I applaud Professor Hufford for this ground-breaking analysis of Night Hag (Phantomania) attacks. Nothing else quite like it since its original publication over 20 years ago.
* As of 2013, I notice several other books have been published concerning this topic. Unfamiliar with their content, so unable to comment on their quality.
Though it begins with, and is occasionally bogged down by some typically tiresome academic prose, for the most part Hufford has the courage to allow the facts - meaning testimonies - to speak for themselves. With the benefit of his methodical and objective reasoning, this approach eventually delivers his subject from the tediousness of too much jargon and equivocation.
And though he wisely resists arriving at any certain conclusions, his courage to at least acknowledge most of the possible explanations - physio/psychological or supernatural - associated with pavor nocturnus is much to his credit.
Many of the eyewitness accounts (which, I think, could have been improved by some editing), actually make for rather scary and unnerving late night reading. If you are familiar with the lackluster Grave's End, you will know what I mean. Likewise, similar examples of such "entity" encounters can be found in numerous other allegedly true haunting accounts. The resemblances and similarities are remarkable and, I submit, establish a pattern of credibility rather than imitation. T
I only wish that the Professor had more thoroughly described the different stages of sleep, including brain wave Hz rates, length and periodicity of cycles and degress of REM activity. It seems to me that an all inclusive scientific study of nightmares should result in some truly surprising insights into the nature of consiousness itself. At the very least a more complete and rigorous background explanation of what we currently understand about sleep would do much to bolster the bona fides of this specific inquiry.
Likewise, Professor Hufford is way overdue for an update considering the limited sources his research was conducted from and based upon. Considering the fact that he has pioneered this topic, his further investigations ought to be of even greater value and objectivity.
* I have found at least one somewhat decent documentary about Night Hag/Shadow People, from @ 2008 which includes Hufford's comments. It is available on YouTube. He wisely maintains an objective, agnostic opinion, though does not indicate whether or not he is still involved in research.
Regarding the entity hypothesis - which I obviously find the most reasonable (yes, that's the right word!), allow me to recommend a perusal of Carlos Castaneda's The Active Side of Infinity, particularly the chapters on Inorganic Awareness and Mud Shadows.
Skeptical? Just take a look, you'll see what I mean.
Not necessarily THE explanation, but there certainly are many interesting correlations!