Seeing The Light

Cutting-edge scientists are dissecting the near-death experience and battling over the evidence. Is it a newly discovered dream state—or are we immortal in some way?

By Pamela Weintraub, published September 2, 2014 - last reviewed on June 9, 2016

In 2009, chauffeur Joe Tiralosi was wheeled into the emergency department at New York-Presbyterian Hospital with nausea and profuse sweating. Moments later, the man went into cardiac arrest—his heart stopped pumping blood and dispatching oxygen to vital organs. Within seconds, Tiralosi’s brain flatlined; electronic monitors recorded no sign that he was able to process feeling, generate thought, or participate in the world. His brain cells were not functioning.

The hospital’s state-of-the-art resuscitation team swung into action, compressing Tiralosi’s chest and delivering electric shocks to his heart for what seemed like forever—two minutes, five minutes, 10 minutes. No response. Tiralosi had crossed what most thought was the point of no return. Conventional wisdom held that after 10 minutes without a heartbeat, damage to the brain from a lack of oxygen becomes permanent.

But the team pushed past the limits by slowing the decay of tissue and preserving the integrity of the brain through sophisticated freezing techniques. They shocked Tiralosi’s heart again and again. Twenty minutes. Thirty minutes. Forty minutes. Tiralosi had been clinically dead for 47 minutes when his heart flickered back on. Less than three weeks later, after surgeons dissolved the blood clots and repaired the narrowed arteries that had stopped his heart, Tiralosi walked out of the hospital, brain and body intact. Just a decade earlier, that would have been impossible.

 Man floating above a sofa into clouds

Before his release, Tiralosi met with Sam Parnia, a critical-care physician at Presbyterian well schooled in the extraordinary new ways of reanimating the dead even hours after their hearts have stopped. Parnia found a warm and gracious man who recalled just one thing from the time he was “dead.” He had an encounter with an ineffable, luminous, “compassionate being that gave him a loving feeling of warmth.”

The encounter, Tiralosi said, transformed him completely because now he no longer feared death. One of the 10 to 20 percent of the declared-dead to return with a tale from “the other side,” Tiralosi described a near-death experience (NDE)—a memory of dying and being dead that classically features deep serenity, whole life review, a sense of leaving the body and watching the scene from above, and, famously, passage through a tunnel of light. Commonly, the NDE is interpreted as a spiritual experience, an encounter with the divine.

Now at Stony Brook University and the author of the book Erasing Death, Parnia says Tiralosi helped him frame some essential questions and ideas about life, death, and consciousness: When is death final and irreversible? What, if anything, was Tiralosi perceiving? And where was his consciousness when his brain was offline—when he was, quite literally, dead? Was Tiralosi hallucinating or had his near-death experience been real?

Before medical science dared to intervene, the line between life and death was sharp and clear: Death always followed cardiac arrest. It took only seconds for the brain to lose function after the heart stopped pumping. Death was a moment, and no one came back.

Things got more complicated in the mid-20th century with the advent of ventilators to keep the lungs working and defibrillators to restart a stopped heart. Even with such mechanical advances, doctors noticed, the brain would sometimes liquefy, its cells losing structure and becoming gel-like. Lungs could be forced to process oxygen and hearts to beat, but treated patients might still be brain dead, past the point of saving.

In 2014, critical-care experts know that careful cooling, with sophisticated freezing techniques, protects brain cells, slowing degradation of the organ and enabling recovery. Contrary to popular and even medical perceptions, Parnia says, death is not the end we once thought it to be. “Death is no longer a specific moment in time, such as when the heart stops beating, respiration ceases, and the brain no longer functions. For many minutes and hours, a dead brain that has been cooled can be restored. Death is a process that can be interrupted well after it has begun.”

 Man floating in sky above trees

If life can be restored, then scientists have a shot at the biggest question of all: Is consciousness annihilated immediately after death, or does it continue to exist? If so, for how long? Parnia believes his ongoing investigations of patient reports from the medical edge may illuminate “age-old concepts of the soul and what happens after death—the so-called afterlife.” Today, as accounts of near-death experiences top best-seller lists, they are perhaps the liveliest front in a long-running battle between science and religion.

Intimations of Immortality

For more than 50 years, ever since doctors developed the first crude method to bring patients back to life, the revived have been reporting seemingly impossible memories of time on “the other side.” There have been, in fact, sporadic, miraculous reports for thousands of years, but in the second half of the 20th century, they began occurring with some frequency.

