How similar, neurologically, is the dream state to the waking state?

I really enjoyed this seen from the 2001 film Waking Life where an individual named Jason T. Hodge states the following:

"In the waking world, the neural system inhibits activation of the vividness of memories. This makes evolutionary sense. It would be maladaptive for the perceptual image of a predator to be mistaken for the memory of one and vice versa; if the memory of a predator conjured up a perceptual image, we would be running off to the bathroom every time we had a scary thought. So you have these serotonic neurons that inhibit hallucinations that they themselves are inhibited during REM sleep. This allows dreams to appear real while preventing competition from other perceptual processes. This is why dreams are mistaken for reality. To the functional system of neural activity that creates our world, there is no difference between dreaming a perception and an action and actually the waking perception and action."

I have found no neuroscientific/neuropsychological research evidence to substantiate this claim; in fact most of the research I have found states the exact opposite. I want to believe that Hodge's statement is at least to some extent grounded in fact, but I can find nothing to back up his claims. Does anyone have any ideas?

I don't know much about the actual chemistry involved, but I do know that a relaxed waking state is the same brainwave frequency in the vast majority of dreams. This is an obstacle in brainwave entrainment(the trick to to go below dreaming, then back up to prolong the dream state). Also, the logic centers in the brain shut down during sleep of any type, it is believed that it is this deactivation that prevents us from becoming lucid in every dream and accounts for the general weirdness.

Yeah, I enjoyed this movie too, even though I didn't understand most of it...

Anyway, this statement seems to be more philosophy than actual science, in my opinion at least. But it should be possible to find more info about receptors blocking hallucinations and so forth, maybe wikipia or scinetific journals....?

maybe it means that the brain does not understand the diference of seiing and imagining

http://web.mit.edu/newsoffice/2000/mindseye.html

OP has a nice nick!

Sorry that I don't have anything to say on topic. Couldn't help but mention the nick. :)

You are going to love this:

http://www.bbsonline.org/Preprints/O....revonsuo.html

A theory that dreaming is an evolutionary function that promotes reproduction. Dreaming is a rehearsal of threatening events... we need not endanger ourselves to practice. Very in depth analysis, and although just a theory, is very convincing. It is a good read with plenty of citation.