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Important paper by the lead researcher of the largest
hospital-based NDE study about the implications of near-death experiences on
theories of continuity of consciousness. In this paper
van Lommel discusses some more general aspects of death, followed by more
details from his prospective study on near-death experience in survivors of
cardiac arrest in the Netherlands, which was published in the Lancet. He also
comments on similar findings from two prospective studies in survivors of
cardiac arrest from the USA and from the United Kingdom. Finally, he
discusses implications for consciousness studies, and how it could be
possible to explain the continuity of our consciousness. About
the Continuity of Our Consciousness
1.
INTRODUCTION
Some people
who have survived a life-threatening crisis report an extraordinary
experience. Near-death experiences (NDE) occur with increasing frequency
because of improved survival rates resulting from modern techniques of
resuscitation. The content of NDE and the effects on patients seem similar
worldwide, across all cultures and times. The subjective nature and absence
of a frame of reference for this experience lead to individual, cultural, and
religious factors determining the vocabulary used to describe and interpret
the experience. NDE can be defined as the reported memory of the whole of
impressions during a special state of consciousness, including a number of
special elements such as out-of-body experience, pleasant feelings, seeing a
tunnel, a light, deceased relatives, or a life review. Many circumstances are
described during which NDE are reported, such as cardiac arrest (clinical
death), shock after loss of blood, traumatic brain injury or intra-cerebral
haemorrhage, near-drowning or asphyxia, but also in serious diseases not
immediately life-threatening. Similar experiences to near-death ones can
occur during the terminal phase of illness, and are called deathbed visions.
Furthermore, identical experiences, so-called “fear-death”
experiences, are mainly reported after situations in which death seemed
unavoidable like serious traffic or mountaineering accidents. The NDE is
transformational, causing profound changes of life-insight and loss of the
fear of death. An NDE seems to be a relatively regularly occurring, and to
many physicians an inexplicable phenomenon and hence an ignored result of
survival in a critical medical situation. And should we
also consider the possibility of conscious experience when someone in coma
has been declared brain dead by physicians, and organ transplantation is
about to be started? Recently several books were published in the Netherlands
about what patients had experienced in their consciousness during coma
following a severe traffic accident, following acute disseminated
encephalomyelitis (ADEM), or following complications with cerebral
hypertension after surgery for a brain tumour, this last patient being
declared brain dead by his neurologist and neurosurgeon, but the family
refused to give permission for organ donation. All these patients reported,
after regaining consciousness, that they had experienced clear consciousness
with memories, emotions, and perception out of and above their body during
the period of their coma, also “seeing” nurses, physicians and
family in and around the ICU. Does brain death really means death, or is it
just the beginning of the process of dying that can last for hours to days,
and what happens to consciousness during this period? Should we also consider
the possibility that someone who is clinically dead during cardiac arrest can
experience consciousness, and even whether there could still be consciousness
after someone really has died, when his body is cold? How is consciousness
related to the integrity of brain function? Is it possible to gain insight in
thisrelationship? In my view the only possible empirical approach to evaluate
theories about consciousness is research on NDE, because in studying the
several universal elements that are reported during NDE, we get the
opportunity to verify all the existing theories about consciousness that have
been discussed until now. Consciousness presents temporal as well as
everlasting experiences. Is there a start or an end to consciousness? In this paper
I first will discuss some more general aspects of death, and after that I
will describe more details from our prospective study on near-death
experience in survivors of cardiac arrest in the Netherlands, which was
published in the Lancet.1 I also want to comment on similar
findings from two prospective studies in survivors of cardiac arrest from the
USA2 and from the United Kingdom.3 Finally, I will
discuss implications for consciousness studies, and how it could be possible
to explain the continuity of our consciousness. Originally
published in: Brain Death and Disorders
of Consciousness. Machado, C. and Shewmon, D.A., Eds.
New York, Boston, Dordrecht, London, Moscow: Kluwer Academic/ Plenum
Publishers, Advances in Experimental Medicine and Biology Adv Exp Med Biol. 2004; 550:
115-132. 2. ABOUT DEATH
First I want
to discuss death. The confrontation with death raises many basic questions,
also for physicians. Why are we afraid of death? Are our concepts about death
correct? Most of us believethat death is the end of our existence; we believe
that it is the end of everything we are. We believe that the death of our
body is the end of our identity, the end of our thoughts and memories, that
it is the end of our consciousness. Do we have to change our concepts about
death, not only based on what has been thought and written about death in
human history around the world in many cultures, in many religions, and in
all times, but also based on insights from recent scientific research on NDE?
What happens
when I am dead? What is death? During our life 500000 cells die each second,
each day about 50 billion cells in our body are replaced, resulting in a new
body each year. So cell death is totally different from body death when you
eventually die. During our life our body changes continuously, each day, each
minute, each second. Each year about 98% of our molecules and atoms in our
body have been replaced. Each living being is in an unstable balance of two
opposing processes of continual disintegration and integration. But no one
realizes this constant change. And from where comes the continuity of our continually
changing body? Cells are just the building blocks of our body, like the
bricks of a house, but who is the architect, who coordinates the building of
this house. When someone has died, only mortal remains are left: only matter.