By 1965, Georgia physician and philosopher Raymond Moody was collecting such reports. He called the phenomenon “near-death experience” and described its features in a book, Life After Life , in 1975. Often it involved the sensation of leaving one’s body—an out-of-body experience, or OBE—sometimes reported by the healthy as well. Neurologists explained the OBE as a trick of the mind.

In the archetypal NDE, the out-of-body sojourner passes through a tunnel of light to some ecstatic, idyllic place. Some report relatives and friends embracing them on arrival and waving them on to a luminous, exquisitely beautiful realm. Others report visions of their lives passing by in panoramic view.

Reports of NDEs have been consistent for thousands of years across continents and cultures, although some details, such as the deity figure that appears, vary by context.

NDEs can have significant aftereffects. University of Connecticut psychologist Kenneth Ring, who cofounded the International Association for Near-Death Studies in 1981, interviewed scores of people who had experienced NDEs and found that they change people’s life, and in consistent ways. Subjects report becoming less materialistic and ambitious, more creative and giving. Their sense of purpose and gusto increases. Most significantly, like Tiralosi, they stop fearing death—because they don’t believe it is final. There is “the now,” interviewees said, and “the beyond,” some infinite existence to come.

The Search for Proof

The very term “near-death experience,” Parnia believes, is now outdated. Recent improvements in medical monitoring technology afford such precision that he can pinpoint exactly when patients stop being alive—when the process of death begins. At least with regard to his cardiac-arrest patients, he prefers the term “actual death experience.” Further, he believes that the ability to sustain the dead for increasing amounts of time may enable them to go deeper into the death experience and, after survival, provide unprecedented evidence of whether it is the product of a hallucinating brain or reflects the survival of consciousness.

For Parnia, the search for evidence of postdeath consciousness requires examination of the phenomenon of “veridical perception”—the perspective of those who feel they left their body and hovered above a scene, looking down. One woman he interviewed, for instance, recounted floating above the bed watching doctors work on her and listening to their conversation. When a surgeon later visited her and told her about the procedure, the woman offered up many details, including the specifics of the chatter—because, she said, she herself had heard all the attending doctors talking.

The doctors dismissed her report of veridical perception, insisting she must have overheard nurses discussing her case after she regained consciousness. Parnia wasn’t so sure. He was determined to design an experiment that could identify the nature of the phenomenon, an experiment that met the strictest standards of science: It would be blind (the researcher would not know which patient was exposed to which test image placed high in the operating room), and the results would be evaluated by an expert who had not been in the room.

Parnia is not the first person attempting to prove that consciousness survives when the brain is offline. The search for proof has a history, and it is fraught. In 2004 and 2005, for instance, University of North Texas counseling professor Janice Miner Holden studied a series of patients undergoing implantation of a cardioverter/defibrillator, a pacemaker-like device. During the procedure, their hearts were shocked to a halt to test whether the device would kick in as intended. While their hearts were stopped, their brains were inactive; they were temporarily dead.

A computer then played a loop of 60 cartoons on a monitor taped to the wall well above the eye level of the medical team but theoretically visible to anyone near the ceiling and looking down—in other words, visible to anyone having a true (and not hallucinatory) OBE. Holden hypothesized that a temporarily dead individual whose consciousness actually separated from his or her body would see a cartoon, along with a time stamp on the monitor, and report it after the procedure. A few recalled a sense of profound peace or seeing a deceased loved one, but no one reported an OBE or full-blown NDE.

 Man lying on ground with spatula next to grill

Big Goals, Big Study

Parnia, meanwhile, is searching for proof through a large-scale study called AWARE, for AWAreness during REsuscitation. AWARE has the added goal of learning more about the physiology of the death process. “We want to identify a marker, some sort of gauge and tool that would enable doctors to substantiate reports of veridical perception in an objective way,” he explains.

The long-term study, launched in 2008 and still running, involves more than 25 major medical centers in Europe, Canada, and the United States. All are testing veridical perception by equipping emergency rooms and critical-care units with pictures strategically placed on special shelves just below the ceiling. Patients entering such theaters are at risk of dying—and being brought back. Those who survive undergo structured interviews devised by Parnia’s team.

Preliminary results, reported late last year, reveal just how hard it will be to get solid proof. Parnia culled data from 15 hospitals reporting a total of 2,060 cardiac arrests and an average survival rate of 16 percent. Just 142 of some 330 survivors could be interviewed; the rest died after discharge, did not respond to requests, or were deemed unsuitable for some reason. Of the 142, 38 percent said they remembered something of the time when their brain was ostensibly offline. They reported dreamlike states or memories that may have formed during the cardiac arrest itself. A scant 9 percent met the bar for an actual NDE.

