Appendix B
A Comprehensive Summary
Throughout this book, I have argued that near-death experiences provide powerful empirical evidence for the soul, the afterlife, and the truth of biblical Christianity. But I have also tried to take seriously the skeptical objection that NDEs are simply produced by a dying brain. That objection deserves a fair hearing — and a thorough answer. This appendix is that answer.
Over the past fifty years, researchers committed to a purely materialistic view of the world have proposed about a dozen naturalistic explanations for NDEs. Each one has been tested. Each one has been found wanting. Pim van Lommel, whose landmark prospective study of cardiac arrest patients was published in The Lancet, walked through every major proposal in his book Consciousness Beyond Life and concluded that no combination of physiological or psychological factors can fully explain the phenomenon.1 John Burke summarizes van Lommel's verdict well: the standard theories cannot account for enhanced consciousness, lucid thought, vivid memory, or accurate perception from outside the body during a clinically dead state.2
In what follows, I will state each major naturalistic explanation as fairly and charitably as I can — what philosophers call "steel-manning" the opposing position. Then I will show why each one fails. As we will see, every one of these theories runs into the same wall: the veridical hurdle. A hallucination, by definition, cannot tell you what shoe is sitting on a third-floor window ledge. A dying brain cannot accurately describe a surgical instrument the patient has never seen. Whatever NDEs are, they are not just brain-generated illusions.
The veridical hurdle. Every naturalistic explanation must clear one fundamental obstacle: it must explain how a dying or non-functioning brain can produce verifiable information about events the patient could not have known through normal sensory means. As I demonstrated in Chapters 6 through 8, NDErs have accurately described surgical procedures, conversations in distant rooms, and even the appearance of deceased relatives whose deaths were unknown to them. No naturalistic theory has yet cleared this hurdle.
The hypothesis. When the heart stops, the brain is starved of oxygen. Reduced oxygen — what doctors call cerebral anoxia or hypoxia — can produce confusion, tunnel vision, and visual disturbances. Therefore, NDEs may simply be the experiences of an oxygen-starved brain on the way out.3 This is by far the most popular naturalistic explanation, and Shaun Tabatt rightly identifies it as the leading candidate among researchers seeking a non-spiritual answer.4
Why it fails. First, the kind of experiences anoxia actually produces are nothing like NDEs. James Whinnery's research with fighter pilots subjected to G-force-induced loss of consciousness — a controlled form of cerebral hypoxia — produced fragmentary, confused, dreamlike experiences, not the coherent, structured, vividly remembered NDEs reported in cardiac arrest.5
Second, anoxia cannot explain veridical information. A confused, oxygen-starved brain does not produce accurate descriptions of distant events.
Third, and most decisively, the statistical evidence rules anoxia out. Van Lommel's prospective Dutch study found that only 18 percent of cardiac arrest survivors reported NDEs.6 But every cardiac arrest patient experienced cerebral anoxia. If oxygen deprivation caused NDEs, we would expect all or most cardiac arrest patients to report them — not just one in five. The fact that anoxia is universal in this population while NDEs are rare among them shows that anoxia cannot be the cause.
Fourth, anoxia cannot account for shared-death experiences (Chapter 10), in which a healthy bystander — whose brain has perfectly normal oxygen levels — shares features of the dying person's experience.
The hypothesis. When breathing fails, carbon dioxide accumulates in the blood. Some studies have suggested that elevated CO2 levels can produce light experiences, tunnel vision, or feelings of well-being. Perhaps NDEs are simply the brain's response to hypercarbia.7
Why it fails. CO2-induced experiences in laboratory settings are typically fragmentary and disorienting — brief flashes, distortions, anxious sensations — not the coherent, transformative narratives of NDEs. More importantly, van Lommel's prospective study measured blood gas levels in cardiac arrest patients and found no correlation between CO2 levels and NDE incidence. Patients with high CO2 were no more likely to report NDEs than patients with normal CO2.8 The hypothesis predicts a correlation that the data simply do not show. The Slovenian researcher Zalika Klemenc-Ketis and her colleagues did report some correlation in a small sample of out-of-hospital cardiac arrest patients, but the correlation was weak, the sample was very limited, and even her own paper acknowledged that hypercarbia could not explain the specific structured features of NDEs. And of course, hypercarbia, like every other naturalistic theory in this appendix, cannot explain veridical perception.
