As per a recent study published by Science, mapping the brain activity of four people as they died showed a burst of activity in their brains after their hearts stopped. The discovery “suggests we are identifying a marker of lucid consciousness,” according to Sam Parnia, a pulmonologist at New York University Langone Medical Center who was not involved in the study.
Even though the moment the heart stops beating has usually been defined as the moment of death, current research has found that brain activity can continue for seconds to hours after the heart stops beating in many animals and humans. According to Parnia, Westerners’ “binary concept of life and death is ancient and outdated.”
Researchers looked at the medical records of four people in comas and on life support on whom physicians had placed electroencephalography caps. The caps constantly monitored the electrical impulses over the brain’s surface before, during, and after the withdrawal of ventilators, the final measured heartbeat, and until all brain activity had stopped. All of the patients were in a bleak scenario.
Two patients’ brains experienced a burst of neuronal activity in the form of high-frequency patterns known as gamma waves seconds after their ventilators were removed; this activity remained even after the patients’ hearts stopped pumping. When a healthy person is actively engaged in memory recall, learning, or dreaming, a similar pattern has been identified in other research; some neuroscientists have even linked these oscillations to the fundamental nature of consciousness itself.
According to Ajmal Zemmar, a neurosurgeon at the University of Louisville, gamma waves may indicate that different brain parts are working together to bring previously unrelated sensations together, such as combining the sight, smell, and sound of a car into a single conscious consciousness. Observing the same gamma waves in dying people provides a biological explanation for stories about the brain reliving remembered memories in those final minutes, even though how the brain does this “is one of the biggest mysteries in neuroscience,” as he puts it.
The temporal-parietal-occipital junction, a region of the brain associated with consciousness and active during lucid dreaming, epileptic convulsions, and extrasensory perception, also revealed increased electrical activity. When the brain’s oxygen supply is cut off, it goes into survival mode, causing a rush of activity. Despite suppressing outward manifestations of consciousness, research on animals suffering from brain death has revealed that the organ begins to release a slew of signaling molecules and generates unusual brainwave patterns to renew itself.
By collaborating with other hospitals, the researchers hope to corroborate their findings about terminally sick patients’ brain activity. Understanding the dying process and how the brain functions during it could lead to a better understanding of death, which Zemmar says is “sort of a mystery—we don’t know what it is.” The study is considered a significant contribution to consciousness studies and could potentially shed light on the nature of consciousness and the mind-body problem.