What do you "see" when you die? Anybody have any interesting Near Death Experiences? I've always wondered what it's going to be like. First I thought it would be pitch blackness, like when you close your eyes. Then I thought it would be brightness and peacefulness. I have many views on what the afterlife is going to be like, but cant decide on one. Please help!?
Near Death Experiences (NDE)
In my work as a neurologist I have primarily treated epilepsy. And as a hospital staff physician I see post-cardiac resuscitation patients in consultation. I have interviewed patients and studied their NDEs. The background is three possible precipitants, blunt or penetrating head trauma, decreased blood flow and/or low pO2 in the brain (Hypoxaemia), and temporal lobe epilepsy (partial complex seizures.)
NDE experiences are largely stereotyped no matter which of the above is the cause. The person is observationally unconscious or in a confusion like state. In the remembered event the patient often perceives an out of body experience (OOBE) which has two forms. One is standing next to ones own body or more often floating above their body, seeming to see people around the bedside such as nurses and doctors. The other is a feeling of limitlessness, expanding and merging with the universe. The OBE is followed by going through a bright tunnel in a dark background. In this phase one might see images of dead relatives, angels, Jesus, or Brahma, or saints. This is followed by a smaller but brighter light. Usually at that point they either come out of it or come out of it (sometimes in reverse.) During the tunnel phase they may hear the voice of a dead parent or God/Jesus/Virgin Mary/Muhammad/Brahma.
On recovery, the patients often feel disappointed, cheated out of Heaven or bliss. They do have often have permanent or transient neurobehavioural changes mainly in short term memory, attention span, and emotional regulation with loss of some inhibition, loss of rational skills, loss of some problem solving efficiency, and changes in efficiency of task specific shifts. Depending on the degree of hypoxia or hypoxaemia, the post-episode impairment varies.
NDEs are only sometimes near (risk of) death. Many occur with cardiac arrests which indeed are life threatening. In such a case, there is a marked decrease or stop in blood flow to the brain temporarily in watershed regions. Watershed areas are the tissue between two different arterial trees and perfusion there is more tenuous. During shock or cardiac arrest blood perfusion to the border zone between the territories of two arteries decreases.
Arteries branch into more and smaller arteries and arterioles. At the peripheral end of an arterial tree, the capillaries merge with those of the neighbouring artery producing the Watershed Area. When blood flow decreases, the area getting the worst deprivation is this watershed area. It is the area suffering any neuronal loss (there is likely always some neuronal loss, varying with the severity of hypoxaemia).
Watershed areas are found all over the body. However, in the inferior medial temporal lobes are arteries named the posterior cerebral and middle cerebral. The sudden hypoxaemia can precipitate temporal lobe like seizures. This Temporal Lobe watershed is the anatomical focus of the Near Death Experience.
Other watershed areas are in the upper parasagittal areas of frontal lobe (rational, inhibitory, analytical), calcarine occipital lobe (visual), and cerebellar (balance, coordination (arteries are Superior Cerebellar, Anterior Inferior Cerebellar, and Posterior Inferior Cerebellar.)
Temporal lobe seizures are epileptic discharges that begin in the mesial inferior temporal lobe spreading to the amygdala and on to multiple cortical association areas generating the event. They can also occur in pure brain hypoxia, in hypoxaemia (deoxygenated blood and poor flow or shock) and in deoxygenated but normal volume blood perfusion.
Complex Partial Epilepsy can and generally is non-hypoxic and non-ischemic. In Epileptics, they have many causes. Some are due to temporal sclerosis (scarring), head trauma, brain tumours, arterio-venous malformations, small haemorrhages, small infarcts/strokes, metabolic imbalances (↓Na+, Renal Failure, ↓Mg++, ↓ or ↑Ca++, ↓blood osmolality, and ↓pH.) They can also occur from a number of different drugs such as cocaine, methamphetamines or drug/alcohol withdrawal.
The electrical discharge begins in the neurons in the region of Ammons Horn in the temporal lobe. The discharge is transmitted to memory association areas of the nearby temporal lobe for visual and auditory memories and odd smell memories. Some go to the superior parietal lobe (body orientation/localization areas) to give the primary OOBE (Out of body experience) phase.
In this situation discharges have an inhibitory effect. Some go to cingulate gyrus as well for the affective component (happiness, mystical, frightened, or angry.) In some cases frontal lobe discharges are recorded. This causes the symptoms I described in the second paragraph.
The third major cause is head trauma. Sudden trauma precipitates seizures. Americans usually remember the televised generalised seizure of Roger Staubach of the Dallas Cowboys in the end zone of a Saturday televised game seen by millions of fans. His career soon ended. But he did not have epilepsy. It was just a post-traumatic seizure. Many trauma patients who have seizures, have partial seizures instead of generalised. These often manifest as Temporal Lobe seizures or focal motor seizures. The Temporal Lobe Seizure may be simple hallucinations auditory or visual which some call Partial Simple Seizures. Many spread across the cortex to a full NDE described in the second paragraph.
The most important thing is that these people are not clinically DEAD. They are unconscious, and in some cases at risk of death. Most Epileptic patients are not at serious death risk unless driving a car. Those who actually die may experience NDEs before they die but cannot tell us about them. The DEAD brain cannot seize. We have no evidence of sentience in a dead brain. That is for you to speculate as you wish.
I would separate the Real Death from Near Death Experiences. The latter do not really die and the brain cells remain functioning. In true death, the brain cells start dying in 4 minutes and electrolyte changes cause cells to take in water and explode into a mushy mass. These people never awaken so we can't ask them about NDE's.
I would say that the experiences in the NDE may well be similar to those in real death just before the brain dies. Unfortunately that memory is permanently lost without neurons, axons, synapses, dendrites, flowing oxygenated blood, and normal glucose levels.
NDE's do not prove a "soul" because they occur in people who are not near death death such as Complex Partial Epileptics who may have many such episodes.
Ardipithecus
