NDE AND OBE: Are they just hallucinations?

Near-death experiences (NDEs) are profound spiritual or mystical experiences that many people report as they approach or start to cross the threshold of death. The contents and after-effects of NDEs suggest that they are more than just hallucinations. The contents do not appear to be influenced by past religious beliefs, but do have a profound effect on religious or spiritual beliefs after the experience. Near-death experiencers (NDErs) also report a consistent positive change in attitude toward the transition from life to death. There is still no accepted scientific cause for NDEs. Each near-death experience is unique, but as a group NDEs display common features.

 Intense emotions: commonly of profound peace, well-being, love; others marked by fear, horror, loss

A perception of seeing one's body from above (called an out-of-body experience, or OBE), sometimes watching medical resuscitation efforts or moving instantaneously to other places

Rapid movement through darkness, often toward an indescribable light

A sense of being "somewhere else," in a landscape that may seem like a spiritual realm or world

Incredibly rapid, sharp thinking and observations

Encounter with deceased loved ones, possibly sacred figures  or unrecognized beings, with whom communication is mind-to-mind; these figures may seem consoling, loving, or terrifying

A life review, reliving actions and feeling their emotional impact on others

In some cases, a flood of knowledge about life and the nature of the universe.

If one examines the medical literature in the last two decades, the most common theories for the occurrence of NDEs have involved either a hallucination brought about by physiological changes during the dying process, or a psychological stress reaction to the perceived threat of death. For many years these two theories have formed the basis of possible scientific explanations. Many brain mediators have been proposed to account for the experiences, although none has yet been shown to be responsible for the phenomenon. These include release of endorphins; the body's own morphine-like substance, lack of brain oxygen, increased carbon dioxide, various drugs and in particular those that can cause hallucinations such as ketamine and temporal lobe seizures. The argument in favour of a psychological explanation has been based largely on observations made from retrospective cases indicating that near death experiences may sometimes occur in those who were not yet physically close to death at the time of the experience - such as in those occurring just before an accident.

Cardiac arrest patients are a subgroup of people who come closest to death. In such a situation an individual initially develops two out of three criteria (the absence of spontaneous breathing and heartbeat) of clinical death. Shortly afterwards (within seconds) these are followed by the third, which occurs due to the loss of activity of the areas of the brain responsible for sustaining life (brainstem) and thought processes (cerebral cortex). Brain monitoring using EEG in animals and humans has also demonstrated that the brain ceases to function at that time. During a cardiac arrest, the blood pressure drops almost immediately to unrecordable levels and at the same time, due to a lack of blood flow, the brain stops functioning as seen by flat brain waves (isoelectric line) on the monitor within around 10 seconds. This then remains the case throughout the time when the heart is given 'electric shock' therapy or when drugs such as adrenaline are given until the heartbeat is finally restored and the patient is resuscitated. Due to the lack of brain function in these circumstances, therefore, one would not expect there to be any lucid, well-structured thought processes, with reasoning and memory formation, which are characteristic of NDEs. Nevertheless, and contrary to what we would expect scientifically, studies have shown that 'near death experiences' do occur in such situations. This therefore raises a question of how such lucid and well-structured thought processes, together with such clear and vivid memories, occur in individuals who have little or no brain function. In other words, it would appear that the mind is seen to continue in a clinical setting in which there is little or no brain function. In particular, there have been reports of people being able to 'see' details from the events that occurred during their cardiac arrest, such as their dentures being removed.

In a study of 344 patients who survived cardiac arrest , all the reported elements of a Near-Death Experience (NDE) like an out-of-body perception, meeting with deceased relatives or a life review were experienced during a transient functional loss of the cortex and of the brainstem, with a flat line EEG. During their cardiac arrest people can have veridical perceptions from a position outside and above their lifeless body. NDE-ers 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 (OBE) is scientifically important because doctors, nurses, and relatives can verify the reported perceptions, and they can also corroborate the precise moment the NDE with OBE occurred during the period of CPR. This proves that an OBE cannot be a hallucination, because this means experiencing a perception that has no basis in “reality”, like in psychosis, neither it can be a delusion, which is an incorrect assessment of a correct perception, nor an illusion, which means a misleading image. Moreover, one needs a functioning brain for experiencing hallucinations, delusions or illusions. Additionally, even people blind from birth have reported veridical perceptions during NDE and OBE. Based on several NDE-studies it seems inevitable to conclude that veridical perception is possible independently of brain function.

Science, until very recently, has not taken seriously the huge amount of material gathered over the past hundred or so years by institutions devoted to recording non-ordinary experiences (near-death experiences) as well as communications to the living from the 'dead.' Nor has it accepted as worthy of scientific attention the experience of visionaries and mystics of all cultures and time that has testified to the existence of that other dimension of reality and the possibility of a direct relationship with it.