According to a study conducted by Dr. Jimo Borjigin, our brain still remains conscious for some seconds after we die. In an experiment that one could consider extremely horrible and basically criminal, she connected electrodes directly to the brains of nine lab rats. Once these were working properly she would induce them into cardiac arrest to see the brain activity prior, during, and after. According to her, the brain activity shown in the studies were higher than expected after the rodents were actually declared dead. She claims that this would explain all these near-death experiences happening in a “brief state of heightened consciousness.” Now, of course, this hasn’t been attempted on humans (thankfully) so there’s no way to know if we actually work in the same way neurologically speaking.
This experiment has brought the attention of many scientists, some who agree with her and some who believe that this doesn’t prove anything at all. That’s the case of Sam Parnia, a cardiologist at Stony Brook University Hospital, who listed several points shattering Borjigin’s theory. To start with, he claims that when we die, our blood flow decreases meaning that the brain doesn’t really get the oxygen and blood needed to function in a conscious way. At the same time, there’s a massive influx of calcium inside the brain cells (which actually leads to brain death). This process can be seen and read in electroencephalographic analysis which could explain the brain activity Borjigin saw (not to mention that according to Parnia she connected the electrodes almost directly to the brain which also shows higher patterns). For Parnia this is way more logical and would explain why all nine rats had similar brain patterns when only about a 20 percent of people who survive cardiac arrest or other near-death experiences, claim to have seen any of the phenomena associated to this state of consciousness.
But what happens with these experiences and how could these be related to the brain activity after we die? If we follow Shaw’s study of these thirty-second lapses of brain life after the body dies, these out-of-body experiences could be explained with the fact that our brain creates images around our lives that are quite similar to reality (something like what we experience when dreaming about places we’ve never been to but that are quite realistic). In that way, it’s not that hard to suppose that when we’re dead we might actually see ourselves in that situation as spectators. As for the light at the end of the tunnel, it has a more ground-based explanation. According to a study made by the Hadassah University of Jerusalem, when we have a considerable loss of blood in the brain, thus oxygen, it’s common to experience tunnel vision that’s followed, almost immediately, by a sudden blackness. That light people claim to see are those last images before the brain blacks out. But, if you ask me, all these would seem that if people remember experiencing these is because their brain is still conscious.