The term Near-Death Experience conjures up thoughts of walking down a long tunnel towards a bright light or floating above an operating table – easy to dismiss as a paranormal myth like a haunted house or an alien abduction. I was certainly sceptical about the existence of such experiences, until I read about scientific studies attempting to explain and characterise NDEs.
It turns out that it’s widely accepted that people have NDEs, but it’s assumed that the experience is ‘all in your head’; the memory is not imagined as such, but perceived by the brain to have been real even though the subject did not, for example, have an actual meeting with God. The reason for this assumption is because during NDE studies, it was found that memories of NDEs had more phenomenological characteristics than memories of both real and imagined events, making them seem ‘realer than real’.
Phenomenological characteristics include visual and other sensory details (such as remembering sounds and smells), knowing the time and location of the event, and remembering one’s thoughts. Memories of real events have more characteristics than imagined ones, so if NDEs were entirely imagined, then you would expect a similar number of characteristics as imagined events, but this was not the case.
There are multiple theories as to what causes NDEs, and how they seem real when they are technically not. Anoxic brain damage and hypoxia, temporal lobe dysfunction, and the effects of sedative administration have all been proposed, but the exact physiological mechanisms are still unknown. It is thought that these physiological changes result in altered memories of real events, or seemingly real memories of events that never occurred as the brain tries to make sense of what has happened.
A study comparing ‘real NDEs’ (those that occurred during a life-threatening situation such as coma or drowning) to ‘NDE-like’ experiences (those that occurred during non-life-threatening situations such as during meditation or after drug use) aimed to discover the most common feelings experienced during both types of NDE, and whether there were any differences in the content and intensity of the experiences.
The researchers found that both groups reported similar memories of their experience, and the vast majority of subjects had positive experiences. The most common feeling was of peacefulness, which 89-93% of subjects reported. Other common feelings included feeling separated from one’s body (74-80%), being surrounded by light (67-84%), and the feeling of time speeding up or slowing down (71-82%). The real NDE and NDE-like memories all had more phenomenological characteristics than those of the control group (who were asked to recall their earliest memory), and were perceived to have more emotional and personal characteristics such as a feeling of the experience being an important part of the person’s life.
The research did point out however, that NDE stories are likely to be repeated many times to friends and family, and could therefore subconsciously become embellished to include more characteristics and be more personal upon retelling. It also said that such an emotional, self-referential memory could be encoded better by the brain, making it more detailed and easier to recall.
The current theory then, is that an NDE cannot be classed as an imaginary memory, but rather a memory similar to a hallucination – not actually real, but perceived as such. There is still work to be done to understand this phenomena, and the exact physiological changes involved, but it is certainly an interesting area of research that will hopefully help us understand more about the brain’s reaction to traumatic experiences.
Thonnard M, Charland-Verville V, Brédart S, Dehon H, Ledoux D, Laureys S, & Vanhaudenhuyse A (2013). Characteristics of near-death experiences memories as compared to real and imagined events memories. PloS one, 8 (3) PMID: 23544039
Charland-Verville V, Jourdan JP, Thonnard M, Ledoux D, Donneau AF, Quertemont E, & Laureys S (2014). Near-death experiences in non-life-threatening events and coma of different etiologies. Frontiers in human neuroscience, 8 PMID: 24904345