Questions of ‘what is life?’ and ‘what is death?’ are typically the topics of biologists and philosophers; religious leaders and humanists. These are not questions that are easy to answer, and they may never be unanswerable.
However, evidence that something is switched on and switched off between passing from a human being classed as ‘alive’ and ‘dead’ has been detected by scientists. This is in the form of evidence of conscious-like activity in the dying brain. This is based on a small study that has identified brain wave patterns in comatose patients who died following cardiac arrest.
The study comes from Michigan Medicine at the University of Michigan, and it lays the foundations, albeit in the form of early evidence, that there is a surge of activity that correlates with consciousness in the dying brain.
Reports of near-death experiences have captured our imagination of writers and the many of the population at large. These accounts share some similarities (such as seeing a white light). This begs the question as to whether there actually is something ‘fundamentally real’ underpinning them.
Have those who have managed to survive death received a glimpse of a consciousness that does not completely disappear, even after the heart stops beating? Scientists refer to this as a “a neuroscientific paradox”.
The researchers began looking at animals and then moved onto humans. They have discovered similar signatures of gamma activation in the dying brains of both animals and humans upon a loss of oxygen following cardiac arrest. This may suggest underlying neurophysiologic mechanisms.
The researchers looked at data relating to four patients who passed away due to cardiac arrest in the hospital while under electroencephalographic (EEG) monitoring. All four of the patients were comatose and unresponsive. They were ultimately determined to be beyond medical help, and, with their families’ permission, each was removed from life support.
Upon removal of ventilator support, two of the patients showed a surge of gamma wave activity. Gamma waves are considered the fastest brain activity, and these are associated with consciousness. The other two patients did not display the increase in brain activity.
The gamma wave activity was detected within the area of the brain thought to be associated with consciousness in, at the junction between the temporal, parietal and occipital lobes, located in the back of the brain. This area is where with dreaming, visual hallucinations in epilepsy, and altered states of consciousness have been identified through other brain studies.
The sample size is very small and therefore the researchers are expressing caution and wish over-interpretation of their findings to be avoided. Furthermore, it is impossible to know what the patients experienced because they did not survive.
However, the findings do provide the basis for a new framework for further understanding of covert consciousness in the dying humans, through further research.
The research appears in the journal Proceedings of the National Academy of Sciences, titled “Surge of neurophysiological coupling and connectivity of gamma oscillations in the dying human brain.”
