It took barely two minutes during a routine deviated septum surgery for Sarah Gamm, just a few weeks shy of 29, to die and come back. While she was gone, she reunited with her dead grandparents and other deceased loved ones before, as she puts it, “God yeeted me out of heaven.”

“Initially, I heard the nurse call out that I had stopped breathing and I prayed for the person to be okay, not realizing she was talking about me,” Gamm remembers of the 2012 experience. Contrary to the blinding lights reported in many similar events, hers unfolded in complete darkness, a total black void she later came to associate with Genesis 1:1–3: “The earth was without form and void; and darkness was upon the face of the deep. Then God said, ‘Let there be light.’” Gamm, who holds a BSc in astrophysics, says the imagery stayed with her long afterwards. “I got to experience the love that existed before there was light,” she says. “Pure unconditional love. It was the most magical, beautiful feeling one can imagine, and even more.”

At some point, she heard God’s voice telling her she had to go back, and her loved ones agreed. She argued she did not want to. She mentioned having free will and that she chose to stay, but God informed her she did not have a choice in the matter. “While joking about being upset they took God’s side, I woke up,” she said. Her reentry to the living world was courtesy of frantic cardiopulmonary resuscitation (CPR) efforts by doctors and nurses back on Earth and an epinephrine shot after a cardiac arrest. Medically, her near-death experience (NDE) lasted less than two minutes but, to her, felt almost eternal.

Gamm is one of millions of people worldwide who report strange and often deeply emotional episodes after cardiac arrest, trauma, or other brushes with death. These experiences frequently include sensations of leaving the body, encountering deceased relatives, entering peaceful or terrifying realms, or experiencing time in radically distorted ways.

Now, a March 2026 hypothesis paper published in Frontiers in Psychology proposes that near-death and end-of-life visions may be a kind of final internally generated “simulation,” built not from a shared external geography of heaven or hell, but from the dying brain’s own stores of memory, emotion, belief, and cultural imagery. In author and researcher Recai Kayış’s model, a brief storm of terminal brain activity combines with dream-like memory processing and a collapse in ordinary time perception. This potentially makes seconds feel vast and transforms a person’s deepest attachments, fears, and expectations into what may become the last world the mind ever enters.

“As the brain approaches death, oxygen and energy supply begin to collapse, and the normal balance of brain activity may become unstable. External sensory input weakens, while internal systems related to memory, emotion, imagery, and selfhood may briefly become highly active or disinhibited,” says Kayış, who studies this phenomenon at Istanbul Aydın University in Turkey. In that condition, he argues, the brain may begin constructing an experience almost entirely from within itself: a closed internal reality assembled from emotional residue, imagination, cultural expectations, and deeply encoded symbolic material. “Memory provides the content,” Kayış says. “Emotion gives that content force. Culture gives it symbolic shape.”

Meanwhile, the dying brain’s timing systems begin to fail. Internal memories and images become extremely dense. A few seconds of biological activity may feel like a long journey, a life review, or even a state without clear temporal boundaries, allowing the experience to feel subjectively vast.

That framework, Kayış writes in the paper, could help explain why NDEs vary so dramatically across cultures while still sharing certain broad emotional themes. In many Western accounts shaped by Christian imagery, experiencers often describe traveling through dark tunnels toward luminous beings, encountering pearly gates, heavenly cities, or panoramic life reviews resembling a final judgment. But Japanese experiencers rarely report tunnels at all; instead, they describe crossings of the Sanzu River, a boundary from Buddhist and Japanese folklore, and peaceful flower gardens. Thai Buddhist accounts more commonly mention encounters with Yamadutas, messengers of the god of death, alongside scenes of karmic judgment. Some Indian Hindu reports involve similar guides escorting souls before Chitragupta, the mythological cosmic accountant said to review the records of a person’s life.

Rather than random hallucinations, Kayış says, these visions may reflect the deepest emotional and symbolic architecture already embedded in the mind. In this interpretation, the “afterlife” is not necessarily a place the brain discovers, but a final inner world the brain constructs.

Science cannot currently verify what happens to consciousness beyond the final brain-based experience.

If the March 2026 hypothesis asks how the dying brain might generate an NDE, another recent study examined what happens when people attempt to explain their own NDEs. In a peer-reviewed 2026 CHI paper, researchers analyzed 200 TikTok videos in which users disclosed NDEs, along with nearly 2,000 comments beneath them. Spiritual and religious themes appeared in most “classical” NDE accounts, especially stories involving deceased relatives, divine beings, altered time perception, life reviews, or encounters with afterlife-like places.

But the study’s deeper insight was not whether these experiences are “real.” Instead, it revealed how rapidly NDEs become public narratives of identity, grief, faith, trauma, and meaning once they are shared online. Viewers responded with prayers, skepticism, neuroscientific explanations, personal stories of loss, and competing interpretations rooted in religion or biology. Even after the experience ends, the researchers suggest, the “afterlife” continues evolving socially through memory, culture, storytelling, and the audiences listening.

Mona Sobhani, PhD, a cognitive neuroscientist and author who studies consciousness and anomalous experiences, says the idea that memory and culture filter NDEs is not controversial in itself. “Whether it’s an NDE, psychedelic state, or any other altered state of consciousness, it is likely, if not certain, that the subjective experience of the person in that state is influenced by their memories and personal experiences,” she says.

But Sobhani is more cautious about reducing all NDEs to internally generated simulations. The most difficult cases for brain-based theories, she argues, are so-called “veridical” reports, instances in which people later describe specific details they seemingly had no normal way of knowing, such as events unfolding in operating rooms or waiting areas while they were unconscious. While such accounts remain controversial and difficult to verify, she says they continue to raise questions for strictly material explanations of consciousness.

Still, Kayış is careful not to overstate what his model can explain. The Dying-Moment Dream Hypothesis, as he calls it, does not claim to prove or disprove religious or spiritual beliefs; it remains a neurobiological framework. “We can study brain activity, cardiac arrest reports, NDEs, end-of-life visions, dreams, memory, emotion, and altered states of consciousness. But science cannot currently verify what happens to consciousness beyond the final brain-based experience,” he says.

Yet for Gamm, the experience did not feel like a simulation, or a dream, or a memory at all.

“It felt as real as me feeling the keys on the keyboard as I type on my phone,” she says. “I could smell my Grandma and was reminded of her soft Ivory soap scent and the Old Spice aftershave on my Grandpa’s face. I heard the slight inflection in a loved one’s tone when he talked that I had forgotten he had, forgot all about a nickname one of them had for me,” she continues in one breath. Even in the void, she recalls knowing exactly where each loved one was standing. When she awoke and saw the doctors and nurses panicked, she says she felt puzzled. “Didn’t they hear God say I would be okay?”

Fourteen years onward, the result of Gamm’s NDE is an uncharacteristic comfort, even affection, toward death. She is convinced, after all, an overwhelming sense of love waits “just through that thin veil,” in the pitch-black place she encountered, the one she is certain was there first, before light itself.