It is reasonable and scientifically appropriate to search for neural correlates of near-death experiences (including out-of-body experiences, OBEs) in the context of altered states of consciousness (ASCs). Our survey of the literature showed direct connections from NDEs via ASCs to brain mechanisms. Dualistic and paranormal approaches, subjective belief, and approaches via quantum physics appear either scientifically inadequate or premature to provide explanations for the NDE/OBE phenomena.

Historically, clinical death was taken as “death” and people wondered about how a dead person with a dead brain could experience something. The assumption emerged that the mind, spirit, or consciousness can survive in the period of death independently of material support: that is, independently of the brain. Modern methods of measuring brain activity have shown that coordinated neuronal activity in networks of the brain can survive clinical death for a while and may produce extraordinary experiences such as NDEs. Themes of NDEs (NDE content) can be reproduced in a variety of experimental models, all leading to altered states of consciousness of the affected persons. The personal truth of NDE stories, verified in the analysis of numerous NDE reports, and the experimental validation of NDE themes in several models under well-controlled conditions, lead to the scientifically adequate conclusion that NDE phenomena are brain-based expressions of neuronal activity in conditions of altered states of consciousness.

Results from studies on brain activity in situations of hypoxia, application of anesthetics and other psychoactive drugs, epileptic seizures, electrical stimulation of brain areas, lucid dreams, and dream-like hallucinations of several geneses have shown that the reports of people who had perceptions and experiences related to these situations showed strong accordance with NDE reports. NDE themes can be reproduced experimentally, often in a predictable way. Such contexts and situations can be used as scientifically appropriate models for NDE release. Knowledge about and control of brain activation during the occurrence of NDE-like phenomena can be essential for understanding their generation.

Near-death experiences often have pervasive and long-lasting aftereffects in the lives of the affected persons. These aftereffects may concern personal attitudes to their own death, beliefs and spiritual life, social relationships, and other important aspects of life such as health care and work. Despite hundreds of collected and analyzed NDE reports, in the publications of many NDE researchers there is no discussion of such aftereffects that take a scientific perspective on NDE phenomena. From a scientific point of view, we can attest stagnation in the field of most NDE research. This stagnation will continue as long as researchers remain in the mental tradition of Moody, misinterpreting or ignoring studies on brain activity in metabolic stress, on brain physiology in the progression to brain death, and on the relationship between levels of consciousness and signatures in electroencephalograms.

By grounding the stories of near-death experiences (NDEs) in modern scientific evidence, the authors aim to demystify them and place them within the broader context of human cognition and perception. This book is an invitation to understand the near-death experience not as an enigmatic anomaly but as a natural part of the human condition, informed by our biology and the remarkable capacities of the brain. It is our hope that readers will gain not only a deeper appreciation for the scientific explanations behind NDEs but also a greater respect for the resilience and complexity of the human mind.

Experimental research about reliability, emotional expression, and possible fantasy and illusion in memories of NDEs is a new field of study. NDEs are stored as episodic memory and constitute an important part of the self-defining memory. NDE memories appear as real as memories of real events, and may contain even more detail and vividness than memories of real events. NED memories also seem to include illusions that may help a person to interpret their extraordinary experience. EEG data suggest that NDE memories reproduce illusions that were encoded as if they were real events. Studies on the encoding, storage, and retrieval of memories built in altered states of consciousness, such as states of dreaming or generation of hallucinations, can be used to model the encoding, storage, and retrieval of NDE memories.

Historical concepts of consciousness will be presented. Consciousness has often been seen as synonymous with soul or mind. Soul and mind can be embedded in dualistic or monistic world views.

The phenomenon of near-death experiences (NDEs) has fascinated humanity for centuries but remains famously difficult to define and study. This book presents a unique source, integrating historical, clinical, psychological, and neuroscientific approaches toward a modern scientific understanding of NDEs. Featuring exciting clinical and experimental details about processes in dying brains, it examines the physiological and psychological underpinnings of this extraordinary phenomenon. Chapters offer science-based accounts of NDEs as a natural part of the human condition informed by our biology and the remarkable capacities of the brain. By proposing that the origin of NDEs can be found in the physiology-dependent mental processes of the experiencer as expressed in altered states of consciousness, this book provides up-to-date insights for psychologists, psychiatrists, neuroscientists, and philosophers alike.

As we all know from our daily experience of waking and sleeping, consciousness exists on a graded scale. Generally, both too much or too little activation of the cerebral cortex prevents conscious awareness. Objective measurements, for example via electroencephalography, of ongoing or stimulus-evoked or internally initiated neural activities in the cerebral cortex are possible. These neural activities can be related to the actual presence or absence or levels of consciousness in a person even when a person appears to be unconscious, for example after cardiac arrest or during the process of dying. Brain-wave activity during clinical death and resuscitation can be measured and compared with brain-wave activity in altered states of consciousness and normal conscious wakefulness.

NDEs and OBEs reflect altered states of consciousness (ASCs) that can experimentally be studied via modern brain scanning and electroencephalographic methods. Scientific literature presents convincing evidence for brain-based explanations of NDEs and OBEs. The disturbance of normal multisensory integration in the temporo-parietal junction (TPJ) of the cerebral cortex via over- or under-excitation or via misalignment of sensory inputs is the most plausible and experimentally confirmed origin of OBEs. NDE generation seems to be based on information exchange in various neural networks of the brain involving different sets of brain areas for different NDE themes. When NDE themes explicitly refer to a first-person perspective, the TPJ is an excellent candidate for a major contribution to NDE occurrence. When visual phenomena are part of the NDE theme, the occipital cortex can be assumed to be strongly involved. There is a clear connection of NDEs with ASCs and the TPJ as a brain center that significantly contributes via brain-wave activity to the regulation of states of consciousness.

For many philosophers, the mind-body problem has to be solved in order to explain consciousness. Consciousness can be described by levels of awareness and wakefulness. The evolution of consciousness in animals shows in which taxa of animals awareness and wakefulness have been reached at levels from absence of consciousness to levels similar to humans. The ontogeny of consciousness in human babies reproduces the evolution of consciousness in animals. Brain injury and disorders in humans can throw back consciousness to animal levels.

Substantial differences in the incidence of NDEs in the literature indicate that this field of research is developing and has not yet reached a state of generally accepted standards. Many anecdotal reports about NDE-like phenomena contrast with few observations under controlled conditions with a minimum of scientific scrutiny. Because the incidence of NDEs depends on so many factors (intrinsic and extrinsic to the affected person), and because the access to the topic may touch the dignity of a person’s last phase of life, NDE-related research mainly remained observational with only few quantitative and/or experimental approaches. Against this background there is ample room for those who wish to come out with fanciful speculations about the genesis of NDEs.

A survey of several neuroscience models of consciousness shows, supported by numerous measurements and experimental data, that consciousness and brain processes are intimately connected. Quantum physical approaches to consciousness are purely speculative and experimentally unsubstantiated.

From a phenomenological point of view, ELDVs, DRSEs, and NDEs show many similarities. The terms ELDVs, DRSEs, and NDEs have been used interchangeably in a large spectrum of contexts involving medicine, psychology, neurosciences, philosophy, theology, metaphysics, and paranormal and mystical accounts.

Raymond Moody’s book Life after Life (1975, latest version 2015) introduced the term “near-death experience.” into modern and widely circulated English-language literature.Right from the beginning, the term NDE was closely linked to the belief in an afterlife. The academic career of Moody and the perception of Moody’s book in the USA show that reported near-death experiences may have expressed personal truth, but without persuasive attempts to explain NDEs scientifically.