To bring the ghostly terror to its maximum,
elements of the dreadful must combine, such as loneliness, darkness,
inexplicable sounds, especially of a dismal character, moving
discerned (or, if discerned, of dreadful aspect), and a vertiginous
baffling of the
(James, 1890, p.
One of the most commonly reported experiences associated with SP
that of the sensed presence. It is also the least specific and perhaps
fundamental experience of the HHEs, one that may serve as a primary
the development of elaborated interpretations associated with incubus
attacks, the old hag, and alien abductions. The notion of a sensed
is not unique to SP. Virtually everyone has, at some time, had the
of feeling that he or she was not alone, despite fairly confident
that there really was no other person around. Sometimes, in the
perceptible evidence, one has a feeling that there is someone, or
close at hand (Reed, 1988; Zusne & Jones, 1982). This feeling may
from a vague, almost embarrassing, suspicion to a feeling of absolute
certainty. We commonly associate such feelings with the dark and with
surroundings, and, of course, being alone. We may have also
presence when walking alone on a dark street, or through a woodlot, or
being home alone, especially if it is a "dark and stormy night"
filled with vague rustlings, howling winds, squeaking shutters, and
animal sounds. Reed (1988) describes the experience of a Professor
alone at the summit of Ben Macdhui (which is described as a "snowy,
featureless" peak) in the Cairngorm peaks in Scotland, hearing
in the snow and becoming convinced that somebody or something was
with him. This feeling became so intense that he fled in panic. From
time, this invisible spectre has troubled many hikers on Ben Macdhui.
argues that this is a concrete, documented historical example of the
by which legends arise from an experiential base.
The terror that accompanies such a presence is extremely common.
sensed presence and fear are so closely connected that it is
these circumstances, to sort out whether the presence brings the fear,
whether fear and apprehension generate the sense of presence, or
simply arise together in intimidating contexts. Indeed, the
giving rise to these experiences are so clearly fear provoking and are
plausible conditions for assailants of all stripes that it seems not
that both might arise independently.
The Phenomenology and Ontology of Presence
On reflection, the notion of pure presence is very odd to
If you were here I could see you, hear your voice, and touch you. My
your presence would seem to be the sum total of all of this evidence
senses. That I would have, in addition to all of this a separate
of your existence seems superfluous. That I would have some need of a
of your presence without the evidence of my senses seems very
Yet, experience of the "sensed" presence would seem to argue that
there is indeed something over and above the sum of our sensory
Perhaps the phrase, "sensed presence" is an oxymoron, for
there is no sensory evidence of the presence. To say that it is
"unsensed" seems even worse. It is more an intuition of a
presence. Perhaps it would be best to call it an "experienced
or an experience of a presence." It is an experience without a
neither seen nor heard, nor able to be touched. In any case these
awkward if, perhaps, somewhat more accurate. We will accept a modicum
incongruity and continue with the phrase, "sensed presence" and
acknowledge that that it not sensory in the usual meaning of having a
Is the sensed presence a hallucination? It clearly lacks the
requirement of discrete sensation. The sensed presence is more like a
awareness or apprehension of a person or thing in the room. Yet there
conviction that the entity exists outside and independently of the
Even without further auditory, tactile, or visual sensations it often
more than the feeling of a mere suspicion or hunch. The sense of
be very strong and it clearly seems to be quite real, external, and
independent. Yet, for all that there remains a sense that there is
feeling of "seeming" to all this, possibly, at least in part,
because of a lack of confirmation from any specific modality. In some
the presence may be described as “invisible.” However, most often it
simply "unseen", that is, respondents report the impression that
the presence is "just out of sight." If only one could turn around
it would prove to be quite visible
Often the sensed presence is described as just that, a neutral, or
slightly uneasy, feeling that someone or something is present in a
surrounding area with the person. As a "mere presence" this
experience has no sensory associates, nor does it provoke a strong
reaction or complex interpretations. One has the definite impression
there is something external to oneself yet with no confirming sensory
experience of that entity.
I 'feel' something,
I just sense something or someone has entered the room.
[I] never saw the entity . . . just felt its presence.