But where is the director of the body?What about our consciousness when we
die? Is someone his body, or do we “have” a body? 3. SCIENTIFIC RESEARCH ON NEAR-DEATH
EXPERIENCE
In 1969
during my rotating internship a patient was successfully resuscitated in the
cardiac ward by electrical defibrillation. The patient regained
consciousness, and was very, very disappointed. He told me about a tunnel,
beautiful colours, a light and beautiful music. I have never forgotten this
event, but I did not do anything with it. Years later, in 1976 Raymond Moody
first described the so-called “near-death experiences”, and only
in 1986 I read about these experiences in the book by George Ritchieentitled
“Return from Tomorrow,” which relates what he experienced during
a period of clinical death of 6-minutes duration in 1943 during his medical
study.4 After reading his book I started to interview my patients
who had survived a cardiac arrest. To my great surprise, within two years
about fifty patients told me about their NDE. My scientific
curiosity started to grow, because according to our current medical concepts,
it is not possible to experience consciousness during a cardiac arrest, when
circulation and breathing have ceased. Several
theories on the origin of an NDE have been proposed. Some think the
experience is caused by physiological changes in the brain such as brain
cells dying as a result of cerebral anoxia, and possibly also caused by
release of endorphins, or NMDA receptor blockade.5 Other theories
encompass a psychological reaction to approaching death6 or a combination of
such reaction and anoxia.7 But until now there was no prospective,
meticulous and scientifically designed study to explain the cause and content
of an NDE. All studies had been retrospective and very selective with respect
to patients. In retrospective studies 5-30 years can elapse between
occurrence of the experience and its investigation, which often prevents
accurate assessment of medical and pharmacological factors. We wanted to know
if there could be a physiological, pharmacological, psychological or
demographic explanation why people experience consciousness during a period
of clinical death. The definition of clinical death was used for the period
of unconsciousness caused by anoxia of the brain due to the arrest of
circulation and breathing that happens during ventricular fibrillation in
patients with acute myocardial infarction. We studied
patients who survived cardiac arrest, because this is a well-described life
threatening medical situation, where patients will ultimately die from
irreversible damage to the brain if cardio-pulmonary resuscitation (CPR) is
not initiated within 5 to 10 minutes. It is the closest model of the process
of dying. So, in 1988
we started a prospective study of 344 consecutive survivors of cardiac arrest
in ten Dutch hospitals with the aim of investigating the frequency, the cause
and the content of an NDE.1 We did a short standardised interview
with sufficiently recovered patients within a few days of resuscitation, and
asked whether they could remember the period of unconsciousness, and what
they recalled. In cases where memories were reported, we coded the
experiences according to a weighted core experience index. In this system the
depth of the NDE was measured according to the reported elements of the
content of the NDE. The more elements were reported, the deeper the
experience was and the higher the resulting score was. Results: 62
patients (18%) reported some recollection of the time of clinical death. Of
these patients 41 (12%) had a core experience with a score of 6 or higher,
and 21 (6%) had a superficial NDE. In the core group 23 patients (7%)
reported a deep or very deep experience with a score of 10 or higher. And 282
patients (82%) had no recollection of the period of cardiac arrest. In the
American prospective study of 116 survivors of cardiac arrest 11 patients
(10%) reported an NDE with a score of 6 or higher; the investigators did not
specify the number of patients with a superficial NDE with a low score.2
In the British prospective study of 63 survivors of cardiac arrest only 4
patients (6.3%) reported an NDE with a score of 6 or higher, and 3 patients
(4.8%) had a superficial NDE, a total of 7 patients (11%) with memories from
the period of cardiac arrest.3 In our study
about 50% of the patients with an NDE reported awareness of being dead, or
had positive emotions, 30% reported moving through a tunnel, had an
observation of a celestial landscape, or had a meeting with deceased
relatives. About 25% of the patients with an NDE had an out-of-body
experience, had communication with “the light,” or observed
colours, 13% experienced a life review, and 8% experienced a border. What might
distinguish the small percentage of patients who report an NDE from those who
do not? We found that neither the duration of cardiac arrest nor the duration
of unconsciousness, nor the need for intubation in complicated CPR, nor
induced cardiac arrest in electrophysiological stimulation (EPS) had any
influence on the frequency of NDE. Neither could we find any relationship
between the frequency of NDE and administered drugs, fear of death before the
arrest, foreknowledge of NDE, religion or education. An NDE was more
frequently reported at ages lower than 60 years, and also by patients who had
had more than one CPR during their hospital stay, and by patients who had
experienced an NDE previously. Patients with memory defects induced by
lengthy CPR reported an NDE less frequently. Good short-term memory seems to
be essential for remembering an NDE. Unexpectedly, we found that
significantly more patients who had an NDE, especially a deep experience,
died within 30 days of CPR (p<0.0001). We performed
a longitudinal study with taped interviews of all late survivors with NDE 2
and 8 years following the cardiac arrest, along with a matched control group
of survivors of cardiac arrest who did not report an NDE.1 This
study was designed to assess whether the transformation in attitude toward
life and death following an NDE is the result of having an NDE or the result
of the cardiac arrest itself. In this follow-up research into
transformational processes after NDE, we found a significant difference
between patients with and without an NDE. The process of transformation took
several years to consolidate. Patients with an NDE did not show any fear of
death, they strongly believed in an afterlife, and their insight in what is
important in life had changed: love and compassion for oneself, for others,
and for nature. They now understood the cosmic law that everything one does
to others will ultimately be returned to oneself: hatred and violence as well
as love and compassion. Remarkably, there was often evidence of increased
intuitive feelings. Furthermore, the long lasting transformational effects of
an experience that lasts only a few minutes was a surprising and unexpected
finding. Several
theories have been proposed to explain NDE. However, in our prospective study
we did not show that psychological, physiological or pharmacological factors
caused these experiences after cardiac arrest. With a purely physiological
explanation such as cerebral anoxia, most patients who had been clinically
dead should report an NDE. All 344 patients had been unconscious because of
anoxia of the brain resulting from their cardiac arrest. Why should only 18%
of the survivors of cardiac arrest report an NDE? And yet,
neurophysiological processes must play some part in NDE, because NDE-like
experiences can be induced through electrical “stimulation” of some
parts of the cortex in patients with epilepsy,8 with high carbon
dioxide levels (hypercarbia)9 and in decreased cerebral perfusion resulting
in local cerebral hypoxia, as in rapid acceleration during training of
fighter pilots,10 or as in hyperventilation followed by Valsalva
maneuver.11 Also NDE-like experiences have been reported after the
use of drugs like ketamine,12 LSD,13 or mushrooms.14
These induced experiences can sometimes result in a period of
unconsciousness, but can at the same time also consist of out-of-body
experiences, perception of sound, light or flashes of recollections from the
past. These recollections, however, consist of fragmented and random memories
unlike the panoramic life-review that can occur in NDE. Further,
transformational processes are rarely reported after induced experiences.
