Is it possible that the process of sleeping is just a period of time where the blood flows from our body to our brain...sort of like it's just a time period when oxygenated blood has a chance to flow to our brain because while we are moving around all day long blood is being pumped throughout the body and sleep is a chance for it to go to the brain.

If this is the case, then dreams would just be a byproduct of the oxygenation of nerve cells in the brain (producing the dream images we experience).

What do you guys think?

Any studies done on this?

I think blood is always flowing to your brain, you dont have to sleep to allow blood in. Can you explain how dreams would form from the oxygen a little more clearly?

you still move a lot during your sleep. i forget which phase(s). i think you could sit still on a chair and rest if it was just about oxygenated blood.

Scientists use PET scans to study blood flow to the brain with the idea that blood supplied to the brain feeds the nerve cells which produce the nerve impulses which produce movement and activity throughout the body. So, the movement of the blood (which serves the purpose of supplying Oxygen) dictates the activity of the nerves. Dreams would be the result of activity that does not normally appear during a wakeful state. So, I guess my reasoning is that more blood goes to the neurons in the brain while we sleep causing neural activity that creates dreams via spontaneous imagery or something.

Has it ever been studied in hibernating bears?

Has anyone ever studied the specific physiology of a bear before and after it's 7 months of hibernation?

There has to be some significance to the fact that a bear can sleep for 7 whole months...no eating, no drinking, no pooping or pissing..............

What physiological changes occur during that time?

I think a lot could be discovered about the effects of sleep if this were studied.

Isn't the blood pumped to the places its needed most? This makes me assume that the activity of the nerves gets the blood pumping there.
We are storytelling creatures who are based in the visual realm. At its most basic this means we communicate in metaphors and fantasy. Its not that we don't have these fantasies happening during our waking life, its just we're too preoccupied to follow the thoughts through to conclusion, plus without our eyes shut and our brain in sleep mode, there is no vivid imagery.

I find it extraordinary that when we rest and sleep that these fantasies run riot while our bodies paralyse us. We're still no closer to understanding what dreams really are. But I think your ideas don't seem to take into account things like lucid-dreaming.

There are probably multiple reasons why we sleep. I think the amount of REM sleep is correlated with memory consolidation. Perhaps new memories from the hippocampus are incorporated with other long-term memories in corresponding cortical areas. I was thinking that many of the things we dream about might be more related to episodic rather than semantic memories, and the hippocampus is known to be most important for forming new episodic memories. I wonder if people with hippocampal lesions dream, or if there dreams are different. They should do studies on that...

[/quote]We are storytelling creatures who are based in the visual realm.
[/quote]

We're not all storytelling creatures. Sure, us "Intellectuals" are, but what about athletes and people whose activities are mostly physical?

I think they dream too.

"Is it possible that the process of sleeping is just a period of time where the blood flows from our body to our brain...sort of like it's just a time period when oxygenated blood has a chance to flow to our brain because while we are moving around all day long blood is being pumped throughout the body and sleep is a chance for it to go to the brain."

If this were the case, then there would even be no need to sleep at all. Lay in a horizontal position for several hours without sleeping and then stand up completely refreshed. Or, how about getting the same amount (or more) of blood rushing to the brain by hanging upside down like a bat for a short period of time, obviating the need for the nightly nap?

It is an intriguing idea however and it is not something i ever thought of.

or, lie a lot. any of you guys familiar with teh first lie detector? lay a man on a board made like a seesaw. if the board tips over to the head side it means he is lying because more blood is moving to the brain!

Without being rude, I think this is a little short sighted. I don't mean in an intellectual way at all, but as a method of knowledge propagation, whether its songs or stories. But the simplest way to understand it is in our exaggerations of the facts to make the stories more attention grabbing:

Fisherman stories - <------------------------- it was this big -------------------->
War stories - There was 30,000 men, all ten feet high with acid for blood and swords bigger than houses. Our group of 300 killed them all.
Global Media - sensationalism sells...
etc. etc. ad nauseum.

