Memories: Brain vs Soul

Question from Marie-Denise:
If memories and thoughts completely come from one’s brain and not from a person’s soul, then why do we keep our memories even though we know every cell in one’s brain is regenerated every few years? Thanks.

Answer by SmartLX:
Quite simply, they’re passed on.

Memories are stored in the brain as electrical patterns, which don’t reside in individual cells but travel around certain areas of the brain as needed, for instance when you’re figuring out where you left your keys. If a brain cell dies while hosting part of a memory, that part can often be recreated by the rest of the brain, or else there’s another copy in there somewhere, so the impact on your overall memory is minimal. (Daniel Dennett is fond of saying, “Every time you read it or say it, you make another copy in your brain.” He then repeats this twice.)

Actually, brain cells aren’t replaced like the other cells in the body. Glial cells are, but the all-important neurons hardly regenerate at all. Therefore maintenance of memory is not really a matter of tagteaming from old cells to new cells, but rather a process of shuffling between existing cells. The brain is only too happy to do this, because it’s by transferring memories and other thoughts from cell to cell that we “think” about them.

The idea that the soul is the source of certain thoughts carries its own conundrums, chiefly the fact that every known mental process can be permanently impaired or completely disabled by sufficient brain damage. If an ethereal soul is solely responsible for any observable function, that function should be impervious to physical injury, and this has never been observed. If instead the brain functions as a conduit for every “action” of the soul, there is no evidence for the existence of an independent soul. Don’t feel put-upon though – believers in an incorporeal “mind” independent of the brain have the same kinds of problems when justifying their view, so this is not purely a matter of theology.

8 thoughts on “Memories: Brain vs Soul”

  1. The question from Marie- Denise about memory retention is
    one I have often heard from Christians who believe that a
    human being posses a soul, that soul being a consciousness that
    is not generated by the brain. In the first place, if they read their bible, they would see that the soul only denotes the physical body.
    A soul according to the bible, is simply a living human being and
    nothing more.
    The bible also says we have a spirit and it says that spirit is not
    Immortal, ceases to exist at death, and only god can restore it.
    And even then, not until the resurrection as described in the book of revelations. What common sense and science tells me is what I believe to be the truth, that the brain generates the consciousness. When the brain dies, that consciousness dies with the body and both are dead and gone, forever. I do not believe there is a god and I do not believe in any resurrection or any life after death. Life after death is an oxymoron and an utterly ridiculous statement. People who believe to the contrary have been brainwashed for so long by religious doctrine that they do not want to hear or know the truth. It is too upsetting for them to hear.
    I have read and studied the bible since early childhood. I have also read and studied evolution. So, I know both sides of the coin. Most christians do not. In fact, I have found that most do not really even know what the bible says about death and after life. They make up their own version of what they want it to say, and what they want to believe. They do not want to know or hear the truth as it is too upsetting for them.
    God is the theory, evolution the fact. Man invented god, Not the other way around. It amazes me that in this day and age, when any one who seeks the truth, and has all the scientific information at their fingertips to prove it, will then opt for the superstitious, mythological and illogical tall tales of the bible instead of the facts that science provides. I call it… out of touch with reality.

  2. If brain cells regenerate like the rest of the rest of the body wouldn’t that mean u r just a clone of ur self because ur whole body changed over the last year but we all know that we are ourselves if we did not possessing a soul that wouldn’t be possible so we do possess a soul

    1. There seems to be much misunderstanding about this issue. A few points:

      The first point is that although peripheral nerve cells, such as in limbs, have some natural degree of self-repair and regeneration, central nervous system (brain and spinal chord) normally do not. That’s why trauma such as injury or stroke has such a devastating effect on memory and our concept of self-identity, as do disease processes like Parkinson’s and Alzheimer’s. We can even observe abrupt changes in sexuality and/or religious belief (both increase and decrease) after brain damage. So it’s patently obvious that memory (and so our subjective sense of self) is encoded in neurons and only in neurons.

      The second point is that memories are not encoded in individual neurons but in specific firing patterns of networks involving hundreds of thousands and millions of neurons. These networks always overlap which is why when you have a thought it automatically leads to a cascade of other thoughts as these overlapping patterns are activated. Anyone who has ever tried to meditate will know how difficult it is to not have any thoughts at all. We (i.e., our sense of self) is not something we have any real control over. We are completely at the mercy of whatever neural firing patterns happen to be activated by whatever stimuli are present at any one time. That’s why nearly all those who have done neuroscience research (including myself, though I no longer work in the field) do not accept that we have a completely free will (i.e., libertarian; Alvin Plantinga-type Christian-style free will). But that’s a whole other subject.

