Here’s what you’ll learn when you read this story…

• A researcher analyzed papers from more than 20 peer-reviewed journals and found that signs of consciousness persist long after patients are technically declared dead.
• The findings suggest that death may unfold across a series of stages, rather than an instantaneous event.
• This could have major ethical implications for things such as organ donation.

Death—and what happens when it happens—is one of nature’s greatest mysteries. Clinical death is currently understood as an immediate, irreversible event that occurs once circulation stops and brain activity is no longer detectable.

However, new research suggests that death might not be as black and white as we once believed. In fact, our consciousness may persist long after the time someone is technically declared dead, wildly blurring the lines between living and dying—which could have some major implications for things like organ donation and the possibility of reversing death.

“We once thought death was an instantaneous event where if circulation and oxygen stops there is no brain function. The brain cells die and this is the end of life,” says Anna Fowler, student researcher at Arizona State University. But according to a talk she gave at the American Association for the Advancement of Science Annual Meeting about her research, there’s a lot more to the story.

Fowler was inspired to explore just what happens when we die or have a near-death experience after attending an event where a speaker shared their experience with A-fib—an irregular heartbeat that can lead to stroke, heart failure, and other heart complications. Her own mother’s experience with A-fib also inspired her work.

In her research—which is currently unpublished, but was overseen by ASU faculty members Marjon Forouzeshyekta, PhD, and Abigail Gómez-Morales, PhD—Fowler analyzed papers from more than 20 peer-reviewed journals, focusing on health events and near-death experiences in cardiac arrest patients, from studies on resuscitation and hypothermia to work on consciousness theories and brain function in coma patients.

Fowler’s findings indicate that consciousness during near-death experiences was similar to what the dying brain would experience. When a medical clinician indicates cardiac arrest has occurred—or that a patient has no pulse, no heartbeat, no breathing, and a lack of oxygen to the brain—EEG recordings, a measure of electrical activity in the brain, were similar to that of individuals in a coma. That suggests some level of consciousness persisted.

Fowler’s analysis revealed that survivors generally reported the near-death narrative we’re familiar with, including a replay of their lives, finding meaning, or feelings of love, after a cardiac arrest event. These experiences suggest organized surges of electrical activity occur in the brain, even during cardiac arrest.

This also suggests that death is not immediate, but a process. For example, in cardiac arrest, if circulation is not restored, the brain begins to shut down. First, activity that can be seen on an EEG will cease; then an ECoG (a more invasive type of EEG) reveals spreading depolarization, which can indicate brain death after a cardiac arrest; and finally death occurs, explains Fowler.

Aside from the physical signs of death, there’s also consciousness to consider. According to some theories, consciousness arises from these electrical surges, meaning your brain may still be firing when your heart stops beating. “Knowing that electrons can fire after circulation in the body stops is a huge thing that should be researched more,” Fowler says.

Previous research further supports the idea that consciousness persists after death as well. For instance, a 2023 study published in Resuscitation found that consciousness and awareness may occur during cardiac events. Patients recalled memories or dream-like experiences during cardiac arrest or resuscitation that suggest consciousness and cognitive activity occur during near-death experiences.

Some survivors were able to recall what was happening around them even at the time their heart stopped beating. About 40 percent of cardiac arrest survivors whose brains had flatlined reported awareness during the event, 20 percent recalled an experience with death, and 11 percent recalled dreamlike experiences, with consciousness emerging as long as 35 to 60 minutes into CPR.

“In both human and animal studies, we now know brain activity can continue for quite some time,” Fowler says. Studies have shown that, while brain activity might be low, it can still be seen up to 102.5 minutes before terminal death in coma patients, for example. This could have implications on organ donation, she says, causing us to reconsider timing: Can organs be removed while someone is still conscious—and what are the ethical implications of that? As we learn more, our understanding of exactly when we declare death, and when we begin harvesting organs for donation, may get complicated.

This also raises the question about whether signs of consciousness should be considered when declaring clinical death. Right now, the premise of death is tied to irreversibility, or the point where vital organ functions can no longer be restored, which Fowler says is not clearly defined.

“The term ‘irreversibility’ was always a factor regarding death declaration,” Fowler says. “With newer technologies and methods in resuscitation there is a gray line with what irreversibility truly means.”

Animal studies also further support this, suggesting our cells don’t die immediately, and that intervention may be possible to restore some function. One study suggests organs can be revived hours after death, and additional animal research found that some brain cells can be regenerated hours after death—though the electrical activity never matched pre-death levels.

According to Fowler, what we consider to be a conscious state, like wakefulness or certain levels of functioning, we can see and observe; however, these things visibly disappear after clinical death. What can’t be seen, but still may be happening, is a firing of neurons in the brain happening once the waking state has diminished. “The fact that neurons can still fire after circulation has stopped is amazing,” Fowler says, adding that there is currently no single study that defines this phenomenon.

These findings suggest that dying may unfold across stages rather than occur as a single instantaneous event, meaning how we define death may need to change. For now, we at least know that death isn’t as simple as “on” and “off,” raising even more questions as scientists continue to unravel one of nature’s greatest mysteries.