10 May 2014

Near-death experiences: hooey

In case you missed it, neuroscientist Steve Novella (who pens the fabulous blog Neurologica) and physicist Sean Carroll recently took on Evan Alexander, a neurosurgeon and author of the hugely popular book Heaven is Real, and Ray Moody, a psychologist and longtime advocate of near-death experiences, in a debate about whether there really is an afterlife or not. The full debate is a lengthy one, but I just wanted to offer a quick comment based on Novella's arguments around the 55 minute mark.




Novella is talking about attempts to introduce scientific controls into near-death experience (NDE) experiments, since the preponderance of evidence for NDEs is from uncontrolled, anecdotal reports. The example he uses is that of cards facing the ceiling, so you could only see them if you were floating above your body.

But the very idea of people "looking down on their bodies", which seems to be a common element of NDEs, is pretty hard evidence against NDEs because it betrays the logical incoherency of the hypothesis. As any theologian will tell you, Heaven is not, presumably, located spatiotemporally "above" the Earth. There's no reason why dead souls shouldn't be suspended in a wall, or the basement, or any other arbitrary space; there's no reason why they should "float" at all. But in our culture, we generally conceptualize people going "up" to Heaven and "down" to hell, and that cultural conditioning reveals itself in how people construct false memories of NDEs. Consider that the overwhelming majority of depictions of Heaven in Western Monotheism show white fluffy clouds, skies, and sunshine. A Google image search for the term "Heaven" reveals this (click to embiggenate):


Even in the resurrection myth, Jesus is portrayed as 'ascending' to Heaven by floating up into the clouds. Given that Heaven is not actually in the sky, this is either a) a reflection of the popular unscientific cosmology of the day (much like when Satan takes Jesus to an unnamed high mountain where he can see "all the kingdoms of the Earth"), or b) God pulling off a parlor trick to impress stupefied peasants.

This description, then, of people floating above their bodies or upward toward Heaven is precisely what we should expect if NDEs are not real, but false memories laden with culturally imprinted biases.


It gets worse for NDEs, though. As my good friend Johno Pearce observed, the idea that people retain visual perception during an NDE is problematic as well. Specifically, why should visual perception be retained, but other physical phenomena lost?

The problem is not merely that advocates of NDEs are asking us to entertain a hypothesis that is poorly understood; the problem is that the very idea of retaining vision after death requires us to abandon everything we know about how vision is produced by the embodied mind. I recently discussed, for example, how color is not a phenomenon of the universe but a concept which arises from the interaction of the universe with our brains [read more]. A disembodied spirit, presumably, retains no ocular organs or physical brain (that's kinda the point, no?); yet, with its invisible presence somehow lingering in the physical world, how can it perceive wavelengths along the electromagnetic spectrum – a physical phenomenon? I'm reminded of one of my favorite quotes from Harvard physicist Lisa Randall, from her book Knocking on Heaven's Door:
A religious or spiritual belief that involves an invisible undetectable force that nonetheless influences human actions and behavior or that of the world itself produces a situation in which a believer has no choice but to have faith and abandon logic--or simply not care.
Sam Harris, in a debate with David Wolpe, Bradley Artson and the late Christopher Hitchens, nicely hit the nail on the head:
Science is not in principle committed to the idea that there’s no afterlife or that the mind is identical to the brain.
If it’s true that consciousness is being run like software on the brain and can – by virtue of ectoplasm or something else we don’t understand – be dissociated from the brain at death, that would be part of our growing scientific understanding of the world if we discover it.
But there are very good reasons to think it’s not true. We know this from 150 years of neurology where you damage areas of the brain, and faculties are lost… You can cease to recognize faces, you can cease to know the names of animals but you still know the names of tools...
What we’re being asked to consider is that you damage one part of the brain, and something about the mind and subjectivity is lost, you damage another and yet more is lost, [but] you damage the whole thing at death, we can rise off the brain with all our faculties intact, recognizing grandma and speaking English!

I must reiterate: the problem is not merely that the claim is mysterious. "There are lots of things we can't yet explain!", the NDE advocate will surely bark even while, as Evan Alexander does, rejecting the embodied mind because of phenomena that are yet unexplained. Rather, the problem is that entertaining the idea that a disembodied consciousness can perceive the physical world whilst floating about requires us to abandon scientific thinking entirely, setting aside all we know about visual cognition and physical law. That alone is sufficient reason to reject NDEs as pseudoscience mired in wishful thinking.

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