Psychiatrist and neurobehavioral scientist Bruce Greyson, author of After (2021) — a science-based look at near-death experiences — offers short videos unpacking the topic via Big Think:

Are near-death experiences real? (7:15 min)

BRUCE GREYSON: When I first started looking into near-death experiences back in the late-1970s, I assumed that there would be some physiological explanation for that. What I found over the decades was that the various simple explanations we could think of like lack of oxygen, drugs given to the people and so forth, don’t pan out- the data do not support them. And furthermore, the phenomena of NDEs, of near-death experiences, seem to defy a simple, materialistic explanation. When we first started presenting this material in medical conferences, there would be a polite silence in the audience. And now in the 21st century, when we do this, it’s rare that doctors don’t stand up in the audience and say, ‘Let me share my experience with you.’ So it’s pretty well accepted now that these are common experiences that people have all the time, and that have profound effects. There’s still, of course, a lot of controversy about what causes them, but not about the fact that they exist, and are fairly common…

Near-death experiences are profound subjective experiences that many people have when they come close to death or sometimes when they are in fact pronounced dead. And they include such difficult to explain phenomena as a sense of leaving the physical body, reviewing one’s entire life, encountering some other entities that aren’t physically present. And at some point coming to a point of no return beyond which they can’t continue and still come back to life. When they return they often are profoundly changed by this experience. As I started my psychiatric training, I started being confronted by patients’ reports of things that I couldn’t explain. (Transcript, April 17, 2022)

Is there an afterlife? (3:46 min)

“Here’s what he saw while he was ‘dead’ What if death isn’t the end? NDEs may complicate what science teaches us about death and consciousness”:

BRUCE GREYSON: Most near-death experiencers around the world talk about an increased sense of spirituality after a near-death experience; by which they mean, roughly, a sense of connectedness to other people, to nature, to the Universe, to the Divine. One of the questions that people often ask about near-death experience is whether they provide proof that we survive death. They don’t provide proof for other people. They certainly provide proof for the experiencer, but not for the rest of us. But there are some experiences that do provide something that’s at least evidence, if not proof. And those are cases in which the experiencer encounters a deceased individual who was not known at the time to have died. … [He details a remarkable case here. Click “Transcript.”* ]

Does that mean we live forever? Not necessarily. It certainly means something about our minds can survive death of the body, at least for a time. Virtually every near-death experiencer that I’ve talked to has said without any doubt in their minds, that we do continue after death. No matter how they describe their NDE, they describe having existed without their physical bodies. When their physical bodies were essentially dead, and yet they were feeling better than ever. There’s got to be more to the world than just the physical realm to explain these events. (Transcript, May 8, 2022)

Scientist defends near-death experiences (3:53 min)

Are near-death experiences just dreams or hallucinations?

BRUCE GREYSON: It’s natural for people to think that near-death experiences are kind of like dreams or hallucinations. No two people have the same type of hallucination. Whereas near-death experiences are basically the same across people, across cultures, across centuries. I think if you look at what things typically cause hallucinations- metabolic changes, drugs, changes in oxygen level, brain injury, those things produce certain known effects: confusion, agitation, belligerence. They’re very different from the typical calm, peaceful, consistent content of a near-death experience. We’ve looked at specific things that may cause a hallucination. It was thought that maybe lack of oxygen to the brain would have a role in near-death experiences, since no matter how you come close to death, lack of oxygen to the brain is one of the final, common pathways. But those who report near-death experiences actually have better oxygen flow to the brain than people who don’t report NDEs.

Likewise, we thought drugs given to people as they approach death may be causing these experiences. And what we find again is that the more drugs people are given as they approach death, the less likely they are to report a near-death experience. So drugs and lack of oxygen are not causing NDEs. They may in fact, repress having an NDE. (Transcript, May 29, 2022)

*Note: In his book, After (2021), Greyson identifies other, similar cases. He also noted: “None of the NDEs in our collection involved an experiencer mistakenly thinking a person still alive had died. NDEs in which the experiencer meets— and is surprised to see— a loved one they hadn’t known had died are not common, but they do occur. ” (p. 136, Kindle)

You may also wish to read:

Agnostic psychiatrist says near-death experiences are real. They change lives but he is unsure what they mean. Bruce Greyson’s book, After, looks at the evidence and finds that there is no reason to dismiss the idea that the human spirit survives the body. (Denyse O’Leary)