      The third point is that memories are not encoded in neuronal firing patterns and then rest in stone forever. These patterns of firing are (damage and aging notwithstanding) always subject to alteration. There is a shedload of psychological research (and more) demonstrating that, at even short intervals, eyewitness reports from multiple people will differ markedly, or that people will reliably erroneously report events that have happened in their own past compared to the objective evidence that is available. We don’t really hold memories; we reconstruct our knowledge about the past using all kinds of inferences from experiences we have had in the meantime. We have no choice but to do this; if the neuronal firing patterns that hold memories aren’t activated on a regular basis, they decay, and we have to fill in the bits that have decayed, or admit to not remembering.

      The fourth point is that there are different types of memories (visual auditory, olfactory etc) as well as different uses of memories (such as working, episodic, declaratory etc) and they are all encoded in different brain regions. You can lose one type of memory or aspect of a memory completely, while maintaining a good recall of other aspects of the same memory.

      The fifth point is that memory loss is not necessarily due to damage to the neuronal networks. Separate neural mechanisms are involved with collecting memories, laying down memories, long-term storage of memories and retrieving of memories. If a mistake happens at any of these stages, the memory will be damaged.

      So where does the soul fit in here? If such a thing exists is it the same one you had 50 years ago, five years ago, or even five minutes ago? Or is it some average of the lot? If you have Alzheimer’s disease, does your soul have Alzheimer’s disease too or is it ‘put on hold’ until you die? And at what point is it put on hold? Pre-dementia? Mild dementia? (the line is not sharp between them), Medium level dementia? Advanced dementia? If you lose your religious belief completely, no matter how pious you were before, as some people with Parkinson’s disease do, which ‘you’, which ‘soul’ gets judged? If you act on your newly developed feelings of uncontrollable paedophilia (as some types of brain tumour can cause), which ‘you’, which ‘soul’ goes to heaven when you die? If God judges people according to their thoughts and behaviours then, in effect, he’s judging people by those aspects of their life that neuroscience is increasingly demonstrating they have either very little or no real control over. Apart from being illogical, it’s downright immoral. Or, of course, its just mythology.

      If theists want people to take concepts like ‘soul’ seriously they need to develop some plausible mechanisms regarding the brain’s relationship between its demonstrated physical machinery and some purported non-physical entity. I’d place my money on the concept of a soul slowly but surely withering away before the naturalistic account of brain function is seriously questioned.

    2. Okay, we’ve already had the briefest possible reply and the comprehensive deconstruction. I’ll try to be more direct.

      Being a clone of oneself is one interesting way to think of what’s constantly happening in a body and a brain that is continuously regenerated. The important thing about what’s happening is that one doesn’t notice it; because the information that constitutes one’s identity is passed on from brain cell to brain cell, one never gets the sense that one is not oneself, even after all the hardware has changed. What we think we “know” about ourselves is irrelevant, and a soul is not required.

  3. The question is what is it that is maintaining our individuality u people claim that brain is the only thing close enough to be called a soul and it is the only thing maintaining our individuality. So if our brain changed over the time we would have no indivdual conscience but we do have one. So brain is not the thing which is superior there is something above it which no one can notice our soul

    1. “So if our brain changed over the time we would have no indivdual conscience but we do have one”

      Just because we experience a sense of possessing an individual ‘self’, it does not follow that an individual ‘self’ actually exists. Our sense of having such a strong individual ‘self’ is most likely an emergent property of neural complexity. In other words, a very convincing ‘neuro-illusion’ which has evolved, probably, to filter out the brain’s Heath Robinson-style parallel processing from our conscious awareness. Only a very, very small percentage of our neural computations make it to consciousness, if this were not so we would be unable to cope with the stimuli that bombard us constantly – and, importantly, we have little choice, other than utilising specific attentional mechanisms (which are far from perfect), as to what makes it to consciousness and what doesn’t. In my previous reply I gave you some examples of how physical changes in the brain, entirely beyond our control, cause changes in our conscious sense of self (lessening consciousness, heightening consciousness, and even in our sense of morality and moral behaviours). These are the very things that we use to characterise ourselves and others as individual ‘selves’. I can give you many, many more examples.

      Once we realise that these observations are universal to not only human beings but to the brains of other primates, the question I would be asking is what evidence is there of the opposite; that we have some “individual conscience” that remains completely unaffected by the integrity of neurons and their interconnections? In other words, is there any aspect of our own sense of ‘self’, or what others would recognise as our personality, that we cannot permanently damage, change or otherwise temporarily alter by changing the way our neurons work?

      If you cannot give any examples (I cannot), then on what basis do you make the claim that there exists something that is separately and identifiably our ‘self’ that is not mediated by brain function?

      Except mythology.

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