Dreaming as an evolutionary advantage

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Dreaming as an evolutionary advantage

Postby piturtle » Tue Aug 24, 2010 9:06 pm UTC

Hi all.

The subject says it all. My question is Why and How.

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Re: Dreaming as an evolutionary advantage

Postby Kow » Tue Aug 24, 2010 9:56 pm UTC

Without dreaming, our brains don't work. Brains not working means you're going to get eaten.
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Re: Dreaming as an evolutionary advantage

Postby Mighty Jalapeno » Tue Aug 24, 2010 11:48 pm UTC

May I recommend The Science Of Discworld. It has a whole section on dreaming and evolution.

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Re: Dreaming as an evolutionary advantage

Postby piturtle » Thu Aug 26, 2010 7:17 pm UTC

Thanks.

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Re: Dreaming as an evolutionary advantage

Postby bpsp » Thu Aug 26, 2010 9:15 pm UTC

Here's a theory I heard once that I've found interesting:

If you're about to be eaten by a cheetah, you need to rely on split-second, rational decisions. In order to make those decisions correctly, the brain needs to practice operating under extraordinary circumstances. For example, extreme danger or embarrassment. So in the beginning, animals dream of running from cheetahs so when this actually happens, their brains will have a better idea how to make good decisions under extreme stress. Now as humans, we dream of other bizarre situations, since having done so so has better prepared ourselves to respond to those situations in real life.

I'm not saying this is a well accepted or well backed-up theory - I just found it plausible and interesting. I could see how dreaming about driving my car into a lake or about showing up to school naked would grow out of the brain practicing operating under stress.

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Re: Dreaming as an evolutionary advantage

Postby mosiajam » Sat Aug 28, 2010 12:51 am UTC

bpsp wrote:Here's a theory I heard once that I've found interesting:

If you're about to be eaten by a cheetah, you need to rely on split-second, rational decisions. In order to make those decisions correctly, the brain needs to practice operating under extraordinary circumstances. For example, extreme danger or embarrassment. So in the beginning, animals dream of running from cheetahs so when this actually happens, their brains will have a better idea how to make good decisions under extreme stress. Now as humans, we dream of other bizarre situations, since having done so so has better prepared ourselves to respond to those situations in real life.

I'm not saying this is a well accepted or well backed-up theory - I just found it plausible and interesting. I could see how dreaming about driving my car into a lake or about showing up to school naked would grow out of the brain practicing operating under stress.


I'm fairly certain you're correct. Say, 90% certain. Having taken a year of college psychology, I sort of remember this being the explanation for dreaming. Humans are among the few animals to passively plan out future events.

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Re: Dreaming as an evolutionary advantage

Postby Clever-Username » Sat Aug 28, 2010 1:42 am UTC

mosiajam wrote:
bpsp wrote:Here's a theory I heard once that I've found interesting:

If you're about to be eaten by a cheetah, you need to rely on split-second, rational decisions. In order to make those decisions correctly, the brain needs to practice operating under extraordinary circumstances. For example, extreme danger or embarrassment. So in the beginning, animals dream of running from cheetahs so when this actually happens, their brains will have a better idea how to make good decisions under extreme stress. Now as humans, we dream of other bizarre situations, since having done so so has better prepared ourselves to respond to those situations in real life.

I'm not saying this is a well accepted or well backed-up theory - I just found it plausible and interesting. I could see how dreaming about driving my car into a lake or about showing up to school naked would grow out of the brain practicing operating under stress.


I'm fairly certain you're correct. Say, 90% certain. Having taken a year of college psychology, I sort of remember this being the explanation for dreaming. Humans are among the few animals to passively plan out future events.


You can't definitively proof a psychological theory like you can in mathematics. The best you can do is support your idea with stronger and stronger evidence until it is widely accepted as being the best explanation for what is observed in experimentation. Theories about dreams are derived from an evolutionary point of view, but there is no way to say 100% sure that one idea is the 'correct' one and the other isn't. In the case of the theory presented above it seems logical from our point of view based on what we understand from the theory of evolution, and so it makes sense that this could be a plausible theory.

