Mystical Experiences @ Death!

That was the title of the lecture I attended last night, by our distinguished visiting professor, Allen Kellehear of the University of Bradford. It was … frustrating. Kellehear does have an excellent background in caring for the dying, and I would have enjoyed (if that’s the word) a discussion of the material and emotional needs of the dying, or hospice policy, or something along those lines, but instead it was an hour of Near Death Experiences (NDEs). I also agreed with his conclusion, that these phenomena are a complex outcome of cultural expectations, and that we actually don’t know much about the biology. It’s just that the journey there was a catalog of unlikely interpretations of mundane events.

He began with the facts and figures, and told us that, for example, 20% of resuscitated individuals report having an NDE, and 30% of people report having a visitation from the dead. My question is: how are these numbers at all meaningful? There is a huge amount of selection bias here (which he admitted to), because my story of losing consciousness and later waking up is not going to draw any attention at all, while Eben Alexander’s fabulous story of going to heaven and meeting an all-powerful, awesome lord of creation gets on the New York Times bestseller list. It’s nice to have statistics, but I want to know how they were collected and interpreted, and without that, they’re meaningless.

I was also confused because later he mentions that these NDE-like experiences were also expressed by people in many stressful situations, like trapped miners. So once again, 20% of what? Shouldn’t the fact that I lost consciousness when I went to bed last night, as I’ve done every night for 6 decades, and did not have an other-worldly, out-of-body experience be counted among the negatives?

He also gave us a list of the canonical events during an NDE: the dark tunnel, the Being of Light, the visiting of dead relatives, etc. I felt like pointing out that he, an authority on this subject, has just now primed a large audience on exactly what they’re supposed to experience if they had an NDE. Not that that’s his fault: there are movies and books and stories told on daytime television that reinforce these perceptions, and there’s a widespread cultural idea about them that we’re already soaking in.

I also wondered…if I were in a coma, and woke up and reported that my consciousness spent that time wandering in a cosmic darkness, or that I remembered visiting the shores of an alien sea and meeting Space Squid, would that even count as an NDE? He’s got a checklist, you know, and if I were asked if I saw the Being of Light, and I said “No,” would that mean I didn’t have an NDE?

Most annoying of all, though, was all the neuroscience bashing. He really is not impressed with the neuroscientific explanations of the phenomenon, and neither am I, because he gave us a long list of scientific explanations that did not include the dominant hypothesis. He talked about scientists sticking electrodes on the heads of unconscious patients to record EEGs during their NDE, or drawing blood to measure blood gases, and hypotheses about anoxia, or endorphins, or ocular pressure increases, or similar attempts to explain NDEs as events that occurred during the trauma or the coma, and the one time he named one of these neuroscientists, it was Michael Persinger. We’re talking fringe of the fringe. The neuroscientists I know would just roll their eyes at these accounts, in the same way we’d dismiss those weird experiments with putting dying people on precision balances to measure the weight of the soul at the moment it left the body. It’s missing the whole point.

But he didn’t even mention how most neuroscientists would explain NDEs. They don’t occur during the event, because the brain is not functioning at all well during that time. They are confabulations assembled by the brain once its function is restored.

Minds abhor gaps. Our consciousness works hard to maintain the illusion of continuity, and we even invent stories to explain where our consciousness “went” during its absence. We do this all the time without even thinking about it.

A mundane example: have you ever lost your keys, or your glasses? It happens all the time. We’re often not thinking about routine events, and we don’t bother to store them in our memories, so I get up in the morning, stumble about in a fog while doing the things I do almost every day, and I don’t have to pay conscious attention to them. But maybe later I wonder where I put my glasses, and my wife tells me, “They’re here on the kitchen counter,” and my brain instantly generates a plausible explanation. “I must have put them there when I was making the coffee,” I think. If I were asked at that moment, I would even put together a fairly detailed narrative about walking into the kitchen and taking them off as I was filling the pot with water — but the thing is, I didn’t know this. I don’t actually remember it. If I had, I wouldn’t have been wondering where I’d put them.

We do this constantly. Memories aren’t detailed recordings of everything you’ve done or experienced, they’re a scattered set of anchoring specifics with a vast amount of narrative filler generated as necessary by your brain, based upon a plausible model of how the world works. So I don’t remember taking my glasses off, but I do have a model of the world that includes me taking them off while doing kitchen tasks, so voila, a story is easily assembled. If I had a world model that included elves, I might have built a story that said, “Those pesky elves must have put them there!”, and then the fun begins, because the observation that my glasses were where I hadn’t remembered putting them becomes confirmation of my model of the world that includes elves.