The hypothesis. Under extreme stress, the brain releases endorphins — natural opiate-like chemicals — that produce calm, euphoria, and freedom from pain. Maybe NDEs are simply an endorphin high during the dying process.9
Why it fails. Michael Sabom addressed this hypothesis directly. Endorphin release does produce a state of painlessness and calm — Sabom himself documented this in a patient who survived a stabbing attack by going limp under endorphin-induced peace.10 But endorphin effects are sedative and drowsy, not hyper-vivid and lucid. As Sabom and others have shown, the endorphin theory cannot account for the structured content of NDEs — the OBE, the life review, the encounter with deceased loved ones, the meeting with a being of light. These specific elements have no parallel in opioid pharmacology. We do not see surgical patients on heavy doses of morphine reporting tunnel experiences and meetings with departed grandparents. And once again, no amount of endogenous morphine can explain how a patient accurately reports the conversation in a waiting room three floors away.
The hypothesis. N,N-dimethyltryptamine (DMT) is a powerful psychedelic compound found in trace amounts in the human body. The psychiatrist Rick Strassman proposed that the dying brain might release a flood of endogenous DMT, producing the visions reported in NDEs.11 The hypothesis became popular in psychedelic research circles and is often cited in materialist writing on NDEs.
Why it fails. First, there is simply no evidence that the human brain releases DMT in sufficient quantities at death to cause hallucinations. Strassman's own work showed only trace amounts in cerebrospinal fluid — orders of magnitude below psychoactive levels. The supposed "DMT flood" remains hypothetical.
Second, the phenomenology is wrong. DMT trips are typically chaotic, bizarre, and filled with insectoid or "machine elf" imagery — utterly unlike the orderly, meaningful, emotionally coherent narratives of NDEs. A 2018 study by Christopher Timmermann directly compared DMT experiences with NDEs and found significant overlap on some surface features but striking differences in content, structure, and aftereffect. NDEs, unlike DMT trips, consistently produce lasting transformation, loss of fear of death, and increased love for others. Drug experiences do not.
Third — and this should be obvious by now — DMT cannot produce verified information about events occurring outside the body.
The hypothesis. Electrical activity or seizures in the temporal lobe of the brain can produce out-of-body sensations, déjà vu, vivid memories, and a sense of an unseen "presence." Michael Persinger at Laurentian University attempted to mimic NDE features by electrically stimulating the brain. Olaf Blanke later showed that stimulating the temporal-parietal junction can produce a sensation of being outside one's body. Therefore, perhaps NDEs are just temporal lobe seizures in the dying brain.12
Why it fails. Sabom devoted a careful section of Light and Death to this hypothesis and found it wholly inadequate.13 Persinger himself acknowledged that the experiences his stimulation produced were fragmentary and variable, while NDEs are integrated and focused.14 Denis Williams's massive study of 2,000 epileptic patients found that seizures do not produce sustained, complex thought — yet NDErs report clear, complex reasoning throughout their experiences.15 Ernst Rodin, a longtime epilepsy specialist, put it plainly: in three decades of treating temporal lobe seizures, he had never encountered the core features of an NDE as part of a seizure.16
Blanke's TPJ research is even less impressive than it first appears. The artificially induced "OBEs" in his lab are brief, vague, disorienting feelings of dislocation — never coherent, never veridical, never accompanied by accurate perception of the room from a new vantage point. Producing a faint sensation of being outside one's body by zapping the brain is not the same as producing an actual NDE — any more than producing flashes of light by pressing on a closed eyelid proves that all visual experience is brain-generated.
The hypothesis. Neurologist Kevin Nelson has argued that NDEs result from REM (rapid eye movement) sleep intruding into wakefulness during a medical crisis. Dream-like experiences spill into conscious awareness, producing the visions reported in NDEs.17
Why it fails. Nelson's hypothesis is correlational, not causal — he found that some NDErs reported a history of sleep paralysis, but correlation does not establish that NDEs are REM intrusions. Other researchers have failed to replicate even his correlation. Critically, during cardiac arrest the brain is not in REM sleep; it is in cardiac arrest. EEG patterns during REM sleep and during cardiac arrest are completely different — REM shows characteristic theta-wave activity in a functioning brain, while cardiac arrest shows progressive isoelectric flattening within seconds. A flatlined brain is not a dreaming brain. Furthermore, dreams are notoriously fragmented, inconsistent, and forgotten. NDEs are coherent, consistent across cultures, and remembered with extraordinary clarity decades later. And once again — REM intrusion cannot explain veridical observations, blind NDEs, or shared-death experiences.
