From: http://www.psywww.com/asc/obe/faq/obe23.html
Most theories of the OBE either claim that something leaves the physical body, or that it does not. Then within these two major categories there are several different types of explanation, and there is perhaps a last possibility; that any such distinction is meaningless and artificial. The theories can be divided up as follows [Bla82]
First there is the kind of explanation which suggests that
we each have a second physical body which can separate from
the usual one. There are two aspects to consider, one being
the status and nature of the double which travels, and the
other being the status and nature of the world in which it
travels. In this theory both are material and interact with
the normal physical world. You may immediately dismiss this
notion, saying that the double is non-physical.
To make this theory even worth considering it is necessary to
assume that this double is composed of some 'finer' or more subtle
material that is invisible to the untrained eye. This kind of
idea is sometimes expressed in occult writings. The idea appears,
for example, as the 'etheric body' of the Theosophists. Objections
to this type of theory are numerous, and are made on both logical
and empirical grounds. First, what could the double be made of?
The possibilities seem to range between a complete solid duplicate
and a kind of misty and insubstantial version. Another problem
with this kind of double is its appearance. If all have a second
body why does it appear to some as a blob or globe, to other
as a flare, or light, and to yet others as a duplicate of the
physical body? Muldoon and Carrington [MC29] wrestled with this
problem and so has Tart [Tar74b].
If the notion of a physical double is problematic, the notion that it travels in the physical world is just as much so. First there are the types of errors made in OB perception. These tend not to be the sort of errors which might arise from a poor perceptual system, but seem often to be fabricated error, or additions, as well as omissions. Then sometimes the OB world is responsive to thought, just as in a dream the scenery can change if the person imagines it changing; and lastly, there is the fact that many OBEs merge into other kinds of experience. The OBEer may find himself seeing places such as never were on earth, or he may meet strange monsters, religious figures or caricature animals. All these features of the OBE make it harder to see the OB world as the physical world at all, and lead one to the conclusion that the OB world is more like a world of thoughts.
Many theories have suggested that the double is not physical
but non-physical, even though it travels in the physical world.
Many occultists believe there to be a whole range of non-physical
worlds of differing qualities. Let us look at some examples
of this sort of theory to try to find out what is meant by
it. Tart [Tar74b, 78] refers to it as the 'natural' explanation.
He describes this theory of the OBE as follows '... in effect
there is no need to explain it; it is just what it seems to
be. Man has a non-physical soul of some sort that is capable,
under certain conditions, of leaving the physical seat of consciousness.
While it is like an ordinary physical body in some ways, it
is not subject to most of the physical laws of space and time
and so is able to travel at will.'
The 'theta aspect' has been mentioned in connection with detection
experiments. Morris et. al. [MHJHR78] explain that '... the OBE
may be more than a special psi-conductive state; they hold that
it may in fact be evidence of an aspect of the self which is
capable of surviving bodily death. For convenience, such a hypothetical
aspect of the self will hereafter be referred to as a Theta Aspect
(T.A.).' According to Osis and Mitchell [OM77] it is possible
that '... some part of the personality is temporarily out of
the body,' and many occult theories involve a non-physical astral
double rather than a physical one.
Blackmore criticizes this view [Bla82]. She claims if the 'soul'
is to interact with the objects of the physical world so as to
perceive them then it should not only be detectable, but all the
other problems of previous theories arise. On the other hand, if
this 'soul' does not interact with the physical, then it cannot
possibly do what is expected of it in this theory, namely travel
in the physical world. She sees no escape from the dilemma. Moreover,
she claims there is already evidence that what is seen in an OBE
is not, in any case, the physical world.
Each of the theories presented thus far support a conclusion
that OBEs do not take place in the physical world at all, but
in a thought-created or mental world. Each of the next three
types of theory start from this premise, but they are very
different and lead to totally different conceptions of the
experience.
The term 'mental world' could mean several different things.
It could mean the purely private world created by each of us
in our thinking. One possibility is that there is another world
(or worlds) which is mental but is in some sense shared, or objective
and in which we can all travel if we attain certain states of
consciousness. The important question now becomes whether the
OB world is peculiar to each individual, or shared and accessible
to all.
Occultists have suggested that there is a shared thought world. There are many other versions of this kind of theory. The pertinent features of this idea are that there is a non-physical OB world which is accessible by thought, that it is manipulable by thought, and that it is the product of the mind of more than just one person.
