Necessary conditions for consciousness

Theophilus Samuels theophilus.samuels at
Tue Feb 6 13:32:25 EST 2001

If you can, I would seriously consider reading the book entitled 'Going
Inside' by John McCrone (ISBN 0-571-20101-6), it is aimed at the general
public but nevertheless contains some very readable material about 'a single
moment of consciousness'.


Jeffrey Kazuo Yoshimi <yoshimi at> wrote in message
news:Pine.OSF.4.30.0102051315330.11515-100000 at
> Hi,
> I am a philosopher studying consciousness and the brain, which tends to be
> sort of annoying (the experimentalists do all this hard work and then
> arm-chair cowboys speculate about it and get it wrong in the process) but
> I appeal to your patience and ask some questions.
> Assume that for a brain to produce conscious experience, it is necessary
> that some set of conditions obtain.  Take away any ci from a
> consciousness-producing brain, and the brain in question no longer
> produces consciousness.  Of course we could not prove that any such
> condition is necessary, but I'm not looking for proof, just empirical
> hypotheses about what such conditions might be.
> I would guess that some such conditions might be:
> c1: At least some number n of neurons must be firing (can there be a
> conscious-brain where no neurons fired?)
> c2: These n neurons must fire above some threshold. (do m > n barely
> active neurons give rise to consciousness?)
> And so forth.
> Perhaps this way of thinking about the question is wrong.  If so, why?  If
> not, are there speculations on how many neurons are minimal for
> consciousness, and /or what threshold must be surpassed?  Are there other
> hypothesized conditions ci?  Perhaps glial cells do something that is
> essential, perhaps a medium which allows an electrical field surpassing
> the local field is essential (i.e. imagine a brain with firing neurons but
> silicon replacements for the glial cells or some sort of insulation
> surrounding all the neurons).
> So I descend into the philosopher's most dangerous luxury--thought
> experiment.
> If any of this stuff is answered in any existing text (I was thinking
> anesthesiology textbooks might be useful), or is speculated about in any
> way, or is completely wrongheaded, I'd like to hear about it.
> Thanks for your patience!
> Jeff Yoshimi
> UC Irvine
> PS: Another good question, to me.  Could sufficient conditions be
> specified such that any brain meeting them produces consciousness?  This
> would be like a recipe for a consciousness-producing brain (is
> "consciousness-producing" an acceptable phrase?) which would encompass
> the necessary conditions above.

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