Bright light, a feeling of euphoria, all-encompassing love, conversations with dead people – those are some of the aspects associated with near-death experience. But is this experience as paranormal as we make it out to be?
Near-death experience is often described as mystical, otherworldly, spiritual experience in which there is no sense of space and time. It is possible that this experience is made up by the brain and psychological constructions that reflect our hopes and dreams.
It turns out that physiological and psychological factors in near-death experiences are closely tied to cultural and social factors. For example, a 40-year-old man from Nebraska told a story about a bright, bearded white man who led him through gates adorned with pearls. Hawaiian and Mapuche people in South America more often see volcanic landscapes. People from Tibet, on the other hand, see light that creates an impression of rebirth, as reported by National Geographic.
Here is what scientists have to say about phenomena that are often used to describe near-death experience:
The feeling of being outside of one’s body is often mentioned in relation to near-death experience. People claim seeing their body as an observer from above. Although it seems like something out of a world of fiction, neuroscientists believe this phenomenon can occur outside of near-death experiences. According to them, this phenomenon can be explained with neuroscience.
Out-of-body experience can occur during sleep paralysis. At least 40% of people have experienced such a phenomenon at least once in their life. Sleep paralysis occurs during fast sleep phase – if a person remains in a fast sleep phase, while the mind becomes partially awake. In this sleep phase, the brain basically paralyses the body to prevent movement while asleep. Believing that the body is asleep the brain keeps the body paralysed, thereby subjecting the person to horrible waking nightmares.
Meeting and talking to whatever embodiment of death a person sees during a near-death experience is another aspect that can be explained with each individual’s hopes. Our culture contains countless stories about reaching heaven and meeting long-dead relatives.
People suffering from Parkinson’s and Alzheimer’s disease often see bright hallucinations involving ghosts or even long-dead relatives. These stories are often associated with pallidotomy, which is a procedure often used in neurosurgery manipulations. Hallucinations cause dopamine dysfunction. This hormone is involved in brain reaction time.
The brain quickly fills any gaps that appear in our perception. For example, all people have a so-called ‘blind area’ – the place when the optic nerve connects to the retina. This is the area in which we cannot see a thing. We, however, do not know this. This is because our brain fills empty spaces for us. If we receive imprecise information, our brain may fill the gaps with goblins and vampires. If a person’s eyesight degrades, the eye starts picking up errors. This results in people claiming having seen ghosts and other hallucinations.
In other words, when a brain hallucinates, it receives conflicting and inappropriate signals.
This is why near-death experiences in which people could allegedly talk to the dead are all that more interesting.
Often stories of near-death experience often tell about a euphoric and happy experience. This may seem odd when talking about something as grave as a near-death experience. However, it has been uncovered that certain narcotic substances can cause visual and emotional aspects that are very, very similar to actual near-death experience.
For example, ketamine (used in anaesthesia) can cause hallucinations, including out-of-body experience, euphoria, etc. Ketamine influences NMDA receptors, the same that are affected by narcotics.
A tunnel of light
The feeling of being sucked into a tunnel with light at the end is one of the most common stories associated with near-death experience. Some scientists believe this phenomenon can be explained with retinal ischaemia.
The retina does not receive oxygen, peripheral sight slowly reduces until the person cannot see anything outside the centre of his eyesight. The vision of a tunnel is a symptom of surrounding fear and lack of oxygen, which is common for the process of dying.
There is no doubt – near-death experience is complicated phenomenon with many mechanisms left to explore. The lack of oxygen affects the brain’s visual systems, forcing the brain to make sense of the strange motions caused by different aspects of our culture. Being close to death (or experiencing a feeling close to it) is a unique physiological and emotional experience.