Out of body experiences and their neural basis
BMJ 2004; 329 doi: https://doi.org/10.1136/bmj.329.7480.1414 (Published 16 December 2004) Cite this as: BMJ 2004;329:1414All rapid responses
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I was interested to read Blanks's paper on 'out of body'
experiences and like Stack (2), there perhaps should
have been more reference to the research on 'near
death experiences' (NDEs). There has been a lot of
research into whether particular types of people are
more susceptible to NDEs. Unfortunately, very few
consistent findings have been found. It seems that
almost anyone can experience NDEs. In fact, it has
been reported that factors such as age, social class,
race, and marital status have little (if any) influence on
NDEs. Other factors that have been found to have little
influence on NDEs include religious belief, prior
knowledge of NDEs, and whether or not the person has
a terminal illness. However, research appears to
suggest that the type of death may influence the type of
NDE. For instance, those involved in car accidents and
other "sudden" events tend to report more cognitive
experiences such as a "life review" where the person’s
life flashes before their eyes. One factor that may make
a person more likely to experience NDEs is a history of
abuse or trauma. The psychologist Kenneth Ring
(University of Connecticut) says that these individuals
are more likely to dissociate from a painful reality and
tune into other realities to feel safe.
The original pioneering academic study of NDEs has
been attributed to the American psychiatrist Elizabeth
Kubler-Ross who wrote the influential book 'On Death
and Dying' in 1969. In her book, she recorded many
accounts of NDEs and "out of body travel" from her
terminally ill patients and formulated the five classic
stages of grieving (denial, anger, bargaining,
depression and acceptance). She also reported that
her patients often spoke to people who had preceded
them in death, and that after death most of their faces
became very peaceful.
In 1975, the first book to bring NDEs to mass public
attention was 'Life After Life', a study of 150 cases
written by Raymond Moody, and in 1988 wrote the
follow-up best seller, The Light Beyond. In 1980, further
research by the psychologist Kenneth Ring published
in his book 'Life At Death' concluded that NDEs consist
of up to five stages. Based on an in-depth study of 102
cases, Ring reported that most people who have NDEs
will experience the first stage but that very few reach the
final one. His stages included peace (60%), body
separation (37%), entering the darkness (23%), seeing
the Light 16%), and entering the Light (10%). As with
most areas, there are other typologies of NDEs that
have been developed. For instance, the psychiatrist
Bruce Greyson (University of Virginia) claimed that
NDEs consisted of four different types – cognitive,
affective, paranormal, and transcendental.
Some scientists are adamant that NDEs can wholly be
explained by biological phenomena. For instance, the
neurologist Ernst Rodin claims that a lack of oxygen
supply to the brain (i.e., cerebral anoxia) causes
delusions and hallucinations, and is a possible cause
of NDEs. Karl Jansen and his colleague the
endocrinologist Daniel Carr maintain that the body’s
own morphine like substances (endorphins) increase
before death and produce the feelings of calm and
peacefulness reported by many who undergo NDEs.
The neurologist Michael Persinger argues that
temporal lobe brain activity and instability above the
right ear is responsible for the deep meaningfulness,
early memories and out-of-body experiences. The
psychologist Susan Blackmore adds to this theory and
argues that instability of the temporal lobe is also
responsible for paranormal and mystical experiences.
She also claims that the "Light at the end of the dark
tunnel" experiences are optical illusions created by the
effects of anoxia and drugs in which random light spots
radiate from the centre of a dark internal visual field
(also known as "cortical disinhibition"). Blackmore also
believes that out-of-body experiences are drug-induced
illusions as these are common experiences for people
who use the drug ketamine recreationally. However,
nearly all of these theories are at best only part
explanations as none of them can fully explain all NDE
accounts.
In addition to biological explanations there have also
been psychological accounts. There are a whole raft of
psychological theories that have been forwarded as an
explanation for NDEs. These range from
historically-based Freudian and Jungian theories
through to more contemporary cognitive explanations.