Thus, induced experiences are not identical to NDE. Another
theory holds that NDE might be a changing state of consciousness
(transcendence, or the theory of continuity), in which memories, identity,
and cognition, with emotion, function independently from the unconscious
body, and retain the possibility of non-sensory perception. Obviously,
consciousness during NDE was experienced independently from the normal
body-linked waking consciousness. With lack of
evidence for any other theories for NDE, the concept thus far assumed but
never scientifically proven, that consciousness and memories are localized in
the brain should be discussed. Traditionally, it has been argued that
thoughts or consciousness are produced by large groups of neurons or neuronal
networks. How could a clear consciousness outside one’s body be
experienced at the moment that the brain no longer functions during a period
of clinical death, with flat EEG?15 Furthermore, blind people have
also described veridical perceptions during out-of-body experiences at the
time of their NDE.16 Scientific study of NDE pushes us to the
limits of our medical and neurophysiological ideas about the range of human
consciousness and relationship of consciousness and memories to the brain. Also Greyson2
writes in his discussion: “No one physiological or psychological model
by itself explains all the common features of NDE. The paradoxical occurrence
of heightened, lucid awareness and logical thought processes during a period
of impaired cerebral perfusion raises particular perplexing questions for our
current understanding of consciousness and its relation to brain function. A
clear sensorium and complex perceptual processes during a period of apparent
clinical death challenge the concept that consciousness is localized
exclusively in the brain.” And Parnia and Fenwick3 write in
their discussion: “The data suggest that the NDE arises during
unconsciousness. This is a surprising conclusion, because when the brain is
so dysfunctional that the patient is deeply comatose, the cerebral
structures, which underpin subjective experience and memory, must be severely
impaired. Complex experiences such as are reported in the NDE should not
arise or be retained in memory. Such patients would be expected to have no
subjective experience [as was the case in the vast majority of patients who
survive cardiac arrest in the three published prospective studies1-3
or at best a confusional state if some brain function is retained. Even if
the unconscious brain is flooded by neurotransmitters this should not produce
clear, lucid remembered experiences, as those cerebral modules, which
generate conscious experience, are impaired by cerebral anoxia. The fact that
in a cardiac arrest loss of cortical function precedes the rapid loss of
brainstem activity lends further support to this view. An alternative
explanation would be that the observed experiences arise during the loss of,
or on regaining consciousness. The transition from consciousness to
unconsciousness is rapid, with the EEG showing changes within a few seconds,
and appearing immediate to the subject. Experiences which occur during the
recovery of consciousness are confusional, which these were not”. In
fact, memory is a very sensitive indicator of brain injury and the length of
amnesia before and after unconsciousness is an indicator of the severity of
the injury. Therefore, events that occur just prior to or just after loss of
consciousness would not be expected to be recalled. And as stated before, in
our study1 patients with loss of memory induced by lengthy CPR reported
significantly fewer NDE. Good short-term memory seems to be essential for
remembering NDE. 4. SOME TYPICAL ELEMENTS OF NDE
Before I
discuss in greater detail some neurophysiological aspects of brain
functioning during cardiac arrest, I would like to reconsider certain
elements of the NDE, like the out-of-body experience, the holographic life
review and preview, the encounter with deceased relatives, the return into
the body and the disappearance of the fear of death. 4.1.
The Out-of-Body Experience
In this
experience people have veridical perceptions from a position outside and
above their lifeless body. NDEers have the feeling that they have apparently
taken off their body like an old coat and to their surprise they appear to
have retained their own identity with the possibility of perception,
emotions, and a very clear consciousness. This out-of-body experience is
scientifically important because doctors, nurses, and relatives can verify
the reported perceptions. This is the report of a nurse of a Coronary Care
Unit: “During
night shift an ambulance brings in a 44-year old cyanotic, comatose man into
the coronary care unit. He was found in coma about 30 minutes before in a
meadow. When we go to intubate the patient, he turns out to have dentures in
his mouth. I remove these upper dentures and put them onto the ‘crash
cart.’ After about an hour and a half the patient has sufficient heart
rhythm and blood pressure, but he is still ventilated and intubated, and he
is still comatose. He is transferred to the intensive care unit to continue
the necessary artificial respiration. Only after more than a week do I meet
again with the patient, who is by now back on the cardiac ward. The moment he
sees me he says: ‘O, that nurse knows where my dentures are.’ I
am very surprised. Then he elucidates: ‘You were there when I was
brought into hospital and you took my dentures out of my mouth and put them
onto that cart, it had all these bottles on it and there was this sliding
drawer underneath, and there you put my teeth.’ I was especially amazed
because I remembered this happening while the man was in deep coma and in the
process of CPR. It appeared that the man had seen himself lying in bed, that
he had perceived from above how nurses and doctors had been busy with the
CPR. He was also able to describe correctly and in detail the small room in
which he had been resuscitated as well as the appearance of those present like
myself. He is deeply impressed by his experience and says he is no longer
afraid of death.” 4.2. The Holographic Life Review
During this
life review the subject feels the presence and renewed experience of not only
every act but also every thought from one’s past life, and one realizes
that all of it is an energy field which influences oneself as well as others.
All that has been done and thought seems to be significant and stored.
Insight is obtained about whether love was given or on the contrary withheld.
