Android dreams

In the episode of Star Trek: The Next Generation called "Phantasms," the android Commander Data continues to pursue his lifelong dream of experiencing what it's like to be human by creating a "dream program" -- a piece of software that activates when he sleeps, allowing him to go into a dreamlike state.  The whole thing goes seriously off the rails when he starts having bizarre nightmares, and then waking hallucinations that spur him to attack the ship's counselor Deanna Troi, an action that leaves him relieved of duty and confined to his quarters.

Of course, being Star Trek, the whole thing has to do with aliens, but the more interesting aspect of the story to me is the question of what an artificial intelligence would dream about.  We've yet to figure out exactly why dreaming is so important to our mental health, but it clearly is (this was the subject of what might be the single creepiest TNG episode ever, "Night Terrors").  Without REM sleep and the dreams that occur during it, we become paranoid, neurotic, and eventually completely non-functional; ultimately we start hallucinating, as if the lack of dreams while we're asleep makes them spill over into our waking hours.

So being that the question of why exactly we dream isn't satisfactorily solved, it's going even further out onto a limb to ask what a different intelligence (artificial or otherwise) would dream about, or even if they'd need to dream at all.  Our own dreams have a few very common themes; just about all of us have dreams of being chased, of being embarrassed, of stressful situations (like the "teaching anxiety" dreams I used to have, usually involving my being in my classroom and having my students misbehaving no matter what I tried to stop it).  I still get anxiety dreams about being in a math class in college (it's always math, for some reason), and showing up to find I have an exam that I haven't studied for.  In some versions, I haven't even attended class for weeks, and have no idea what's going on.

Grieving or trauma can induce dreams; we often dream about loved ones we've lost or terrifying situations we've been in.  Most of us have erotic dreams, sometimes acting out situations we'd never dream of participating in while awake.

So although the content of dreams is pretty universal, and in fact shares a lot with the visions induced by psychedelic drugs, why we dream is still unknown.  So it was with considerable curiosity that I read a paper that showed up in the journal Neuroscience of Consciousness this month called, "Neural Network Models for DMT-induced Visual Hallucinations," by Michael Schartner (Université de Genève) and Christopher Timmermann (University College London), who took an AI neural network and introduced input to it that mimicked the kind of endogenous (self-created) visual input that occurs during a hallucination, and watched what happened.

The authors write:

Using two deep convolutional network architectures, we pointed out the potential to generate changes in natural images that are in line with subjective reports of DMT-induced hallucinations. Unlike human paintings of psychedelic hallucinations—the traditional way to illustrate psychedelic imagery—using well-defined deep network architectures allows to draw parallels to brain mechanisms, in particular with respect to a perturbed balance between sensory information and prior information, mediated by the serotonergic system.

In our first model, NVIDIA’s generative model StyleGAN, we show how perturbation of the noise input can lead to image distortions reminiscent of verbal reports from controlled experiments in which DMT has been administered.  In particular, the omission of noise leads to a smoother, painterly look of the images, illustrating a potential hypothesis that can be conceptualized with such models: as a 5-HT2A receptor agonist, DMT induces a state in which environmental (i.e. exogenous) sensory information is partially blocked—gated by the inserted noise—and system-internal (endogenous) signals are influencing conscious imagery more strongly.  Contents of immersive imagery experienced in eyes-closed conditions during DMT administration would thereby correspond to the system’s prior information for the construction of a consciously perceived scene.

If you're ready for some nightmares yourself, here's one of their images of the output from introducing psychedelic-like noise into the input of a face-recognition software:

For more disturbing images that come out of giving AI hallucinogens, and a more in-depth explanation of the research than I'm giving here (or am even capable of giving), I direct you to the paper itself, which is fascinating.  The study gives a new lens into the question of our own consciousness -- whether it's an illusion generated by our brain chemistry, or if there really is something more there (a soul, spirit, mind, whatever you might want to call it) that is in some sense independent of the neural underpinning.  The authors write:

Research on image encoding in IT suggests that ‘the computational mission of IT face patches is to generate a robust, efficient, and invariant code for faces, which can then be read-out for any behavioural/cognitive purpose downstream’ (Kornblith and Tsao 2017).  The latent information entering the NVIDIA generative model may thus be interpreted as activity in IT and the output image as the consciously perceived scene, constructed during the read-out by other cortical areas.  How this read-out creates an experience is at the heart of the mind-body problem and we suggest that modelling the effects of DMT on the balance between exogenous and endogenous information may provide experimentally testable hypotheses about this central question of consciousness science.