Tart [74b, 78], as one of his five theories of the OBE, suggests what he calls the 'mentally-manipulatable-state explanation.' He raises here the familiar problem of, as he puts it 'where the pajamas come from.' That is, if the OBE involves the separation of a 'spirit' or 'soul' we have to include the possibility of spiritual dinner jackets and tie pins. Of course any theory which postulates 'thought created' world solves this problem. Tart therefore suggested that a non-physical second body travels in a non-physical world which is capable of being manipulated or changed by 'the conscious and non-conscious thoughts and desires of the person whose second body is in that space.'
In 1951 Muldoon and Carrington had come to a similar conclusion [MC51]. Muldoon states '... one thing is clear to me -- the clothing of the phantom is created, and is not a counterpart of the physical clothing.' Through his observations he came to the conclusion that 'Thought creates in the astral, ... In fact the whole astral world is governed by thought.' But he did not mean it was a private world of thoughts.
Also relevant here is the occult notion of thought forms. Theosophists Besant and Leadbeater describe the creation of thought forms by the mental and desire bodies, and their manifestations as floating forms in the mental and astral planes. All physical objects are supposed to have their astral counterparts and so when traveling in the astral one sees a mixture of the astral forms of physical things and thought created, or purely astral, entities.
There are other versions of a similar idea. For example Whiteman questions the 'one-space theory' of OBEs [Whi75], and Poynton follow him suggesting '... what is described is not the physical world as actualized by the senses of the physical body, but a copy, more or less exact, of the physical world' [Poy75]. Rogo [Rog78b] suggests that the OBE takes place in a non-physical duplicate world which is just as 'real' to the OBEer as our world is to us.
The idea of shared thought world, attractive as it is, has some serious problems. The first problem relates to how the thoughts of different people could be combined together to create an astral world and the second problem concerns the storage of ideas. The idea that thoughts can persist independently of the brain has been a cornerstone of many occult theories, but also parapsychologists have used a similar idea to try to explain ESP.
According to Blackmore [Bla82] the problem is essentially one
of coding. We know that when a person remembers something he has
first processed the incoming information, thought about it, structured
it, and turned it into a manageable form using some sort of code.
We presume that the information persists in this form until needed
when the person can use the same coding system to retrieve it and
use it. Even if we don't understand the details of how this system
works, there is in principle no problem for one person because
he uses the same system both in storing the material and retrieving
it. But if thoughts are stored in the astral world, then we have
to say that one person can store them there and another can get
them out again. And that other person may have entirely different
ways of coding information. So how can these thoughts in the astral
possibly make sense to him?
The OBE might involve only imaginary traveling in a private imaginary
world. According to this type of theory, nothing leaves the body
in an OBE. The advantage of such a theory is that it avoids all
the problems of the previous ones since it involves no astral
worlds and other bodies. Certain parapsychologists have tried
to incorporate the evidence that ESP occurs during OBEs by suggesting
that the OBE is 'imagination plus ESP' or PK. For example, one
of Tarts's five theories is the 'hallucination-plus-psi explanation.'
According to this theory, 'For those cases of OBEs in which veridical
information about distant events is obtained, it is postulated
that ESP, which is well proved, works on a nonconscious level,
and this information is used by the subconscious mind to arrange
the hallucinatory or dream scene so that it corresponds to the
reality scene' [Tar78].
Osis [Osi75] contrasts his 'ecsomatic hypothesis' with 'traveling
fantasy plus ESP' and Morris [MHJHR78] compares the theory that
'some tangible aspect of self can expand beyond the body' with
what he call the 'psi-favorable state' theory. In parapsychology
many states have been thought to be conducive to ESP. They include
relaxation, the use of ganzfeld or unpatterned stimulation, and
dreaming. There are many reasons why an OBE might be thought
of as a psi-conductive state. Palmer suggested that it might
induce attitudes and expectations consistent with psi, thereby
facilitating its occurrence [Pal74].
This sort of theory is not satisfying. It appears to avoid all the previous problems and yet to be able to cope with the paranormal aspects of the experience. According to Blackmore 'Calling the OBE imagination or hallucination tells us very little, and adding the words 'plus ESP' adds nothing. We know little enough about ESP. It is defined negatively, and we cannot stop and start it or control it in any way.'