As noted above the sensed presence is not a part
everyone's SP experience. Moreover, those who do report the sensed
do not report having the experience every time. "1/3 of the occasions
through my life, the disturbance has been accompanied with a feeling
of a presence
in my bedroom. A great fear usually overcomes me, but only about a 1/3
events do I feel a presence." The foregoing quote also illustrates the
sense of fear that often accompanies the sense of presence. The
between the sense of presence and fear will become increasingly
evident as we
proceed. This may also be experienced as a feeling of threat or
"The sensation is of a presence which is more powerful than me and
A Monitoring Presence
The presence associated with sleep presence may also be endowed with
minimal "psychological" qualities such as that of attention. The
presence is often somehow attending to, watching, or monitoring the
It is "as if someone that I couldn't see was there, watching." One
of the most common comments about the SP experience is that "It feels
if someone is standing there watching me." Respondents are frequently
puzzled that they are unable to specify how they know this or even
precisely they think the presence is located. "You feel that someone
looking at you and you don't know where they specifically are." Aside
from being very disconcerting this must certainly contribute to the
otherworldly sense of the presence. In slightly stronger terms other
will describe the presence as "staring at," rather than merely
The sensed presence may form the core of subsequent hallucinations
involving several modalities. The sensed presence may form the core of
subsequent hallucinations involving several modalities. Although very
people actually make the suggestion spontaneously, one respondent was
specific about the transformation. "The unseen presence starts to
as a formed being." Since the presence is usually perceived of as
threatening, the interpretation is usually of a presumably readily
innate, "prepared," or conventional image of image of something
mysterious and threatening.
The presence is not always immediately interpreted as something
frightening. Occasionally, the presence is thought to be someone who
plausibly be thought to be ready to hand.
At some point in the
also usually think that one of my roommates is trying to wake me up,
I thought the presence was my roommate returning from class.
Most of these experiences are reasonable
interpret a feeling that someone or something is present in the room.
Sometimes the presence may be associated with sensory experiences.
of my own experiences, I sometimes thought my wife had come into the
but subsequently realized that she was not there at which time the
rapidly turned into a sinister presence. In this case I had been
making a low
moaning sound in an attempt to alert her to my condition. After a few
I heard footsteps coming up the stairs, along the hall, and into the
inferred was that it was my wife approaching. The footsteps appeared
at the side of the bed and I waited for her hand to shake my shoulder.
this did not happen I realized that she was not there and, on
realized that she was not even in the house. I was then immediately
with a sense of dread and formed a distinct awareness of a sinister
in the room. In this case the sense of a sinister presence was
with, and seemed to be caused by, the auditory experiences.
A similar experience involving the hallucination of someone
approaching to arouse one from SP was reported by one of the
the following case we also have an illustration of the interaction
confusion) between endogenous and exogenous sources, and between
reality, that characterize the HHEs of SP.
The oddest experience
had was the last episode I had. My boyfriend was watching TV in the
room and I was taking a nap on my couch, I was going through SP but
to wait it out. All of a sudden I felt a presence behind me. It was
horrifying sound (I thought Death himself came to visit me). I
mouth had a little opening. I started to breathe as hard as I could to
boyfriend's attention. It worked. He sat next to me. I was so relieved
for the first time I had reached somebody while I was in this phase. I
thought he touched me on the forehead so that I could be released from
but it was my imagination that thought he touched me. When I realized
didn't touch me I started breathing hard again. Right after that, I
of the SP and saw my boyfriend next to me. I asked him why he didn't
when I was panting in my sleep. He thought I was having a bad
Very often, however, the presence is associated
threat and menace. The threatening presence is not always subject to
or otherworldly interpretations. Often people make very plausible
of the situation in terms of conventional sources of danger.
Sometimes, in these
I feel like there might be a prowler in the house, even though I know
I constantly think that there are 'bad' people (such as burglars,
etc.) in the room with me.
The second episode I ever had involved a strange man sitting on the
my bed. The room was dark, but my eyes
were open and I
was terrified that
there was someone in my room (or so I thought).
