Near death experiences all in the head

Scientists at the universities of Edinburgh and Cambridge have pin-pointed biological explanations for near-death experiences.

The researchers conducted a review of the experiences, bringing together the fields of neuroscience and psychology to help understand the phenomenon.

According to a 1982 poll by Gallup and Proctor, up to 15 per cent of people in the US claim to have had a near-death experience. Episodes often include out-of-body experiences, visions of tunnels of light or encounters with dead relatives.

While sufferers have often attributed these symptoms to the paranormal, this new collaborative study has shown that such experiences are attributable to changes in brain function, stemming from the brain’s attempt to make sense of a traumatic situation.

One of the collaborators, Dr Caroline Watt, is the Senior Lecturer at the University of Edinburgh's School of Philosophy, Psychology and Language Sciences. She told The Journal: “As psychologists and scientists it’s good to know what lies behind near death experiences; the research tells us a lot about normal brain function and what happens when we go through traumatic experiences.”

The study has shown how oxygen deprivation may affect the brain’s visual system, leading to the appearance of tunnels and bright lights. Similarly, if trauma causes the brain’s multi-sensory processes to be affected this could lead to what appears to be an out-of-body experience.

The researchers’ work has also identified noradrenaline, a hormone released be the mid-brain, as a factor which may lead to a near-death experience. If triggered at the time of a traumatic event, it may cause positive emotions and hallucinations which could explain the feeling of unconditional love often reported following a near death experience.

The trauma which causes the experience need not be life threatening, yet in most cases the subject believed they were going to die, which seemed to trigger biological responses.

The full review, co-authored by Dr Watt and Dr Dean Mobbs of the University of Cambridge, is titled There is nothing paranormal about near death experiences and is available in the journal Trends in Cognitive Sciences.