All of this points out something I've said many times here at Skeptophilia; that we are only beginning to understand how our own brains work.  To quote my friend and mentor, Dr. Rita Calvo, Professor Emeritus of Human Genetics at Cornell University, with respect to brain science we're about where we were with respect to genetics in 1921 -- we know a little bit about some of the effects, and a little bit about where things happen, but almost no understanding at all about the mechanisms that are driving the whole thing.  But with research like Schartner and Timmermann's recent paper, we're finally getting a glimpse of the inner workings of that mysterious organ that lies between your ears, the one that is allowing you to read and understand this blog post right now.

***********************************

I'm always amazed by the resilience we humans can sometimes show.  Knocked down again and again, in circumstances that "adverse" doesn't even begin to describe, we rise above and move beyond, sometimes accomplishing great things despite catastrophic setbacks.

In Why Fish Don't Exist: A Story of Love, Loss, and the Hidden Order of Life, journalist Lulu Miller looks at the life of David Starr Jordan, a taxonomist whose fascination with aquatic life led him to the discovery of a fifth of the species of fish known in his day.  But to say the man had bad luck is a ridiculous understatement.  He lost his collections, drawings, and notes repeatedly, first to lightning, then to fire, and finally and catastrophically to the 1906 San Francisco Earthquake, which shattered just about every specimen bottle he had.

But Jordan refused to give up.  After the earthquake he set about rebuilding one more time, becoming the founding president of Stanford University and living and working until his death in 1931 at the age of eighty.  Miller's biography of Jordan looks at his scientific achievements and incredible tenacity -- but doesn't shy away from his darker side as an early proponent of eugenics, and the allegations that he might have been complicit in the coverup of a murder.

She paints a picture of a complex, fascinating man, and her vivid writing style brings him and the world he lived in to life.  If you are looking for a wonderful biography, give Why Fish Don't Exist a read.  You won't be able to put it down.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

DMT and NDEs

No one would be happier than me if it turned out there was an afterlife.

Well, at least some types of afterlife.  The tortured-forever-in-the-fiery-furnace version doesn't appeal much to me, especially given my status as an evil godless heathen.  Reincarnation, in my opinion, would also kind of suck, since it's basically getting sent back to the beginning of the game.  Valhalla would be kind of cool, though.  I could definitely get into swordfighting and quaffing mead.  And some of the ones where you get to relax in fields of flowers, with every need taken care of, also sound good, especially on work days.

The problem is, there's no real evidence of any of them.  Not that you'd expect there'd be; after all, to get to the afterlife you pretty much have to be dead.  And as Michael Shermer put it, it's easy to talk to the dead -- the hard part is getting them to respond.

There are people who claim there's evidence from near-death experiences -- NDEs, in common parlance.  The idea is that people who have had NDEs report back a lot of common features, including the well-known "tunnel of light" and feelings of oneness, bliss, and transcendence.  The argument goes that since what people claim to have experienced is often very similar, there must be something to it -- those people have peeked across the threshold, and come back to tell us about it.

[Image is in the Public Domain]

I've never found that argument terribly convincing.  Since we all have brains (although some of us could stand to use them more frequently), you'd expect that they'd respond similarly under similar circumstances of oxygen deprivation, neural shutdown, and all the other things that happens when a person dies.  And that stance has been bolstered considerably by a study done at Imperial College (London) last month, in which thirteen volunteers were given a chemical called dimethyltryptamine (DMT), and reported back experiences identical to what has been heard from people who have had NDEs.

DMT has become well-known because it is the main psychotropic ingredient in ayahuasca, a plant extract used in the Amazon Basin to induce hallucinations.  DMT interacts with serotonin and dopamine receptors in the brain, and that seems to be the cause of its effects, which include euphoria, visual disturbances, and -- most strikingly -- the sensation of communicating with non-corporeal beings.