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Re: Dreaming as an evolutionary advantage

Postby Telchar » Sat Aug 28, 2010 4:14 am UTC

Psychology doesn't even know why we sleep, let alone dream. Dreaming probably has something to do with your brain needing waking up from stage 4 sleep, but not becoming fully awake, so it creates a reality to hang out in.

The best theory out right now is that we sleep simply because we can't function in the dark so rather than wander around and get ourselves into trouble and hurt/killed, we sleep. However, you can't stay in stage 4 sleep for long periods or your die (SIDS is thought to be caused by the inability of the newborn brain to wake itself up to REM sleep) so you need your body to wake back up. Thus, REM sleep and dreaming.
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Re: Dreaming as an evolutionary advantage

Postby silvermace » Sat Aug 28, 2010 10:49 pm UTC

The old Freudian theory was that dreams were expressions of our unconscious desires, but none of the cool psychologists still follow Freud these days. Besides, if Freud was right far too many people have a sick fetish for being forced to take pop quizzes in their underwear.
Others have suggested dreaming is a way for our brain to formulate new ideas through the use of "random thought mutations" (one of you New Age musicians out there, you can have that album title for free).
Another theory states that dreaming is our brain tidying itself up and disposing of useless "junk thoughts." In order to buy this idea, though, you have to accept that the average guy's dreams about tits and being Batman are junk, and we're sure you agree that's simply unacceptable.
Of course both of these seem awfully high-minded when you consider that animals also dream. Does your dog really have excess thoughts he has to get out of his overloaded doggy brain?
Perhaps weirdest of all is the mounting evidence that much of what influences our dreams comes from outside, not inside, our heads. Noises and scents may have an effect on the content of our dreams, and we bet your wacky tealeaf reading, dream-interpreting aunt didn't take into account the Earth's geomagnetic activity during her analysis.

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Re: Dreaming as an evolutionary advantage

Postby mosiajam » Sun Aug 29, 2010 1:41 pm UTC

Eh, there's a reason why psychology isn't considered a "pure" science. It isn't exactly a precise study, nor is it anywhere near as pure and objective as the other sciences.

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Re: Dreaming as an evolutionary advantage

Postby Whelan » Sun Aug 29, 2010 3:38 pm UTC

silvermace wrote:Perhaps weirdest of all is the mounting evidence that much of what influences our dreams comes from outside, not inside, our heads. Noises and scents may have an effect on the content of our dreams, and we bet your wacky tealeaf reading, dream-interpreting aunt didn't take into account the Earth's geomagnetic activity during her analysis.

Anecdotal evidence and all that, but I know personally I've had dreams influenced by sounds in my room. Regularly I'll dream something, and then later people at school will be talking about it. Turns out I was dreaming along to the news on the radio. I've also had dreams involving my alarm clock, like the one where I had to figure out which apple was making the beeping, or the one where it was the signal for a barracks full of soldiers to shoot at my head.

By the way, how in the seven hells are those gonna be useful, under this theory?
bpsp wrote:If you're about to be eaten by a cheetah, you need to rely on split-second, rational decisions. In order to make those decisions correctly, the brain needs to practice operating under extraordinary circumstances. For example, extreme danger or embarrassment. So in the beginning, animals dream of running from cheetahs so when this actually happens, their brains will have a better idea how to make good decisions under extreme stress. Now as humans, we dream of other bizarre situations, since having done so so has better prepared ourselves to respond to those situations in real life.
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Re: Dreaming as an evolutionary advantage

Postby Sir_Elderberry » Sun Aug 29, 2010 5:36 pm UTC

Telchar wrote:The best theory out right now is that we sleep simply because we can't function in the dark so rather than wander around and get ourselves into trouble and hurt/killed, we sleep.

I find this pretty suspect. If sleeping is something we do simply because we can't do anything else, why is it so physiologically necessary?

how in the seven hells

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Re: Dreaming as an evolutionary advantage

Postby GeorgeH » Sun Aug 29, 2010 6:41 pm UTC

My knowledge of the subjects most directly relevant to evolution and dreaming is pedestrian at best, so please don’t read the following without first taking an extra large caplet of skepticism; it's nothing but my personal thoughts on the question.