An Evil Presence
Even with no further information or untoward incidence, many
appear to have an immediate intuition that the presence is someone or
something to be feared. "The presence brought fear with it." The
presence is commonly interpreted as possessed of a malevolent, evil
Some descriptions never become elaborated beyond a sense of dread, and
of impending doom and even death, provoked by this evil presence. "It
like something threatening was standing beside me." A feeling of
and flight may accompany the feelings of fear. "I always feel like I
in grave danger if I don't wake myself up as soon as I can." The
presence may even be personified as death. "I've also felt a presence
but never see it. Like Death was breathing down my back." The presence
may be rendered even more concrete. "My only thought of death was not
from my paralysis, rather, from my fear of the 'reality' of my
I thought 'My God! What is this sicko going to do?!?'" We have
especially struck with the frequency that the specific term "evil"
is applied to this presence, even by people to whom this term does not
readily spring to mind.
There is usually
always an intense
feeling of extreme evil surrounding me.
I also feel a presence in my mind (like something sinister or evil)
trying to draw me into an extremely deep, permanent sleep. I feel that
succumb, I will never wake up.
The presence of evil taking over my body?
I was very afraid and I felt an evil presence or presences that I
—usually an evil presence
Scary sensation, like something evil was in the room.
The sense of evil is often made concrete by the
of the presence as a devil, demon, or other inhuman, even unnatural,
At times I thought it
devil, other times it was aliens, but almost always I felt the
going to harm me.
The worst time was: I was lying on my back and when the episode
opened my eyes and saw what I thought at the time was the devil coming
bullet straight at me.
A few times, I felt like I was with the devil (I always think it is
devil). He is usually behind me and I feel like we are flying
the air at warp speed and I actually see the view of the room as I am
and passing by everything.
I saw/felt that I was being attacked by a VERY ferocious phantom dog,
mythical in nature.
Often people run quite explicitly through a series of possibilities,
alternating between considering mundane and exotic, vague and
benign and frightening, possibilities. It is also clear that these
alternatives are often entertained as possibilities, as hypotheses
varying merits. Some or all of these hypotheses may be recognized and
identified as preposterous or at least extremely unlikely. Such
do not, however, necessarily detract from the vividness or compelling
of the experiences. As one respondent put it, the experience is "100%
REALISM. But makes no sense." The entire affair is, experientially,
utterly compelling, while at the same time capable of interpretation
terms that are often quite unbelievable. In some case there appears to
blurring of sensed presence and visual hallucinations.
Sometimes it's an
sometimes like an alien, and recently, some kind of demonic presence. Quite
Have seen everything from giant spiders (3' diameter) to dead friends
(suicide-related), rarely seen form clearly. [There are] several
tall strong but "formless" bodies where you can't see exact entity
but a haze or black cutout figure. Other times with child-like
. . will see small child-like creatures, but hardly believe these to
entities but from imagination or inserted image
The first shape I saw was a cloth-like triangle hanging or
mid air and appeared to be a crude form with a hat. Funnily enough it
reminded me of the Sandeman logo. I sat up after this went away and
minute or two was in shock as to what this was. I lay down to think
do. A visible figure appeared at a height of about 18 inches approx.
the angle and the width of the bed meant it must have been hovering.
first appearance I was paralyzed and had pain I have described it was a
forceful presence which 'breathed' with an aspirated wheezing.
I have imagined burglars, rapists, terrorists, monsters, demons, and
devil all in my room. Sometimes they just stare or laugh at me while I
helpless and other times they try to attack me. Often times I
evil spirits have put a spell on me and are trying to steal my soul
am asleep and helpless to stop them or wake up.
There are a variety of different hallucinations from wolves to
children to daemons. Mine appear as demons. I have no fear of death or
ordinary life happenings like dogs or murderers . . . I see demons.
it is one regular visitor whom I have never met
Not surprisingly, some women experience not only
threat of rape but sometimes also rape itself. Occasionally, the
a bit more active, moving about but usually remaining close to the
"Once, I felt as if someone were walking around my bed, and then they
sat down next to me." Or worse, The threat becomes more
I feel fairly certain
that if I
let the apparitions get all the way up to me, they will kill me. I
fought out of this to prevent getting too close to the possibility.
it happens, I am scared they will kill me, especially if I let them
out of my body.