We really don’t like the idea that our consciousness isn’t always present in our heads, that it’s an epiphenomenon of constant invention, so we have explanations for where it goes when it isn’t particularly active. I intentionally put my glasses on the counter, I just forgot. Most interestingly, we go through a period of unconsciousness every day, and we don’t freak out about where our minds went. We were “sleeping”, we say, our minds were still there, busily doing nothing, and this word “sleep” consoles us that our consciousness did not stop existing for hours and hours.

Similarly, NDEs are a conscious narrative we build to explain what happened to ourselves during radical, traumatic events. We blanked out, our minds stopped humming along, where did our self go? It had to have gone somewhere, it can’t just stop, so our brains build a story from conventional expectations to prevent an existential crisis. It’s what we do. And if it’s near-death, how convenient that we throw in Dead Uncle Bob, who we know is dead, but we have these niggling questions about where Uncle Bob went, so clearly we must have both gone to the same place. The idea that a consciousness ceased to exist is inconceivable, after all.

If Kellehear had actually discussed what neuroscientists believe, it would have been something along those lines, on the ephemeral and contingent nature of consciousness, and he wouldn’t have brought up silly ol’ crackpot Persinger as representative. It would have also revealed that neuroscientists are actually in alignment with his ideas about the importance of history and culture and religion and emotion in shaping human responses to death, that it’s not really a hard-wired part of our neural circuitry. So that was a little unsatisfying.

There was also a bit near the end where he got into a bit of Dawkins bashing — but for all the wrong reasons. He railed against the arrogance of a scientist claiming to know that there is no god. I felt like saying that that arrogance pales in comparison with the ubiquitous, overbearing hubris of claiming to not only know that there is a god, but that one knows exactly what kinds of sexual behaviors that god enjoys, and that one has this certainty in spite of the fact that there is no independent evidence of any kind that this supreme being even exists. But I was being nice. It was also an event packed full of community members — “townies” — who were there to listen to an academic reinforce their model of the world, and they weren’t going to appreciate someone telling them that elves aren’t real.

Teams of Memes, bursting from the seams

Image courtesy of the googles.

Daniel Dennett’s From Bacteria to Bach and Back is a lengthy and winding journey. It is characterized (including by its publisher) as a general explanation of the evolution of minds and various peculiar mental functions, consciousness and language being the two most hotly discussed by philosophers, but there’s a better way to read it. As its best, the book is a tour of Dennett’s personal philosophical repertoire, illustrating how ideas from his books and papers fit together.

Dennett’s general theory of the development of genetics stems from his broad theory of memes, where a meme is any informational entity that can be transmitted and replicated. The rough idea is that minds are meme-machines in the way that organisms are gene-machines (in Dawkins’ analogy of the gene’s-eye-view). This is a fruitful analogy, in some respects, though I think it can and should draw some skepticism from readers. I’ll return to those worries later.

The basic building blocks of Dennett’s view are indicated by gestures and short explanations, which is a challenge since he’s spent so much time discussing and arguing for them elsewhere in his work. In any case, there are really two that it is important to understand.

[Read more…]

I was compelled to post this

I said I didn’t want to say anything about free will, and I still don’t, but Massimo Pigliucci weighed in, and Jerry Coyne responded, and so did Sean Carroll, and of course I created a free will thread for everyone else to talk about it, so I guess there’s a fair bit of momentum behind it all.

I don’t understand why free will was getting all tangled up in indeterminacy vs. determinism, since that seems to be a completely independent issue. I’ll sum up my opinion by agreeing with Jerry Coyne:

Of course, whether the laws of physics are deterministic or probabilistic is, to me, irrelevant to whether there’s free will, which in my take means that we can override the laws of physics with some intangible “will” that allows us to make different decisions given identical configurations of the molecules of the universe. That kind of dualism is palpable nonsense, of course, which is why I think the commonsense notion of free will is wrong.

My mind is a product of the physical properties of my brain; it is not above them or beyond them or somehow independent of them. It doesn’t even make sense to talk about “me”, which is ultimately simply yet another emergent property of the substrate of the brain, modifying the how the brain acts. It is how the brain acts.

I think consciousness is a product of self-referential modeling of how decisions are made in the brain in the absence of any specific information about the mechanisms of decision-making — it’s an illusion generated by a high-level ‘theory of mind’ module that generates highly simplified, highly derived models of how brains work that also happens to be applied to our own brain.

(Also on FtB)

What have the students been up to this week?