Statement:
Dreaming is the result of errors caused by an overtaxed and overheated brain. It has no direct evolutionary benefit, but instead is a side product of the strong benefit of having a high performance brain for short periods of time instead of a lower performing brain for long periods of time.

Supporting Observations:
1)
When we get tired, we yawn. Yawning has been shown to be related to brain temperature, in that a cooler brain is less likely to yawn. The need for extra cooling before sleep seems to indicate that the brain operates fairly close to its highest average level possible over the course of the day, then shuts down for recovery at night. Why we would yawn in the morning as well as the evening is being carefully ignored. :)

2)
Hallucinations and eventually death will result if we prevent the brain from sleeping/dreaming for a long enough period of time. The progression indicates that the brain gradually begins to accumulate more and more errors as it overheats until it fails completely. Note that the mechanism probably isn’t directly temperature related, but some much messier biological/chemical breakdown process for which “overheating” is simply convenient shorthand.

3)
If intelligence is pattern recognition and predicting the most likely future, dreaming would seem to be nothing but corrupted intelligence, or in other words the product of a malfunctioning brain. We know (for various values of “know”) that the content of our dreams is affected by our waking thoughts and circumstances, that there can be value in correctly “interpreting” our dreams, and that dreams are composed of a high percentage of nonsense - all of which seem to indicate that dreams are just the continuation of our waking thought processes with a lot of additional errors thrown in.

4)
Without difficulty (or malfunction) we cannot remember our dreams nor can we physically act them out. The brain cannot shut down without the side effect of death, so the best way to deal with errors would be to greatly diminish the brain’s ability to act on and remember them, which is what we find with dreaming.

5)
In the CPU world, most compute tasks are much more energy efficient if they are run on a high power system for a short period of time instead of a low power system for long periods of time; this is one reason why CPU and OS makers typically try to have their products to operate in short, intense bursts of activity followed by long periods of relative inactivity. If the brain and its operation can be considered analogous to a computer, energy efficiency would seem to be a strong selective pressure to have it operate at a very high, unsustainable rate followed by periods of rest. More quickly realizing that something is going to eat you probably doesn’t hurt, either.


… and a few more, but I’ve a felling the straws I’m grasping at are becoming more ethereal at an exponential rate. ;)

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Re: Dreaming as an evolutionary advantage

Postby ++$_ » Sun Aug 29, 2010 9:21 pm UTC

Dreaming is probably very old, evolutionarily speaking. All mammals seem to do it.

My guess is that it's a spandrel. It's been shown that REM sleep is important for memory, and dreaming is probably just a consequence of neuronal activation during REM episodes. Of course, that leaves open the question of why REM sleep exists at all. My guess is that it constitutes an essential part of making long-term memories, and the best time to do that process is during sleep when you don't have much else to do.
]However, you can't stay in stage 4 sleep for long periods or your die (SIDS is thought to be caused by the inability of the newborn brain to wake itself up to REM sleep) so you need your body to wake back up.
[citation needed]
I've never heard of this.

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Re: Dreaming as an evolutionary advantage

Postby Telchar » Mon Aug 30, 2010 4:38 pm UTC

Sir_Elderberry wrote:
Telchar wrote:The best theory out right now is that we sleep simply because we can't function in the dark so rather than wander around and get ourselves into trouble and hurt/killed, we sleep.

I find this pretty suspect. If sleeping is something we do simply because we can't do anything else, why is it so physiologically necessary?


One of two possible explanations

The first is that sleep now has been coopted by a more fundamentally important proccess, though there is little evidence of this, and death by sleep deprivation isn't very well understood.

The second is simply because your body runs out of energy. Sleeping saves you vast ammounts of energy, especially in the brain. Without this, your brain simply is put under too much stress for too long a period.
Zamfir wrote:Yeah, that's a good point. Everyone is all about presumption of innocence in rape threads. But when Mexican drug lords build APCs to carry their henchmen around, we immediately jump to criminal conclusions without hard evidence.