The dreams we have are simply emotional stories that we are telling ourselves. Some dreams actually have a lasting change on our personalities and personal goals. I bet some athletes have been inspired by dreams of winning Gold for their country in the Olympics.

02 exchange with hemoglobin is based on osmotic pressure. Even venous blood has a large amount of 02 left in it. The oxygen moves from the blood to the cerbrospinal fluid based on how much 02 is left in the cerbrospinal fluid. This is a very consistent process that does'nt changed based on blood flow, pressure etc.
It CAN be changed by a shift in environmental 02 levels and external pressures, but this isn't anything that occurs due to sleep. Even hyperventilation and hypoventilation don't actually effect how much oxygen an individual neuron takes up (for the most part). So no, sleep is not to increase Oxygen.

Trojan, they were actually 12 feet high and spit acid (reallllly bad acid reflux). And there were only 150 of us.

Last night i tried sleeping standing up (very scientific experiment). It didnt work too well so therefore i believe that this here blood theory is indeed correct.

Haha, a man called horse!
I hope that last sentence is a joke though LastClick, because you have to attempt to prove the theory wrong and fail, rather than try to prove it right and succeed

People do walk, drive and even eat in their sleep...

So I've heard.

So...

I dunno if this proves me wrong, but I'm sticking with my blood story.

I have to add to the discussion that, during sleep, the temporary memories are written into the permanent memories. Memory consolidation may perhaps be a reason for the necessity of sleep.

Read this if you're interested.
memory-key. com/ NatureofMemory/ sleep.htm

I dont think anyone is in the position yet to state one way or another what the function of sleep is. The latest research in depression shows that too much dreaming gives less time to the apparent regenerative phase of sleep. Upping the amount of seratonin can block dreaming.

Sleep is necessary for the body. The ultimate state of relaxation for a vessel that is in constant ebb and flow. A much needed chance to
re-energize

It seems to me that dreams are the mind's ability to play with the past, present and future.

an elaborate dream may occur because of flower you pass everyday in the corner of your living room, a TV show, song movie, friend etc. It could be caused by the sounds or vibrations you are feeling during sleep, or it simply can be a glimpse of what is to come.

Every time i have taken the time to make a dream journal, I have been able to pinpoint the cause of the dream. Except on the rare occasion that the dream foretells an event, then i have to wait.

You are assuming that oxygen triggers glutamic innervation, but it is (assumed to be) the other way around, that excited neurons require more oxygen to supply their needs for activity.

It's an interesting thought, but one reason I would suggest that it is the activity which causes the rise in blood oxygen levels rather than the reverse is that oxygen levels as indicated on PETs or fMRIs do succeed neuronal activation, so the rise in blood flow (and hence oxygen, hemoglobin, etc.) actually occurs following initial activation. So the activation precedes the obvious rise in blood flow.

Also, if oxygen causes excitation, then how would we control our movements, thoughts, etc., if they are solely activated by oxygen without inhibitory control?

And it's also possible to sleep sitting up.

Do we dream more or more feverishly were we to sleep hanging upside down?

IMO we sleep for 3 reasons:

saving energy. differences in sleep length between species generally depends on how alert they need to be to avoid ending up being something's lunch as well as how much time individuals of a species need to eat.

Body growth and maintainence. Sleep is when most growth and general body upkeep occurs.

Memory consolidation. During REM sleep the hippocampi are busy making connections between old and new memories. I'll guess vivid dreams (dreaming occurs all all stages of sleep, but the most vivid dreams mostly occur during REM sleep) are a side effect of memory consolidation to some extent.

I'd definitely agree with those. Also, REM sleep frequently varies by species: those with larger cortices tend to have longer bouts of REM. --Perhaps related to the amount of memory consolidation needed to take place, especially if length of sleep doesn't necessarily increase simply due to larger brains (I believe the fruit fly has about an 8-hour sleep period).

PS- Nice to see you here, Taylor.

Thanks!

Brain is a part of body ..do not segregate it ..it may confuse you .. ..hava nice sleep with lots of dream ..