In the last moments of a person’s life, does that person’s whole life story flashback through his mind, like a movie? This is one of the ideas that have a lot to do with death, but there isn’t a lot of scientific evidence to back it up. Now, a group of neuroscientists from around the world says they’ve found signs that this might actually happen.
Sometimes, science can move forward because of an accident. They were studying an 87-year-old Canadian man who had epilepsy in 2016. The team was doing an electroencephalogram (EEG) to figure out what was going on during the attacks. Unfortunately, the man died of a heart attack at that time. In the journal Frontiers in Aging Neuroscience, there is now a paper about what happened that people can read.
Unexpectedly, the patient’s death turned out to be the first time that a brain at the time of death was filmed. In the 30 seconds before and after the man’s heart stopped, his brain waves looked a lot like those seen in dreams, remembrances, and contemplation. This suggests that people can see the past “pass before their eyes” when they die.
Some people who have had near-death experiences have said that they keep remembering their memories when they die. Until now, there has been no proof that this flashback could be real. Because this is only one person’s case study, it isn’t possible to make any more assumptions about whether this is a common thing or how it felt.
Before and right after the patient died, the researchers took about 900 seconds of brain activity. This way, they could see how his brain waves changed as he died. There was an unusual change in the 30 seconds before and after his heart stopped: the so-called gamma waves came out of his body.
Brain waves are classified by how quickly they move. People see gamma waves in their brains when they access their memory center, which is called the hippocampus, in their dreams. They have a frequency of between 30 and 100 hertz. This is the highest of all the waves that people see.
The team also looked at other types of waves that happen during death, like delta, theta, alpha, and beta waves. This is known as “vital memory,” and it’s what the man’s brain was doing when it made gamma waves.
Experiments with rats have shown that rodents also have gamma oscillations around the time of death. So, the researchers think that most mammalian brains that die have memories of their lives, even though there isn’t a lot of evidence to back this up.
Much more to learn. The patient was old and had epilepsy, which can change the activity of gamma waves. When it comes to the man’s past memories, there is no way to tell if the man was actually seeing his old memories, or just in a dream-like state brought on by the deterioration of his brain.