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Re: Dreaming as an evolutionary advantage

Postby Sir_Elderberry » Mon Aug 30, 2010 4:50 pm UTC

In that case, though, "sleeping evolved for rest and energy conservation" makes way more sense than "sleeping stops us from doing something stupid in the dark".
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Re: Dreaming as an evolutionary advantage

Postby gmalivuk » Mon Aug 30, 2010 5:18 pm UTC

Especially considering nocturnal creatures sleep, too.
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Re: Dreaming as an evolutionary advantage

Postby Telchar » Mon Aug 30, 2010 8:35 pm UTC

Sir_Elderberry wrote:In that case, though, "sleeping evolved for rest and energy conservation" makes way more sense than "sleeping stops us from doing something stupid in the dark".


It's probably equal parts. If diurnal creatures could be doing productive things at night, they would. If you could gather food as effectively at night as during the day and avoid obstacles, then you wouldn't neccisarily need to sleep. You could continue getting nutrients. As is, primitive diurnal mammals would do what at night? Can you imagine just staying up looking around in the dark? It wastes a ton of energy, not just in the brain but in the digestive system as well.

gmalivuk wrote:Especially considering nocturnal creatures sleep, too.


Right, because they can't function as effectively in daylight. Sleep evolved as a way to conserve energy and keep the animal from getting into danger/trouble in an environment it couldn't effectively function in.
Zamfir wrote:Yeah, that's a good point. Everyone is all about presumption of innocence in rape threads. But when Mexican drug lords build APCs to carry their henchmen around, we immediately jump to criminal conclusions without hard evidence.

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Re: Dreaming as an evolutionary advantage

Postby gmalivuk » Mon Aug 30, 2010 8:47 pm UTC

Do abyssal creatures sleep? I suspect they still have to, to conserve energy. So it's primarily an energy conservation thing, and then the minor detail of *when* to sleep results from the decreased ability to do anything useful during that time of day, anyway.
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Re: Dreaming as an evolutionary advantage

Postby ++$_ » Mon Aug 30, 2010 8:57 pm UTC

Surely it doesn't conserve that much energy. I mean, the human brain is an energy hog, but I don't think that's true of other creatures, is it?

Also, even in humans, even NREM sleep only reduces the brain's energy consumption by 3-10% in stage 2. Stage 3 gives a significant reduction of 25-44%, but that's <20% of your sleep time. And REM sleep doesn't reduce the brain's energy consumption at all. If you put it all together (and use the 44% and 10% figures, and neglect REM sleep), sleeping probably reduces your brain's daily energy budget by about 5.5%. Is that really important enough to justify an 8 hour period of unawareness?

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Re: Dreaming as an evolutionary advantage

Postby Telchar » Mon Aug 30, 2010 9:29 pm UTC

gmalivuk wrote:Do abyssal creatures sleep? I suspect they still have to, to conserve energy. So it's primarily an energy conservation thing, and then the minor detail of *when* to sleep results from the decreased ability to do anything useful during that time of day, anyway.


I can't find anything about brain activity in abyssal creatures, but apparently they never stop moving. /shrug

++$_ wrote:Surely it doesn't conserve that much energy. I mean, the human brain is an energy hog, but I don't think that's true of other creatures, is it?
Also, even in humans, even NREM sleep only reduces the brain's energy consumption by 3-10% in stage 2. Stage 3 gives a significant reduction of 25-44%, but that's <20% of your sleep time. And REM sleep doesn't reduce the brain's energy consumption at all. If you put it all together (and use the 44% and 10% figures, and neglect REM sleep), sleeping probably reduces your brain's daily energy budget by about 5.5%. Is that really important enough to justify an 8 hour period of unawareness?


Sleeping doesn't just slow down your brains energy consumption. It saves energy in practically every bodily system. On top of that, it happens during a period of inability anyway. You don't need your body to be running at peak effeciency when you are unable to function.
Zamfir wrote:Yeah, that's a good point. Everyone is all about presumption of innocence in rape threads. But when Mexican drug lords build APCs to carry their henchmen around, we immediately jump to criminal conclusions without hard evidence.

