Near Death Experiences(NDE)

Presented by

Jennifer Kwok

Jennifer Tom

Luong Phan

What is the near death experience? Occurs when a person enters “clinical

death” and usually has a profound personal experience which can include:

What is the near death experience? Occurs when a person enters “clinical

death” and usually has a profound personal experience which can include:

A sensation of leaving the body

What is the near death experience? Occurs when a person enters “clinical

death” and usually has a profound personal experience which can include:

A sensation of leaving the body Following a bright light

What is the near death experience? Occurs when a person enters “clinical

death” and usually has a profound personal experience which can include:

A sensation of leaving the body Following a bright light Encounter with a higher being (God,

Buddha, Aliens, etc.)

Background Information What is “clinical death” then?

Background Information What is “clinical death” then? Clinical death: no cardiac output, no

respiration, fixed dilated pupils

Background Information What is “clinical death” then? Clinical death: no cardiac output, no

respiration, fixed dilated pupils Focus of our research evidence are

centered on cardiac arrest patients because they all exhibit clinical death

Background Information Raymond Moody (1975)

Wrote Life After Life First compilation of NDE survivor stories

Coined the term “near death experience”

Background Information Why care about NDE?

NDE have been recorded through history and in many different cultures.

Description of Er’s experience in Plato’s Republic resemble modern NDEs.

Best chance to study death because these patients return from “dying”

Theorized Causes Disturbance of brain chemistry (Parnia

2001) alpha-endopsychosin, hypoxia, NDMA, etc.

Theorized Causes Disturbance of brain chemistry (Parnia

2001) alpha-endopsychosin, hypoxia, NDMA, etc.

Psychological response to perceived threat of death (Parnia 2001) Wish fulfillment in response to perceived threat of

death

Theorized Causes REM intrusion (Nelson 2006)

When things normally experienced during sleep carry over into wakefulness

Theorized Causes REM intrusion (Nelson 2006)

When things normally experienced during sleep carry over into wakefulness

Usually occurs before sleep or just after wakefulness

Theorized Causes REM intrusion (Nelson 2006)

When things normally experienced during sleep carry over into wakefulness

Usually occurs before sleep or just after wakefulness

Occurs in times of extreme stress in which one may be in REM sleep and partially awake at the same time

Theorized Causes: REM Int. Cont’ REM centers in the brainstem

Higher brain areas in the cortex quickly blank out during hypoxia, the brainstem (since it’s more primitive) remains active for several minutes

Theorized Causes: REM Int. Cont’ REM centers in the brainstem

Higher brain areas in the cortex quickly blank out during hypoxia, the brainstem (since it’s more primitive) remains active for several minutes

An NDE that seems to last many minutes might occur in the few seconds right before or right after the cortex blanks out

Theorized Causes: REM Int. Cont’ REM centers in the brainstem

Higher brain areas in the cortex quickly blank out during hypoxia, the brainstem (since it’s more primitive) remains active for several minutes

An NDE that seems to last many minutes might occur in the few seconds right before or right after the cortex blanks out

NDE may also be very brief but be perceived as prolong because REM compresses time

Theorized Causes: REM Int. Cont’ Vagus nerve: A cranial nerve that connects the

brainstem to the heart and lungs REM intrusion and the vagus nerve (Fox 2006)

In times of extreme stress (heart attacks or near drowning) blood pressure or blood oxygen levels quickly drop, or levels of carbon dioxide in the blood quickly rise.

