Well this has been known effect of oxygen deprivation with in the brain. Similar effects have been observed in centrifuge training with pilots and astronauts. It also has been observed sometimes in conditions such as hypoxia. There is a decent documentary on netflix that details scientific causes of near death experiences. However, a few anomalies have occured that an explination has eluded science.
I would be a televangelist....but I have too much of a soul.