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Re: Dreaming as an evolutionary advantage

Postby gmalivuk » Mon Aug 30, 2010 10:15 pm UTC

++$_ wrote:Is that really important enough to justify an 8 hour period of unawareness?
It's not just your brain that saves energy during sleep, and to save energy in the rest of your bodily systems, it wouldn't do to have your brain thinking away as usual during that whole time.
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Re: Dreaming as an evolutionary advantage

Postby firechicago » Tue Aug 31, 2010 1:33 am UTC

Energy conservation can't possibly be the only reason for sleep to exist. If that were the case, it would be possible to stay up forever as long as you kept eating enough. I suspect the necessity of ~8 hours of downtime a day has a lot more to do with the body performing "routine maintenance" (rebuilding the immune system, fixing calcium into the bones wound healing and all that other good stuff) than with simply conserving energy.

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Re: Dreaming as an evolutionary advantage

Postby TheNorm05 » Tue Aug 31, 2010 8:19 am UTC

Aren't nerve impulses caused by some kind of Chemical reaction? I would imagine they are. In more developed brains(especially those with greater volume) if it's a chemical process that needs to be maintained in order to continue to function then as the brain size increases, the harder it would be to maintain the chemical balance needed. As the chemical process is in a sense undone, the brain probably would need to slow it's rate of use to allow everything to catch up, and while re-balancing, it possibly works it's way through some old ideas and reworks some thought streams causing some dreams. This would somewhat align with what the other guy was saying about "overheating". I don't know for sure, as no one really does, but just something to think about.

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Re: Dreaming as an evolutionary advantage

Postby mosiajam » Tue Aug 31, 2010 12:12 pm UTC

TheNorm05 wrote:Aren't nerve impulses caused by some kind of Chemical reaction? I would imagine they are. In more developed brains(especially those with greater volume) if it's a chemical process that needs to be maintained in order to continue to function then as the brain size increases, the harder it would be to maintain the chemical balance needed. As the chemical process is in a sense undone, the brain probably would need to slow it's rate of use to allow everything to catch up, and while re-balancing, it possibly works it's way through some old ideas and reworks some thought streams causing some dreams. This would somewhat align with what the other guy was saying about "overheating". I don't know for sure, as no one really does, but just something to think about.


What happens is that neurons polarize briefly to send an electrical signal down their axons. This polarization is caused, if I remember correctly, by the diffusion of Ca+ and K+. Or something. Thing is, neurons unpolarize almost immediately, otherwise it then could not physically do anything else until it unpolarizes. Anyhow, it takes very little energy (if at all) to unpolarize.

At the end of an axon is a bunch of neurotransmitter release sites. The electrical impulse sent down through polarization triggers the release of a select few. These neurotransmitters cross the synaptic gap and hit the next neuron. Now, the next neuron picks up the neurotransmitter, "records" it, and then the original neuron reuptakes those neurotransmitters.

So, at the beginning and end of the electrochemical process for brain signalling, everything is back to normal. I guess what I'm saying is that there is no chemical reaction, at least on the cellular level, that leaves a neuron "tired" and "overworked". They're always as capable and ready to work after an impulse than they were before.

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Re: Dreaming as an evolutionary advantage

Postby Levelheaded » Tue Aug 31, 2010 12:36 pm UTC

I think sleep is our bodies way of conserving energy in the safest / least useful time. It does seem like there would be an evolutionary pressure to remain inactive / hidden during the time that a species is most poorly adapted for and vulnerable - be it during the day for nocturnal animals or night for dinural animals.

I would think that our bodies would evolve to run as much 'maintenance' during those times as well.

Now, ++$_ poined out that our brain doesn't conserve much energy during those times. The 20-30 calories / day the brain saves probably isn't significant enough to make up for increased vulnerability of sleep, but it is something. If we take it as a given that the body is going to be inactive anyway, that may end up being enough of an evolutionary advantage if resources are really tight without even considering the benefits of 'practicing' stressful situations.

Also, keep in mind that sleep isn't necessarily that vulnerable of a time. We sleep deeply and ignore sounds around us because we know that we are safe, but in a dangerous environment many people can stay very alert to dangers while they sleep. I would even say some people are more alert asleep than they would be if they were awake but lost in their own thoughts. If you don't believe this you haven't tried to sleep next to a new mother when her baby is sleeping in the next room. They wake up for everything that baby does. You often get the same thing with a combat veteran.