Because one is connected with the memories, emotions and consciousness of
another person, you experience the consequences of your own thoughts, words
and actions to that other person at the very moment in the past that they
occurred. Hence there is during a life review a connection withthe fields of
consciousness of other persons as well as with your own fields of
consciousness (interconnectedness).
Patients survey their whole life in one glance; time and space do not seem to
exist during such an experience. Instantaneously they are where they
concentrate upon (non-locality),
and they can talk for hours about the content of the life review even though
the resuscitation only took minutes. Quotation: “All
of my life up till the present seemed to be placed before me in a kind of
panoramic, three-dimensional review, and each event seemed to be accompanied
by a consciousness of good or evil or with an insight into cause or effect.
Not only did I perceive everything from my own viewpoint, but I also knew the
thoughts of everyone involved in the event, as if I had their thoughts within
me. This meant that I perceived not only what I had done or thought, but even
in what way it had influenced others, as if I saw things with all-seeing
eyes. And so even your thoughts are apparently not wiped out. And all the
time during the review the importance of love was emphasised. Looking back, I
cannot say how long this life review and life insight lasted, it may have
been long, for every subject came up, but at the same time it seemed just a
fraction of a second, because I perceived it all at the same moment. Time and
distance seemed not to exist. I was in all places at the same time, and
sometimes my attention was drawn to something, and then I would be present
there.” Also a
preview can be experienced, in which both future images from personal life
events (sometimes remembered only later in the shape of “déja
vu”) as well as more general images from the future occur, even though
it must be stressed that these surveyed images should be considered purely as
possibilities. And again it seems as if time and space do not exist during
this review. Quotation: “I
had a nice eye contact, they looked at me full of love, and then I surveyed a
great part of my life to come; the care for my children, the terminal illness
of my wife, the circumstances I would be mixed up with, in my job and
besides. I surveyed it completely; and then I got the feeling that I had to
decide now: ‘I may stay here, or I have to go back,’ but I had to
decide now.” 4.3. The Encounter with Deceased
Relatives
If deceased
acquaintances or relatives are encountered in an otherworldly dimension, they
are usually recognized by their appearance, while communication is possible
through thought transfer. Thus, during an NDE it is also possible to come
into contact with fields of consciousness of deceased persons (interconnectedness). Sometimes
persons are met whose death was impossible to have known; sometimes persons
unknown to them are encountered during an NDE. Quotation: “During
my cardiac arrest I had a extensive experience (…) and later I saw,
apart from my deceased grandmother, a man who had looked at me lovingly, but whom
I did not know. More than 10 years later, at my mother’s deathbed, she
confessed to me that I had been born out of an extramarital relationship, my
father being a Jewish man who had been deported and killed during the second
World War, and my mother showed me his picture. The unknown man that I had
seen more than 10 years before during my NDE turned out to be my biological
father.” 4.4. The Return into the Body
Some patients
can describe how they returned into their body, mostly through the top of the
head, after they had come to understand through wordless communication with a
Being of Light or a deceased relative that “it wasn’t their time
yet” or that “they still had a task to fulfil.” The
conscious return into the body is experienced as something very oppressive.
They regain consciousness in their body and realize that they are
“locked up” in their body, meaning again all the pain and
restriction of their disease. They also realize that a part of their
consciousness with deep knowledge and understanding as well as the feeling of
unconditional love and acceptance have been taken away from them again.
Quotation: “And
when I regained consciousness in my body, it was so terrible, so
terrible… that experience was so beautiful, I never would have liked to
come back, I wanted to stay there… and still I came back. And from that
moment on it was a very difficult experience to live my life again in my
body, with all the limitations I felt in that period.” 4.5. The Disappearance of Fear of
Death
Nearly all
people who have experienced an NDE lose their fear of death. This is due to
the realization that there is a continuation of consciousness, even when you
have been declared dead by bystanders or even by doctors. You are separated
from the lifeless body, retaining the ability of perception. Quotation: “It
is outside my domain to discuss something that can only be proven by death.
For me, however, the experience was decisive in convincing me that
consciousness lives on beyond the grave. Death was not death, but another
form of life.” Another
quotation: “This
experience is a blessing for me, for now I know for sure that body and mind
are separated, and that there is life after death.” Following an
NDE people know of the continuity of their consciousness, retaining all
thoughts and past events. And this insight causes exactly their process of
transformation and the loss of fear of death. Man appears to be more than
just a body. 5. NEUROPHYSIOLOGY IN CARDIAC ARREST
All these
elements of an NDE were experienced during the period of cardiac arrest,
during the period of apparent unconsciousness, during the period of clinical
death! But how is it possible to explain these experiences during the period
of temporary loss of all functions of the brain due to acute pancerebral
ischemia? We know that
patients with cardiac arrest are unconscious within seconds. But how do we
know that the electroencephalogram (EEG) is flat in those patients, and how
can we study this? Complete cessation of cerebral circulation is found in cardiac
arrest due to ventricular fibrillation (VF) during threshold testing at
implantation of internal defibrillators. This complete cerebral ischemic
model can be used to study the result of anoxia of the brain. In VF
complete cardiac arrest occurs, with complete cessation of cerebral flow,
resulting in acute pancerebral anoxia. The middle cerebral artery blood flow,
Vmca, which is a reliable trend monitor of the cerebral blood
flow, decreases to 0 cm/sec immediately after the induction of VF.17
Through many studies in both human and animal models, cerebral function has