An early psychiatric explanation claimed that NDEs
were linked with theories of depersonalization which
"defend" the nervous system from the mental
disorganization during the death crisis. Other
psychologists claimed that depersonalization produces
an altered passage of time, vivid and accelerated
thoughts, a sense of detachment, unreality, automatic
movements, and revival of memories. Some
psychiatrists such as Ronald Siegal claim that NDEs
are simply hallucinations (albeit very ordered ones)
whereas some psychoanalysts claim that NDEs are a
denial of death – a hallucinatory wish fulfillment
defending the ego from its impending annihilation.
Other psychoanalysts claim that "birth trauma" is the
root of all neuroses and therefore explain NDEs as a
regression to infantile object relations with the dark
tunnel as the mother’s birth canal and the bright light
as the mother’s radiant face. The famous cosmologist
Carl Sagan saw some merit in this idea and proposed
that people who have NDEs are reliving their descent
down the birth canal. However, this has not been
without its critics. On the technical side, it has been
argued that infants descending down the birth canal not
only have their eyes closed but their brains are too
underdeveloped to allow memories of birth. Susan
Blackmore has also pointed out that that those born by
Caesarian section are equally as likely as those born
naturally to have NDEs which feature tunnels and
out-of-body experiences! A more recent theory by the
psychologist Susan Blackwell claims that the human
mind creates various mental models of reality based
on its experiences, and the most stable one wins out
as the favoured version. She claims that NDEs occur
when the mind is in crisis and makes up models of
reality such as out-of-body experiences, imagining the
mind to be floating up above the body.
Whatever the explanation for NDEs, study of them from
them is clearly an interesting area for both researchers
and the public alike. Whether the explanations are
biologically, psychologically, or spiritually defined, it will
not stop the growth of scientific research in this
fascinating area.
Further reading
E. Kubler-Ross (1969). On Death And Dying. New York :
MacMillan
R. Moody (1975). Life After Life. New York :
Bantam/Mocking bird.
R. Moody (1988). The Light Beyond. New York :
Bantam/Mocking bird.
M. Morse (1990). Closer To The Light : Learning From
The Near-Death Experiences Of Children.
K. Ring (1980). Life At Death. New York : William
Morrow Co.
References
(1) Blanke O. Out of body experiences and their neural
basis. BMJ 2004; 329: 1414-1415.
(2) Stack G. Near Death (Rapid response). BMJ, 17
December 2004.
Competing interests:
None declared
Competing interests: No competing interests
In an interesting editorial about “out of body experiences”, Olaf
Blanke reviews what are the possible neural basis for this phenomena (1).
Although temporo-parietal junction seems to play a key role regulating
self processing, beyond the anatomical basis there is an increasing
evidence supporting the relationship between N-methyl-D-aspartate (NDMA)
receptor antagonism and the occurrence of “out of body experiences”. It is
well known how certain drugs can produce them. Thus, NMDA antagonists as
phencyclidine (PCP), ketamine or high doses of dextromethorphan have been
associated with this sensations (2-4). In fact, “out of body experiences”
are sought by certain subjects that use these drugs in order to achieve
strong hallucinogenic experiences. Thus, during ketamine intoxication some
users report to be in a state denominated ‘K-hole’. Subjects report
travelling through a dark tunnel into light at a high speed, with intense
visions, spiritual thoughts and “out of body experiences”, sometimes lived
as near death experiences (5,6). Glutamatergic stimulation plays an
important role mediating perceptions of the self and also corporeal
awareness. Interrupting this process can therefore produce a dissociation
between self and extra-personal space. We agree that investigation of out
of body experiences might allow us to improve our neuroscientific models
of self and corporal awareness. Furthermore, beyond anatomical basis,
neuroimaging or behavioural techniques, NDMA receptor research could allow
us to develop new pharmacological tools for diseases as schizophrenia or
autism.
1. Olaf Blanke. Out of body experiences and their neural basis. BMJ
2004;329:1414-1415.
2. Hartvig P, Valtysson J, Lindner KJ, Kristensen J, Karlsten R,
Gustafsson LL, et al. Central nervous system effects of subdissociative
doses of (S)-ketamine are related to plasma and brain concentrations
measured with
positron emission tomography in healthy volunteers. Clin PharmacolTher
1995;58:165-173.