Telchar wrote:(SIDS is thought to be caused by the inability of the newborn brain to wake itself up to REM sleep)


I would need to see some citations for this one...as far as I know the actual cause of SIDS is unknown (and probably a combination of factors).

When my daughter was born six months ago they told us that the most likely cause is poor airflow - infants can create a pocket of CO2 and don't breath deeply enough to clear it and are too small and sleep too deeply to move out of it. That's why they tell you to have infants sleep on their back, and no stuffed animals / blankets / pillows / anything in the crib with them. According to our doctor, this is supported by studies that show just leaving a fan on to circulate air lowers occurrences of SIDS significantly.

So, I guess infants sleeping deeply could be a contributing factor, but it's not the cause of SIDS.

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Re: Dreaming as an evolutionary advantage

Postby gmalivuk » Tue Aug 31, 2010 3:57 pm UTC

firechicago wrote:I suspect the necessity of ~8 hours of downtime a day has a lot more to do with the body performing "routine maintenance" (rebuilding the immune system, fixing calcium into the bones wound healing and all that other good stuff) than with simply conserving energy.
Right. Healing and muscle growth and memory formation and a number of other things all happen during sleep. Dreaming itself seems like little more than the usual hallucinatory artifact of being (semi)conscious without sensory input making it all the way to that consciousness, combined with whatever else the brain has to do to store long-term memories.
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Re: Dreaming as an evolutionary advantage

Postby Gaza » Wed Sep 01, 2010 6:13 am UTC

I know this was mentioned towards the top but I haven't frequented these forums in forever and I stopped by because I find dreaming fascinating.

bpsp wrote:Here's a theory I heard once that I've found interesting:

If you're about to be eaten by a cheetah, you need to rely on split-second, rational decisions. In order to make those decisions correctly, the brain needs to practice operating under extraordinary circumstances. For example, extreme danger or embarrassment. So in the beginning, animals dream of running from cheetahs so when this actually happens, their brains will have a better idea how to make good decisions under extreme stress. Now as humans, we dream of other bizarre situations, since having done so so has better prepared ourselves to respond to those situations in real life.

I'm not saying this is a well accepted or well backed-up theory - I just found it plausible and interesting. I could see how dreaming about driving my car into a lake or about showing up to school naked would grow out of the brain practicing operating under stress.


I found what bpsp said very interesting when I applied it to myself. Whenever I dream I am usually put into a dangerous or undesirable scenario. Logic would dictate that when I find myself in these scenarios (even though I'm dreaming), I would do all that is in my power to make it a more likable situation. However, this isn't the case 99.99% of the time. Instead I start shutting down. My head starts to lower to the point where I can't lift it and observe my surroundings, my ability to move is gradually taken away until I am paralyzed, and my vision starts narrowing to the point where I become blind. For some reason, I can still hear and feel, but those are my only connections left to my dream. For example, I was once handed a sniper rifle and told to take out a zeppelin, but immediately after I took it I started to shut down. Another: someone started to chase me for one reason or another until I shut down and couldn't move. They then proceeded to kick me off a ledge and I woke up with the feeling of falling into my bed. I feel like I contradict the preparation theory.

Also, if this makes my situation make anymore sense whatsoever, I have always felt it would be better to run from a fight than fight it. In the words of a very famous man, "Those who live by the sword, die by the sword and violence is self-defeating."

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Re: Dreaming as an evolutionary advantage

Postby Telchar » Wed Sep 01, 2010 7:22 pm UTC

Levelheaded wrote:
Telchar wrote:(SIDS is thought to be caused by the inability of the newborn brain to wake itself up to REM sleep)


I would need to see some citations for this one...as far as I know the actual cause of SIDS is unknown (and probably a combination of factors).

When my daughter was born six months ago they told us that the most likely cause is poor airflow - infants can create a pocket of CO2 and don't breath deeply enough to clear it and are too small and sleep too deeply to move out of it. That's why they tell you to have infants sleep on their back, and no stuffed animals / blankets / pillows / anything in the crib with them. According to our doctor, this is supported by studies that show just leaving a fan on to circulate air lowers occurrences of SIDS significantly.

