Bright lights, warmth, detachment from the body, life flashbacks, encounters with spirits; these are all things that thousands, perhaps even millions of people have reported when they have approached death. These so-called near-death-experiences (NDEs) are widely recognized phenomena, but they have been met with considerable skepticism among the medical and scientific community and many consider them to be merely hallucinatory or illusory in nature.
Despite the considerable number of anecdotal reports on NDEs, which seem to be increasing in frequency because of developments in cardiac resuscitation techniques, very few objective studies into these experiences exist. But now, researchers from the University of Southampton have just completed a four-year international study on over 2,000 cardiac arrest patients, and it’s given us a fascinating insight into this eerie topic.
As described in Resuscitation, the AWARE (awareness during resuscitation) study set out to examine the broad range of awareness and mental experiences associated with cardiac arrest. They tested the validity of the reported experiences using objective markers to determine whether the claims corresponded to actual events or hallucinations.
Of the 2,060 patients enrolled in the study, 330 survived and 140 were able to complete structured interviews about their memories of the event. They found that 39% of these individuals described some awareness of the time preceding resuscitation, i.e. when their hearts had stopped beating. The majority of these patients, however, did not have specific memories of the event, suggesting that many people do indeed have mental activity during cardiac arrest, but lose their memories after recovery. According to lead author Dr. Parnia, this could be due to brain injury or sedative drugs.
For example, ketamine—a dissociative anesthetic used for sedation and general anesthesia—has been known to make users feel a strong sense of detachment from their bodies and a sense of peace or joy. The induced state is often described as similar to that of near-death experiences.
A previous study that examined the brain activity of seven critically ill patients removed from life support found a spike of neural activity at or near the time of death. The lead author of the study reported that seizures in the memory regions of the patient's brain could be responsible for NDEs.
Although the patients in the current study could not recall specific details, many had memories with specific themes. According to the National Post, 20% said they felt peaceful and almost one third felt that time had either slowed down or sped up. Some had tranquil experiences and saw bright lights and animals, whereas others felt fear and even recounted the feeling of being dragged through deep water.
Interestingly, 13% of these individuals felt separated from their bodies, and one man recalled leaving his body entirely and watching his resuscitation from the corner of the room. It took three minutes to start this man’s heart again, but he could describe specific details of both the staff and the procedure. He also recalled two beeps from a machine that only makes noise every three minutes.
“We know the brain can’t function when the heart has stopped beating,” Dr. Parnia told National Post. “But in this case conscious awareness appears to have continued for up to three minutes into the period when the heart wasn’t beating, even though the brain typically shuts down within 20-30 seconds after the heart has stopped.”
Although only 2% of patients could explicitly recall ‘seeing’ or ‘hearing’ actual events, because the details were consistent with verified events, it is impossible to discredit them at this stage and more work is needed.
[Via University of Southampton, Resuscitation, and National Post]