A Table Comparing 5 Studies of Near-Death Experiences

Sudden cardiac arrest is a major cause of death, suddenly killing about 350,000 each year in the United States alone. Of those who experience sudden cardiac arrest outside of a hospital, few survive. 

A big recent study on what goes on in near-death experiences is now available in preprint form. It is the study "Psychometric evaluation of the Danish Near-Death Experience Content scale in a sample of out-of-hospital cardiac arrest survivors," which you can read here. 

The study by Tobias Anker Stripp MD and someone else used as its starting point 2,785 people who survived out-of-hospital cardiac arrest. They were asked, "A life-threatening situation or illness (such as an accident, cardiac arrest, or cancer) can cause some people to lose or experience an altered sense of consciousness. Some may subsequently recount memories from the time when they had lost, or experienced an altered state of consciousness, whereas others cannot remember anything. Do you have any memories from such an experience?” Those responding "yes" or "don't know" were sent out a survey about near-death experiences, and according to page 10 of the preprint, 738 answered this survey. This gives a response pool much larger than the other surveys summarized in the table below, as those other surveys all involve fewer than 100 respondents. 

Let's compare the results of this study with the results of similar studies. The papers mentioned in the table below are these:

Study 1: The phenomenology of near-death experiences,” 78 subjects (link), a 1980 study, producing results similar to a smaller study group year 2003 in-hospital study by one of its co-authors. 

Study 2: "Qualitative thematic analysis of the phenomenology of near-death experiences,” 34 subjects (link), a 2017 study on people who survived cardiac arrest. 

Study 3: "Near-death experience in survivors of cardiac arrest: a prospective study in the Netherlands," a 2001 study of 62 subjects who were known to have suffered cardiac arrest and survived it, and who also reported a near-death experience (a subset that was 12% of a larger group of cardiac arrest survivors), link. The average duration of cardiac arrest was 4 minutes. 74% were interviewed within 5 days of their cardiac arrest. 

Study 4: "Different Kinds of Near-Death Experience: A Report on a Survey of Near-Death Experiences in Germany," 82 subjects (link).

Study 5: "Psychometric evaluation of the Danish Near-Death Experience Content scale in a sample of out-of-hospital cardiac arrest survivors," 738 subjects (link).  This involved a scale in which you could answer between 1 and 5, with "0 – not at all; none”, “1 – slightly”, “2 – moderately”, “3 – strongly; equivalent in degree to any other strong experience”, and “4 – extremely; more than any other time in my life."  Only responses of 2 or greater are included in the percentages listed in the "Study 5" column below. So in the "Study 5" column below I give the mathematical sum of the right-most 3 columns of particular rows in Table 1 of this study, which appears after the main text of the paper. 

In the table below, blank squares occur whenever the survey had no question corresponding to the question on the left side of the row. Blank squares do not mean that 0% answered "yes" to a question.  

The recent study described in the Study 5 column gives results similar to those of previous studies on near-death experiences. 

	Study 1	Study 2	Study 3	Study 4	Study 5
Seeing a light or “unusual visual phenomena” such as lights or auras	48%	74%	> 23%	40%	17%
Meeting other beings	55%	44%	32%	48%	14%
Positive emotions or intense feeling of well-being	37-50%	29%	56%	50%	40%
“Hyper-lucidity” or thoughts speeded up		41%			36%
ESP during the near-death experience	39%	12%			23%
"Awareness of being dead" or awareness of dying		26%	50%		23%
Distortion of time	79%	47%			38%
Celestial landscape or other realm of existence	72%		29%	51%	19%
Contact or communi-cation with the dead	30%	23%	19%	16%	14%**
Out-of-body experience	75% (27%?)*	35%	24%	31%	20%
Having some sort of non- physical body separate from the physical body	58%
Passing through tunnel or similar structure	31%	26%	31%	38%	13%***
Reaching a border or point of no return	57%		8%		12%
Life reviewed or relived	27%	15%	13%	44%	13%

*Study 1 says, "The impression or feeling of seeing oneself to be out-side the physical body, an 'out-of-the-body experience,’ was reported by 75% of our respondents." But the study's Table 1 gives a different figure of only 27%. 

