Since its early days, humanity has been fascinated by death, what happens before it, during our final moments, and possibly after, and recent scientific discoveries have revealed a consistent set of near-death experiences (NDEs) shared across subjects.
Indeed, a multidisciplinary team led by the University of Liège has proposed a unified neuroscientific model explaining the mechanism behind NDEs, based on converging empirical findings across neurobiology, psychology, and evolutionary theory, per a Medical Express report published on April 2.
Common NDEs
Specifically, these findings indicate that factors like oxygen deprivation, increased carbon dioxide, and disrupted brain energy metabolism can initiate brain responses that create vivid perceptual and emotional experiences that people often report during NDEs, such as:
- Out-of-body experiences, a dissociative sense of leaving the physical body,
- One’s life ‘flashing’ before their eyes,
- A feeling that time has slowed down, stopped, or sped up,
- An emotional sense of calm, peace, and well-being,
- Bright lights, long tunnels, deceased relatives, or unknown figures, perceived as sentient, spiritual, or mystical imagery.
Science refers to these as episodes of disconnected consciousness in contexts that involve actual or perceived physical threats, and reported experiences vary in terms of content and interpretation based on the individual’s imagination, selection bias, psychological state, and physiological response.
Near-death brain activity patterns
Upon observing cardiac arrest and other critical events in patients, the study authors have discovered a consistent pattern of physiological disruption, including hypoxia and elevated carbon dioxide levels triggered by reduced cerebral blood flow.
Following this, a cascade of factors sparks cerebral acidosis and drains adenosine triphosphate (ATP), the cell’s primary energy source, and creates a surge in neurotransmitter release across multiple brain systems, including dopamine, serotonin, noradrenaline, GABA, glutamate, acetylcholine, and endorphins.
The feelings of hyper-reality and visual hallucinations could, in part, be the result of increased serotonin levels and 5-HT2A receptor activation, dopamine release may influence emotional response, noradrenaline and acetylcholine are linked to memory encoding, while GABA and endorphins are believed to produce calming sensations.
Furthermore, the scientists discovered parallels between NDEs and states induced by psychedelics like DMT and ketamine, which affect similar receptor systems, as well as connecting psychological traits like dissociation proneness and REM sleep intrusion tendencies with NDE likelihood under stress.
Not only that, but they also found that NDEs and death-feigning behaviors (thanatosis), like tonic immobility or ‘freezing,’ fainting, catatonic state, dissociation, memory blackouts, and others in extreme situations, may share evolutionary roots as coping mechanisms.
In line with their discoveries, the researchers created the NEPTUNE (Neurophysiological Evolutionary Psychological Theory Understanding Near-death Experience) model to provide a comprehensive framework integrating the convergence of neurobiological and psychological responses to severe stress.
As they explained:
“Our NEPTUNE model, although theoretical at present, provides a foundation for the next research phase, which will entail empirical testing of each mechanism.”
Meanwhile, Meta’s announced mind-reading artificial intelligence (AI) model that can reconstruct sentences from the mind solely by reading brain signals could help researchers learn more about our experiences near death, and finally settle some debates surrounding them.
ReadNext
