posted on Jul, 14 2010 @ 06:35 AM
That's an interesting question. The problem is that "nightmare" isn't an objective thing, it's just a dream that bothers the dreamer.
Even attempts to make the category crisper, such as requiring that the dreamer awake from the dream in order for it to "count," don't get very far.
Plenty of people routinely wake up immediately after dreaming. We're "almost awake" during REM sleep anyway.
Intuitively, it's easy to imagine that strong affect would make it easier to remember a particular dream, and fright may be an easy affect to evoke.
We know from waking life that some thoughts seem to be accompanied with an "urgency tag." Some things, when we think of them (Is my fly unzipped?),
mobilize us to take prompt action.
So, dreams being thoughts, maybe some of them use strong affect as an "urgency tag," too. "Pay attention to me!" That wouldn't be too far
fetched.
Anyway, I wouldn't be worried about having too few of something that can't be measured in the first place. Although that does sound like a good plot
premise for a nightmare, doesn't it?