What the researchers did with the test subjects in this study is to administer DMT under controlled conditions, and not only monitored their physical and mental states, but asked them for their subjective experiences when they "sobered up."  And there was an amazing similarity between the DMT trips and reports of NDEs.

One test subject described a "tunnel" that she felt impelled to enter, and once she did so, the anxiety she'd felt evaporated completely.  She was "shown" various images, and they all appeared to her to be critical to understanding her life.  "One image I do remember is lots of books flipping open and rainbows zooming out," she said.  "I felt a presence lift my head and tell me to pay attention: 'You came to discover something.'  But it was a juxtaposition because I felt disembodied at the same time. It was a strange paradox...  The normal laws of physics didn't apply.  I was walking around my consciousness in a lucid dream.  Imagine dreaming and things morph and the normal laws of physics don't apply.  I was walking around my consciousness in a lucid dream."

What strikes me about all this is that if it's easy to simulate an NDE by altering your brain chemistry, maybe altering your brain chemistry is what causes an NDE.  As I tell my neuroscience students, if you monkey around with your neurotransmitters, you should expect bizarre things to happen; and, after all, since every experience we have is filtered through our neurotransmitters, it's bound to change your perception of the world.

It doesn't, however, mean that any of it is real.

There's also been a conjecture by more than one neuroscientist that endogenous (self-produced) DMT exists to protect our cells from the effects of oxygen starvation, so it's released in one big shot when our heart stops in a last-ditch effort to keep our brain cells alive.  If that's true, no wonder everyone experiences the same sorts of sensations in an NDE -- and their similarity to a DMT psychedelic trip.

So the DMT experiment is fascinating, but it seems to me not to bolster the case for an afterlife.  It does make me curious about the experience, however.  A friend of mine asked me whether I would take DMT or psilocybin if it was under controlled, safe circumstances, and I knew I wouldn't get arrested.  My answer was, "Absolutely."  The idea of creating the sensation of a transcendent experience sounds pretty appealing even if I don't believe it necessarily reflects any sort of external reality.

And, after all, my other alternative is to wait until I die, which strikes me as being less than optimal given that after having the transcendent experience, I'll be dead.

Kind of a downside, that.

******************************

This week's Skeptophilia book recommendation is a fun one.  If you've never read anything by Mary Roach, you don't know what you're missing.  She investigates various human phenomena -- eating, space travel, sex, death, and war being a few of the ones she's tackled -- and writes about them with an analytical lens and a fantastically light sense of humor.  This week, my recommendation is Spook, in which she looks at the idea of an afterlife, trying to find out if there's anything to it from a scientific perspective.  It's an engaging, and at times laugh-out-loud funny, read.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]

Brains, mysticism, and melting faces

"Well, I saw it. I saw it with my own eyes."

You hear that a lot, in claims of the paranormal.   I was just sitting there, in my room, and the ghost floated in through the wall.   I was outside at night, and I saw the UFO zoom across the sky.  I was at the lake, and I saw ripples in the water, and a dinosaur's head poked out and looked at me.

In a court of law, "eyewitness testimony" is considered one of the strongest pieces of evidence, and yet time and again experimental science has shown that your sensory apparatus and your memory are flawed and unreliable.   It doesn't take much to confuse your perception -- witness how persuasive many optical illusions are -- and if you couple that with how easily things get muddled in your memory, it's no wonder that when eyewitness claims of the paranormal are presented to scientists, most scientists say, "Sorry. We need more than that."

A fascinating study published in the Journal of Neuroscience has put another nail in the coffin of our perceptual integrative systems, showing how easy it is to trigger someone to see something that isn't there in a completely convincing way.  Ron Blackwell, an epileptic, was in the hospital having tests done to see if a bit of his brain that was causing his seizures could be safely removed.  As part of the pre-surgical tests at Stanford University Hospital, his doctor, Dr. Josef Parvizi, had placed a strip of electrodes across his fusiform gyrus, a structure in the temporal lobe of the cerebrum.  And when the electrodes were activated, Blackwell saw Dr. Parvizi's face melt.