been shown to be severely compromised during cardiac arrest, and electrical
activity in both cerebral cortex and the deeper structures of the brain has
been shown to be absent after a very short period of time. Monitoring of the
electrical activity of the cortex (EEG) has shown that ischemia produces a
decrease of power in fast activity and in delta activity and an increase of
slow delta I activity, sometimes also an increase in amplitude of theta
activity, progressively and ultimately declining to isoelectricity. More
often initial slowing and attenuation of the EEG waves is the first sign of
cerebral ischemia. The first ischemic changes in the EEG are detected an
average of 6.5 seconds after circulatory arrest. With prolongation of the
cerebral ischemia, progression to isoelectricity occurs within 10 to 20 (mean
15) seconds from the onset of cardiac arrest.18-21 After
defibrillation the Vmca, measured by transcranial Doppler
technique, returns rapidly within 1-5 seconds after a cardiac arrest of short
duration. However, in the case of a prolonged cardiac arrest of more than 37
seconds, the Vmca shows an initial overshoot upon reperfusion, a
transient global hyperaemia, followed by a significant decrease in cerebral
blood flow up to 50% or less of normal.22 This results also in an
initial overshoot of cerebral oxygen uptake (hyperoxia) with a fast decrease
in cerebral oxygen uptake to borderline values for a considerable time due to
delayed hypoperfusion.18,22 In the case of a prolonged cardiac
arrest the EEG recovery also takes more time, and normal EEG activity may not
return for many minutes to hours after cardiac function has been restored,
depending on the duration of the cardiac arrest, despite maintenance of
adequate blood pressure during the recovery phase. Additionally, EEG recovery
underestimates the metabolic recovery of the brain, and cerebral oxygen
uptake may be depressed for a considerable time after restoration of
circulation.18 In acute myocardial infarction the duration of cardiac arrest
(VF) in the Coronary Care Unit (CCU) is usually 60-120 seconds, on the
cardiac ward 2-5 minutes, and in out-of-hospital arrest it usually exceeds
5-10 minutes. Only during threshold testing of internal defibrillators or
during electrophysiological stimulation studies will the duration of cardiac
arrest rarely exceed 30-60 seconds. Anoxia causes
loss of function of our cell systems. However, in anoxia of only some
minute’s duration this loss may be transient; in prolonged anoxia cell
death occurs, with permanent functional loss. During an embolic event a small
clot obstructs the blood flow in a small vessel of the cortex, resulting in
anoxia of that part of the brain, with loss of electrical activity. This
results in a functional loss of the cortex like hemiplegia or aphasia. When
the clot is dissolved or broken down within several minutes the lost cortical
function is restored. This is called a transient ischemic attack (TIA).
However, when the clot obstructs the cerebral vessel for minutes to hours, it
will result in neuronal cell death, with a permanent loss of function of this
part of the brain, with persistent hemiplegia or aphasia, and the diagnosis
of cerebrovascular accident (CVA) is made. So transient anoxia results in
transient loss of function. In cardiac
arrest global anoxia of the brain occurs within seconds. Timely and adequate
CPR reverses this functional loss of the brain, because definitive damage of
the brain cells, resulting in cell death, has been prevented. Long lasting
anoxia, caused by cessation of blood flow to the brain for more than 5-10
minutes, results in irreversible damage and extensive cell death in the
brain. This is called brain death, and most patients will ultimately die. From these
studies we know that in our prospective study1 as well as in the
other studies2,3 of patients who have been clinically dead (VF on
the ECG), total lack of electric activity of the cortex of the brain (flat
EEG) must have been the only possibility, but also the abolition of
brain-stem activity, such as the loss of the corneal reflex, fixed and
dilated pupils, and the loss of the gag reflex, is a clinical finding in
those patients. However, patients with an NDE can report a clear consciousness,
in which cognitive functioning, emotion, sense of identity, and memory from
early childhood was possible, as well as perception from a position out and
above their “dead” body. Because of the occasional and verifiable
out-of-body experiences, like the one involving the dentures in our study,1
we know that the NDE must happen during the period of unconsciousness, and
not in the first or last seconds of this period. There is also a well
documented report of a patient with constant registration of the EEG during
surgery for an gigantic aneurysm at the base of the brain, operated with a
body temperature between 10 and 15 degrees Celsius. She was connected to a
heart-lung machine, with VF, with all blood drained from her head, with a
flat line EEG, with clicking devices in both ears, with eyes taped shut, and
this patient experienced an NDE with an out-of-body experience, and all
details she perceived and heard could later be verified.15 So we have to
conclude that NDE in our study,1 as well as in the American2
and the British study,3 was experienced during a transient
functional loss of all functions of the cortex and of the brainstem. How
could a clear consciousness outside one’s body be experienced at the
moment that the brain no longer functions during a period of clinical death,
with a flat EEG? Such a brain would be roughly analogous to a computer with
its power source unplugged and its circuits detached. It couldn’t
hallucinate; it couldn’t do anything at all. As stated before, up to
the present it has generally been assumed that consciousness and memories are
localized inside the brain, that the brain produces them. According to this
unproven concept, consciousness and memories ought to vanish with physical
death, and necessary also during clinical death or brain death. However,
during an NDE patients experience the continuity of their consciousness with
the possibility of perception outside and above one’s lifeless body.
Consciousness can be experienced in another dimension without our conventional
body-linked concept of time and space, where all past, present and future
events exist and can be observed simultaneously and instantaneously (non-locality). In the other
dimension, one can be connected with the personal memories and fields of
consciousness of oneself as well as others, including deceased relatives (universal interconnectedness). And
the conscious return into one’s body can be experienced, together with
the feeling of bodily limitation, and also sometimes the awareness of the
loss of universal wisdom and love they had experienced during their NDE. 6.
