Near death experience (NDE) is precipitated by life-threatening experiences such as heart attack, blunt trauma, shock, asphyxia and so on. The phenomenon is well established – about 10 per cent of cardiac-arrest patients in hospital report an NDE.
Most NDEs (75 per cent) are very positive experiences but some people report negative experiences. Positive NDEs mostly follow the same pattern, involving the mind “leaving” the dead body and having certain blissful experiences before returning to the body which is then rebooted to life. Some people believe NDEs demonstrate the existence of the soul and life after death.
Science assumes NDEs have an entirely physiological explanation and scientists are interested in the phenomenon as an opportunity to study the mind-body connection. The current state of play in this field is summarised by Christof Koch in Scientific American (June 2020).
Most NDEs follow the same general pattern. Subjects report that the experience is not dream-like, but feels “realer than real”. People report leaving their pain-wracked bodies and entering a blissful pain-free realm beyond everyday experience, unhindered by limits of time and space.
NDE reports of light at the end of a dark tunnel could simply reflect oxygen levels falling in the retina
Seeing a bright light at the end of a dark tunnel is very common, as is leaving one’s body and floating above it or even journeying off into space. Meeting loved ones, living or dead, as well as other beings such as angels, or even major figures such as Moses or Jesus, is frequently reported. Subjects feel bathed in unconditional love and deeply connected to the cosmos.
Sometimes subjects are asked, after seeing a review of their lifetime memories, what efforts they made during their lives to grow in wisdom and love. Subjects want to remain in this realm, but are told they must return to their bodies. Interestingly atheists are as likely to have NDEs as religious people.
NDEs are not a new phenomenon and reports go back to the Middle Ages. For example, Francis Beaufort (the Beaufort wind scale), a British Navy admiral and Irishman, reported a vivid NDE in 1791, when he almost drowned.
NDEs raise the possibility that human consciousness (mind), can exist independently of the human brain. Patients report, for example, floating upwards and observing doctors and nurses frantically working on their body on the operating table below. Later these patients accurately report the activities they saw and heard. But no report to date has absolutely and convincingly indicated a disembodied mind.
Some NDE reports are very intriguing, such as Maria, a migrant worker, who had a cardiac arrest and NDE in a Seattle hospital in 1977. Next day she told a social worker that during resuscitation she left her body, floated upwards and out the window and looked around outside before returning to her body.
While outside the building, she saw a tennis shoe sitting on a third floor window ledge. The social worker located this window ledge and saw the tennis shoe, sitting and looking as Maria described in detail. After checking the entire scene the social worker concluded it was impossible to see the tennis shoe from the operating theatre. A year later NDE researchers sought to interview Maria but could not trace her.
Research on NDEs is very active. One approach is to carefully rig operating theatres with messages located in places, for example, on high ledges near the ceiling, unobservable by people normally standing or walking around the theatre. All patients who report NDEs following operations there are interviewed. Nobody has yet reported seeing a hidden message.
As a scientist my working hypothesis is that NDEs simply reflect the activity of the dying brain as oxygen levels fall and carbon dioxide levels rise. For example, NDE reports of light at the end of a dark tunnel could simply reflect oxygen levels falling in the retina, starting at the periphery and moving inwards towards the centre, producing tunnel vision. Various other experiences reported in NDEs, for example, out of body experiences, can be simulated, even if only weakly, by stimulating certain parts of the brain and they are also reported by astronauts after fainting from exposure to high g-levels.
Nevertheless, disembodied consciousness has yet to be definitively ruled out. Imagine the excitement if rigorous testing eventually rules it in! We would then have to reimagine the mind as some sort of complex electromagnetic algorithm normally coupled to the brain but also capable of detaching from this base.
William Reville is an emeritus professor of biochemistry at UCC