This theory amounts to the statement that all the details of
the OBE are to be accounted for in psychological terms. Nothing
leaves the body in an OBE, the astral body and astral world
are products of the imagination and the OBE itself provides
no hope for survival. Osis has called the followers of such
theories 'nothing but-ers,' reducing the OBE to 'nothing but
a psychopathological oddity' [Osi81].
Among psychological approaches there have been psychoanalytic
interpretations, analogies between the 'tunnel' and the birth
experience; the creation of the double has been seen as an
act of narcissism or as a way of denying the inevitable mortality
of the human body. Then there have been theories which treat
the near-death experience as a form of depersonalization or
regression to primitive modes of thinking, and those which
treat it as involving an archetype.
John Palmer used a mixture of psychological and psychoanalytical concepts in his account [Pal78a]. He made the crucial point that the OBE is neither potentially nor actually a psychic phenomenon. An OBE may be associated with psychic events but the experience itself, just like any other experience, is not the kind of thing which can be either psychic or not. He went on to suggest that the OBE almost always occurs in a hypnagogic state. Within this state it is triggered by a change in the person's body concept which results from a reduction or other change in proprioceptive stimulation. This change then threatens the self concept and the threat activates deep unconscious processes. These processes try to re-establish the person's sense of individual identity as quickly and economically as possible in a way that follows the laws of the Freudian primary process. According to Palmer it is this attempt to regain identity which constitutes the OBE.
Since the whole purpose of the OBE is to avoid a threat, the person will usually remain unaware of that threat and of the change in body image which precipitated it. However, Palmer adds that it is possible, with practice, to gain ego-control over the primary process activity. Of course the OBE is, at best, only a partial solution to the threat and both ego and primary process strive to regain the normal body concept. As soon as they succeed the OBE ends. For Palmer any psychic abilities which manifest themselves during an OBE do so more because of the hypnagogic state than because anything leaves the body.
This theory has much in its favor. It has no need of astral bodies or other worlds and so avoids all the problems of the earlier theories. It makes sense of the situations in which the OBE occurs, and the way it varies with the situation, and it relates the OBE to other experiences. However, the theory is not without its own problems. It depends heavily on the idea that the OBE is a means of avoiding a threat to the integrity of the individual and the anxiety which such a threat would arouse. But it is not clear that the OBE would not provide an even greater threat than the original change in body concepts. Sometimes OBEers are terrified that they will not be able to 'get back in' which is surely also a threat.
Susan Blackmore [Bla82] bases her theory on the claim that the evidence of paranormal events during the OBE is limited and unconvincing. She therefore asserts that the claims for ESP and PK in OBEs are not impossible but there is actually not very much evidence which has to be 'explained away' in this fashion. Blackmore suggests that the OBE is best seen as an altered state of consciousness (ASC) and is best understood in relation to other ASCs. Everything perceived in an OBE is a product of memory and imagination, and during the OBE one's own imagination is more vividly experienced than it is in everyday life. In other words the experience is a kind of privileged peek into the contents of one's own mind.
Blackmore suggests that in the case of the OBE the following are necessary: vivid and detailed imagery; low reality testing so that memories and images may seems 'real'; sensory input from the body reduced or not attended to; awareness and logical thinking maintained. She shows how these prerequisites can lead to an altered state of which one form is the semi-stable OBE and indicates related states, such as lucid dreaming, and shows how experience can change into others when conditions, or ways or thinking, change.
This theory accounts adequately for cases of so-called traveling clairvoyance, where the subject does not necessarily see his body, but is aware of a distant scene. It accounts less well for cases of conscious projection, where the subjects feels himself to be at a distant location and is actually perceived by a person at that location. It also underestimates the veridical aspect of perception in cases where there is no apparent distortion by the imagination, in other words when the scene viewed from another point of space corresponds exactly with what one might expect to observe from that point; for instance a room seen from the vantage point of the ceiling. The question of perceptual distortion is related to the degree of interference by the imagination: the greater the imaginative element, the less veridical the perception of the place.