It’s another update on the bloggin’ students in my Neuroscience course, and what they’ve been thinking about.

They all welcome visits and comments!

(Also on FtB)

What have my students been thinking about lately?

I gave them an exam, that’s what. That and long boring lecturings at 8am on pattern formation in the nervous system. But otherwise, I’ve had them blogging, so we can take a peek into the brain of a typical college student and see what actually engages them.

I understand these are all the things all college students everywhere are contemplating.

(Also on FtB)

What have my students been thinking about this week?

I’ve got my neurobiology students blogging — all I ask is that they write something relevant to understanding how brains work. Let’s see where their minds are at this week, shall we?

(Also on FtB)

Wiring the brain

This story is some kind of awesome:

For those who don’t want to watch the whole thing, the observation in brief is that color perception is affected by color language. The investigators compare Westerners with our familiar language categories for color (red, blue, green, yellow, etc.) to the people of the Himba tribe in Africa who have very different categories: they use “zoozu”, for instance, for dark colors, which includes reds, greens, blues, and purples, “vapa” for white and some yellows, “borou” for specific shades of green and blue. Linguistically, they lump together some colors for which we have distinct names, and they also discriminate other colors that we lump together as one.

The cool thing about it all is that when they give adults a color discrimination test, there are differences in how readily we process and recognize different colors that corresponds well to our language categories. Perception in the brain is colored (see what I did there?) by our experiences while growing up.

The study is still missing one part, though. It’s presented as an example of plasticity in wiring the brain, where language modulates color perception…but we don’t know whether people of the Himba tribe might also have subtle genetic differences that effect color processing. The next cool experiment would be to raise a European/American child in a Himba home, or a Himba child in a Western home (this latter experiment is more likely to occur than the former, admittedly) and see if the differences are due entirely to language, or whether there are some actual inherited differences. It would also be interesting to see if adults who learned to be bilingual late experience any shifts in color perception.

(Also on FtB)

Neuro student articles

I’m teaching an upper-level course in neurobiology this term, and as I usually do, I made all the poor suffering students go out and create blogs, and I also told them they had to write one post a week about neuroscience. Today I was asked if I was going to pharyngulate their blogs, and of course I said I would. So go forth and harrass them! A word of warning, though: as many people learned last time I did this, these are not passive, cowed students, but feisty upperclassmen who are comfortable with biting back; the worst thing you can do is be condescending or patronizing.

(Also on FtB)

How am I going to fit an MRI in the bedroom?

Maybe you’ve seen this before: it’s a diagram of the sensory and motor cortex of the brain, with a little man or homunculus drawn over it to illustrate the somatic areas associated with each region. You see where the little man’s knee is on the left image of the sensory cortex? Stick an electrode in there and zap it, and a patient/victim will feel a sensation in his knee. Put the patient in an MRI and tickle his knee, and that region of the brain will light up. Cool, huh?

i-6fdc72c53c2cbd69db616bab3cd28e94-homunculus-thumb-500x271-68162.gif

Another cute feature: look in the medial longitudinal fissure. You see the homunculus’s toes, and right down there, located beyond the toes, is where the genital sensory area is located. Poke at that with an electrode and…we’re talking happy time at the Mad Scientists’ convention. But notice, though, that in the diagram of the homunculus, the poor creature’s genitals are drawn, and they’re male. It’s a bit sexist, don’t you think?

This bias has now been corrected.

a team led by Lars Michels at University Children’s Hospital in Zurich, Switzerland, used functional magnetic resonance imaging to confirm that the position of the clitoris on the homunculus was in approximately the same position as the penis in men. Barry Komisaruk at Rutgers University in Newark, New Jersey, and his colleagues have now used the same method to map the position of the clitoris, vagina and cervix on the sensory cortex as women stimulated themselves.

I read these things, and I think to myself that I really went into the wrong research field. Oh, well.

They also discovered something else.

Komisaruk also checked what happened when women’s nipples were stimulated, and was surprised to find that in addition to the chest area of the cortex lighting up, the genital area was also activated. “When I tell my male neuroscientist colleagues about this, they say: ‘Wow, that’s an exception to the classical homunculus,'” he says. “But when I tell the women they say: ‘Well, yeah?'” It may help explain why a lot of women claim that nipple stimulation is erotic, he adds.

Now, as a true nerd and as a typical male who has always been mystified by the female sexual response, I feel a deep craving to plumb the mysteries with my own personal fMRI scanner. It’ll also be a research project that will go over well at the next Mad Scientists’ convention.

(Also on FtB)