Thursday, March 26, 2015

Dr. Eben Alexander's Near-Death Experience

"I Had a Dream"

Dr. Eben Alexander had a dream that was real to him. Hallucinations can be "real" to those who have them. A brain deprived of oxygen functions differently. His claim that his brain was completely shut down has been disproved.

However, even if you accept his description of his medical condition, how do we properly assess his primary conclusion?: "Death is not the end of consciousness." This is what the religious call the "soul."

Dr. Eben is arguing that his near-death experience provides evidence that a soul exists. Others have made this argument, which in a more-developed form goes like this:

Sometimes, when people are near death, they have weird experiences: experiences that seem like their consciousness is leaving their body. These experiences are rare -- even those who believe in the soul acknowledge that near-death experiences only happen to a small proportion of people near death -- but they happen.

And there are some reports that people having these experiences see things they could not have known were there. These experiences can only be explained -- so the argument goes -- by a soul, separate from the brain, that departs from the brain when it is near death, and returns to it when death is staved off. And, this soul, separate from the brain, survives actual physical death.

Thus, the issue boils down to the concept of consciousness. Either consciousness is a physical, biological product of the brain -- or it has a component other than brain function: a soul that is separate from the brain, and that survives when the brain dies.

The evidence supporting the "biological product of the brain" explanation of consciousness comes from rigorously-gathered, carefully-tested, thoroughly cross-checked, double-blinded, placebo-controlled, replicated, peer-reviewed research. An enormous mountain of research. A mountain of research that is growing more mountainous every day.

This is the increasingly clear conclusion of the science: consciousness is a product of the brain. Period.

Now, compare this to the other argument, the "independent soul" explanation of consciousness. This includes near-death experiences like Dr. Eben's, and the supposedly inexplicable things that happen to some people during them.

The evidence supporting the "independent soul" explanation is flimsy at best. It is unsubstantiated. It comes largely from personal anecdotes. It is internally inconsistent. It is shot through with discrepancies. It is loaded with biases and cognitive errors -- especially confirmation bias, the tendency to exaggerate evidence that confirms what we already believe, and to ignore evidence that contradicts it. It has methodological errors that a sixth-grade science project winner could spot in ten seconds. And that includes the evidence of near-death experiences.

Every time a claim about a soul leaving the body when near death has been tested, using good, rigorous methods, it has utterly fallen apart. Every single rigorously done study examining claims about near death experiences has completely failed to show any perceptions or predictions that could not have been entirely natural.

And I have yet to see a good explanation for a believer in near-death experiences of why they do not happen to everyone: why they only happen to a small percentage of people who are near death. Are they saying that only about ten percent of people have souls? Really? Is that an argument you want to make?

What is more, believers in the immortal soul, and in near-death experiences as evidence of this soul, consistently fall back on bad arguments and poor logic to defend it:

"You can't prove with 100 percent certainty that it isn't true; therefore, it could hypothetically be true; therefore, it's reasonable to think it's true."

"Neither side can prove their case with absolute certainty; therefore, both sides are equally likely; therefore, it's reasonable for me to believe whatever I want to."

"Science has been wrong before; therefore, it could be wrong this time; therefore, I don't have to provide any good evidence for why it's wrong this time."

"Scientists are human, subject to as much human bias as anyone else; therefore, I don't have to show exactly how their bias is affecting their conclusions in order to reject them."

"Lots of smart people believe it; even some neurosurgeons (well, at least one) and scientists believe it; therefore, it's reasonable to think it's true."

It seems clear that, for most believers in an immortal soul, this belief is unfalsifiable -- you just cannot prove that it is false. It should not be; in theory, this is an evidence-based conclusion that should be open to changing upon seeing better evidence.

But in practice, it clearly is. In practice, for most believers, there is no possible evidence that could convince them that they are wrong. They will reject the best available evidence, and clutch at the worst, since the latter confirms their belief and the former contradicts it. (Which is understandable -- death sucks, and we would all (well most of us) like to live forever and see our dead loved ones again -- but it does not make their arguments very convincing.)

Given that the evidence supporting the "biological process of the brain" explanation is rigorously gathered, carefully tested, thoroughly cross-checked, internally consistent, consistent with everything we know about how the brain and the mind work, able to produce mind-bogglingly accurate predictions, not slanted toward wishful thinking, and is expanding our understanding of the mind every day.

Given that the evidence supporting the "immortal soul separate from the brain" explanation is flimsy, anecdotal, internally inconsistent, blasted into non-existence upon careful examination, totally at odds with everything we know about how the brain and the mind work, and strongly biased toward what people most desperately want to believe.

Which of these explanations of consciousness seems more likely?

And which explanation of near-death experiences seems more likely?

Yes, weird things sometimes happen to some people's minds when they are near death. Weird things often happen to people's minds during altered states of consciousness. Exhaustion, stress, distraction, trance-like repetition, optical illusion, sleep deprivation, sensory deprivation, sensory overload ... any of these physical changes to the brain, and more, can create vivid "perceptions" that are entirely disconnected from reality. It has been extensively demonstrated.

And being near death is an altered state of consciousness, a physical change to the brain. Near death experiences are not death. What happens to consciousness when the brain is briefly deprived of oxygen tells us nothing about what happens to consciousness when the brain is decayed in the grave into dust and nothingness.

So which explanation of this weirdness is more plausible? The physical one -- the one that says, "Yeah, the brain does weird things sometimes when deprived of oxygen or otherwise altered, and these experiences are completely consistent with what we know about the brain"? The one that's backed up by a mountain of rigorous, replicated research?

Or the supernatural one -- the one that is backed up by anecdotes, cognitive biases, bad logic, and wishful thinking?

Reality wins. Reality is more important than anything we could make up about it. (And it is a whole lot more interesting.) If we want to be intimately connected with the universe, we need to accept what the universe is telling us, through evidence, is true about itself. We need to not treat the world we make up in our heads as more important than the world outside our heads. If we want to be intimately connected with the universe, we need to accept the reality about it.

Even when that reality contradicts our most cherished beliefs.

Even when that reality is frightening, or painful, or sad.

And that includes the reality of death.

When we let go of religious or spiritual beliefs, it can be painful to accept the reality and permanence of death. But we can take comfort in the knowledge that, whatever secular philosophies of death we have, they are not based on sloppy evidence and wishful thinking and an intense effort to avoid cognitive dissonance. We can take comfort in the knowledge that our philosophies of death are built on a solid foundation of good evidence, reason, plausibility, and the acceptance of reality.

And that is more comforting than any spiritual belief I have ever held.

-- Greta Christina

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