The hypothesis. Even when an EEG appears flat, perhaps deeper brain structures retain some level of micro-activity that we cannot yet measure. NDEs might be produced by this residual activity during the moments around cardiac arrest.18
Why it fails. The Pam Reynolds case (Chapter 7) is decisive against this hypothesis. During Reynolds's "standstill" surgery, every available measure of brain function was zero: a flat EEG, absent brainstem evoked potentials confirmed by 100-decibel ear speakers monitoring brainstem response, and no blood flow to the brain at all — the blood had been deliberately drained. By every clinical test, her brain was dead. Yet she had the deepest NDE in Sabom's entire Atlanta Study.19
Beyond Reynolds, there is a more fundamental logical problem with this hypothesis. A severely impaired brain should produce less coherent experience, not more. Yet NDErs consistently describe their experience as "realer than real" — sharper, clearer, faster, more lucid than ordinary waking consciousness.20 The residual brain activity hypothesis predicts the opposite of what we observe. And it cannot account for terminal lucidity (Chapter 34), in which patients with structurally destroyed brains regain perfect clarity in their final hours.
The hypothesis. NDEs simply reflect what people expect to happen at death. Christians see Jesus because they expect Jesus. Hindus see Yamaraj because they expect Yamaraj. The content is shaped by prior belief, not by an actual encounter with another reality.21
What children's NDEs tell us. The single most powerful refutation of the expectation hypothesis is the consistent finding from children's NDEs (Chapter 9). Very young children — ages 3 to 7 — have minimal cultural conditioning about what death is "supposed" to be like. Their cultural exposure consists of cartoons and fairy tales: ghosts in white sheets, skeletons, harps on clouds. None of those images appear in children's NDEs. Instead, children report the same core elements as adults: leaving the body, brilliant light, deceased relatives, beautiful landscapes. Pediatric oncologist Diane Komp found children describing things they had never been taught to expect.22
Why it fails. First, as the callout above notes, children consistently report NDE content for which they had no expectation. Second, NDErs frequently encounter deceased relatives whose deaths were unknown to them — they could not have been expecting to meet someone they did not know was dead.23 Third, the cross-cultural data show striking consistency in the core features of NDEs (OBE, light, life review, encounters with deceased), with cultural variation only in the surface details — the opposite of what the expectation hypothesis predicts. Fourth, atheists and agnostics, who expect oblivion, often have classic NDEs.24 Fifth, NDErs frequently report content that contradicts their prior beliefs — Christians who saw no streets of gold, atheists who met a personal God, secular Westerners who returned with a deepened conviction that something beyond the natural world is real.
The hypothesis. NDE memories are not formed during the medical crisis at all. They are constructed afterward, when the patient is told what happened and the brain fills in a coherent narrative. The "memory" of seeing the doctors, hearing the conversations, watching the resuscitation — all of it is unconsciously fabricated after the fact.
Why it fails. The veridical details rule confabulation out. Patients have reported specific information — the precise color and location of a tennis shoe on a third-floor window ledge (Maria's case), the exact appearance of a Midas Rex bone saw never seen before (Reynolds), the upper denture removed and placed in a drawer (the AWARE-precursor case). These are not vague impressions that could be unconsciously filled in from later conversation; they are concrete, falsifiable details that were verified independently by witnesses. False memories do not produce verifiable new information.
Furthermore, NDE memories are unusually stable over time. Bruce Greyson's longitudinal research demonstrated that NDE accounts remain consistent over decades — far more consistent than ordinary autobiographical memories, which drift and change with retelling.25 If NDEs were confabulations, we would expect them to drift like other false memories. They do not.
The hypothesis. Under extreme stress, the brain "dissociates" — splitting consciousness from immediate experience as a defense mechanism. The OBE component of NDEs may simply be a stress-induced dissociative episode.
