During the surgical implantation of automatic implantable cardioverters/defibrillators (ICDs), cardiac arrest was induced under closely monitored conditions to test the device. A computer displayed unusual visual targets visible only from above eye level, looking down on the unconscious patient, to test the accuracy of out-of-body perceptions reported in near-death experiences. In a series of 52 induced cardiac arrests, no patient reported having had a near-death experience, and none reported a sense of leaving the physical body or observing from an out-of-body visual perspective. This failure to find a single NDE may have been due to preoperative reassurances.
A new scale, the veridical Near-Death Experience Scale (vNDE Scale), was developed to assess how strong the evidence is for perceptions reported during near-death experiences. Experts in near-death experiences reached consensus on eight criteria covering timing, medical conditions, third-party verification, and the type and quality of perceptions, scored on a four-level Likert scale. When 11 human raters and three artificial raters using large language models applied the scale to 17 cases, overall agreement between human and artificial judges exceeded 75% in 14 of the 17 cases (82.3%), considering adjacent levels of evidence strength. The scale offers a practical way to evaluate the evidential strength of such perceptions.
Combat near-death experiences (cNDEs) are not signs of mental illness. In a survey of 68 military personnel who survived close brushes with death during combat, 20 met criteria for a near-death experience. Compared to near-death experiencers from other studies, combat experiencers scored lower overall on the Near-Death Experience Scale and on its Affective and Transcendental subscales, but higher on the Cognitive subscale. On a measure of life changes, combat experiencers showed changes in the same direction as other near-death experiencers, but only changes in spirituality and total change showed medium effect sizes; other differences were small and not statistically significant.