Near-death experiences: not as paranormal as they sound?
The quote above comes from a 48-year-old woman who, on one occasion, almost died from complications related to a spinal tumor; it evokes much of the general emotion associated with a classic near-death experience story.
The term "near-death experience" (NDE) is well-known throughout America, but the phenomenon is not restricted solely to the Western world. Most cultures have an equivalent experience; even children have related NDEs.
An NDE might involve walking toward a bright light at the end of a tunnel, meeting gods, speaking with relatives who are long-dead, out-of-body experiences (OBEs) or feeling bathed in light.
Almost unanimously a significant life experience, conversations about NDEs are often accompanied by discussions of the afterlife and the mind surviving the mortal body.
These kinds of esoteric tales would normally be banished to the realms of pseudoscience and parapsychology, but their pervasive nature - an estimated 3 percent of Americans report having experienced an NDE - has sparked a smattering of genuine scientific research and a wealth of conjecture.
What do NDEs consist of?
One Dutch study, published in The Lancet, set out to investigate the regularity of NDEs and tried to tease apart causal factors.
The investigators reported that 50 percent of individuals who experienced an NDE mentioned an awareness of being dead, 56 percent regarded it a positive experience, 24 percent reported an OBE, 31 percent described traveling through a tunnel and 32 percent spoke of interacting with deceased people.
The study also showed that, of the patients they interviewed, although all were clinically dead at one point, only a small percentage (18 percent) experienced, or remembered, the NDE. The likelihood of having an NDE was not related to the level of cerebral anoxia (lack of oxygen to the brain), the amount of preceding fear or the type of medication they were taking.
According to the paper, NDEs were more often experienced by patients under 60, and women more commonly described deeper experiences. Conversely, those with memory deficits following resuscitation were less likely to report NDEs, which is to be expected.
There is obviously something driving these experiences, but the factors that impact them are still very much up for debate.
Cultural flexibility in NDEs
The NDE phenomenon is particularly fascinating because the psychological and physiological factors are intimately tied to social and cultural factors. For instance, the NDE of a 40-year-old white male from Nebraska might include visions of a shimmering white, bearded male beckoning him through pearl-encrusted gates; the NDE of a 12-year-old boy from Papa New Guinea probably will not.
The Mapuche people of South America and residents of Hawaii are more likely to see landscapes and volcanoes, whereas NDEs in Thailand and India rarely involve landmarks, tunnels or light; for Tibetans, light features more heavily, as do illusions of reincarnation.
The following narrative comes from an African NDE, reported in 1992. A young man had been attacked by a lioness after attempting to capture one of her cubs:
"I could see myself going into some kind of a trance. A highway suddenly opened up before me. It seemed to be going endlessly into the sky. Along it were a lot of stars, also spreading up to the sky.
Each time I tried to get on the highway, the stars would block my way. I just stood there not knowing what to do. After a while, the highway and stars disappeared. I woke up and found myself in a hospital bed."
Europeans and North Americans often visualize beautiful gardens; intriguingly, the Kalai of Melanesia are more inclined to see an industrialized world of factories.
Culture and a person's hopes or dreams clearly influence the nature of NDEs; but what biological mechanisms could be behind this strange phenomenon?
What is behind NDEs?
A phenomenon so widely experienced cannot be dismissed as just another old wives' tale, there has to be something biological at work to explain its prevalence.
Some observers claim that NDEs display a rift in current neuroscientific theory, and that the experience shows another, more esoteric facet to our existence.
Can neuroscience unpick the mysteries of the NDE?
Many believe we should split the mind from the functions of the brain, once and for all.
However, this type of thinking is not necessary to explain NDEs; rather than claiming paranormal origins, the field of cognitive neuroscience has attacked the problem as it would any other: as an output of the brain.
There are a few potential explanations, any number of which might be involved in each individual's experience. The following are some attempts to explain the biological origin of NDEs.
The role of expectation
Expectation surely plays a part in the overall NDE; the differences between cultures mentioned above are testament to that. But expectation seems to play an even deeper role.
Interestingly, NDEs sometimes occur in people who were, in reality, nowhere near death, they just thought they were. One study that included 58 patients' experiences of NDEs found that 30 were not, in fact, close to dying. However, there is more to an NDE than expectations, as we shall see.
On the next page, we look at some scientific explanations of various aspects of the NDE experience.