But only two patients reported a veridical perception, the experience of leaving their bodies and observing events in the room during the time their brains were offline. And just one of those patients felt well enough to return to the hospital for a second interview by AWARE investigators. The man reported encountering an entity “with lovely curly hair” that he “perceived to be an angel.”

He also served up a detail researchers could confirm. To jolt him out of cardiac arrest caused by ventricular fibrillation (fluttering of the heart muscle fibers, leaving the organ unable to pump or beat rhythmically), the Southampton team had used a piece of equipment not usually found in hospitals: an automatic external defibrillator, normally meant for use by laypersons in nonmedical settings. A distinguishing feature of the machine was that it gave verbal feedback to users via a mechanical voice. “I can remember vividly an automated voice saying, ‘Shock the patient, shock the patient,’” the man told interviewers. But the cardiac arrest occurred in a room without the strategically placed shelf or image; blinded proof of veridical perception eludes AWARE still.

Parnia concedes that collecting data has been surprisingly difficult but still contends that consciousness continues when brain cells shut down. “The evidence thus far suggests that in the first few minutes after death, consciousness is not annihilated. Whether it fades away afterwards, we do not know, but right after death, consciousness is not lost.”

The Hallucinogenic Brain

Many scientists disagree. Absent empirical proof of alleged veridical perception, neuroscientists prefer to label the NDE a hallucination, nothing more. University of California at Los Angeles psychologist Ron Siegel has found that elements of the NDE—from the light to the life review—can be induced by non-life-threatening situations such as fever, fainting, injury, infection, stress, or even psychological upset severe enough to affect respiration and heartbeat or the autonomic nervous system, causing a brief reduction of oxygen delivery to the brain.

British psychologist Susan Blackmore has long been interested in NDEs, particularly in the similarity of reports worldwide. Asian Indians might describe encounters with a Hindu figure and Americans with someone Christ-like, but the life review, the light, the sense of peace hold steady. Her own ad hoc survey of eight individuals in India in 1993 confirmed her view. “One heard sweet music, three reported a tunnel or dark space, four saw bright light, four experienced joy or peace, and three claimed effects on their life or beliefs.”

The commonalities suggested to her that “either we all have a spirit or soul that survives death or we all have similar brains that die in similar ways.” Blackmore came down on the side of what she called “the dying brain hypothesis”: Death is an engine of hallucination, although that doesn’t diminish the profound, life-changing import of the event for many.

Many people “think they have glimpsed some kind of truth,” Blackmore says. “They tell the story to others, they try to remember it for themselves in images and words, but images and words cannot capture how it felt, the ‘real thing.’ If there is any ‘real thing,’ it is as ineffable as a moment of bliss.”

But how does bliss seize control of the brain? What happens in neural circuits that makes NDEs seem so real? Blackmore hypothesized that the NDE emerges as external senses collapse and the brain struggles to reconstruct an internally based model of the world.

The internal world of those in the process of death is being explored in scientific detail by Kevin Nelson, a neurologist at the University of Kentucky, where he is also director of medical affairs. He became entranced by NDEs as an intern, when a patient, a day laborer recently out of intensive care, showed him a sketch. The patient depicted himself on a respirator; in the background, the devil and an angel battled over his life. The devil was winning until a Christ-like figure in the foreground dispensed with the devil and the man knew he would survive. “He told me the story with great intensity, and he was absolutely convinced it was real,” Nelson recalls.

Over the years, the neurologist has heard similar, if less detailed, stories from patients on the threshold of death. In his readings, he ran across the case of Mrs. Martin, a woman said to suffer a cardiac arrest while in radiology—“one of the most horrifying places to have a life-threatening event because such units are ill prepared to deal with it,” Nelson says. The radiologist called the referring physician and said, “I killed Mrs. Martin, your patient.” But Mrs. Martin, who heard it all, knew she wasn’t dead. “I just couldn’t move,” she recalled.

Nelson, who believes that NDEs reveal much about the brain’s physiology, especially as it struggles to maintain awareness of the world, pondered how someone could be alert and retain memory, yet appear so dead. Perhaps the diagnosis of cardiac arrest and death had been wrong? “There had to be a paralytic process going on,” he felt. “And then boom, it hit me. There is a paralytic process each of us goes through every night, when we dream, called rapid eye movement, or REM, sleep.” As we dream, we’re largely paralyzed, so we don’t act out our dreams.