[image courtesy of the Wikimedia Commons]

"You just turned into somebody else," Blackwell said.  "Your face metamorphosed.  Your nose got saggy, went to the left.  You almost looked like somebody I'd seen before, but somebody different."  He added, rather unnecessarily, "That was a trip."

This study has three interesting outcomes, as far as I'm concerned.

First, it shows that the fusiform gyrus has something to do with facial recognition.  I'm personally interested in this, because as I've described before in Skeptophilia, I have a peculiar inability to recall faces.  I don't have the complete prosopagnosia that people like the late great science writer Oliver Sacks had -- where he didn't even recognize his own face in a mirror -- but the fact remains that I can see a person I've met many times before in an unfamiliar place or circumstance, and literally have no idea if I've ever seen them before.  However -- and this is relevant to Parvizi's study -- other human features, such as stance, gait, and voice, I find easily and instantly recognizable.  And indeed, Blackwell's experience of seeing his doctor's face morph left other body parts intact, and even while the electrodes were activated, Blackwell knew that Dr. Parvizi's body and hands were "his."  So it seems that what psychologists have claimed -- that we have a dedicated module devoted solely to facial recognition -- is correct, and this study has apparently pinpointed its location.

Second, this further supports a point I've made many times, which is that if you fool your brain, that's what you perceive.  Suppose Blackwell's experience had occurred a different way; suppose his fusiform gyrus had been stimulated by one of his seizures, away from a hospital, away from anyone who could immediately reassure him that what he was seeing wasn't real, with no one there who could simply turn the electrodes off and make the illusion vanish.  Is it any wonder that some people report absolutely convincing, and bizarre, visions of the paranormal?  If your brain firing pattern goes awry -- for whatever reason -- you will perceive reality abnormally.  And if you are already primed to accept the testimony of your eyes, you very likely will interpret what you saw as some sidestep into the spirit world.  Most importantly, your vehement claims that what you saw was real cannot be accepted into evidence by science. Ockham's Razor demands that we accept the simpler explanation, that requires fewer ad hoc assumptions, which is (sorry) that you simply had an aberrant firing pattern occur in your brain.

Third, this study has significant bearing on the stories of people who claim to have had "spiritual visions" while under the influence of psychoactive drugs.  One in particular, DMT (dimethyltryptamine), present in such ritual concoctions as ayahuasca, is supposed to create a "window into the divine."  A number of writers, particularly Terence McKenna and Rick Strassman (the latter wrote a book called DMT: The Spirit Molecule), claim that DMT is allowing you to see and communicate with real entities that are always there, but which only the drug allows you to experience.  Consider McKenna's account of his first experience with the chemical:

So I did it and...there was a something, like a flower, like a chrysanthemum in orange and yellow that was sort of spinning, spinning, and then it was like I was pushed from behind and I fell through the chrysanthemum into another place that didn't seem like a state of mind, it seemed like another place.  And what was going on in this place aside from the tastefully soffited indirect lighting, and the crawling geometric hallucinations along the domed walls, what was happening was that there were a lot of beings in there, what I call self-transforming machine elves.  Sort of like jewelled basketballs all dribbling their way toward me.  And if they'd had faces they would have been grinning, but they didn't have faces.  And they assured me that they loved me and they told me not to be amazed; not to give way to astonishment.

A generation earlier, Carlos Castañeda recounted similar sorts of experiences after ingesting datura root and psilocybe mushrooms, and like McKenna and Strassman, Castañeda was convinced that what he was seeing was absolutely real, more real in fact than the ordinary world around us.

My response, predictably, is: of course you saw weird stuff, and thought it was real.  What did you expect?  You monkey around with your brain chemistry, and you will obviously foul up your perceptual apparatus and your ability to integrate what's being observed.  It's no more surprising that this happens than it would be if you spilled a cup of coffee on your computer, and it proceeded to behave abnormally.  If you short out your neural circuitry, either electrically (as Parvizi did) or chemically (as McKenna and others did), it should come as no shock that things don't work right.  And those altered perceptions are hardly evidence of the existence of a mystical world.