So, I guess infants sleeping deeply could be a contributing factor, but it's not the cause of SIDS.


http://www.ncbi.nlm.nih.gov/pubmed/9638661

It's not that they sleep too deeply, it's the immature CNS, particularly the lower brain, has a decreased ability to jump from stage 4 to REM (known as an arousal reflex) and so the infant essentially suffocates.
Zamfir wrote:Yeah, that's a good point. Everyone is all about presumption of innocence in rape threads. But when Mexican drug lords build APCs to carry their henchmen around, we immediately jump to criminal conclusions without hard evidence.

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Re: Dreaming as an evolutionary advantage

Postby ++$_ » Wed Sep 01, 2010 8:16 pm UTC

That's not what the abstract says, and I can't access the full text. The abstract says that infants who are vulnerable to SIDS experience more REM sleep between 2 and 5 AM, and hypothesize that it might be indicative of an underlying CNS abnormality. They certainly don't suggest a decrease in REM sleep for SIDS infants or an inability to enter REM sleep, at not least in the abstract.

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Telchar
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Re: Dreaming as an evolutionary advantage

Postby Telchar » Wed Sep 01, 2010 9:06 pm UTC

You're right. I had skimmed through the abstract and conflated the C and R groups. Given the mechanisms involved, it seems odd that an increase in REM sleep would cause SIDS, but I can't access the article fully at work. I'll take a look when I can access my uni account at home.
Zamfir wrote:Yeah, that's a good point. Everyone is all about presumption of innocence in rape threads. But when Mexican drug lords build APCs to carry their henchmen around, we immediately jump to criminal conclusions without hard evidence.

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Re: Dreaming as an evolutionary advantage

Postby Hatter » Fri Sep 03, 2010 7:32 pm UTC

Gaza wrote:I know this was mentioned towards the top but I haven't frequented these forums in forever and I stopped by because I find dreaming fascinating.

bpsp wrote:Here's a theory I heard once that I've found interesting:

If you're about to be eaten by a cheetah, you need to rely on split-second, rational decisions. In order to make those decisions correctly, the brain needs to practice operating under extraordinary circumstances. For example, extreme danger or embarrassment. So in the beginning, animals dream of running from cheetahs so when this actually happens, their brains will have a better idea how to make good decisions under extreme stress. Now as humans, we dream of other bizarre situations, since having done so so has better prepared ourselves to respond to those situations in real life.

I'm not saying this is a well accepted or well backed-up theory - I just found it plausible and interesting. I could see how dreaming about driving my car into a lake or about showing up to school naked would grow out of the brain practicing operating under stress.


I found what bpsp said very interesting when I applied it to myself. Whenever I dream I am usually put into a dangerous or undesirable scenario. Logic would dictate that when I find myself in these scenarios (even though I'm dreaming), I would do all that is in my power to make it a more likable situation. However, this isn't the case 99.99% of the time. Instead I start shutting down. My head starts to lower to the point where I can't lift it and observe my surroundings, my ability to move is gradually taken away until I am paralyzed, and my vision starts narrowing to the point where I become blind. For some reason, I can still hear and feel, but those are my only connections left to my dream. For example, I was once handed a sniper rifle and told to take out a zeppelin, but immediately after I took it I started to shut down. Another: someone started to chase me for one reason or another until I shut down and couldn't move. They then proceeded to kick me off a ledge and I woke up with the feeling of falling into my bed. I feel like I contradict the preparation theory.

Also, if this makes my situation make anymore sense whatsoever, I have always felt it would be better to run from a fight than fight it. In the words of a very famous man, "Those who live by the sword, die by the sword and violence is self-defeating."


I believe that in your case, the dream is not preparing you for 'what to do if you are asked to shoot a zeppelin' but 'what to do if you are asked to shoot a zeppelin and you begin to paralyze'. This may seem weired, but I imagine that before modern culture you would not know or worry about zeppelins and becoming paralyzed, so you would not dream about it. Instead you would dream about more relevant survival things.

Also, I don't know if it has been noted or not but I could not see it, the difference between sleeping and dreaming is important. We only dream 2 hours per night, so much of the time must be used for other things. Also I have heard the reason most people don't remember dreams is because, like earlier stated, it seems the time is used for something to do with memory.


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