joeylittle
Sponsor
I know what you both mean, @digger and @Fadeaway - I think I didn't say it right. Whether or not we remember dreams, and how much of them, theoretically - lets emphasize theoretically, because it's just a bunch of knowledge extracted from studies, but there are still always exceptions - has to do with how the brain operates during REM sleep. Short-term memory and long-term memory are switched 'on' and 'off' at various points in the sleep cycle.
So, when you get to REM, and then wake up unexpectedly, directly from the middle of REM, you are coming directly out of a dream state and only have a brief short-term recollection - but upon awaking, your long-term memory will re-engage. How well it does this depends on some other factors. That's a more detailed reason why a dream can be 'captured' when waking in the middle of REM. If you wake at the end of a REM cycle naturally, without any external interference, you wake up more slowly, and may barely remember dreaming, but not the content, while your long-term recall is still warming up. You are actually waking up in a final round of the first cycle of sleep.
There are dreams possibly happening in the earlier phases of sleep as well, they are (thought to be) less vivid, and generally they are less frequently recalled. Lots of drugs that work on nightmares do it by f*cking with your REM sleep - either keeping you from getting into it fully or putting you very deeply into it. An uninterrupted sleep cycle is 90-110 minutes long, with 20-25% of that being REM deep sleep. Phase one is very light sleep, and short; phase two is medium, and quite long - 40-55% - and non-vivid dreaming can occur here (so, if you waken early from here, you may remember something), third and fourth are getting into deep sleep territory, very hard to waken from - the brain is producing only delta waves, and when you wake up from here, you are groggy for quite awhile. Then, after stage 4, there's REM - which is very active for the brain. Much dreaming. Then, a restore to phase 1.
It's fascinating stuff, also because the empirical data does not create a complete picture yet - there are people who are exceptions to pretty much every 'rule' of sleep. But, pretty much all sleep phenomenon can be attributed in one way or another to brain activity, what it's doing, what turns off and on when, and genetic or medical factors that alter what the brain is doing, when.
So, when you get to REM, and then wake up unexpectedly, directly from the middle of REM, you are coming directly out of a dream state and only have a brief short-term recollection - but upon awaking, your long-term memory will re-engage. How well it does this depends on some other factors. That's a more detailed reason why a dream can be 'captured' when waking in the middle of REM. If you wake at the end of a REM cycle naturally, without any external interference, you wake up more slowly, and may barely remember dreaming, but not the content, while your long-term recall is still warming up. You are actually waking up in a final round of the first cycle of sleep.
There are dreams possibly happening in the earlier phases of sleep as well, they are (thought to be) less vivid, and generally they are less frequently recalled. Lots of drugs that work on nightmares do it by f*cking with your REM sleep - either keeping you from getting into it fully or putting you very deeply into it. An uninterrupted sleep cycle is 90-110 minutes long, with 20-25% of that being REM deep sleep. Phase one is very light sleep, and short; phase two is medium, and quite long - 40-55% - and non-vivid dreaming can occur here (so, if you waken early from here, you may remember something), third and fourth are getting into deep sleep territory, very hard to waken from - the brain is producing only delta waves, and when you wake up from here, you are groggy for quite awhile. Then, after stage 4, there's REM - which is very active for the brain. Much dreaming. Then, a restore to phase 1.
It's fascinating stuff, also because the empirical data does not create a complete picture yet - there are people who are exceptions to pretty much every 'rule' of sleep. But, pretty much all sleep phenomenon can be attributed in one way or another to brain activity, what it's doing, what turns off and on when, and genetic or medical factors that alter what the brain is doing, when.