A huge body of neuroscience already testified to the existence of brain states that blend REM with waking consciousness in a variety of ways. One blended state of consciousness is the lucid dream, in which dreamers have enough awareness to control the action. During ordinary REM sleep and regular dreaming, the part of the brain commanding executive function—the dorsal prefrontal cortex—is turned off, removing conscious control. But if the dorsal prefrontal cortex switches back on, either spontaneously or stimulated by an outside event, consciousness invades REM sleep, enabling lucid control of dreams.

 Man lying on ground but shadow is standing

Sleep paralysis, in many ways the inverse of the lucid dream, is another blended state. The dorsal prefrontal cortex switches on and the person is alert while the paralyzing neurochemicals of dream sleep and REM continue to permeate the body, making movement impossible. Nelson was intrigued by blended states of consciousness, because nightmare images like ghosts and monsters that often appeared during sleep paralysis—attributed by neuroscientists to stimulation of the amygdala, the brain’s fear center—were somewhat evocative of the NDE.

Could the NDE be another blended state, involving some of the same brain structures and chemicals as sleep paralysis and lucid dreaming and, most important, involving REM? Of those who died and came back to report an NDE, how many were especially likely in ordinary circumstances to blend waking consciousness with REM? How many reported lucid dreams—and how many were paralyzed after waking, reporting visual hallucinations of aliens or ghosts?

After interviewing 55 people describing NDEs, Nelson found that 60 percent regularly reported blended states of consciousness through lucid dreams or sleep paralysis, compared to just 24 percent of controls who had never had an NDE. “Under circumstances of peril, an NDE is more likely in those with previous REM intrusion,” Nelson reported in one of science’s premier journals, Neurology, known for its rigorous peer review.

In a follow-up study, also published in Neurology, Nelson tackled the out-of-body experience. “People don’t realize how common the OBE is; it happens to one in 20 of us,” he observes. It occurs in 75 percent of those reporting an NDE. Brain scans suggest that both the OBE and the NDE occur with the shutdown of the temporal parietal region, the seat of embodiment. With the ability to sense the body turned off, people feel as if they are floating aloft. It is likely a response to threatened or disrupted blood flow to that part of the brain.

Researchers at the University of Michigan have also found evidence that NDEs may reflect hallucinations provoked by an oxygen-starved brain, rather than the postdeath survival of consciousness. They measured brain activity in mice 30 seconds after inducing clinical death by cardiac arrest. The scientists expected to find the dead brains chaotic and dysfunctional, if active at all. Instead, they measured greater activity than during normal, alert wakefulness—with brain waves so organized and coherent they seemed to indicate a truly functional mind.

Reporting in the Proceedings of the National Academy of Sciences, the Michigan team pointed out that the NDE has long been invoked as evidence that consciousness transcends death, based on a conviction that the brain can’t generate “highly vivid and lucid conscious experiences” during clinical death. But here they were, “presenting evidence of highly organized brain activity and neurophysiologic features consistent with conscious processing at near-death.” At least for a while, the technically dead brain is organized and, in some sense, capable of neural work—a possible explanation for “highly lucid and realer-than-real” NDE reports.

Nelson insists that you don’t need to be dead—or even in medical danger—to experience the elements of an NDE. “When blood flow slows, the retina can fall into darkness from the outside in, producing the sense of a tunnel. Light at the end of the tunnel might just be the light of the sun, or generated within the brain itself. The OBE catapults people through the tunnel, and REM—provoked by many types of crisis—makes them paralyzed and seemingly dead.”

Parnia, who argues that the dead brain is flatlined, disputes such an interpretation. Following death, “you shouldn’t have the ability to dream or hallucinate. So what else is going on?”

He is critical of many studies of NDEs, contending that they muddy the data by including patients with medical conditions that could affect mental states. What’s needed, he says, are new studies that focus on “the final common biological pathway of death, cardiac arrest, a well-described process.” He notes, “wherever there is imprecision in science, there is debate.”

Until the work is done, questions remain. “If the mind can continue to function when the brain does not,” Parnia says, it raises the possibility that the mind is “a separate undiscovered scientific entity that is not produced through the brain’s usual electrical or chemical processes.” Most neuroscientists reject the idea that consciousness exists outside the brain’s neural circuits, although the origins and nature of consciousness remains one of the biggest open questions in science today.

Reports from the frontiers of medicine have made disagreement over survival of consciousness and life after death fiercer than ever. At a recent debate held in New York City, Moody said he himself was convinced that “at death, personal consciousness is taken up into a more inclusive state of existence”—in other words, it survives the body and exists as a force or energy in the universe at large.

“We would like it to be true,” said Cal Tech physicist Sean Carroll, a cosmologist who sees no need for religious beliefs to explain the universe. “But our brains fool us all the time.”