In any case, Parvizi's accidental discovery is a fascinating one, and will have wide-reaching effects on the study of perceptual neuroscience.  All of which supports what a friend of mine, a retired Cornell University professor of human genetics, once told me: the 21st century will be the century of the brain.  We are, she said, at a point of our understanding of how the brain works that corresponds to where geneticists were in 1915 -- we can see some of the pieces, but have no idea how the whole system fits together.  Soon, she predicts, we will begin to put together the underlying mechanism.  And at that point, we will be starting to develop a complete picture of how our most complex organ actually works.

The "honey trap," perception, and our sense of self

I think the human brain is fascinating.  Not a surprising statement, I suppose, coming from someone who teaches (amongst other things) an introductory neurology course.  What intrigues me most, though, is the way all of this rock-solid sense of self we all have -- the sum of our perceptions, attitudes, experiences, and memories -- is the result of a bunch of chemicals jittering around in 1.3 kilograms of skull-glop, and an electrical output that would only be sufficient to illuminate a twenty-watt light bulb.

And if that's not humbling enough, our personalities may not be as rock-solid as all that.  If something changes the chemistry or the pattern of electrical firings in your brain, who you are and what you experience changes.  As my long-ago physiology professor said, "In a very real way, your brain is the only sensory organ you have.  If your brain gets tricked, that is what you think you've seen, or heard, or felt."

It works all the way up to the level of our emotions and personality, too -- realms of the human experience that are supposed to be somehow "different."  Okay, we can accept it when a drug makes you hallucinate; that's just the brain's neural firings being altered.  But our attitudes, biases, preferences, emotional reactions -- no, that's something else entirely.  Those are all part of this "me" that is independent of the "meat machine" in my skull, this spiritual entity that is separate from mere biochemistry, a personal being that can well be imagined going on after the animal part dies.

Right?

Eight scientists in the Department of Human Environment Studies at Kyushu University in Japan have just punched another hole in this belief, with a paper that appeared in Nature last week entitled, "Minocycline, a microglial inhibitor, reduces 'honey trap' risk in human economic exchange."  In this study, Motoki Watabe et al. had observed that minocycline, a tetracycline-derivative antibiotic, had not only been useful for fighting infections but had led to improvement in psychological disorders in patients who were taking it.  In particular, taking minocycline seemed to improve patient's capacity for "sober decision-making."  So the group at Kyushu University decided to see if they could pinpoint what, exactly, was changing in the brain of a person on minocycline.

The results were, to say the least, eye-opening.

It's long been known that human males tend to trust physically attractive females, sometimes leading to their betrayal -- a tendency called the "honey trap" that has been used as a plot twist in hundreds of thrillers, all the way back to Milady Winter and d'Artagnan in The Three Musketeers.

Well, the "honey trap" response vanishes in men on minocycline.

The men in the experiment were split into two groups -- one group got the antibiotic, the others a placebo.  None knew which they'd gotten:

In this experiment, 98 healthy males played a trust game with 8 photographed young females after a 4-day oral treatment course of either minocycline or placebo. Looking at a picture showing a female's face, male players decided how much out of 1300 yen (approximately 13 USD) they would give to each female. Males then evaluated how trustworthy each female was and how physically attractive she was using a 11-point Likert Scale (0: Not at all – 10: Perfectly so). Of note, all of the photographed females had actually decided, in advance, to choose ‘betray’ against the male players. Therefore, male participants played with untrustworthy female partners, but were unaware of the deception.

Overwhelmingly, the men who were in the control group showed a strong correlation between rating a woman as highly attractive and being trustworthy; the group on minocycline showed no such correlation.  They recognized attractiveness, ranking some photographs as more attractive than others; but they ranked all of the women as about equal in trustworthiness.

A much more reasonable response, given that they all were strangers!

Watabe et al. suggested that this indicates a role in cognition for the microglia -- cells that heretofore were thought mostly to mediate the brain's immune defense system and blood/brain barrier, and which are inhibited by minocycline.  Me, I'm more intrigued by the larger issue, that who we are, the central core of our personalities, might be far more dependent on minor changes in brain chemistry than most of us are comfortable admitting.

