Does your consciousness “operate independently” when your brain is close to death?

It’s 2001, and more than a week after a man regains consciousness following cardiac arrest in the Netherlands. The coronary care nurse who helped resuscitate him is in for quite a surprise. The 44-year-old patient recounts how, while he was clinically unconscious, he watched the nurse remove his dentures before intubation and place them on the sliding shelf of a crash cart. The nurse, identified only as T.G., is flabbergasted. That is exactly what he had done. He had never told the patient where he had placed the dentures, yet the man recalls their exact location from a time when consciousness—to the best medical knowledge—should have been impossible.

In the Dutch case, it was a forgotten pair of dentures, but other equally extraordinary reports from the brink of death exist. They involve patients relaying snippets of conversations among medical staff, describing unexpected events in the operating room, or even encountering a recently deceased person whose death they had not yet learned about but was later independently confirmed.

Collectively, these extraordinary reports are known as veridical near-death experiences (vNDEs)—cases in which people later describe perceptions they seemingly could not have had while clinically unconscious, and whose accounts are, in some instances, independently corroborated.

As fascinating as these cases are, they come with a major caveat: researchers almost always investigate them retrospectively, reconstructing what happened only after patients recover, through interviews, medical records, and witness testimony. That has long forced scientists to wrestle with an unsettling question: are vNDEs glimpses of something genuinely anomalous, or are do they simply illustrate the brain’s uncanny ability to piece together memories from residual sensory information, fragments of experience, and coincidence?

Now, researchers believe they may finally have a way to start answering that question.

In a paper published in Frontiers in Psychology, a team worked with a panel of 13 leading near-death experts to create what they describe as the first standardized tool for evaluating the evidential strength of vNDEs. Rather than relying on intuition, the Veridical Near-Death Experience (vNDE) Scale grades each case against eight criteria, including whether the patient was demonstrably unconscious, whether the reported perceptions were independently verified, whether ordinary sensory explanations could account for them, and whether any details turned out to be wrong. The team then put the scale to its first real-world test and applied it to 17 published cases. Eleven experts and three artificial intelligence (AI) systems independently scored these cases. While the raters did not always agree on a case's exact score, they generally agreed on which cases offered stronger evidence and which appeared much weaker.

“The body of published [vNDE] cases numbers well over 120, though the quality and documentation standards vary widely across this set,” says Patrizio Tressoldi, PhD, a psychologist and consciousness researcher at the University of Padua in Italy who co-authored the study. The new scale aims to bring order to that patchwork of evidence by giving researchers a common yardstick for judging which cases provide the strongest evidence.

The stakes could hardly be higher. For decades, researchers including psychiatrist Bruce Greyson, who co-created the new scale, and cardiologist Pim van Lommel, who has a study of NDEs in The Lancet, have argued that the strongest vNDEs deserve serious scientific attention. If they continue to withstand every conventional explanation, they may hint at one of the most unsettling possibilities in science: that consciousness is not confined to the brain and may, under certain circumstances, operate independently of it.

And if future evidence ultimately supports that possibility, it would upend one of modern neuroscience’s central assumptions—that every thought, memory, and conscious experience emerges from the three-pound organ inside our skull.

“If a substantial number of cases were verified at the highest evidential level, this would challenge standard neurophysiological (brain-based) accounts of perception and memory, and would strengthen the hypothesis that consciousness can in some circumstances operate independently of the physical brain,” confirms Tressoldi.

Others, however, see the scale as an important step—but not yet a game changer.

Robert Alexander, PhD, an attention researcher and neuroscience expert at the New York Institute of Technology, agrees that the new scale represents an important methodological advance. Standardized criteria, he says, can help researchers distinguish weaker reports from well-documented cases. But he cautions that even a highly rated case is not, by itself, extraordinary evidence.

“For claims that consciousness can operate outside the brain or body, Carl Sagan's standard applies: extraordinary claims require extraordinary evidence,” Alexander says. “A high score on a case report, even using a well-standardized reporting tool, is not extraordinary evidence.”

For him, the central question is one of timing: exactly when did the experience form? Did it occur while the brain was incapable of supporting ordinary awareness? As it was shutting down? As it was recovering? Or only later, when memory pieced together stray sensory clues into a coherent narrative?

Even the AI systems used in the study (namely, ChatGPT, Gemini, and Mistral) cannot answer those questions. They may apply the scoring criteria consistently, Alexander says, but they cannot reveal whether a patient’s memories capture something genuinely beyond conventional explanation or simply reflect the brain’s gift for weaving stray sensory clues into a convincing memory. Nor, he adds, does AI eliminate the risk of bias. These systems “often mimic human biases, and have biases of their own,” he says.

Still, Alexander is careful not to close the door entirely. “Cases that withstand rigorous scrutiny may deserve attention,” he says. “When rigorous observations withstand conventional explanations, we must be missing something. But gaps in our understanding do not automatically imply that consciousness floats free of biology.”