The Presence and the
One major difference between SP with HHEs and dreams is the
high rate of reporting fear during the former. McCarley & Hobson
that only slightly more than 12% of dream reports make reference to
although half of these were to fearful emotions. More recently Hobson
colleagues have reported much higher proportions (95%), presumably as a
result of using specific probes for emotion (Merritt, Stickgold,
Williams, & Hobson, 1994). In that study slightly less than
the reports were of anxiety or fear. In contrast, we have found that,
depending on the sample characteristics, between 66% and 98% of
reports of SP
report experiences of fear. The higher percentage was reported by
responses to a web survey and may be biased by the fact that people
had more frightening experiences during SP were more likely to seek
questionnaires. The other samples were not self-selected and this bias
not have been present. Nonetheless, the estimates of two-thirds are
considerably higher than those reported for dreams in general and
with the rate of 67% reported for SP by Spanos, McNulty, DuBreuil,
Burgess, (1995). Given the prevalence of interpretations of threat and
associated with the sensed presence it is scarcely surprising that the
emotion is that of
fear, or rather, in the words of one
respondent, "absolute cold terror." Respondents are often most
emphatic about the extreme nature of their fear,
The greatest primal
that I have ever witnessed: Character forming stuff - I can't imagine
in reality that could cause greater fear than these episodes.
There are not words strong enough to describe the horrific fear I felt
Nearly always I feel a fear or a horror.
The whole experience is extremely terrifying.
Many respond to our query about “fear” with unabashed contempt for the
inadequacy of the term to describe their emotion.
The word 'fear' doesn't even come close.
Panic is more like it!
Fear is not a strong enough word! Terrified or panicked might be a
How about "overwhelming terror?" These attacks leave me
shuddering and crying. Sometimes I'm so scared I get sick to my
These experiences of dread and terror associated
sensed presence are also clearly different from fear associated with
fears of paralysis, death, or suffocation. “I have had paralysis,
where by I
had difficulty breathing that was not associated with a presence and I
like I might die. Or an urgency to wake up and if I didn't I might
however, these experiences are distinct and different than the
having a presence in the room.” Although the fear may sometimes be
to the fear of the paralysis itself, or that the presence will cause
physically harm, many acknowledge that there is something uncanny
sense of dread. "I literally fear for my soul."
Auditory experiences are much more common than visual experience
although both are significantly associated with the sensed presence.
between sensed presence and auditory and visual hallucinations is only
slightly consistent than that between sensed presence and fear. In
visual hallucinations are probably quite rare outside of dreaming.
hallucinations during SP are extremely diverse. Two qualities do seem
pervade all of this diversity, however. The sounds are very distinctly
experienced as being external to the hearer rather than “in the head.”
a student of Esquirol (1846), distinguished between purely "psychic"
and "psych-sensorial" auditory hallucinations. The former appears
to correspond to “inner speech”, is more thought-like, and may be
taken to be
self-generated. The latter seem to be more like "hearing voices",
to be heard by, what St. Teresa referred to, as the "bodily ears",
and not likely to be taken to be self generated (Johnson, 1978). More
recently, Symons (1995), following Seligman & Yellen (1987), has
distinguished between hallucinatory and non-hallucinatory (conjured)
In contrast to dreams the auditory experiences associated with SP are
overwhelming of the former "hallucinatory" type.
Sounds — elementary. Very often the auditory experiences are
only as "buzzing", "grinding," "humming," "ringing,
"roaring", "rushing", "screeching",
"squeaking", "vibrating", "whirring", and "whistling"
sounds. These are sometimes accompanied by bodily sensations described
"numbness", or "vibration". There may be some synesthesia
being experienced here. These elementary sounds are often described as
very loud and "mechanical." There is little or no interpretative
elaboration of these sensations. They are
described is the
most basic sensory
terms available to the respondents.
During the waking
don't recall any sounds, but during the hypnagogic ones I get a loud
sound in my ears. Something like it sounds like when you put your
your ears only it is very loud.
Sounds crescendo as the apparitions approach me. Whirling/ringing
gets unbearably intense. Once I thought my window fan was 'roaring'—
pitch gets higher sometimes, too.
Yes, during the 'buzz' which precedes or accompanies SP. I have heard
resonating vibrations (at different frequencies) and arrhythmic
A high, humming sound that gets louder and louder the farther I fall
On one occasion upon waking up in a paralysis, I heard pure tones of
wasn't music. It was very erratic and unorganized.
These particular auditory experiences are very
what some people describe as bodily sensations.
Usually when waking
usually accompanied by INTENSE bodily vibrations.
I feel like my body is shaking like I am having a seizure or
Right as it starts, I feel like I'm being electrocuted slowly.
