People can recall death experiences for up to an hour after their hearts have stopped beating, according to new research from the NYU Grossman School of Medicine.
Some patients revived by cardiopulmonary resuscitation (CPR) had clear memories of experiencing death. While unconscious, these individuals had brain patterns linked to thought and memory, the researchers found.
The study, known as the AWAreness during REsuscitation (AWARE)-II, was focused on 567 cardiac arrest patients in hospitals between May 2017 and March 2020.
The standardized conditions, which included CPR and resuscitation methods, were carefully monitored to ensure accuracy. Only 10% of the patients recovered sufficiently for discharge after receiving in-hospital CPR.
The experts also analyzed insights from 126 community survivors of cardiac arrest with self-reported memories. The goal was to better understand the themes linked to the vivid experience of death.
Remarkably, 40% of survivors recalled some degree of consciousness during CPR, an experience that previously went unnoticed by conventional measures.
Among a subset of patients who underwent brain monitoring during CPR, nearly 40% displayed brain activity that revived to almost normal states from a “flatline” status, sometimes as long as an hour into CPR.
Using EEG technology, experts observed notable spikes in gamma, delta, theta, alpha, and beta waves associated with higher mental functions.
Survivor accounts of heightened awareness, powerful experiences, and a perception of separation from the body have long been reported.
These experiences include observing events without pain or distress and a profound evaluation of their actions and relationships.
Crucially, the study distinguished these death experiences from dreams, hallucinations, and other similar states.
According to the researchers, death experiences might be linked to the disinhibition process, where the dying brain removes natural inhibitory systems.
The researchers suggest that this type of disengagement might allow access to “new dimensions of reality,” potentially including clear recollection of all memories from early childhood to death, as seen from a moral perspective.
Study senior author Dr. Sam Parnia is an associate professor in the Department of Medicine at NYU Langone Health and director of critical care and resuscitation research at NYU Langone.
“Although doctors have long thought that the brain suffers permanent damage about 10 minutes after the heart stops supplying it with oxygen, our work found that the brain can show signs of electrical recovery long into ongoing CPR,” said Dr. Parnia.
“This is the first large study to show that these recollections and brain wave changes may be signs of universal, shared elements of so-called near-death experiences.”
“These experiences provide a glimpse into a real, yet little understood dimension of human consciousness that becomes uncovered with death. The findings may also guide the design of new ways to restart the heart or prevent brain injuries and hold implications for transplantation.”
The researchers emphasize that the findings neither validate nor negate the experiences’ reality or meaning associated with death and call for further research on the subject.
They say the recalled experience surrounding death merits further empirical investigation and plan to conduct studies that more precisely define biomarkers of clinical consciousness and that monitor the long-term psychological effects of resuscitation after cardiac arrest.
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