you wake up. There might be a dreamless period after falling asleep where your body is literally lobotomized until a new consciousness is sparked and begins accessing the patterns embedded in the circuitry for cues about how to get started.

In this sense, consciousness might replicate itself daily, the same way cells replicate themselves at different rates. You might have cells in your body older than your current consciousness, only you fail to realize it because you derive a sense of continuity from your memories, knowledge, ego, etc.

Is that less scifi?

 

[ThomasEdison]

The issue of molecular turnover is a real issue for material reductionism. Fortunately the answer does not invove souls, reincarnation, or other mystical beliefs.

Here is a column I wrote for Lancet Neurology a few years back...

++++++

How do you persist when your molecules don’t? Holism says the whole shapes the parts. And here is how the mind does indeed act to form the brain, reversing the usual reductionist story.

Do you know the half-life of a microtubule, the protein filaments that form the internal scaffolding of a cell? Just ten minutes. That’s an average of ten minutes between assembly and destruction.

Now the brain is supposed to be some sort of computer. It is an intricate network of some 1,000 trillion synaptic connections, each of these synapses having been lovingly crafted by experience to have a particular shape, a particular neurochemistry. It is of course the information represented at these junctions that makes us who we are. But how the heck do these synapses retain a stable identity when the chemistry of cells is almost on the boil, with large molecules falling apart nearly as soon as they are made?

The issue of molecular turnover is starting to hit home in neuroscience, especially now that the latest research techniques such as fluorescent tagging are revealing a far more frantic pace of activity than ever suspected. For instance, the actin filaments in dendrites can need replacing within 40 seconds, making microtubules look like positive greybeards (Star et al, 2002).

A turnover time of five days for NMDA receptors seemed pretty steep when it was reported a few years back. (Shimizu et al, 2000). But recently Michael Ehlers at Duke University Medical Center in Durham, North Carolina, reported that the entire post-synaptic density (PSD) - the protein-packed zone that powers synaptic activity - is replaced, molecule for molecule, almost by the hour. Ehlers had expected the turnover to take days and when he found no labelled protein on his first 24 hour assay, he thought he must have mucked up the experiment

Myelin and RNA molecules seem to last months. And DNA is of course fairly hardy, though it still needs continual repair. But on the kinds of figures that are coming out now, it seems like the whole brain must get recycled about every other month. And certainly everything points to the synapses as being about the most dynamic part of the whole system.

Clearly the shape of the synapses IS somehow maintained despite the molecular turmoil. But there is an issue here that demands some specific theory. The stability of brain circuits cannot simply be taken for granted.

Princeton University's Joe Tsien – famous for making mice smarter by splicing in slower-closing NMDA receptors – is one of a number of researchers pursuing the idea that synaptic structure may be stabilised by pressure from both above and below.

Many people know about the emerging "below" picture of how shifts in gene expression patterns could be necessary to underpin neural learning. Put simply, the genes remember what kind of state a junction ought to be in and so keep rebuilding the same old structure. As a relative oasis of calm in the thermodynamic bustle of a cell, the genes could anchor the homeostatic network needed to allow a given synaptic pattern to persist.

Of course, this story is complicated by evidence that RNA actually in the dendrites may do the same job. But it seems to be a "loops within loops" mechanism with short-loop local feedback nested in long-loop feedback between synapses and genes (Lisman and Fallon, 1999).

But Tsien says that as well as this shape-maintaining pressure from within, synapses may be just as dependent on pressures from without - the old "jangling trace" hypothesis. Back in the early 1990s it was discovered that there is a kind of compressed replay of the day's accumulated memories during slow wave sleep. The networks of cells active during learning would burst to life again. This led to the theory that the hippocampus consolidates new learning to the cortex when the brain is off-line.

But Tsien feels this spontaneous jangling of neural traces is probably a much more general homeostatic mechanism that helps to keep labile synapses stabilised. And the jangling probably goes on around the clock, in all areas of the brain, at regular intervals to remind each synaptic connection of its place in the great scheme of things (Wittenberg et al, 2002).

All this Byzantine complexity does matter. To make sense of the brain as an information processing system, clearly we must be physically able to locate its information. And it’s long been an almost unquestioned tenet of neuroscience that neurons with their weighted junctions and crisp connection patterns are devices for trapping information. The hardwired network is the solid foundation for all the pretty patterns that play across it.

Yet when we zero in on these synapses, suddenly their “information” appears to scatter. The synapses turn out to be merely reflecting a living confluence of top-down and bottom-up pressures. The information is now out there in the system and it is making the synaptic patterns we observe.

This kind of topsy-turvey picture can only be resolved by taking a more holistic view of the brain as the organ of consciousness. The whole shapes the parts as much as the parts shape the whole. No component of the system is itself stable but the entire production locks together to have stable existence. This is how you can manage to persist even though much of you is being recycled by day if not the hour.

References

Star EN, Kwiatkowski DJ and Murthy VN. Rapid turnover of actin in dendritic
spines and its regulation by activity, Nature Neuroscience 5:239-246 (2002)

Ehlers MD. Activity-dependent regulation of postsynaptic composition and signaling by the ubiquitin-proteasome system. Nature Neuroscience 6:231-242 (2003)

Shimizu E, Tang YP, Rampon C and Tsien JZ. NMDA receptor dependent synaptic reinforcement as a crucial process for memory consolidation. Science 290:1170–1174 (2000)

Lisman JE and Fallon JR. What maintains memories? Science 283:339-340 (1999)

Wittenberg GM, Sullivan MR and Tsien JZ. Synaptic Reentry Reinforcement Based Network Model for Long-Term Memory Consolidation Hippocampus 12:637–647 (2002)

That's a really good article you wrote.

Can you give me the source for this part?

"Back in the early 1990s it was discovered that there is a kind of compressed replay of the day's accumulated memories during slow wave sleep. The networks of cells active during learning would burst to life again. This led to the theory that the hippocampus consolidates new learning to the cortex when the brain is off-line. "


I've thought that for a long time but never heard of any proof. Who made the discovery? Where can I read about this idea?

I always assumed that's what dreams were and that the symbolism within dreams was a way of compressing/encoding the information but like I said I never heard about anyone else having that opinion much less any proof.

 

[apeiron]

I've thought that for a long time but never heard of any proof. Who made the discovery? Where can I read about this idea?

I always assumed that's what dreams were and that the symbolism within dreams was a way of compressing/encoding the information but like I said I never heard about anyone else having that opinion much less any proof.

Thanks Thomas. The original paper was...
http://www.sciencemag.org/cgi/content/abstract/sci;265/5172/676

I actually first heard about the research on a trip round McNaughton's lab before publication.

But note that this is an NREM story rather than REM. So not dreaming sleep at all. (And in rats of course).

Also worth pointing out that there is a suggestion of 90 minute rhythms throughout the day (so even during waking) when some kind of "jangling" could be going on. But I don't remember how definite that finding was.

I've studied sleep and dreams quite a lot and personally see REM as essentially functionless. It is just a way of getting brain back up to waking speed without actually waking.