Near-death experiences are not paranormal but triggered by a change in normal brain function, according to researchers. Psychologists who reviewed a range of phenomena such as out-of-body experiences, visions of tunnels of light or encounters with dead relatives, say they are tricks of the mind rather than a glimpse of the afterlife. Reactions in the brain Researchers at the Universities of Edinburgh and Cambridge say that most of the experiences can be explained by a reaction in the brain prompted by a traumatic and sometimes harmless event. The researchers say that many common near-death experiences could be caused by the brain’s attempt to make sense of unusual sensations and perceptions occurring during a traumatic event. The research is published in the Journal Trends in Cognitive Sciences. Some of the studies we examined show that many of the people experiencing a near-death experience were not actually in danger of dying, although most thought they were. The scientific evidence suggests that all aspects of the near-death experience have a biological basis. Caroline WattSchool of Philosophy, Psychology and Language Sciences Multi-sensory processes Out-of-body experiences, for example, may happen when there is a breakdown in the brain’s multi-sensory processes, and visions of tunnels and bright lights could stem from a breakdown in the brain’s visual system caused by oxygen deprivation. The new study also points to the effects of noradrenaline, a hormone released by the mid-brain which, when triggered, may evoke positive emotions, hallucinations and other features of the near-death experience. Biological links Approximately three per cent of the US population say they have had a near-death experience, according to a Gallup poll. Near-death experiences are reported across cultures and can be found in literature dating back to ancient Greece. Related links School of Philosophy, Psychology and Language Sciences MRC Cognition and Brain Sciences Unit, University of Cambridge Publication date 15 Oct, 2015