NEUROPHYSIOLOGY IN A NORMAL FUNCTIONING BRAIN
For decades,
extensive research has been done to localize consciousness and memories
inside the brain, so far without success. In connection with the unproven
assumption that consciousness and memories are produced and stored inside the
brain, we should ask ourselves how a non-material activity such as
concentrated attention or thinking can correspond to an observable (material)
reaction in the form of measurable electrical, magnetic, and chemical
activity at a certain place in the brain,23-25 even an increase in
cerebral blood flow is observed during such a non-material activity as
thinking.26 Neurophysiological studies have shown these aforesaid
activities through EEG, magnetoencephalography (MEG), magnetic resonance
imaging (MRI) and positron emission tomography (PET) scanning. Specific areas
of the brain have been shown to become metabolically active in response to a
thought or feeling. However, those studies, although providing evidence for
the role of neuronal networks as an intermediary for the manifestation of
thoughts, do not necessary imply that those cells also produce the thoughts.
Direct evidence of how neurons or neuronal networks could possibly produce
the subjective essence of the mind and thoughts is currently lacking. It is
also not well understood how to explain that in a sensory experiment, the
subject stated that he was aware (conscious) of the sensation a few thousands
of a second following the stimulation, whereas neuronal adequacy in the
subject’s brain wasn’t achieved until a full 500 msec following
the sensation. This experiment has led to the so-called delay-and-antedating
hypothesis,27 and it is a challenge to our current neurophysiological
theories, as well as phenomena like anticipatory activation, or presentiment,28
with changes on MRI up to 3 seconds preceding emotional stimuli. 29
The brain
contains about 100 billion neurons, 20 billion of which are situated in the
cerebral cortex. Several thousand neurons die each day, and there is a
continuous renewal of the proteins and lipids constituting cellular membranes
on a time-span basis ranging from several days to a few weeks.30
During life the cerebral cortex continuously adaptively modifies its neuronal
network, including changing the number and location of synapses. All neurons
show an electrical potential across their cell membranes, and each neuron has
tens to hundreds of synapses that influence other neurons. Transportation of
information along neurons occurs predominantly by means of action potentials,
differences in membrane potential caused by synaptic depolarization and
hyperpolarization. The sum total of changes along neurons causes transient
electric fields and therefore also transient magnetic fields along the
synchronously activated dendrites. During cerebral activity, these electrical
and magnetic patterns of the 100 billion neurons change each nanosecond.
Neither the number of neurons, nor the precise shape of the dendrites, nor
the position of synapses, nor the firing of individual neurons seem to be
crucial for information processing properties, but the derivative, the
fleeting, highly ordered 4-dimensional (space and time) patterns of the
electromagnetic fields generated along the dendritic trees of specialized
neuronal networks. These patterns should be thought of as the final product
of chaotic, dynamically governed self-organization.31 The influence
of external localized magnetic and electric fields on these constant changing
electromagnetic fields during normal functioning of the brain should now be
mentioned. Neurophysiological research is being performed using transcranial
magnetic stimulation (TMS),32 in the course of which localized
magnetic fields are produced. TMS can excite or inhibit different parts of
the brain, depending of the amount of energy given, allowing functional
mapping of cortical regions and creation of transient functional lesions. It allows assessing the
function in focal brain regions on a millisecond scale, and it can study the
contribution of cortical networks to specific cognitive functions. TMS can
interfere with visual and motion perception, by interrupting cortical processing for 80-100
milliseconds. Intracortical inhibition and facilitation obtained during
paired-pulse studies with TMS reflect the activity of interneurons in the
cortex. Also TMS can alter the functioning of the brain beyond the time of
stimulation, but it does not appear to leave any lasting effect.32
Interrupting
the electrical fields of local neuronal networks in parts of the cortex also
disturbs the normal functioning of the brain. By localized electrical
stimulation of the temporal and parietal lobe during surgery for epilepsy the
neurosurgeon and Nobel prize winner Wilder Penfield could sometimes induce
flashes of recollection of the past (never a complete life review),
experiences of light, sound or music, and rarely a kind of out-of-body
experience (OBE).33,34 These experiences did not produce any
life-attitude transformation. The effect of
the external magnetic or electrical stimulation depends on the intensity and
duration of energy given. There may be no clinical effect; sometimes an
effect occurs when only a small amount of energy is given. But during stimulation
with higher energy, inhibition
of local cortical functions occurs by extinction of their electrical and
magnetic fields (personal communication Dr. Olaf Blanke, neurologist,
Laboratory for Presurgical Epilepsy Evaluation and Functional Brain Mapping
Laboratory, Department of Neurology, University Hospital of Geneva,
Switzerland). Blanke recently described a patient with induced OBE by inhibition of cortical activity
caused by more intense external electrical stimulation of neuronal networks
in the gyrus angularis in a patient with epilepsy.35 We have to
conclude that localized artificial stimulation with real photons (electrical
or magnetic energy) disturbs and inhibits the constantly changing
electromagnetic fields of our neuronal networks, thereby influencing and
inhibiting the normal functions of our brain. Could consciousness and
memories be the product or the result of these constantly changing fields of
photons? Could these photons be the elementary carriers of consciousness?31
Some
researchers try to create artificial intelligence by computer technology,
hoping to simulate programs evoking consciousness. But Roger Penrose, a
quantum physicist, argues that “Algorithmic computations cannot
simulate mathematical reasoning. The brain, as a closed system capable of
internal and consistent computations, is insufficient to elicit human
consciousness.”36 Penrose offers a quantum mechanical
hypothesis to explain the relation between consciousness and the brain. And
Simon Berkovitch, a professor in Computer Science of the George Washington
University, has calculated that the brain has an absolutely inadequate
capacity to produce and store all the informational processes of all our
memories with associative thoughts. We would need 1024 operations
per second, which is absolutely impossible for our neurons.37
Herms Romijn, a Dutch neurobiologist, comes to the same conclusion.30
One should conclude that the brain has not enough computing capacity to store
all the memories with associative thoughts from one’s life, has not
enough retrieval abilities, and seems not to be able to elicit consciousness.
7.
