Eventually something happens that makes you realise it is a dream. The method converts nightmares into pleasant lucid dreams. These two states alternate in a roughly 90 minute cycle. That's odd, because they should, like lucid dreams, occur mostly in the second half of the night, when there is much more REM sleep. It seems then that, like the SWS type, REM nightmares are triggered by some sensitivity early in the sleep period.
Nightmare sufferers are generally jumpy people.
With night terrors, the person awakes suddenly, often in great fright and screaming, but typically there is no dream activity reported. Interestingly, the individual usually has no recall of the episode in the morning. It is of concern only to those around. There are no physiological indicators that the night terror is about to happen. The vast majority of nightmares are frightening REM dreams.