Neuroscientists offer their explanations for the visions that appear to a person before death.
About a third of all people who have ever died and survived say they have experienced hallucinations. These "death dreams" usually feature a dark tunnel with light at the end, meetings with relatives and deities, and "the experience of leaving one's own body." Most of these visions are positive and give people confidence that their existence will continue even after their earthly death. But visions of a different kind also happen: they bring a feeling of horror, helplessness and inevitable Last Judgment.
Human brain experts suggest a different division of these hallucinations: right-sided and left-sided. Activity in the left hemisphere of the brain provokes an altered sense of time and a sense of flight. The processes taking place in the right hemisphere are responsible for voices and music that arise in consciousness, images of people, communication with spirits and deities.
But the specific mechanisms that lead to the appearance of such hallucinations are still unknown to scientists. According to one version, such visions are the result of the release of endorphins, which are actively released into the blood in response to stress. Similar biochemical processes are observed, for example, with the introduction of ketamine, a substance that is used for anesthesia. In this case, patients also often experience hallucinations.
Another theory is hypoxic. A person sees strange things when his brain lacks oxygen. Airplane pilots experience similar feelings when accelerating strongly. Lack of oxygen leads to disruptions in the temporal lobes of the brain, which are responsible for processing visual and auditory information.
The most original of the theories is the dying brain theory. According to her, hallucinations are caused by substances that secrete dying brain cells, as well as by their chaotic neural impulses.