Imagine reliving your entire life in the space of seconds. Like a flash of lightning, you are outside of your body, watching memorable moments you lived through. This process, known as “life recall,” can be similar to what it is like to have a near-death experience.
What happens inside your brain during these experiences and after death are questions that have puzzled neuroscientists for centuries.
However, a new study from Dr. Ajmal Zemmar of the University of Louisville and colleagues throughout the world, “Enhanced Interplay of Neuronal Coherence and Coupling in the Dying Human Brain,” published in Frontiers in Aging Neuroscience, suggests that your brain may remain active and coordinated during and even after the transition to death, and be programmed to orchestrate the whole ordeal.
When an 87-year-old patient developed epilepsy, Dr. Raul Vicente of the University of Tartu, Estonia, and colleagues used continuous electroencephalography to detect the seizures and treat the patient. During these recordings, the patient had a heart attack and passed away.
This unexpected event allowed the scientists to record the activity of a dying human brain for the first time ever.
What did they find?
"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 Zemmar, a neurosurgeon at the University of Louisville, who organized the study.
“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.”
Brain oscillations are more commonly known as brain waves. They are patterns of rhythmic brain activity normally present in living human brains. The different types of oscillations, including gamma, are involved in high-cognitive functions, such as concentrating, dreaming, meditation, memory retrieval, information processing and conscious perception, just like those associated with memory flashbacks.
“Through generating brain 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,” Zemmar speculated.
The findings question what we believe we know about the moment of death.
“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,” Zemmar said.
“Every human alive has at some point an encounter when they lose a loved one and every one of us someday will go death themselves, so the interest obviously has been there. I've lost my grandfather. I've lost my grandmother with whom I was very, very close,” Zemmar said.
“And you ask yourself, what does the brain do? As a Ph.D. in neuroscience and a neurosurgeon, you think about these things.”
What do the findings tell us?
“You could probably categorize it in in three different categories to say what can we take from this,” Zemmar said. “One is scientific, one is metaphysical and philosophical and one is spiritual.
“Scientifically, it's very difficult to interpret the data because the brain had suffered bleeding, seizures, swelling – and then it's just one case. So we can't make very big assumptions and claims based on this case.
“On the metaphysical side, if you have these things, it is intriguing to speculate to say that these mechanisms – these brain activity patterns that occur when we have memory recall and dreaming and meditative states – they recall just before we go to die. So maybe they're letting us have a replay of life in the last seconds when we die.
“On the spiritual side, I think it is somewhat calming. I face this at times when you have patients that pass away and you talk their families; you have to be the bearer of bad news. Right now, we don't know anything about what happens to their loved one’s brain when they're dying. I think if we know that there is something happening in their brain, that they are remembering nice moments, we can tell these families and it builds a feeling of warmth that in that moment when they are falling, this can help a little bit to catch them.
“It opens an interesting question to me on when you define death. That plays a big role for questions such as, when do you go ahead with organ donation? When are we dead? When the heart stops beating because the brain keeps going. Should we record EEG activity in addition to EKG to declare death? This is a very, very interesting question for me. When is exactly the time when we die? We may have tapped the door open now to start a discussion about that exact time onset.”