Some people who have had severe heart attacks, and most movie buffs, know the implications of the light many survivors of near-death experiences have seen. In spite of the belief by many that they have glimpsed the afterlife, it turns out that there is a scientific explanation for the phenomena. When blood flow stops, the brain keeps working for as long as 30 seconds.
The implications of this finding are explained in the study that is published in the Proceedings of the National Academy of Sciences. The study, from University of Michigan scientists, examined lab rats on which they induced cardiac arrest. The brain activity was observed to continue after the heart was stopped, indicating high arousal in the mental states. When the rats were near death, there were familiar electrical signatures of consciousness that were at higher levels than are found during the waking state. Researchers determined that this indicates there is well-organized electrical activity during the early stages when clinical death occurs.
The significance of this finding, in relation to the white light experiences is that there is a reduction of either oxygen or the combination of oxygen and glucose when cardiac arrest occurs. As a result, the brain activity is stimulated, which is characteristic to conscious processing. This period of high brain activity is at the same time during which people have near-death experiences, including visions which include the bright light. Although the researchers at University of Michigan feel confident that these results provide a conclusive explanation for the familiar near-death experience, others feel that the results obtained on rats should not be assumed accurate in humans.