yan king yin <y.k.y@(no spam please)lycos.com> wrote in message
news:9pnkq8$jjs14 at imsp212.netvigator.com...
> "Filip van den Bergh":
> > Usually, I refrain from posting into a thread I have not read entirely.
But
> > the sun is shining and I live in the Netherlands, so it's not a usual
day.
> >
> > You are wondering as I understand about the function of sleep. I do not
know
> > from what perspective you appreciate sleep, but an evolutionairy
perspective
> > seems useful when sleep and the mind are seen as biological. The
following
> > is not my intellectual property, it can be read in Kalat (1998). I'm
unsure
> > where he got it, and I don't have a copy here.
> >
> > Why sleep? I ask you a different question: why be awake?
>> I have read the relevant chapter in Kalat's book "Biological Psychology".
> I can only get the 1988 edition, the 2001 one being borrowed. I guess
> i understand the basic argument for the evolutionary perspective. It
> makes a lot of sense, especially when comparing total sleep time among
> species, but i have some objection.
>> As a human being i sometimes feel that i sleep way too much and i
> think it should be much more advantageous for me if i can sleep less.
> Is this unique to human beings? Are we the only species that occupy
> ourselves with so many activities?
>> But it seems likely that the need for more wakeful time is also true for
> other species -- better chance to escape from predators, more time for
> reproduction, etc. Thus, if sleep does NOT serve any special function,
> then sleepless animals would have evolved and replaced the sleeping
> population.
I think that you are wrong here. Being awake is costly to an animal. Moving
around itself costs resources, therefore, an animal will find a precise
balance between sleep and gathering resources. There are great differences
between animals, some sleeping only several hours each day. Animals that can
afford to sleep will do so. Humans are taken out of evolutionairy context,
their struggle for resources is much different from the struggle they
evolved to survive. This may explain your adverse effects.
> The conclusion seems to be that sleep has some special function. It
> could be recuperative, such as replenishing neurotransmitter stores.
Well, sleep is essential for the hippocampus to consolidate memory (although
that theory may be old by now). During REM sleep, activation of memory
structures allows for a more permanent storage of memories. But still, I
would say the function of sleep is to avoid the encumbrance of being awake.
> So i think the waking state, rather than sleep, should be regarded as
> the "default" state.
>> y.k.y
>
I disagree. I believe there is a careful balance between the two, in that an
animal walks around as much as it can afford.
Filip