[bodily] tingling and vibrating
Right as it starts, I feel like I'm being electrocuted slowly.
My whole body felt like it was vibrating inside at some incredible
rate. I was afraid that my body and my brain would not
able to stand it.
I also felt a numbness and electrical vibration, and would feel stuck
Like electricity going through my head
Maybe I might feel numb. It's really hard to tell when you can't move
you're numb or not. I definitely don't feel any tingling.
vibration in my hands is painful if prolonged
I have frequent thought that the bed was being shaken.
One person explicitly made such a connection. In
responding to a question about sounds this person remarked that it was
"More of a bodily buzzing and swirling." Another suggested that
"It's not exactly a sound. I felt a vibration inside my head that
produced a noise. I felt as if satellite had been connected to my
vibration increases and don't stop until I manage to move. The last
happened, it affected my left ear and I felt pain, as if my ear would
up. The pain lasted for two days.
Sounds - Technological. Many of these sounds are very much like the
inanimate sounds except that they are identified with technical
that might produce such sounds.
There is always a
screeching that gets louder and louder and some nights it's almost
The voice sounds from the ringing of the telephone, in a way wake to
notice that I am paralyzed.
Two sounds are recurrent. One sound is like air entering a vacuum, it
sometimes when entering or leaving the state as the ears become
again. The other sound is like a radio being heard from another room
house. Many stations at the same time, barely intelligible.
The sound was like high pitched power tools....drills or band-saws
close to my ears and gained in volume and intensity until I felt like
was going to explode.
A very loud combination of sounds...a constant crashing, glass
loud sirens...almost deafening
Sounds — Natural. Alternatively, these sounds may
attributed, perhaps by the less
minded, to natural
A gust of wind
though no windows are open
shrill whistling sounds, sound of 'wind'
A rushing/roaring sound like waves in a sea shell almost or maybe
I felt I was in a sandstorm. I could hear the wind and sand rushing
ears with a loud (sound) gust of wind
Sounds of Movement. Although the quality of the
be modified slightly when experiencing a ringing sound as a telephone,
rushing sound as the wind it seems unlikely that the next set of
simple transformations of simple sounds described above. A commonly
sound is that of footsteps.
Usually, it sounds
walking around the apartment. (I live alone.)
There was a sound rather like a cardboard box of some weight being
across a dusty wooden floor
Animal Sounds. Similarly, animal sounds of growling, snarling or just
seem unlikely to be merely elaborations of simple sounds.
I have heard 'growls' like a dog from hell or some other
Can be sounds of an explosion or really loud music or just recently, a
like a herd of animals howling and screeching
Human Non-speech Vocalizations.
Sometimes sounds of moaning, screaming are reported, Laughing is
sometimes reported as well.
Sounds — Voices - indistinct and/or unintelligible. Symons argues
dreams, voices are seldom heard as external sounds. Rather,
experienced “in the head” as internal dialogue. The sense and meaning
conversations in dreams are what are experienced. Bergson (1901/1958)
discusses essentially the same idea. "Most of us at one time or
. . . have dreamed about speaking to someone or being engaged in a
conversation only to have forced on us the singular realization that
not speaking and had not spoken, and that our interlocutor had not
single word. We had exchanged our thoughts and carried on an
conversation, yet we had heard nothing" (p. 27-28). Bergson further
noted that "unless we are provided with some phonic substance, it is
hard for us to fabricate sounds in our dreams" (p. 28). In contrast to
dream voices SP voices are experienced as definitely externally
sounds but of indefinite or nonsensical meaning. The voices may be
experienced as quite loud shouting or soft whispering but, in either
the sense of what is being said is elusive.
I heard loud voices
there were people outside of my car, but there were not. (This person
reported SP while napping in car.)
I also frequently hear voices saying nonsensical things when falling
I sometimes hear people (who I think are in the room talking), or
I think my family or friends are playing.
I heard strange garbled voices whispering in my ears.
moaning and voices
I also frequently hear voices saying nonsensical things when falling
Loud noises and talking, but I could not make out what was being
Vague voices speaking sentences that were nonsense (but in English
Usually the sounds are that of people talking or yelling outside.
it will be a familiar voice like that of my mother. Usually
times I will hear high pitched noises, very loud, usually increasing
don't wake up.
