The last few days I have been reading the book “The Terror That Comes in the Night” which is a great book based on a study done by David J. Hufford and the supernatural assault traditions. Basically the book is about the “Old Hag” syndrome which is given the name from a experience of a combination of sleep paralysis and hypnagogic hallucinations.
Though I am not done with the book yet, I did read a part of the book that I was most interested in as Hufford briefly talks about the other types of sleep disorders that sometimes are related to bad dreams and nightmares. Night Terrors been something that I have thought about a great deal of time and what causes the problem. One thing that I didn’t understand is how Night Terrors only seem to affect people while only in sleep stages NREM 3 and 4, but not 2. If you ask a Night Terror sufferer when this happened to them, they will reply with, I don’t remember (as they experience a type of amnesia during the event) or they will repeat what their doctor tells them. Many times Night Terrors do occur during the NREM stages 3 and 4, but also they do occur during stage 2, according to Hufford. This to me would mean that the event is not limited to the events occurring in the brain during stages 3 and 4 of sleep, but something in common of those events along with stage 2 of sleep. Also during the first 90 min of sleep your body goes through a complete cycle of stages 1-5 and back to 2-5, but after that amount of time it no longer goes to stages 3-4 after 5 but 2-5. This means that Night terrors most likely will occur in the first 90 minutes of sleep if limited to mainly stages 3 or 4 but if not; will occur more often than normal after 90 minutes of sleep.
It would be interesting to find out what time frame the Night Terrors do occur dependent on the amount of time asleep. It would my guess that Night Terrors are not limited to a stage of sleep, but more a malfunction of a process during the phases of sleep.