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Article 2546 of comp.ai.philosophy:
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>From: weemba@libra.wistar.upenn.edu (Matthew P Wiener)
Newsgroups: comp.ai.philosophy
Subject: Re: Waking up is hard to do, but somebody's got to do it
Message-ID: <61668@netnews.upenn.edu>
Date: 8 Jan 92 15:57:20 GMT
References: <60551@netnews.upenn.edu> <334@tdatirv.UUCP> <60759@netnews.upenn.edu> <350@tdatirv.UUCP>
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Reply-To: weemba@libra.wistar.upenn.edu (Matthew P Wiener)
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In-reply-to: sarima@tdatirv.UUCP (Stanley Friesen)

Since you've been away for two weeks, I have edited less than usual.

In article <350@tdatirv.UUCP>, sarima@tdatirv (Stanley Friesen) writes:
>In article <60759@netnews.upenn.edu> weemba@libra.wistar.upenn.edu (Matthew P Wiener) writes:

>|>I guess I have a hard time seeing such an *expensive*, *dangerous* (in the
>|>wild) activity being a mere byproduct of some other, rather generalized
>|>process.

>|It's easy, if you think of the whole picture.  Predators have always been
>|one step ahead in the evolutionary game.  They have to be.  So guess who
>|develops sleeping first?  The beastie that isn't at risk.

>It's not that simple.  A large, fierce predator, when it is asleep,
>is at risk from even smaller, less powerful predators.  Lions sleep
>in prides at least in part so one wakeful individual can guard those
>sleeping from hyenas.

But sleep *did* evolve.  Your lion example is not in contradiction to my
one-line scenario.  Lions today are at risk because hyenas are smart enough
to recognize when a lion is asleep.  I'm hypothesizing a situation where
no big creature has the problem of intelligent enemies.

Consider the bizarre case of the Indus dolphin.  It is extremely dangerous
for it to sleep.  Its habitat is the Indus estuary.  This species is blind,
and relies on sonar to avoid collisions.  Sleeping for even five minutes
means it risks crashing into rocks, or miscellaneous debris (especially
during monsoon season).  Yet sleep it apparently does--in frequent 10-30
second-long "catnaps".  The porpoise and the bottlenose dolphin sleep
half a brain for one hour at a time.  They would drown if they slept
normally.

>The difficulty comes in at the level of incremental function.  Does the
>added cognitive function derived from *minimal* consciousness (in a brain
>just above the condensation point) provide sufficient extra adaptability
>to offset the danger of sleeping.

This is only a difficulty if you postulate full sleep at first.  I do not.
I'm conceiving of partial or occasional consciousness, having a penalty of
just needing to doze (like your rabbit below) or frequent catnap or half a
brain at a time sleep.

>A good example is a film I saw on TV a few weeks ago, of a Beaded Lizard
>(related to the Gila Monster) stalking a dozing rabbit.  The rabbit, since
>it was only dozing, and not fully asleep, was alerted and slipped away.
>But stalking a sleeping animal must be successful occasionally, or the
>Beaded Lizard's ancestors would have evolved mechanisms to avoid the waste
>of time and energy. [...]

Remember: evolution of sleep did occur, even though some animals lose.

>So what behavioral benefits come automatically with any consciousness at all?

Desire to survive is better than just instinct to survive.

>|Truce can evolve quite naturally in the middle of war.  See Robert Axelrod
>|THE EVOLUTION OF COOPERATION for detailed examples.  I see no conceptual
>|difficulty in translating his sociological perspective into an ethological
>|one.

>Except it hasn't, sleep in nature is still very dangerous.

Well yes.  But I mentioned the truce example as an extreme: what we actually
have is a slow down in the intensity.

>							     That is why
>most small animals sleep in burrows or holes in trees, and even bears seek
>out obscure, hard to find caves. [and why we generally limit our sleeping
>to our artificial caves - where we feel safe].

And warmth has nothing to do with it?  Assuming the dinosaurs were cold-
blooded, I'd expect that there was a massive slowdown of animal activity
at night 1e8 years BP.  Enough so that the mammals could get away with
evolving sleep.

>|Try again.  As an evolutionary biologist, you've responded too quickly.

>As stated above, your model of predation fails to allow adequately for
>opportunistic kills.  A very common occurance in nature.

No, opportunistic kills will still occur in my view.

>|>And it is not really an assumption or even a conclusion so much as a
>|>hypothesis.  But I consider it a reasonable one, and it removes the *need*
>|>for a seperate, purely neurological, explanation for sleep.

>|Here you go again, focussing on mind and not mind_and_sleep.  The latter
>|is just as apriori likely as the former to be the correct domain to study.

>Perhaps, but it is necessary to demonstrate the need for the linkage.
>A linkage is an added component that needs independent verification.

There is independent verification: no physiological basis for sleep is
known, despite decades of research, and massive amounts of mind-based
correlations with sleep and near-sleep and waking are known.

>I tend to see evolutionary origins for most specific details of animal
>behavior, and do not see many of them as being *necessary* to cognition,
>only related to it by implementation.

So what's your model of the evolution of sleep?  I've only seen one book
on the subject, and it doesn't get into the whys.

>Thus an entity that did not sleep, but could still talk intelligently would
>still be a candidate for being considered conscious.  Some additional
>evidence would be needed to *exclude* the possibility.

For sure.  Total sleep deprivation of mice leads to death within three
weeks.  One presentation of encephalitis lethargica was agrypnia, and
those victims died within two weeks.  There are a few (extremely few)
documented cases of agrypnia lasting for months, ending in death.  They
were conscious and had nighttime headaches/hallucinations, but I know
of no such case with an accompying neurological examination.

>I guess I am mainly taking a "show me" attitude.  Searle's, and to some
>degree Perlman's, seems too philosophical to me to be considered reliable.

And I'm taking a "consider this" attitude.  Grounded in as little philosophy
as possible.
-- 
-Matthew P Wiener (weemba@libra.wistar.upenn.edu)


