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Article 2619 of comp.ai.philosophy:
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>From: sarima@tdatirv.UUCP (Stanley Friesen)
Newsgroups: comp.ai.philosophy
Subject: Re: Waking up is hard to do, but somebody's got to do it
Message-ID: <363@tdatirv.UUCP>
Date: 9 Jan 92 17:07:30 GMT
References: <60551@netnews.upenn.edu> <334@tdatirv.UUCP> <60759@netnews.upenn.edu> <350@tdatirv.UUCP> <61668@netnews.upenn.edu>
Reply-To: sarima@tdatirv.UUCP (Stanley Friesen)
Organization: Teradata Corp., Irvine
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In article <61668@netnews.upenn.edu> weemba@libra.wistar.upenn.edu (Matthew P Wiener) writes:
|Remember: evolution of sleep did occur, even though some animals lose.

That is my point, sort of.  It evolved, so the added benefit of sleeping
*must* exceed the danger.  I think my model explains the benefit quite well.
Especially since sleep does *not* seem to be correlated with anything like
'intelligence'.  Even reptiles enter torpor of some sort at various times.
It is not entirely clear that this is really any different than mammalian sleep.

|>So what behavioral benefits come automatically with any consciousness at all?
|
|Desire to survive is better than just instinct to survive.

What does this mean?  What is a desire except a particular class of instinct?
Or do you restrict the word 'instinct' to refer to insect style pre-wired
behavior?  If so, there is precious little instinct amoung amniotes.
[In short, I suspect the 'survival instinct' of even reptiles takes the form
of *feelings*, like fear, hunger and so forth].

|>							     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?

Not in the tropics.  Humans live in buildings even in the warmest climates.

| 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.

There is a problem here. Almost all Cretaceous mammals were *nocturnal*,
sleeping, if at all, during the *day*, when the dinosaurs *were* active.

Also, given that crocodiles doze, and birds apparently sleep, it is quite
likely that dinosaurs themselves slept from time to time.  [A crocodile's
dozing is *not* strictly temperature related torpor, they can switch quickly
from dozing to full activity, which would be impossible if it were low-temp
torpor].

|>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.

Exactly, and opportunistic kills are what makes sleep dangerous, so dangerous
that it must have a simple, direct survival advantage.

I still do not see enough of an advantage to minimal consciousness to offset
the danger of opportunistic kills.

|>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.

Unfortunately, these are also very weak, since sleep occurs in animals with
relatively simple brains, and hence minds.  It is almost as if any level of
processing above that of reflex requires some form of sleep.  [I have heard
it said that even fish sleep, and they have almost no cerebral cortex].

|>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.

I have already stated, it is for the purpose of Preventative Maintenance.
It allows the body and brain to clear out the accumulation of crud associated
with the day's activities.

|For sure.  Total sleep deprivation of mice leads to death within three
|weeks. 

But what did they die *of*?  What was the *proximal* cause?  If it was
any sort of physical collapse (like heart failure), this is perfectly
consistant with the PM hypothesis.  In fact this level of toxicity in
unrested tissues would *easily* override the much smaller risk of death
while sleeping.

What reason is there to think the death in this experiment was due to
*mental* causes?

|>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.

I *am* considering it.  I just don't intend to accept it until it is
demonstrated.
-- 
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uunet!tdatirv!sarima				(Stanley Friesen)



