Amazing stuff!
"A multidisciplinary team led by the University of Liège has proposed a unified neuroscientific model explaining the mechanisms behind near-death experiences (NDEs), drawing on converging empirical findings across neurobiology, psychology, and evolutionary theory.
Findings suggest that factors such as oxygen deprivation, increased carbon dioxide, and disrupted brain energy metabolism can initiate brain responses that lead to vivid perceptual and emotional experiences often reported during NDEs. ...
A consistent pattern of physiological disruption emerged during cardiac arrest and other critical events. Reduced cerebral blood flow triggers hypoxia and elevates carbon dioxide levels.
A cascade of factors then induces cerebral acidosis and depletes ATP, the cell's primary energy source, and produces a surge in neurotransmitter release across multiple brain systems, including serotonin, dopamine, glutamate, noradrenaline, GABA, acetylcholine, and endorphins.
Key mechanistic details include elevated serotonin levels and 5-HT2A receptor activation, potentially contributing to visual hallucinations and feelings of hyper-reality. Dopamine release may influence emotional salience. Noradrenaline and acetylcholine appear linked to memory encoding. GABA and endorphins are proposed to induce calming sensations.
Researchers found parallels between NDEs and psychedelic-induced states, particularly with substances like DMT and ketamine, which affect similar receptor systems.
Psychological traits such as dissociation proneness and REM sleep intrusion tendencies may predispose individuals to experiencing NDEs under stress.
Findings also suggest that NDEs and death-feigning behaviors (thanatosis) may share evolutionary roots as coping mechanisms.
Based on the convergence of neurobiological and psychological responses to severe physiological stress, researchers crafted NEPTUNE (Neurophysiological Evolutionary Psychological Theory Understanding Near-death Experience), a model to provide a comprehensive framework integrating diverse lines of evidence. ..."
From the abstract:
"Near-death experiences (NDEs) are episodes of disconnected consciousness that typically occur in situations that involve an actual or potential physical threat or are perceived as such, and the experiences are characterized by a rich content with prototypical mystical features.
Several explanatory theories for NDEs have been proposed, ranging from psychological or neurophysiological to evolutionary models. However, these concepts were often formulated independently, and, owing to the fragmented nature of research in this domain, integration of these ideas has been limited. Lines of empirical evidence from different areas of neuroscience, including non-human studies, studies investigating psychedelic-induced mystical experiences in humans, and research on the dying brain, are now converging to provide a comprehensive explanation for NDEs.
In this Review, we discuss processes that might underlie the rich conscious experience in NDEs, mostly focusing on prototypical examples and addressing both the potential psychological mechanisms and neurophysiological changes, including cellular and electrophysiological brain network modifications and alterations in neurotransmitter release.
On the basis of this discussion, we propose a model for NDEs that encompasses a cascade of concomitant psychological and neurophysiological processes within an evolutionary framework. We also consider how NDE research can inform the debate on the emergence of consciousness in near-death conditions that arise before brain death."
A new neuroscientific model to explain near-death experiences (NDEs) (original news release) "In an article recently published in Nature Reviews Neurology, a team of researchers ... propose a new neuroscientific model of near-death experiences (NDEs). For the first time in the field, this article integrates data from various neuroscience disciplines and an in-depth analysis of the different mechanisms at work, offering a solid explanation for the occurrence of these fascinating phenomena in critical contexts, such as cardiac arrest."
A neuroscientific model of near-death experiences (no public access)
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