This stimulates the vague nerve Since the REM centers are in the brainstem, this causes

the REM centers to snap on without warning

Theorized Causes: REM Int. Cont’ Evidence for vagus nerve in REM intrusion (Fox

2006) Animal studies

When electrically stimulating the vagus nerve in various animal preparations, stimulation enhances REM and causes atonia

Stimulating the vagus nerve in cats pushes them into REM sleep within 45 seconds

Human studies Epilepsy patients whose condition is treated with implants

stimulate their vagus nerve also slip more quickly into REM during daytime naps

Theorized Causes: REM Int. Cont’ Temporal-parietal junction (Fox 2006)

Known to cause out-of-body sensations when it malfunctions

Since it is located at the end of a tree of blood vessels, if blood pressure drops, perfusion in this area is first to go

Thus if blood pressure drops when one is fainting, this explains why they may experience NDE-like symptoms

Theorized Causes: REM Int. Cont’ Could be possible that NDE enhances

subsequent REM intrusion SUPPORTED by: people with Post Traumatic

Stress Disorder subsequently have more frequent REM intrusion

Evidence: REM intrusion and NDE REM intrusion during wakefulness is a

normal occurrence but infrequently recognized (Nelson 2005)

Evidence: REM intrusion and NDE REM intrusion during wakefulness is a

normal occurrence but infrequently recognized (Nelson 2005)

Underlies other clinical conditions such as narcolepsy

Evidence: REM intrusion and NDE Common feature of narcolepsy

Neurological disorder characterized by uncontrollable bouts of sleep that can cause elaborate hallucinations and out-of-body experiences

Evidence: REM intrusion and NDE Common feature of narcolepsy

Neurological disorder characterized by uncontrollable bouts of sleep that can cause elaborate hallucinations and out-of-body experiences

Narcoleptics’ REM systems can activate leading to out of body experiences

Evidence: REM intrusion and NDE Common feature of narcolepsy

Neurological disorder characterized by uncontrollable bouts of sleep that can cause elaborate hallucinations and out-of-body experiences

Narcoleptics’ REM systems can activate leading to out of body experiences

Combination of dreaming and wakefulness causes people with narcolepsy to recall their hallucinations vividly

Evidence: REM intrusion and NDE Another form of REM intrusion is sleep

paralysis Awaken with part of brain still in REM sleep so

body feel paralyzed Result: terrified that you’re unable to move,

visual/auditory hallucinations, and pressure on the chest

Evidence: REM intrusion and NDE Nelson: surveyed of REM intrusion: 55 people

who had NDE from a variety of situations and 55 controls matched for age and gender Found that around 60% of NDE group reported having

experiencing some kind of symptoms of REM intrusion, either before or after their NDE, compared with just 24 % of the control

REM intrusions in NDE group were more elaborate (not just sleep paralysis but also hallucinations

Evidence: REM intrusion and NDE Nelson: surveyed of REM intrusion: 55 people

who had NDE from a variety of situations and 55 controls matched for age and gender Not conclusive but good preliminary correlational

experience Not conclusive because possible that REM intrusion

makes you more susceptible to NDE; also suggests that you do not need to have a near-death experience to have NDE

Why NDE is an ASC NDE is a deviation from the normal waking

state Experience clinical death Experience another reality Large population can experience NDE

Prevalence of REM intrusion 10% cardiac arrest patients develop memories

consistent with NDE What about the other 90%? Still experience but don’t

remember?

ReferencesBosveld, Jane. "Soul Search: Can Science Ever Decipher the Secrets of the Human Soul?" Discover

magazine, June 2007.

Fox, Douglas. "Light at the End of the Tunnel." New Scientist. Retrieved from the web, http://www.newscientist.com, 2008 March 3.

Nelson, Kevin R., MD et al (2006). Does the arousal system contribute to near death experience? Neurology, 66:1003-1009.

Parnia, Sam et al (2001). A qualitative and quantitative study of the incidence, features and aetiology of near death experiences in cardiac arrest survivors. Resuscitation,  48:149-156.

Parnia, Sam and Peter Fenwick (2002). Near death experiences in cardiac arrest: visions of a dying brain or visions of a new science of consciousness. Resuscitation, 52:5-11.

Wallace, Benjamin and Leslie E. Fisher. Consciousness and Behavior, Fourth Edition. Waveland Press Inc., Prospect Heights, pp. 218-220.