Re: consciousness based on information or computation?

From: Wei Dai <weidai.domain.name.hidden>
Date: Wed, 27 Jan 1999 16:18:09 -0800

On Wed, Jan 27, 1999 at 01:22:02PM -0500, Jacques M Mallah wrote:
> And it's not at all clear to me that static strings, without
> dynamics or decisions, could have anything to do with consciousness.
> Stalemate. We may never agree on this one. I think more people
> would support my position than yours, but that's not saying much.

Let's see if there isn't a reasonable way out of this stalemate. First of
all it's obvious that consciousness must have something to do with
information. Now a binary string is the simplest kind of object that can
contain information, but any discrete structure that can contain
information can also be encoded as binary strings. Therefore binary
strings are a universal container of information. If pure structure can
sustain consciousness, then binaries strings can sustain consciousness. Do
you agree so far?

You don't seem to think that pure structure is sufficient for
consciousness. Why? Clearly we experience dynamics and decisions, but
could they not just be illusions? Is there a deeper reason why dynamics
and decisions are necessary for consciousness?

> No, that's not what I said. For the shortest program, the
> simulated environment would no doubt be vastly simplified compared to what
> we observe. But the basic elements of competition for survival and
> the advantages of communication would be there. It will take many
> generations to evolve intelligence, of course.

But there is no reason to think that intelligence will easily evolve in
any competitive environment. Neural networks have been in existence a lot
longer than intelligence. Some people even argue that the evolution of
intelligence on earth is a pure coincidence. I wouldn't go that far, but
the evolution of intelligence clearly depends on a fairly small set of
environments.

> You know as well as I do that an approximate solution is good
> enough for our purposes and much easier to find. To be fair, the length
> of both the form you proposed (and which I had earlier rejected), and of
> the competitors such as the neural nets in the simple environment, should
> be estimated. Maybe a good (and neutral) computer scientist could give us
> those estimates without too much work.
> My proposal to find a definition of implementation of a
> computation is much more conservative than your approach, since it also
> applies to regular theories of physics, and is in the established
> tradition of computationalism. I admit it requires more work but I don't
> think it's hopeless; and if it is, that's just as important to know.

I think your approach is an interesting one, and not hopeless (as far as I
can see). But then it's quite difficult to discuss an approach that
is missing the definition for a basic concept.

> Just that it would take a big program. Of course the neurons must
> also be numbered in some sensible way.

Ok, you have your estimate, and I have mine. The numbering of course can
be based on spatial position.

> On the contrary. Some programs will just rewrite the same part of
> the tape, and those we can neglect for now. But some will keep printing
> out copies of the same string end on end, and the ones that halt will have
> zero measure compared to those, since more copies means more measure.
> This gives a slight advantage to short strings.

No I assume that each tape only contributes to the measure of the entire
string on the tape, not to the measures of substrings. (I.e., you can only
be an entire tape, not part of a tape, if you want to think of it that
way) Otherwise the measure will be completely dominated by simple counting
programs that write out 0's and 1's as fast as they can.

> Here is a serious problem for you. The Turing machines start out
> will all possible programs, that is, with all possible infinite strings on
> the tapes. At any finite time, no matter how large [and therefore in the
> limit], the fraction of the tape that even the repeat printers have
> covered is equal to zero. So the printed strings have zero measure
> compared to the infinity of random strings on the as yet untouched part of
> the tape, even though the fraction of those that are conscious is small.

That is not the model I have in mind. It doesn't seem sensible to think of
a universe with a continuous infinity of Turing machines. Instead I assume
that the universe starts with one Turing machine with a blank (read-only)
input tape, then before each clock cycle each existing Turing machine is
cloned, with 0 appended to the input tape of one copy, and 1 appended to
the input tape of the other.
Received on Wed Jan 27 1999 - 16:20:08 PST