When an 87-year-old hospital patient with severe health problems developed epilepsy, the doctors used continuous electroencephalography (EEG) to detect the seizures and provide prompt treatment. During the recording, the patient had an unexpected heart attack and died, allowing scientists to record the activity of a dying human brain for the first time in history.
The findings, recently published in the journal Frontiers in Aging Neuroscience, suggest that the brain may remain active and coordinated during and after the transition to death, and could even have a fundamental role in orchestrating the whole ordeal.
“We measured 900 seconds of brain activity around the time of death and set a specific focus to investigate what happened in the 30 seconds before and after the heart stopped beating,” said study senior author Dr. Ajmal Zemmar, a neurosurgeon at the University of Louisville. “Just before and after the heart stopped working, we saw changes in a specific band of neural oscillations, so-called gamma oscillations, but also in others such as delta, theta, alpha, and beta oscillations.”
These brain oscillations, or brain waves, are patterns of rhythmic brain activity normally present in living human beings, and are involved in high-cognitive functions including concentrating, conscious perception, information processing, dreaming, meditation, and memory retrieval.
“Through generating oscillations involved in memory retrieval, the brain may be playing a last recall of important life events just before we die, similar to the ones reported in near-death experiences,” Dr. Zemmar speculated. “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.”
Although this study is the first to measure brain activity during the process of dying in humans, similar changes in gamma oscillations have previously been found in rats kept in controlled environments. This could suggest that, during death, the brain organizes and executes a biological response which may be conserved across species.
Since the current study has investigated the brain patterns of a single dying patient who had previously suffered injuries, seizures, and swelling, scientists should be cautious in generalizing these findings. Further observations of more case studies are necessary before drawing any clear, scientific conclusions regarding what happens when we die.