We have often heard stories about the famous ‘white light’. It’s described as a flash at the end of a tunnel, a gateway to the afterlife, a tape that shows in an instant all the stages of life, a loved one, now deceased, reaching out to us.
All these feelings, which can take place in a dying brain, are known as near-death experiences and people have long wondered what is behind it.
A recent study, conducted by a group of researchers at the University of Michigan and published in the journal Proceedings of the National Academy of Science, seems to have found a possible explanation for these experiences.
During the investigations, carried out by Dr. Jimo Borjigin and her team, very similar gamma activation signals have been recorded in the dying brains of humans and animals following a loss of oxygen after cardiac arrest.
What happens in the brain after death?
The group of researchers has analyzed the brain activity of four patients who died of cardiac arrest. All four, in coma, were monitored by electroencephalogram before and after death.
After death, two of them showed an increase in cardiac activity and gamma waves, the oscillations with higher frequency and lower amplitude that are related to consciousness, attentional focus and memory management.
Moreover, such brain activity has been recorded in the zone of the neural correlates of consciousness, which is related to dreams, hallucinations and altered states.
However, the other two patients did not show similar signs when they were taken off life support, something that leads the research team to more cautious conclusions.
“We are unable to make correlations of the observed neural signatures of consciousness with a corresponding experience in the same patients in this study,” the study concluded.
“However, the observed findings are definitely exciting and provide a new framework for our understanding of covert consciousness in the dying humans.”