Why it fails. This proposal was actually one of the earliest naturalistic explanations attempted, and it has been thoroughly tested. Clinical depersonalization is consistently described as unreal — patients feel detached, dreamlike, foggy, "as if behind glass." NDEs are described as the opposite: more real than ordinary experience, hyper-lucid, vivid in a way that ordinary waking consciousness is not.26 The phenomenology runs in opposite directions. Furthermore, dissociation is purely subjective — a feeling about one's own state, not an accurate perception of external events. It has no mechanism for producing verified information about the operating room, the waiting area, or events miles away. Penny Sartori, in her five-year prospective UK hospital study, also found that NDE accounts were structurally consistent across patients in a way that random dissociative episodes simply are not — dissociation produces idiosyncratic, individual content, while NDEs produce a recognizable shared phenomenology.
I want to close this appendix by pointing out something easy to miss when we examine each theory in isolation. Each of these naturalistic explanations has been tailored to address one feature of NDEs. Anoxia is supposed to explain the tunnel and the light. Endorphins are supposed to explain the peace. Temporal lobe stimulation is supposed to explain the OBE. DMT is supposed to explain the visions. REM intrusion is supposed to explain the dreamlike quality.
But NDEs are not just one feature. They are an integrated, structured, repeatable phenomenon that includes all of these elements together — plus veridical perception, plus cross-cultural consistency, plus profound personality transformation afterwards, plus blind NDEs, plus children's NDEs, plus shared-death experiences, plus terminal lucidity. To account for the whole phenomenon, the physicalist would need to combine half a dozen unrelated mechanisms — none of which has been demonstrated to operate in the way required, and none of which clears the veridical hurdle.
Where this leaves us. John Cooper, the dean of evangelical biblical anthropology, examined the NDE evidence and offered a careful conclusion: while NDEs do not by themselves prove the soul's survival of death, they do support dualism, and they require more than a standard physiological account of consciousness.27 I would put it more strongly than Cooper does. The cumulative evidence from veridical NDEs, blind NDEs, children's NDEs, shared-death experiences, and terminal lucidity — none of which can be explained by any of the naturalistic theories surveyed in this appendix — points decisively to the conclusion that consciousness can function independently of the brain. That is exactly what substance dualism predicts (Chapters 5 and 35). And it is exactly what the Bible has taught all along.
Bruce Greyson, after more than forty years of NDE research and over a hundred peer-reviewed publications, has written that there is enough evidence to take seriously both a physiological mechanism for NDEs and the continued functioning of the mind independent of the brain.28 Greyson is being characteristically cautious. The evidence I have surveyed in this appendix — and throughout this book — goes well beyond mere "taking seriously." Every naturalistic explanation has been proposed, tested, and found inadequate. The simplest explanation that accounts for all the data is the one Christian theology has held for two thousand years: the soul is real, the soul survives the death of the body, and the God who made us meets us at the threshold of eternity.
1 Pim van Lommel's comprehensive treatment of these theories appears in Consciousness Beyond Life: The Science of the Near-Death Experience (New York: HarperOne, 2010), chaps. 6–8. ↩
2 John Burke, Imagine Heaven: Near-Death Experiences, God's Promises, and the Exhilarating Future That Awaits You (Grand Rapids, MI: Baker Books, 2015), "Appendix B: Alternate Explanations for NDEs." ↩
3 Susan Blackmore, Dying to Live: Near-Death Experiences (Buffalo, NY: Prometheus Books, 1993) is the most influential book-length defense of the cerebral anoxia hypothesis. ↩
4 Shaun Tabatt, The NDE Conspiracy (Shippensburg, PA: Destiny Image, 2025), chap. 3, "Are NDEs Real?" ↩
