Wednesday, December 26, 2007

Human consciousness could be immortal

Our subjective experience of the 'continuity' of consciousness is surely an illusion. But what makes that illusion and why is it so compelling? That's a deep question but here are I think two fundamental reasons:

1. Embodiment. You are an embodied intelligence. It is a mistake to think of mind and body as somehow separate. Our conscious experience and its awakening as a developing child is surely deeply rooted in our physical experience of the world as mediated through our senses.

2. Environmental continuity. Our experience of the world changes 'relatively' slowly. The word relative is important here since I mean relative to the rate at which our conscious experience updates itself. Of course we do experience the discontinuity of going to sleep then waking to the changed world of a new sunrise, but this is both deeply familiar and predictable.

A word that encompasses both of these is situatedness. Our intelligence, and hence also conscious experience is inextricably situated in our bodies and in the world. Let me illustrate what this might mean with a thought experiment.

Imagine a brain transplant. Your brain complete with its memories and life's experience, together with as much of your central nervous system as might be needed for it to function properly were to be transplanted into a different body. You would wake from the procedure into this new body. I strongly suspect that you would experience a profound and traumatic discontinuity of consciousness and, well, go mad. Indeed it's entirely possible that you simply couldn't (and perhaps mercifully) regain or experience any sort of consciousness at all. Why? Because the conditions for the emergence of consciousness and the illusion of its continuity have been irreversibly broken.

However, if what I have said above is true, there's a flip side to the story that could have extraordinary consequences.

If the continuity of consciousness is an illusion then, in principle at least, it might be possible to artificially perpetuate that illusion.

Imagine that at some future time we have a sufficiently deep understanding of the human brain that we can scan its internal structures for memories, acquired skills, and all of those (at present dimly understood) attributes that make you you. It's surely safe to assume that if we're able to decode a brain in this way, then we would also be able to scan the body structures (dynamics, musculature and deep wiring of the nervous system). It would then be a simple matter to scan, at or just before the point of death, and transfer those structures into a virtual avatar within a virtual world. The simulated brain structures would be 'wired' to the avatar's virtual body in exactly the same way as the real brain was wired to its real body, thus satisfying the requirement for embodiment. If the virtual world is also a high fidelity replica of the real world then we would also satisfy the second requirement, environmental continuity.

I would argue that, under these circumstances, the illusion of the continuity of consciousness could be maintained. Thus, on dying you would awake (in e-heaven), almost as if nothing had happened. Except, of course, that you could be greeted by the avatars of your dead relatives. Even better, because e-heaven is just a virtual environment in the real-world, then you could just as easily be visited by your living friends and relatives. Could this be the retirement home of the far future?

In this way human consciousness could, I believe, be immortal.


  1. Every cell in my body will be replaced in something like the next 10 year. So my body will be entirely different, yet my mind will keep the same identity. So it is actually very reasonable to think of the body and mind as separate entities. Plus they do not have the same properties. Your mind is too abstract to be "downloaded." If I was blown up, you couldn't bring me back by reconstructing my body atom for atom. Even if you did create a conscious being (doubtful), it would a new person. Why? Because what happens if you construct 2 or 3 new "me's," which particular body do "I" continue to live in. Obviously none of them, I am dead. The new persons, even with memories of being me, are simply not the same. You will die, and either there is a spiritual afterlife to which you will go, or your existence will end.

  2. The continuity of consciousness is not an illusion, your consciousness continues while you are asleep (that is why you can hear your alarm clock in the morning).

    If I was blown to pieces, and you reconstructed my body atom for atom and created a conscious body with all my memories (probably not even possible in any sense), you may be deluded into thinking it is me, but it would not be. It would be a new consciousness, and I would still be dead. If you disagree with that, ask yourself what would happen if you created 2 or 3 identical copies of my body. They would all remember being me, but none really would be. I would still be dead. Now even if you could download your consciousness (ridiculous idea, you can't), it would be no different to creating a new brain, which would remember being an old dead person but would not be. Plus your "e-heaven" is a cruel and illusory existence for the poor mind you choose to create and stick in there, it would have false memories, interact with false relatives, come to question the reality of its existence but still be a slave to the supercomputer in which its information is written.

    I'll just take my chances with real heaven. If not, my existence will end and I won't know any better. Still I expect the mind exists in a way more remarkable than what we understand, because there are concepts that exist in the mind (pleasure and pain) that do not have any basis or reality in the physical world. What are concepts, how does the mind comprehend them, how does their existence come about? Questions we cannot answer probably because the mind is a little beyond our understanding.

    1. Continuity SEEMS so real it is just a lack of imagination that makes us refuse to consider it illusory. But imagine this. At each moment as your mind and memory changes, you experience consciousness, memories, introspection, etc. You remember thebprevious instant and so of course it sems constinuous. If you were copied several times, evennif there was a delay in the process, each "you" would have memories, totally false for the copies, of having existed in the past. All of "you" would be thoroughly convinced you existes before..just like the real you would fel that and for the exact same reasons. You can only experience then "specious present" as it is called. All else is just memory. No reason it cant be copied leading to the same experience in the present of havingnlived in the past. You would not have tonworry about "ceasing to exist" if you were for instance to step into a star trek transporter. Their IS NO continuity to be broken. Their isb only in each instant having memories of the past. Naturally you in thenpresent feel there was a you in the past that lived those memories. But your present consciousness is the same even if those memories are false. You have no way of knowing in each consecutive present instant if younwere just then created with all your memories already in place. There is no experience of continuity but only your present memory of having been you all your life. Even if you KNOW this to be true it isnpretty much impossible to convice yourself of it as our brains only work on the assumption that our memories are would one feel though if a video existed which one accepted as real showing one being grown in a tank, implanted with memories, at your computer, and "started up" only five minutes ago? How do you know this didnt happpen. The present "you" can deny it but future younis nonexistent and past you is only accessible through memory of ezperience, not real experience. Because as I said there is ONLY the exact present moment, all else is in the mind, as far as you can ever be aware. Scary, no?

  3. Hello David

    Thank you very much for your interesting comments. You've made too many points for me to answer here, so I propose to write a new blog post over the next week or two. In particular I want to address the puzzle of how you continue to be you, even when - as you rightly point out - the cells in your body are replaced every 7 years or so. Actually I think the answer is not as puzzling as it may seem, nor does it require a separately existing 'mind' distinct from body.

    Thanks again David.