[extropy-chat] Fragmentation of computations

Stathis Papaioannou stathisp at gmail.com
Wed Mar 21 12:39:04 UTC 2007

On 3/21/07, Eugen Leitl <eugen at leitl.org> wrote:
> On Wed, Mar 21, 2007 at 08:57:48PM +1100, Stathis Papaioannou wrote:
> >
> >    Computationalism implies that a stream of consciousness survives
> >    fragmentation of the process generating the stream. If it did not,
> >    then there would be some change in experience as a result of
> >    fragmentation. For example, if an experience supervenes on past
> I don't know what computationalism is, so I take that as a definition.

It's not the definition, it's what I'm trying to prove. Computationalism is
the idea that you could swap your brain for an appropriately configured
digital computer and continue to have the same kinds of subjective
experiences. Computationalism would be wrong if we had a God-given soul or
if Penrose were right and the brain is not Turing-emulable.

Computationalism means that the trajectory sequence doesn't matter.

I think it does, but it appears that you think it doesn't.

The immediate objection: which process produces the trajectory slices
> which are out of sequence, but belong to the same trajectory?
> Enumeration only works for trivial state space sizes. Computing
> shortcuts are available only for some trivial systems, so you have
> to compute the trajectory in sequence, which defies the purpose
> of assembling the trajectory out of sequence.

That objection relates to how the states will be generated, not to what
would happen if they were generated out of sequence. If I asked you whether
a car would still function as a car if it were thrown together in exactly
the right configuration by a storm rather than assembled in a factory, would
you answer that it wouldn't, because it is very unlikely that such a thing
would happen? In any case, you can assume that the computation is run in
sequence the first time, then out of sequence on the second run using
information from the first run.

How do you verify the subjective experience? The only way to do that would
> to
> access the trajectory frames, which requires information about
> the sequence of trajectory frames.
> See, there's a giant can of worms implied.

You verify it the way any psychological experimenter would: by observing the
subject's behaviour, in this case perhaps on a computer screen if the
program includes a visual representation of the action.

>    computational states as well as on the present instantaneous state,
> >    then arbitrarily slicing up the computation will change and perhaps
> How would you "arbitrarily slice up the computation"?

By stopping it and starting it at various intervals,  changing the clock
speed, changing the computer, saving it at various points and using this
information the second time to run it out of sequence.

>    completely disrupt the stream of consciousness. Consider a time
> >    interval t1t2t3 in which a simulated subject perceives a light
> >    stimulus (t1, t2, t3 are according to the clock within the
> >    simulation). The light is shone into his eyes at t1, and he presses a
> >    button at t3 to indicate that he has seen it. Now, suppose that the
> >    computation is cut at t2, so that the interval t1t2 is run several
> >    real time days before t2t3, or several days after, or not at all.
> Then
> >    since the experience during t2t3 is dependent not only on the
> >    computational activity going on in that interval, but also on what
> has
> >    gone on before, perhaps by excising t1t2 from its normal position in
> >    relation to t2t3 the subject will not perceive the stimulus, or not
> >    perceive it in time to press the button at t3. But that would mean
> the
> >    same computation (and same physical activity in the computer
> >    generating the computation) in t2t3 would in one case result in the
> >    subject pressing the button and in the other case not, which is
> absurd
> >    if computationalism is correct. Hence, the only reasonable way to
> look
> >    at it is to say that consciousness supervenes on the instantaneous
> You keep using that word. Nobody but you knows that that word means.

Consciousness, supervenes on or instantaneous?

consciousness =  having experiences
supervenes on = a little involved, see
http://en.wikipedia.org/wiki/Supervene, but let's just say it means "caused
by" for the sake of this argument
instantaneous = same usage as in calculus (approximately, since
computational states are discrete)

>    computational state (or more simply, consciousness *is* the
> >    instantaneous computational state), which makes it impossible to know
> >    from the inside whether your computation has been fragmented.
> You still haven't replied how to verify the subjective experience of a
> Hash Life observer in a observer/virtual world implemented in the Life
> CA. Verify as: measure.

You can't really *know* what someone else is thinking, but you can observe
his behaviour or ask him.

Stathis Papaioannou
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20070321/d8b78640/attachment.html>

More information about the extropy-chat mailing list