5 James E. Whinnery, "Psychophysiologic Correlates of Unconsciousness and Near-Death Experiences," Journal of Near-Death Studies 15, no. 4 (Summer 1997): 231–58. Discussed in Michael Sabom, Light and Death: One Doctor's Fascinating Account of Near-Death Experiences (Grand Rapids, MI: Zondervan, 1998), chap. 10, "Light and Death." ↩
6 Pim van Lommel et al., "Near-Death Experience in Survivors of Cardiac Arrest: A Prospective Study in the Netherlands," The Lancet 358, no. 9298 (December 15, 2001): 2039–45. ↩
7 Zalika Klemenc-Ketis, Janko Kersnik, and Stefek Grmec, "The Effect of Carbon Dioxide on Near-Death Experiences in Out-of-Hospital Cardiac Arrest Survivors: A Prospective Observational Study," Critical Care 14, no. 2 (2010): R56. ↩
8 Van Lommel, Consciousness Beyond Life, 117–22. ↩
9 Daniel Carr, "Pathophysiology of Stress-Induced Limbic Lobe Dysfunction: A Hypothesis for NDEs," Anabiosis 2 (1981): 75–89. ↩
10 Sabom, Light and Death, chap. 10, "Light and Death," in the section discussing endorphins and the dying brain. ↩
11 Rick Strassman, DMT: The Spirit Molecule (Rochester, VT: Park Street Press, 2001). For a critical evaluation, see Christopher Timmermann et al., "DMT Models the Near-Death Experience," Frontiers in Psychology 9 (August 2018): 1424. ↩
12 Olaf Blanke et al., "Stimulating Illusory Own-Body Perceptions," Nature 419 (September 19, 2002): 269–70. ↩
13 Sabom, Light and Death, chap. 10, in the discussion of "Dying Brain" theories and temporal lobe seizures. ↩
14 Michael A. Persinger, "Modern Neuroscience and Near-Death Experiences: Expectancies and Implications. Comments on 'A Neurobiological Model for Near-Death Experiences,'" Journal of Near-Death Studies 7, no. 4 (Summer 1989): 233–39. ↩
15 Denis Williams, "The Structure of Emotions Reflected in Epileptic Experiences," Brain 79 (1956): 28–67. ↩
16 Ernst Rodin, "Comments on 'A Neurobiological Model for Near-Death Experiences,'" Journal of Near-Death Studies 7, no. 4 (Summer 1989): 255–59. ↩
17 Kevin Nelson et al., "Does the Arousal System Contribute to Near-Death Experience?" Neurology 66, no. 7 (April 2006): 1003–9. ↩
18 Jimo Borjigin et al., "Surge of Neurophysiological Coherence and Connectivity in the Dying Brain," Proceedings of the National Academy of Sciences 110, no. 35 (August 2013): 14432–37. ↩
19 Sabom, Light and Death, chap. 3, "Death: Defining the Final Frontier," and chap. 4, "Pam's Story." ↩
20 Jeffrey Long, God and the Afterlife: The Groundbreaking New Evidence for God and Near-Death Experience (New York: HarperOne, 2016), 36. ↩
21 An influential version of this view is found in Susan Blackmore, "Near-Death Experiences in India: They Have Tunnels Too," Journal of Near-Death Studies 11, no. 4 (1993): 205–17. ↩
22 J. Steve Miller, Deathbed Experiences as Evidence for the Afterlife, Volume 1: A Groundbreaking, Scientific Apologetic (Acworth, GA: Wisdom Creek Press, 2021), chap. 1, "Phenomena before Death," in the discussion of children's experiences and Diane Komp's research. ↩
23 J. Steve Miller, Is Christianity Compatible with Deathbed and Near-Death Experiences? The Surprising Presence of Jesus, Scarcity of Anti-Christian Elements, and Compatibility with Historic Christian Teachings (Acworth, GA: Wisdom Creek Press, 2023), chap. 1, "Reviewing My Argument Thus Far." ↩
24 Long, God and the Afterlife, 192. ↩
25 Bruce Greyson, "Consistency of Near-Death Experience Accounts over Two Decades: Are Reports Embellished over Time?" Resuscitation 73, no. 3 (June 2007): 407–11. See also Bruce Greyson, After: A Doctor Explores What Near-Death Experiences Reveal about Life and Beyond (New York: St. Martin's Essentials, 2021). ↩
26 J. Steve Miller, "Deathbed Experiences as Evidence for the Afterlife: A Multicultural Examination of the Literature" (Ph.D. diss., Columbia International University, 2019), in the discussion of dissociation and depersonalization in the comparison with NDE phenomenology. ↩
27 John W. Cooper, Body, Soul, and Life Everlasting: Biblical Anthropology and the Monism-Dualism Debate (Grand Rapids, MI: Eerdmans, 2000), 214–15. ↩
28 Tabatt, NDE Conspiracy, chap. 3, in his discussion of the balance between physiological and spiritual explanations, where Tabatt cites Greyson on this point. ↩
Blackmore, Susan. Dying to Live: Near-Death Experiences. Buffalo, NY: Prometheus Books, 1993.