3. Smith GS, Schloesser R, Brodie JD, Dewey SL, Logan J, Vitkun SA,
et al. Glutamate modulation of dopamine measured in vivo with positron
emission tomography (PET) and 11C-raclopride in normal human
subjects.Neuropsychopharmacology 1998;18:18-25.
4. Abanades S, Peiró AM, Farré M. [Club drugs: old medicines as new
party drugs]Med Clin (Barc) 2004;123:305-311.
5. Jansen KL. A review of the nonmedical use of ketamine: use, users
andconsequences. J Psychoactive Drugs 2000;32:419-433.
6. Curran HV, Monaghan L. In and out of the K-hole: a comparison of
the acute and residual effects of ketamine in frequent and infrequent
ketamine users. Addiction 2001;96:749-760.
Competing interests:
None declared
Competing interests: No competing interests
To answer the question of Lara U. Pizzorno,
You should be interested by this paper “Maria’s Near-Death
Experience: Waiting for the Other Shoe to Drop”, published in the
Skeptical Inquirer vol. 20(4), 1996.
H. Ebbern, S. Mulligan and L. Beyerstein investigated this case. They
found that the legend exaggerated the facts: the shoe may have been
perfectly visible from the outside ground level as well as from the
hospital room windows. If Maria did not see the shoe by herself, before or
after her operation, she could have heard a conversation about it. Her
testimony about her NDE may be a reconstruction based on different
elements, gained by perfectly ordinary means.
I want to put emphasis on one conclusive note from the authors: "On
delving into this incident, we were first disappointed, then amused, that
such a weak case should have achieved the importance it has been
accorded." I think that the testimonial "facts" in favour of NDE should be
more critically assessed before being accepted.
Competing interests:
None declared
Competing interests: No competing interests
As a young trainee in medical technology, I was picked as guinea pig
to demonstrate how one does a venipuncture. I had always been frightened
of injections (thanks to an older brother!), and had never had a puncture
done on me.
Despite my ardent protestations, I was restrained and the instructor
proceeded with the demonstration. The room was in an old building whose
ceilings were about 14 feet high. I found myself up in a corner where
ceiling and wall met, looking down on the entire procedure.
This was over fifty years ago, and I can still recall it vividly. I
wasn't ill, do not have epilepsy nor any other neurological problem. I've
always thought it occurred because I was so frightened and just wanted to
get away from what was going to be done to me.
Competing interests:
None declared
Competing interests: No competing interests
I wonder if it is possible to explain out of body experiences (in
which a person sees his body and other objects which he couldn't have seen
from within his body) if man is just one entity.
Furthermore, if human nature/structure is dual, which aspect is the real
man, seeing the other aspect as body?
Is it possible to have a scientific model that will explain all
experiences of man in health and in disease, in wakefulness and sleep, and
in birth and death?
Competing interests:
None declared
Competing interests: No competing interests
It is not unusual in out of body experiences for the individual to
"see" objects that would not be visible from his or her physical position.
One example of which I am aware is the viewing of a red tennis shoe on a
ledge near the top of a hospital building reported by a woman patient in
the hospital on a much lower floor. Can you posit a theory that would
explain such occurrences?
Competing interests:
None
Competing interests: No competing interests
You offer a (credible) explanation for out of body experiences but do
not even mention the particular group which probably attracts most
attention - those people who experience a particular out of body
experience while they are literally at death's door, a near death
experience. They usually describe a profound feeling of happiness and
peace and of an approaching brilliant light or brightness.
Are you implying that they have the same mechanism?
Nollaig Shona dibh go léir!
Competing interests:
Being alive.
Competing interests: No competing interests
Out-of-body subject leaves evidence of experience
Is there much anecdotal or other evidence for the out-of-body subject
interacting with another person or object and leaving an effect that
could be documented by other parties? I experienced such an incident,
and would like to hear more on this subject.
Competing interests:
None declared
Competing interests: No competing interests