All this talk of sleep problems last time got me thinking about my own sleep and dream issues which, I think, are intimately linked. In part, I think dreams are the brain's way of sorting through, and explaining to itself, the intra- and extracorporeal phenomena it is picking up while asleep (I don't know if those are real words but I like the way they look).
See, I have sleep apnea. Don't worry, it's not contagious. For those of you not familiar with this, it basically means I wake up a bunch of times during the night without realizing it. And here, I'm going to regurgitate a bunch of information I kind of remember from various doctors and a biological psychology class from college so, if you're interested, you may want to research this yourself as I could be way off on a lot of this.
Anyway, as I think we talked about in class, there are various stages of sleep, right? Stage 1, 2, 3, etc., 1 being when you're just falling asleep, all the way up to Stage 4 or 5 or something, whatever REM sleep is, when you're in deep, dreaming sleep. In moving into deep sleep, the muscles in the body lose tension and relax. This includes tissue in the soft palate which, in many people, sags a bit in the back of the throat, causing them to snore. In some people, though, this tissue relaxes so much it collapses completely and obstructs the airway. This is where sleep apnea comes in. With the soft palate collapsed, the person experiencing an episode of apnea (we'll call him Jim) can't breathe. Jim may go through two, three, maybe even four or five attempts at breathing before coming out of REM sleep and gasping for air. Here in Stage 3 sleep, Jim's muscles regain tension and his breathing resumes its normal rhythms, all without Jim regaining complete consciousness. After a while, Jim falls back into deep sleep and the process starts all over again. These episodes may be especially acute if Jim is lying on his back, or if Jim is overweight, or if Jim has been drinking.
Now, the neurological process behind this was explained to me during one of my doctor visits like this: during an apneatic episode, Jim's brain registers a drop in the blood's oxygen level. Jim's brain, however, is not clever enough to realize that Jim isn't breathing. Rather, Jim's brain thinks, at first, the problem is that there's not enough blood pumping through Jim's system. In order to compensate for this, Jim's brain releases hormones into the circulatory system which increases blood pressure. More blood circulating equals more oxygen, right? But after this initial increase in blood pressure, Jim's brain finds that Jim's oxygen levels aren't rising. So Jim's brain further increases blood pressure. Eventually, Jim's brain comes to the conclusion that the reason there isn't enough oxygen in Jim's body isn't because there's a lack of blood pumping through Jim's system, but because Jim's pulmonary faculties, due to the obstruction in the throat, can't get any oxygen into Jim's blood. Finally, as a last ditch effort, Jim's brain basically shakes Jim's body awake (but, usually, not into full consciousness). Jim gasps for air and, after some time, his blood pressure falls back to normal and Jim gradually slips back into deep sleep where the process starts over again.
Basically, when Jim has an apneatic episode and his brain shakes him out of deep sleep, Jim finds himself in a high state of arousal. His heart is pumping like mad, he's breathing rapidly, his sinuses are wide open and he's probably sweating so his body can cool itself down from all the effort. So, regardless of Jim's physiological issues, what kind of dreams do you think Jim finds himself having when he wakes up like this?
Now, here's where the bio-psych comes into play. There's a theory out there - don't ask me to name who came up with this or anything too particular because I don't know; like I said, all I have is a vague memory from my undergrad years - which holds that our dreams are actually our brains way of sorting through and explaining all the information its being bombarded with while we're sleeping. Think about it. Even though we're out of it, our brains are still bombarded with an insane amount of information - nerve impulses, breathing and heart rates, sounds, touches, etc. (And if you think our brains simply ignore these things, why would we wake up in the night to go pee, or why would alarm clocks work?) What this theory says is that, since it can't simply explain away these impulses with waking phenomena, the brain more-or-less makes up a story that fits the information flooding the brain - a kind of "filling-in-the-gap" of consciousness while we sleep. For example, are you dreaming about running? Maybe you're having muscle twitches in your legs. Skin covered in bees? You may well have slept on your arm and then rolled off of it, causing your arm to tingle and burn. Think about how many times we've dreamt about getting caught in a thunderstorm or hearing an alarm going off, only to wake up and find a thunderstorm going on outside or our alarms buzzing. Perhaps, then, recurring dreams are like the mind's shorthand way of explaining something that happens frequently during sleep. So like, whenever I grind my teeth, my brain gives me a teeth-falling-out sequence. I don't know. It seems reasonable enough to me.
So what about Jim (and people who have sleep apnea, like me?) What's his brain supposed to make of his jacked-up state of arousal? What kinds of dreams does Jim experience when he's having one of his "spells?"
Well, if Jim is anything like me, and I think he is, I can tell you that Jim has seen some pretty crazy stuff. Not bad dreams necessarily, but intense, vivid dreams, dreams that his brain makes in order to explain why his physical state of arousal is close to being maxed out. Like me, Jim probably has lots of dreams where he can't breathe – things like being trapped underwater; suffocating under a rockslide or an avalanche (if it's cold in Jim's room); bad guys choking him to death. He also probably has lots of dreams where something is happening that would make his heart beat really hard - running away from monsters; getting in fights with big bad dudes; falling out of trees or high buildings. But we all have intense dreams sometimes so how is this any different from anyone else?
The difference is, I think, two fold. First, Jim's physiological state of arousal is such that Jim's brain has to resort to these story lines more frequently than most people's brains in order to explain what's going on with Jim's body. Second, due to his apnea, Jim wakes up more frequently than most people while he's having these kinds of dreams so he tends to remember them with greater clarity (Isn't it generally accept that we only remember our dreams if we wake up while we're having them?)
So Jim's dreams - and mine, and maybe many other people's with sleep apnea - might tend to be more intense or frightening than most, and occur with a greater regularity and a greater vividness, because, thanks to Jim's little condition, Jim finds himself waking up more frequently during the night (which increases the chances he will remember his dreams) and Jim finds himself in an elevated state of arousal which leads the brain to certain kinds of interpretations. At least, that's how I explain to to myself. Anyone else have any thoughts?