QUANTUM MECHANICS AND THE BRAIN
With our
current medical and scientific concepts it seems impossible to explain all
aspects of the subjective experiences as reported by patients with an NDE
during their period of cardiac arrest, during a transient loss of all
functions of the brain. But science, I believe, is the search for explaining
new mysteries rather than the cataloguing of old facts and concepts. So it is
a scientific challenge to discuss new hypotheses that could explain the
reported interconnectedness
with the consciousness of other persons and of deceased relatives, to explain
the possibility to experience instantaneously and simultaneously (non-locality) a review and a preview
of someone’s life in a dimensionwithout
our conventional body-linked concept of time and space, where all
past, present and future events exist, and the possibility to have clear
consciousness with memories from early childhood, with self-identity, with
cognition, and with emotion, and the possibility of perception out and above
one’s lifeless body. We should
conclude, like many others, that quantum mechanical processes could have
something critical to do with how consciousness and memories relate with the
brain and the body during normal daily activities as well as during brain
death or clinical death. I would like
now to discuss some aspects of quantum physics, because this seems necessary
to understand my concept of the continuity of consciousness. Quantum physics
has completely overturned the existing view of our material, manifest world,
the so-called real-space. It tells us that particles can propagate like
waves, and so can be described by a quantum mechanical wave function. It can
be proven that light in some experiments behaves like particles (photons),
and in other experiments it behaves like waves, and both experiments are
true. So waves and particles are complementary
aspects of light (Bohr).38 The experiment of Aspect,
based on Bell’s theorem, has established non-locality in quantum mechanics (non-local interconnectedness).39
Non-locality happens because all events are interrelated and influence each
other. Phase-space
is an invisible, non-local, higher-dimensional space consisting of fields ofprobability, where every
past and future event is available as a possibility.Within this phase-space
no matter is present, everything belongs to uncertainty, and neither
measurements nor observations are possible by physicists.40 The
act of observation instantly changes a probability into an actuality by
collapse of the wave function. Roger Penrose calls this resolution of
multiple possibilities into one definitive state “objective
reduction”.35 So it seems that no observation is possible
without fundamentally changing the observed subject; only subjectivity remains. The
phase-speed in this invisible and non-measurable phase-space varies from the
speed of light to infinity, while the speed of particles in our manifest
physical real-space varies from zero to the speed of light. At the speed of
light, the speed of a particle and the speed of the wave are identical. But
the slower the particle, the faster the wave-speed, and when the particle
stops, the wave-speed is infinite. The phase-space generates events that can
be located in our space-time continuum, the manifest world, or real-space.
Everything visible emanates form the invisible. According to
Stuart Hameroff and Roger Penrose, microtubules in neurons may process information
generated by self-organizing patterns, giving rise to coherent states, and
these states could be the explanation of the possibility of experiencing
consciousness.42 Herms Romijn argues that the continuously
changing electromagnetic fields of the neuronal networks, which can be
considered as a biological quantum coherence phenomenon, possibly could be
the elementary “carriers” of consciousness.31 Quantum
physics cannot explain the essence of consciousness or the secret of life,
but in my concept it is helpful for understanding the transition between the
fields of consciousness in the phase-space (to be compared with the
probability fields as we know from quantum mechanics) and the body-linked
waking consciousness in the real-space, because these are the two complementary aspects of
consciousness.41 Our whole and undivided consciousness with
declarative memories finds its origin in, and is stored in this phase-space,
and the cortex only serves as a relay station for parts of our consciousness
and parts of our memories to be received into our waking consciousness. In
this concept consciousness is not physically rooted. This could be compared
with the internet, which does not originate from the computer itself, but is
only received by it. Life createsthe
transition from phase-space into our manifest real-space; according to our
hypothesis life creates the possibility to receive the fields of
consciousness (waves) into the waking consciousness which belongs to our
physical body (particles). During life, our consciousness has an aspect of
waves as well asofparticles, and there is a permanent interaction between
these two aspects of consciousness. This concept is a complementary theory,
like both the wave and particle aspects of light, and not a dualistic theory.
Subjective (conscious) experiences and the corresponding objective physical
properties are two fundamentally different manifestations of one and the same
underlying deeper reality; they cannot be reduced to each other.30
The particle aspect, the physical aspect of consciousness in the material
world, originates from the wave aspect of our consciousness from the
phase-space by collapse of the wave function into particles (“objective
reduction”), and can be measured by means of EEG, MEG, MRI, and PET
scan. And different neuronal networks function as interface for different
aspects of our consciousness, as can be demonstrated by changing images
during these registrations of EEG, MRI or PET scan. The wave aspect of our
indestructible consciousness in phase-space, with non-local
interconnectedness, is inherently not measurable by physical means. When we
die, our consciousness will no longer have an aspect of particles, but only
an eternal aspect of waves. With this new
concept about consciousness and the mind-brain relation all reported elements
of an NDE during cardiac arrest could be explained. This concept is also
compatible with the non-local interconnectedness with fields of consciousness
of other persons in phase-space. Following an NDE most people, often to their
own amazement and confusion, experience an enhanced intuitive sensibility,
like clairvoyance and clairaudience, or prognostic dreams, in which they
“dream” about future events. In people with an NDE the functional
receiving capacity seems to be permanently enhanced. When you compare this
with a TV set, you receive not only Channel 1, the transmission of your
personal consciousness, but simultaneously Channels 2, 3 and 4 with aspects
of consciousness of others. This remote, non-local
communication seems to have been demonstrated scientifically by
positioning subject pairs in two separate Faraday chambers, which effectively
rules out any electromagnetic transfer mechanism. A visual pattern-reversal
stimulus is used to elicit visual evoked responses in the EEG registration of
the stimulated subject, and this was instantaneously
received by the non-stimulated subject resulting in an analogous neural event
with a similar brain wave morphology, or transferred potentials, as revealed
on the EEG.43,44 8.
