Over the past couple of years, I have become increasingly aware of a curious phenomenon: when I sleep on my back, I tend to have more vivid dreams than when I sleep on my side or chest.  I don’t mean vivid as in “nightmare” — it’s been a long time since I’ve had a nightmare — I just mean that they seem more colorful, have better plots, have better sound, and generally are more intense.

Ordinarily, I find my sides and my chest to be more comfortable than my back for sleeping, but every once in a while some good back sleep fits the bill.  Sometimes I’ll drift off to sleep while on my back.  Other times I’ll go to sleep not on my back but wake up mid-dream and find myself on my back.

There are a variety of potential issues with my observed back-sleep–vivid-dreams correlation:

1. There could be a strong reporting bias — if I sleep on my back and don’t have  a vivid dream, the event passes unnoticed.
2. The occurrence of vivid dreams on the back could be no higher than in any other position, but they might seem more notable because I tend not to sleep on my back.
3. Dreams are highly personal experiences, so external observation and objective measurement are impossible.
4. Correlation is not causation — perhaps having vivid dreams causes me to sleep on my back, not the other way around.
5. The back dreams might not actually be any more vivid than dreams in other positions, as quantifying dream vividness is fraught with challenges.
6. There might be something about sleeping on my back that simply makes me more likely to remember my dreams.

The final item in the list could be crucial: what if something about me sleeping on my back simply makes me more likely to remember a dream?  That implies that something is causing me to wake up during the dream.  As it turns out, I am aware of just such a thing: snoring.

I snore.  I’ve never heard myself snore, but I know from the accounts of others (and midnight jabs in the side) that I snore.  (If I snore like my grandpa snored, then — well, I apologize.  I hope it isn’t that bad.)  Anyway, I’ve noticed that I’m more likely to snore when I sleep on my back.  Assuming that I really am having more vivid dreams while sleeping on my back, perhaps they are related to my snoring.

Maybe the snoring noise is seeding the dreams with information on which to operate. Perhaps my snoring is waking me up, causing me to remember the dreams.  Perhaps my snoring wakes other people up, which causes them to jab me and wake me up, which would also lead me to remember the dreams.  Or maybe something about the snoring is affecting oxygen levels in my brain and thus its behavior.

I post this not because I have answers but because I have questions.  A search of the literature produced no promising leads, so the next step is to find out: am I alone?  Have others experienced predictable dreaming changes based on their bodies’ positions during sleep?