A team of researchers has now identified a mysterious surge of activity in the brain of two people who were on the verge of dying and as they transitioned into death.
Researchers have long been trying to understand the science of the brain and what happens in the final fleeting moments before it completely shuts down and a person dies. Scientists from the US-based University of Michigan analysed the EEG and ECG signals in four dying patients before and after the withdrawal of ventilatory support.
Researchers found global hypoxia marked by stimulated gamma activities in two of the patients. "Brain function around the time of cardiac arrest is poorly understood. While the loss of overt consciousness is invariably associated with cardiac arrest, it is unclear whether patients can possess covert consciousness during the dying process," scientists said in the paper.
"Internal perception of bright light or familiar faces reported by survivors of clinical death suggests a preserved capacity in the dying brain to process internally generated vision. It remains to be determined if the posterior cortical regions are activated in the dying human brain," the paper read.
The gamma wave was initially located in a part of the brain known as hot zone, which has in the past been associated with people dreaming, and seizure patients who report having visual hallucinations. The hot zone in the brain is a region postulated to be critical for conscious processing. However, the patients did not survive to describe what they saw due to the elevated gamma wave.