Near-death experience: arising from the borderlands of consciousness in crisis.

Near-death experiences—sensations of light, out-of-body episodes, and encounters with deceased loved ones or spiritual beings—arise from brain activity rather than a single physiological or biochemical system. During impaired cerebral blood flow from syncope or cardiac arrest, the boundary between consciousness and unconsciousness blurs, and a person may enter a borderland of heightened awareness. Consciousness can fluctuate as blood flow crosses critical thresholds. Brain ischemia disrupts the balance between conscious states, leading the brainstem to blend REM and waking into an unfamiliar reality. Most people who have near-death experiences have brains predisposed to fusing REM and waking consciousness, and they are as likely to have out-of-body experiences during that blended state as during near-death itself.

Study at a glance

Abstract

Brain activity explains the essential features of near-death experience, including the perceptions of envelopment by light, out-of-body, and meeting deceased loved ones or spiritual beings. To achieve their fullest expression, such near-death experiences require a confluence of events and draw upon more than a single physiological or biochemical system, or one anatomical structure. During impaired cerebral blood flow from syncope or cardiac arrest that commonly precedes near-death, the boundary between consciousness and unconsciousness is often indistinct and a person may enter a borderland and be far more aware than is appreciated by others. Consciousness can also come and go if blood flow rises and falls across a crucial threshold. During crisis the brain's prime biologic purpose to keep itself alive lies at the heart of many spiritual experiences and inextricably binds them to the primal brain. Brain ischemia can disrupt the physiological balance between conscious states by leading the brainstem to blend rapid eye movement (REM) and waking into another borderland of consciousness during near-death. Evidence converges from many points to support this notion, including the observation that the majority of people with a near-death experience possess brains predisposed to fusing REM and waking consciousness into an unfamiliar reality, and are as likely to have out-of-body experience while blending REM and waking consciousness as they are to have out-of-body experience during near-death.