Reports of vivid experiences during near-death states appear throughout religious and folk literature long before modern medicine, but the pattern was named and popularised for a general audience by psychiatrist Raymond Moody, whose 1975 book Life After Life collected first-person accounts sharing recurring elements: a sense of separating from the physical body, moving through darkness or a tunnel toward a light, meeting deceased relatives or a being of light, a rapid review of one's life, and a reluctant return. Moody's book was a popular rather than a clinical study, but it set the template later researchers tested formally.
Dutch cardiologist Pim van Lommel conducted the most cited prospective clinical study, published in The Lancet in 2001, interviewing 344 patients who had been successfully resuscitated after cardiac arrest as soon as feasible after the event: 62 patients, about 18 percent, recalled some memory from the period of clinical unconsciousness, and 41 of those, about 12 percent of the total, described a experience meeting the classic near-death criteria, including a reported out-of-body sense in some cases. Van Lommel argued the timing, since these experiences were reported during a period when standard measures suggested minimal brain activity, posed a genuine puzzle for a purely physiological account of consciousness, a claim that drew immediate and continuing pushback from neuroscientists.