THE ROLE OF DNA
How should we
understand the interaction between our consciousness and ourfunctioning brain
in our continuously changing body? As stated before, during our life the
composition of our body changes continuously, as during each second 500000
cells are being replaced in our body. What could be the basis of the
continuity of our changing body? Cells and molecules are just the building
blocks. In assessing all the theories mentioned above, it seems reasonable to
consider the person-specific DNA in our cells as the place of resonance, or
the interface across which a constant informational exchange takes place
between our personal material body and the phase-space, where all fields of
our personal consciousness are available as fields of possibility. DNA is a
molecule, composed of nucleotides, with a double helix structure. In humans
it is organized into 23 pairs of chromosomes, defines 30,000 genes, and
contains about 3 billion base pairs.45 About 95% of human DNA has
a still unknown function, for which reason it is called “junk
DNA,” non-protein-coding DNA, or introns,46 and the 5%
protein-coding called exons. The more complex a species is, the more introns
it has. Simon Berkovich assumes that this “junk DNA” could have
an identifying purpose, comparable to a kind of “barcode”
functionality. According to his hypothesis DNA itself does not contain the
hereditary material, but is capable of receiving hereditary information and
memories from the past, as well as the morphogenetic information, which
contains the way the body will be built with all its different cell systems
with specialized functions.47 Person-specific DNA is in this model
the receiver as well as the transmitter of our permanently evolving personal
consciousness. According to
Erwin Schrödinger, a quantum physicist, DNA is an a-statistic molecule,
and a-statistic processes are quantum mechanical processes which originate
from phase-space.48 In his theory DNA should function as a
quantum antenna with non-local communication, and also Stuart Hameroff
considers DNA as a chain of quantum bits (qubits) with helical twist, and
according to him DNA could function in a way analogous to superconductive
quantum interference devices. In his quantum computer model the 3
billion base pairs should function as qubits with quantum superposition of
simultaneously zero and one.49 Following a
heart transplant, the donor heart contains DNA material foreign to the
recipient. In a few recent books it has been reported that sometimes
the recipient experiences thoughts and feelings that are totally strange and
new, and later it becomes obvious that they fit with the character and
consciousness of the deceased donor.50,51 The DNA in the donor
heart seems to give rise to fields of consciousness that are received by the
organ recipient. Unfortunately, until now scientific research on this has not
been possible due to the reluctance of the transplant centers. 9.
ANALOGY WITH WORLDWIDE COMMUNICATION
In trying to
understand this concept of quantum mechanical mutual interaction between the
invisible phase-space and our visible, material body, it seems appropriate to
compare it with modern worldwide communication. There is a continuous
exchange of objective information by means of electromagnetic fields for radio,
TV, mobile telephone, or laptop computer. We are unaware of the vast amounts
of electromagnetic fields that constantly, day and night, exist around us and
through us, as well as through structures like walls and buildings. We only
become aware of these electromagnetic informational fields at the moment we
use our mobile telephone or by switching on our radio, TV or laptop. What we
receive is not inside the instrument, nor in the components, but thanks to
the receiver, the information from the electromagnetic fields becomes
observable to our senses and hence perception occurs in our consciousness.
The voice we hear over our telephone is not inside the telephone. The concert
we hear over our radio is transmitted to our radio. The images and music we
hear and see on TV are transmitted to our TV set. The internet is not located
inside our laptop. We can receive what is transmitted with the speed of light
from a distance of some hundreds or thousands of miles. And if we switch off
the TV set, the reception disappears, but the transmission continues. The
information transmitted remains present within the electromagnetic fields.
The connection has been interrupted, but it has not vanished and can still be
received elsewhere by using another TV set (“non-locality”). Could our
brain be compared to the TV set, which receives electromagnetic waves and
transforms them into image and sound, as well as to the TV camera, which
transforms image and sound into electromagnetic waves? This electromagnetic
radiation holds the essence of all information, but is only perceivable by
our senses through suitable instruments like camera and TV set. The
informational fields of our consciousness and of our memories, both evolving
during our lifetime by our experiences and by the informational input from
our sense organs, are present around us,and become available to our waking
consciousness only through our functioning brain (and other cells of our
body) in the shape of electromagnetic fields. As soon as the function of the
brain has been lost, as in clinical death or brain death, memories and
consciousness do still exist, but the receptivity is lost, the connection is
interrupted. 10.
CONCLUSION
According to
our concept, grounded on the reported aspects of consciousness experienced
during cardiac arrest, we can conclude that our consciousness could be based
on fields of information, consisting of waves, and that it originates in the
phase-space. During cardiac arrest, the functioning of the brain and of other
cells in our body stops because of anoxia. The electromagnetic fields of our
neurons and other cells disappear, and the possibility of resonance, the
interface between consciousness and physical body, is interrupted. Such
understanding fundamentally changes one’s opinion about death, because
of the almost unavoidable conclusion that at the time of physical death
consciousness will continue to be experienced in another dimension, in an
invisible and immaterial world, the phase-space, in which all past, present
and future is enclosed. Research on NDE cannot give us the irrefutable
scientific proof of this conclusion, because people with an NDE did not quite
die, but they all were very, very close to death, without a functioning
brain. The
conclusion that consciousness can be experienced independently of brain
function might well induce a huge change in the scientific paradigm in
western medicine, and could have practical implications in actual medical and
ethical problems such as the care for comatose or dying patients, euthanasia,
abortion, and the removal of organs for transplantation from somebody in the
dying process with a beating heart in a warm body but a diagnosis of brain
death. There are
still more questions than answers, but, based on the aforementioned theoretical
aspects of the obviously experienced continuity of our consciousness, we
finally should consider the possibility that death, like birth, may well be a
mere passing from one state of consciousness to another. 11.
REFERENCES
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