Stephen LaBerge describes a theory in which OBEs occur when people lose input from their sense organs, as happens at the onset of sleep, while retaining consciousness [LL91]. This combination of events is especially likely when a person passes directly from waking into REM sleep. In both states the mind is alert and active, but in waking it is processing sensory input from the outside world, while in dreaming it is creating a mental model independent of sensory input. This model includes a body. When dreaming, we generally experience ourselves in a body much like the 'real' one, because that is what we are used to. However, our internal senses reside in the physical body, which when we are awake inform us about our position in space and about the movement of our limbs. This information is cut off in REM sleep. Therefore, we can dream of doing all kinds of things with our dream bodies -- flying, dancing, running from monsters, being dismembered -- all while our physical bodies lie safely in bed.
During a WILD, or sleep paralysis, the awake and alert mind keeps up its good work of showing us the world it expects is out there -- although it can no longer sense it. So, then we are in a mental dream world. Possibly we feel the cessation of the sensation of gravity as that part of sensory input shuts down, and then feel that we are suddenly lighter and float up, rising from the place where we know our real body to be lying still. The room around us looks about the same as it would if we were awake, because such in image represents our brain's best guess about where we are. If we did not know that we had just fallen asleep, we might well think that we were awake, still in touch with the physical world, and that something mighty strange was happening -- a departure of the mind from the physical body.
The unusual feeling of leaving the body is exciting and alarming. This, combined with the realistic imagery of the bedroom is enough to account for the conviction of many OBE experients' that 'it was too real to be a dream.' Dreams, too, can be astonishingly real, especially if you are attending to their realness. Usually, we pass through our dreams without thinking much about them, and upon awakening remember little of them. Hence, they seem 'unreal.' But waking life is also like that -- our memory for a typical, mundane day is flat and lacking in detail. It is only the novel, exciting, or frightening events that leave vivid impressions. If we stop what we are doing, we can look around and say, 'Yes, this world looks solid and real.' But, if you look back and try to recall, for instance, brushing your teeth this morning, your memory is likely to be vague and not very life-like. Contrast this kind of event to a past event that excited or alarmed you, which is likely to seem much more 'real' in retrospect.
Perhaps all the distinctions and problems are artificial, perhaps
the mind is neither 'in' nor 'out' of the body. Grosso argues
the possibility [Gro81] that one is always 'out' and in an
OBE just becomes conscious of that fact. Should the distinction
between normal and paranormal then be dropped?
Let us consider the state of affair that is considered normal:
the 'in-the-body' experience. What does it mean to be in a body?
LaBerge [LL91] argues that saying that one is in a body implies
that the self is an object with definite borders capable of being
contained by the boundaries of another object -- the physical
body. However, we do not have any evidence that the self is
such a concrete thing. What we think of as 'out-of-body' in
an OBE is the experience of the self. This experience of being
'in' a body is normally based on perceptual input from the
senses of both the world external to the body and the processes
within the body. These things give us a sense of localization
of the self in space. However, it is the body, and its sense
organs, that occupy a specific locus, not the self. The self
is not the body or the brain. If we think that the self is
a product of brain function, even this does not make it reasonable
to state that the self is in the brain -- is the meaning contained
in these words in this page? It may not make any sense on an
objective level to say that the self is anywhere. Rather, the
self is where it feels itself to be. Its location is purely
subjective and derived from input from the sensory organs.
Putting aside the question of the essential nature of the self, perception is undeniably a phenomenon tied to brain function. So, when we find ourselves experiencing a world that seems much like the one we are used to perceiving with our usual equipment -- eyes, ears, etc., all things linked to our brains, it would be logical to assume that it is our usual brain creating the experience. And, if we were to really leave our bodies -- severing all connection with them -- it would be illogical to assume that we would see the world in the same way. Therefore, LaBerge points out, although no amount of contradictory evidence can rule out the possibility of a real 'out of body experience,' in which an individual exists in some form entirely independent of the body, it is highly unlikely that such a form would utilize perceptual systems identical to those of the physical human form.
Spiritual teachings tell us that we have a reality beyond that of this world. LaBerge concludes that the OBE may not be, as it is easily interpreted, a literal separation of the soul from the crude physical body, but it is an indication of the vastness of the potential that lies wholly within our minds. 'The worlds we create in dreams and OBEs are as real as this one, and yet hold infinitely more variety. How much more exhilarating to be "out-of-body" in a world where the only limit is the imagination than to be in the physical world in a powerless body of ether! Freed of the constraints imposed by physical life, expanded by awareness that limits can be transcended, who knows what we could be, or become?' [LL91].