Blanke, Olaf, Stéphanie Ortigue, Theodor Landis, and Margitta Seeck. "Stimulating Illusory Own-Body Perceptions." Nature 419 (September 19, 2002): 269–70.
Borjigin, Jimo, et al. "Surge of Neurophysiological Coherence and Connectivity in the Dying Brain." Proceedings of the National Academy of Sciences 110, no. 35 (August 2013): 14432–37.
Burke, John. Imagine Heaven: Near-Death Experiences, God's Promises, and the Exhilarating Future That Awaits You. Grand Rapids, MI: Baker Books, 2015.
Carr, Daniel. "Pathophysiology of Stress-Induced Limbic Lobe Dysfunction: A Hypothesis for NDEs." Anabiosis 2 (1981): 75–89.
Cooper, John W. Body, Soul, and Life Everlasting: Biblical Anthropology and the Monism-Dualism Debate. Grand Rapids, MI: Eerdmans, 2000.
Greyson, Bruce. After: A Doctor Explores What Near-Death Experiences Reveal about Life and Beyond. New York: St. Martin's Essentials, 2021.
Greyson, Bruce. "Consistency of Near-Death Experience Accounts over Two Decades: Are Reports Embellished over Time?" Resuscitation 73, no. 3 (June 2007): 407–11.
Klemenc-Ketis, Zalika, Janko Kersnik, and Stefek Grmec. "The Effect of Carbon Dioxide on Near-Death Experiences in Out-of-Hospital Cardiac Arrest Survivors: A Prospective Observational Study." Critical Care 14, no. 2 (2010): R56.
Long, Jeffrey. God and the Afterlife: The Groundbreaking New Evidence for God and Near-Death Experience. New York: HarperOne, 2016.
Miller, J. Steve. Deathbed Experiences as Evidence for the Afterlife, Volume 1: A Groundbreaking, Scientific Apologetic. Acworth, GA: Wisdom Creek Press, 2021.
Miller, J. Steve. "Deathbed Experiences as Evidence for the Afterlife: A Multicultural Examination of the Literature." Ph.D. dissertation, Columbia International University, 2019.
Miller, J. Steve. Is Christianity Compatible with Deathbed and Near-Death Experiences? The Surprising Presence of Jesus, Scarcity of Anti-Christian Elements, and Compatibility with Historic Christian Teachings. Acworth, GA: Wisdom Creek Press, 2023.
Nelson, Kevin, et al. "Does the Arousal System Contribute to Near-Death Experience?" Neurology 66, no. 7 (April 2006): 1003–9.
Persinger, Michael A. "Modern Neuroscience and Near-Death Experiences: Expectancies and Implications. Comments on 'A Neurobiological Model for Near-Death Experiences.'" Journal of Near-Death Studies 7, no. 4 (Summer 1989): 233–39.
Rodin, Ernst. "Comments on 'A Neurobiological Model for Near-Death Experiences.'" Journal of Near-Death Studies 7, no. 4 (Summer 1989): 255–59.
Sabom, Michael. Light and Death: One Doctor's Fascinating Account of Near-Death Experiences. Grand Rapids, MI: Zondervan, 1998.
Strassman, Rick. DMT: The Spirit Molecule. Rochester, VT: Park Street Press, 2001.
Tabatt, Shaun. The NDE Conspiracy. Shippensburg, PA: Destiny Image, 2025.
Timmermann, Christopher, et al. "DMT Models the Near-Death Experience." Frontiers in Psychology 9 (August 2018): 1424.
Van Lommel, Pim. Consciousness Beyond Life: The Science of the Near-Death Experience. New York: HarperOne, 2010.
Van Lommel, Pim, Ruud van Wees, Vincent Meyers, and Ingrid Elfferich. "Near-Death Experience in Survivors of Cardiac Arrest: A Prospective Study in the Netherlands." The Lancet 358, no. 9298 (December 15, 2001): 2039–45.
Whinnery, James E. "Psychophysiologic Correlates of Unconsciousness and Near-Death Experiences." Journal of Near-Death Studies 15, no. 4 (Summer 1997): 231–58.
Williams, Denis. "The Structure of Emotions Reflected in Epileptic Experiences." Brain 79 (1956): 28–67.