Loud noises and talking, but I could not make out what was being
Have had the sense that I was hearing sinister voices - saying nothing
screaming like sounds
One time I awoke to find half snake/half human thing shouting
gibberish in my
On a few occasions it has whispered heavily in my ears. Once it spoke
language I couldn't understand, the other times I couldn't remember
had said after I woke up.
Laughing and babbling background voices are
Sounds — Voices – distinct. Occasionally the voices may produce
intelligible utterances, but these are usually simple commands.
But as I listened I
this 'thing' walk to hover over my head - very close directly
ear. It said 'Freya!' . . . The voice continued 'I've got work
to do!' Then I listened as the presence hovered for a few seconds more
moved across the room to sit on my roommate's bed.
Sometimes hear voices, e.g., my name being called.
Usually voices. One time he (?) was using my name when speaking to
I heard a voice telling me I was playing the game wrong and I had to
right or quit. it was a woman's voice and she sounded as though
were in a lot of pain and very far away, then she said, he's coming
In one case, a respondent heard the voice of
had actually threatened her in the recent past. "But as I listened I
could sense this 'thing' walk to hover over my head - very close
over my ear. It said 'Freya!' At first I thought - just my roomie -
recognized the voice as a mystery caller who has harassed me twice."
is an interesting instance because we may be seeing here an example of
someone explicitly running through a series of plausible
this unusual experience and settling on perhaps the most plausible
context of sensed presence, fear and the recent threatening
Visual imagery in SP is experienced not only less frequently than
experiences but often less vividly. The sense of presence seems to
the less definite visual images. "It was more like an image than
real presence." Visual imagery seems also to take its cues from other
experiences. Sometimes it is the sensed presence that begins to take
"Always accompanied by the presence, I've seen shapes/beings, from
snake/humans type things that shout gibberish in my ears. I've seen
devil, bats etc. Most of the time it's a human shape that's completely
black." As in the case of the sensed presence the visual images are
almost out of sight, just on the periphery of vision. "[It was a
ugly creature behind me, which I could only see from the corner of my
Sometimes imagery may be associated with the pressure on the chest
on "The Incubus"). "Once I had one of this old lady, that was
sitting on top my chest beating the living daylights out my head, I
myself to and my head was pounding." Not surprisingly, the images may
associated with threats.
Until lately, all my SP involved a visible black shaped 'presence' in
room, meaning to do me harm.
I feel fairly certain that if I let the apparitions get all the way up
they will kill me. I have fought out of this to prevent getting too
the possibility. Each time it happens, I am scared they will kill me,
especially if I let them 'take' me out of my body.
On one occasion I felt like a presence and saw a kind of specter. It
misty form floating above my feet, and I felt that it was the cause of
I once woke up to what I thought was a man
me in bed who had my
right arm in a tight grip, holding me down on the bed. The man just
'pinned' by the wrist and I was frozen for what seemed like forever
up into his face (probably lasted less than a minute). The room was
the face was in shadows, so I mostly saw an outline of the face. When
I could move, I whispered 'What do you want?' and the face seemed to
disappear into the flowered pattern of my bedroom drapes. My right arm
'asleep' and as I then moved it I had extremely painful 'pins
needles' sensation. It was a terrifying experience, but something that
The second time, in the first house, I saw a beige roundish being over
bed. The energy was female and it was very, very angry. The second
the experience above, however, I did not see the presence that was in
room, however, I had visions, that the woman who had died there had. I
two of her children at the edge of the bed.
I've seen images on the bedcovers.
Once it was an arm reaching out of my floor as if trying to pull
other times it was vague almost faces and movements in my peripheral
The formed shape is usually an unusual geometric shape that floats
room. I only see this when the room is dark. It used to
when I was a child.
Usually larger than me, always male. It never has a face.
There was a woman - whom I could sense but not see - behind me. I
It seemed to be a scene from the past century.
Vision —Well-defined Images
In one of the relatively rare cases of specific and concrete imagery, a
Native American woman drew upon her heritage. Curiously she then adds
apparently incongruous image of medical personnel.
Spider woman came from the ceiling and wrapped me up and sang songs to
was l0 and later the deerwoman would come and stand at the foot of my
then lab coated people with monitors. I have never been hospitalized.
deerwoman still comes.