** In Survey 5 the question was, "You encountered a presence and/or an entity (who might be deceased)."

*** In Survey 5 the question was, "You saw or entered a gateway (for instance a tunnel or a door)."

The recent study (Study 5) getting results for so many survivors of sudden cardiac arrest provides powerful new evidence against all attempts to naturally near-death experiences. During sudden cardiac arrest, the electrical system of the heart malfunctions, and the result is a stopping of the heart that produces a flatlining of brain signals (called asystole) within 15 or 20 seconds after the heart stops. We cannot explain near-death experiences in such people by imagining that they were hallucinating. A flatlining brain that has electrically shut down cannot hallucinate. 

Below is part of Figure S1A from the supplemental information of a 2023 paper. We see the brain waves of the dying Patient One in blue (EEG readings), and we see in the last row a red ECG reading that is a  measure of heart activity.  The brain waves flatline very quickly after the heart stops beating. 

The term "isoelectric" or iso-electric in reference to brain waves means a flat-lining equivalent to no electrical activity in the brain, as measured by EEG readings. The paper here states, "Within 10 to 40 seconds after circulatory arrest the EEG becomes iso-electric." Figure 1 of the paper here says that such an isoelectric flat-lining occurred within 26 seconds after the start of ventricular fibrillation, the "V-fib" that is a common cause of sudden cardiac death, with "cortical activity absent." Also referring to a flat-lining of brain waves meaning a stopping of brain electrical activity, and using the term "ischemia" meaning a lack of blood to the heart, another scientific paper says, "several studies have shown that EEG becomes isoelectric within 15 s [seconds] after ischemia without a significant decrease in ATP level (Naritomi et al., 1988; Alger et al., 1989)."  Another paper tells us this about brain waves and infarction (obstruction of blood flow), using CBF to mean cerebral blood flow, and the phrase "the EEG becomes isoelectric" to mean a flat-lining of brain electrical signals:

"When normal CBF declines, the EEG first loses the higher frequencies (alpha and beta bands), while the lower frequencies (delta and theta bands) gradually increase. When the CBF decreases further towards an infarction threshold, the EEG becomes isoelectric." 

Similarly, another paper refers to blood pressure, and tells us, "When flow is below 20 mL/100 g/min (60% below normal), EEG becomes isoelectric," meaning that brain electrical activity flat-lines. The 85-page "Cerebral Protection" document here states, "During cardiac arrest, the EEG becomes isoelectric within 20-30 sec and this persists for several minutes after resuscitation." Another scientific paper states this, using the term "isoelectric" which means flatlining. 

"Of importance, during cardiac arrest, chest compliance is not confounded by muscle activity. The EEG becomes isoelectric within 15 to 20 seconds, and the patient becomes flaccid (Clark, 1992; Bang, 2003)."

Attempts to naturally explain near-death experiences tend to ignore this reality that such experiences typically occur during cardiac arrest when the brain has flatlined, a reality excluding a hallucination explanation. 

I normally think of The Conversation as being a materialist web site, given the type of articles it so typically publishes. So I was surprised to recently read an article at that site favorably covering near-death experiences and candidly discussing some of their currently inexplicable features. In the article we read this:

"A subset of out-of-body experiences involve verifiable perceptions. In other words, the patient recalls perceiving something they should not have while unconscious (beyond simple memory reconstruction). The International Association of Near Death Studies published a compilation of more than 100 cases in the second edition of The Self Does Not Die in 2023. These include descriptions of objects in places that were out of reach to those in the room, even if they were trying to look. For example, 'a 1985 quarter lying on the right-hand corner of the eight-foot-high cardiac monitor,' which a physician found upon climbing a ladder. Another example is a 12-digit serial number on top of a seven-foot respirator, referred to by a patient with obsessive-compulsive disorder. In this case, the serial number was confirmed by a technician."

My post here summarizes many of the best cases of this type published in that book.