Near-Death in the Borderlands of Consciousness

Near-death experiences arise from a blend of waking and REM sleep consciousness caused by reduced blood flow to the brain (ischemia). When the brainstem arousal system is disrupted by ischemia, it can produce a hybrid state called REM intrusion, which explains key features of near-death: seeing light, appearing motionless, out-of-body sensations, euphoria, and a rich narrative landscape. REM intrusion also accounts for why diverse conditions, including non-threatening ones, can trigger near-death and why cerebral ischemia most often does so. Evidence shows that people who have near-death experiences are physiologically susceptible to REM intrusion. Near-death experiences share features with mystical experiences but remain distinct, driven by different neurophysiologic processes.

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Abstract

Abstract Near-death experiences have gained wide attention, forging an indelible image of spiritual experience in many people today. This chapter examines the neuroscience underpinnings of near-death, including principles that have often been neglected or distorted, often skewing the common impression of near-death. During near-death from fainting or cardiac arrest, the boundary between consciousness and unconsciousness blurs in moments of insufficient cerebral blood flow (ischemia). Brain ischemia can also disrupt the physiological balance between conscious states, leading the brainstem arousal system controlling conscious states to blend waking and rapid eye movement (REM) consciousness into a hybrid state (REM intrusion). The concept of REM intrusion contributing to near-death addresses otherwise vexing issues. First, REM intrusion explains how diverse conditions evoke near-death, including non-threatening conditions. Secondly, it provides an understanding of how cerebral ischemia most often triggers near-death. Lastly, REM intrusion offers a cohesive physiologic system underlying key features of near-death: light, motionless appearance of death, out-of-body sensations, euphoria, and rich narrative landscape. Independent evidence converges from many points supporting this notion, including multiple observations that individuals experiencing near-death are physiologically susceptible to REM intrusion. Furthermore, review of current evidence indicates that near-death shares features with the classically described mystical experience, but the two experiences remain distinct varieties of spiritual expression driven by different neurophysiologic processes.