Does life really flash before your eyes?

It’s long been a staple of books and films – the conception that, when a person is dying, they see much of (or all of) their life flashing before their eyes. People who have faced near-death experiences have reported this as fact, and a number of psychologists attempted to analyse the phenomenon, but it’s incredibly hard to conduct any non-subjective research. Yet, through an accident in another study, scientists have been able to observe the brain as it shuts down for the first time. According to the research, published in Frontiers in Aging Neuroscience, there may be evidence to back up the idea that you do in fact see your life in review in your final moments.

   The brain scan emerged during the treatment of an 87-year-old man for epilepsy. He’d been admitted to a hospital emergency department after a fall resulted in a bleed in the brain, which subsequently deteriorated. Doctors carried out an electroencephalography (EEG), which records brain activity, during which the man had a sudden fatal heart attack. While he was dying, the EEG continued recording his brain activity, offering an image of the 15 minutes around his death.

   In an analysis of recordings of the 30 seconds before and after the man’s heart stopped beating, the team saw that he experienced changes in different types of brain waves, including alpha and gamma brain waves. This indicates that interactions between the different brain waves continue after blood stops flowing in the brain, but the findings also raise another possibility: “Given that cross-coupling between alpha and gamma activity is involved in cognitive processes and memory recall in healthy subjects, it is intriguing to speculate that such activity could support a last ‘recall of life’ that may take place in the near-death state.”

So the gamma oscillations recorded imply we experience the same neural activity as dreaming or recalling memories as we die

   During the death, gamma wave activity increased. These waves are associated with more sophisticated cognitive functions, and they’re particularly active when we concentrate, dream or meditate. They’re also indicative of retrieving memories and processing information, so the gamma oscillations recorded imply we experience the same neural activity as dreaming or recalling memories as we die.

   Dr Ajmal Zemmar, a neurosurgeon at the University of Louisville who led the study, said: “These findings challenge our understanding of when exactly life ends and generate important subsequent questions, such as those related to the timing of organ donation. As a neurosurgeon, I deal with loss at times. It is indescribably difficult to deliver the news of death to distraught family members. Something we may learn from this research is that, although our loved ones have their eyes closed and are ready to leave us to rest, their brains may be replaying some of the nicest moments they experienced in their lives.”

   The researchers were quick to caveat these findings – they’re based on one person, and a brain from an epileptic patient that was bleeding and swollen. They noted that the brain activity could also have been affected by anticonvulsant medication given to the man. There is no guarantee that these results are representative, and it’s not ethically impossible to intentionally gather a collection of similar data. However, Dr Zemmar noted “astonishing” similarities to a study conducted in 2013 on healthy rats, where US researchers reported high levels of brain waves at the point of death until 30 seconds after the rats’ hearts stopped beating.

   Other scientists have expressed scepticism about how far these conclusions may go. Sussex neuroscientist Professor Anil Seth, also comparing this work to the 2013 study, said: “This study, showing similar findings in a dying human, is both moving and fascinating, but whether the recorded activity underlies any particular kind of subjective experience – whether so-called ‘near death experiences’, or impressions of life flashing before one’s eyes – is impossible to say, and will likely remain so.” Dr Steve Taylor, a psychologist at Leeds Beckett University, agreed: “I don’t think we can assume this is a representative example of how the human brain behaves at the point of death.” He also noted that life review cases were also reported when people were not physiologically close to death.

   Despite the caveats, the team hopes that this study will lead to other studies on the final moments of life and the neuroscience of death. Dr Zemmar added: “I think there’s something mystical and spiritual about this whole near-death experience. And findings like this – it’s a moment that scientists lives for.”