For the most part, however, visual images tend to be indefinite and
insubstantial. This is in strong contrast to the vividness of visual
in dreams (Symons, 1995) and auditory imagery in SP reported above.
hallucinations frequently appear to be somewhere between full
and pseudo-hallucinations. Reed characterizes pseudo hallucinations as
lacking the substantiality of externally perceived stimuli and as
in inner subjective space. The visual imagery of SP often appear to be
substantial than normal perception but are clearly taken to be
Some writers appear to require that hallucinations also be believed to
true by those experiencing them (e.g., Reed, 1988). That is, they
that the person be deluded by their experiences. Comments by several
respondents suggest that this is a very problematic stance. Many
are quite emphatic that the hallucinations are entirely compelling but
able to maintain a critical stance. Their faith in rationality and
conventionality triumphs, as it were, over the evidence of their
respondent provided a vivid account of alien abduction, complete with
procedures, associated with his SP experiences.
At one point, long
pressed across chest to induce unconsciousness hands picking up and
mine. Fingernail clippings removed. Painful examinations syringes,
exposure of brain, magical 'surgery' sometimes I find that I am like a
being repaired by human owner. Was COMPLETELY SHOCKED to watch similar
in Star Trek First Contact. Never seen this scene before my experience
experience is almost captured in scene with Data
This respondent was most emphatic that his
were totally compelling but that, considering himself a hard-headed
sensible person, he did not believe any of it for a minute. His
was of abduction but this did not make it true, even for him.
The Intruder and REM
The present discussion of SP and associated HHEs is much
the activation-synthesis theory of dreaming (Hobson & McCarley,
McCarley & Hobson, 1979). According to that theory, REM is
inhibitory activity of the REM-off cells in reciprocal interaction
REM-on cells (See section on SP and REM for a more detailed
These brain-stem mechanisms inhibit motor output and sensory input and
provide the cortex with internally generated activation. The function
cortical centers is one of synthesizing quasi-random activation into
meaningful patterns. Although the activation-synthesis model has not
emphasized affective components, the pervasiveness of fear and the
presence in the phenomenology of SP indicates that the role of the
may need to be considered central in understanding the SP night-mare.
hypothesize that the experience of a threatening presence during SP is
associated with the thalamic projections to the amygdala. During REM,
of activation originating in the brain stem pass through the thalamus,
has direct projections, not only to specific cortical areas but also
amygdala (Charney, Grillon, & Bremner, 1998; LeDoux, 1994). The
subcortical thalamo-amygdala pathway provides a coarse-grained
stimuli sufficient to ensure that dangerous or threatening events are
responded to with emergency reactions without the delay of detailed
via the sensory cortex (LeDoux, 1994, 1996). We argue that the sense
presence and its strongly associated sense of terror during SP are a
of activation of the amygdala by bursts originating in the pontine
areas. In normal emergency fear reactions the immediate sensing of
quickly confirmed or disconfirmed. Reciprocal projections to the
association cortex directly from the amygdala enhance analysis of
features of the threatening stimulus corroborate the nature and
of the threat (Ledoux, 1994). In the absence of exogenous origins,
to analyze the source of fear will inevitably fail to produce
Hence the state of apprehensive "suspicion" that normally might
last only milliseconds may last many seconds or even minutes during
such conditions subjects might experience a protracted but
"thalamic" consciousness (Head & Holmes, 1911; Smythies, 1997)
of an indefinite presence strongly associated with fear. The preceding
explains the high correlation found between sensed presence and fear
previous research (Cheyne, Newby-Clark, & Rueffer, 1998,
When the SP episode persists, the presence may motivate continuing
disambiguation and shape increasingly elaborate interpretations of
consistent with external threat. These may arise endogenously, via
driven oculomotor or middle ear activity, or exogenously, as shadows
ambient sounds. These sensations may be interpreted as approaching
or apparitions that are concrete instantiations of the threatening
Such conflict between endogenous and exogenous stimulation is possible
because the visual and auditory systems are fully functional during SP
(Hishikawa, 1976; Hishikawa & Kaneko, 1965) and hence compete with
endogenous sources of activation. This cluster of presence, fear, and
auditory and visual experiences consistent with mechanisms underlying
responses to predation (LeDoux, 1996) and with a
narrative of stalking and
threat of attack.