It's also why I have a hard time accepting the idea that the visions experienced by people on dimethyltryptamine (DMT) actually mean anything, in the spiritual sense.  People on DMT report overwhelming hallucinations that were "spiritually transforming," in which they had the sense of being connected with "higher mind" -- i.e., with god.  Terrence McKenna, one of the primary exponents of the use of this drug for inducing spiritual experiences, describes one of his trips this way:

(Y)ou, when you're shown one of these things, a single one of them, you look at it an you know, without a shadow of a doubt, in the moment of looking at this thing, that if it were right here, right now, this world would go mad.  It's like something from another dimension.  It's like an artifact from a flying saucer. It's like something falling out of the mind of God - such objects DO not exist in this universe, and yet, you're looking at it.  [Source]

My problem with all of this is not some kind of moralistic "don't do that stuff to your body," nor is it even a concern for the side effects; it's more that the whole thing strikes me as kind of... silly.  If you throw a monkey wrench into your neurotransmitters, of course you're going to see weird shit.  Acting as if what you're seeing has some sort of external reality seems to me to be a major stretch, landing us right into the weird world of such wingnuts as Carlos Castañeda with his datura root and magic mushrooms as a means of contacting the "ally."

I know, however, that we're also getting perilously close to a topic I touched briefly on a few weeks ago, namely, how we can prove that anything outside our experiences is real.  And I've no desire to skate out onto that philosophical thin ice once again.  But I do think that the scientists in Japan have given yet another blow to our sense of having some kind of permanent external "self" that is independent of our biology.  If all it takes is an antibiotic tablet to change who we trust, it seems that we are, on a fundamental level, what our brain chemistry is at the moment -- and not very much else.

Brains, mysticism, and melting faces

"Well, I saw it.  I saw it with my own eyes."

You hear that a lot, in claims of the paranormal.  I was just sitting there, in my room, and the ghost floated in through the wall.  I was outside at night, and I saw the UFO zoom across the sky.  I was at the lake, and I saw ripples in the water, and a dinosaur's head poked out and looked at me.

In a court of law, "eyewitness testimony" is considered one of the strongest pieces of evidence, and yet time and again experimental science has shown that your sensory apparatus and your memory are flawed and unreliable.  It doesn't take much to confuse your perception -- witness how persuasive many optical illusions are -- and if you couple that with how easily things get muddled in your memory, it's no wonder that when eyewitness claims of the paranormal are presented to scientists, most scientists say, "Sorry.  We need more than that."

Just last week, a study published in the Journal of Neuroscience put another nail in the coffin of our perceptual integrative systems, showing how easy it is to trigger someone to see something that isn't there in a completely convincing way.  [Source]  Ron Blackwell, an epileptic, was in the hospital having tests done to see if a bit of his brain that was causing his seizures could be safely removed.  As part of the pre-surgical tests at Stanford University Hospital, his doctor, Dr. Josef Parvizi, had placed a strip of electrodes across his fusiform gyrus, a structure in the temporal lobe of the cerebrum.  And when the electrodes were activated, Blackwell saw Dr. Parvizi's face melt.

"You just turned into somebody else," Blackwell said. "Your face metamorphosed.  Your nose got saggy, went to the left.  You almost looked like somebody I'd seen before, but somebody different."  He added, rather unnecessarily, "That was a trip."

This study has three interesting outcomes, as far as I'm concerned.

First, it shows that the fusiform gyrus has something to do with facial recognition.  I'm personally interested in this, because as I've described before in Skeptophilia, I have a peculiar inability to recognize faces.  I don't have the complete prosopagnosia that people like the eminent science writer Oliver Sacks has -- where he doesn't even recognize his own face in a mirror -- but the fact remains that I can see a person I've met many times before in an unfamiliar place or circumstance, and literally have no idea if I've ever seen them before.  However -- and this is relevant to Parvizi's study -- other human features, such as stance, gait, and voice, I find easily and instantly recognizable.  And indeed, Blackwell's experience of seeing his doctor's face morph left other body parts intact, and even while the electrodes were activated, Blackwell knew that Dr. Parvizi's body and hands were "his."  So it seems that what psychologists have claimed -- that we have a dedicated module devoted solely to facial recognition -- is correct, and this study has apparently pinpointed its location.

Second, this further supports a point I've made many times, which is that if you fool your brain, that's what you perceive.  Suppose Blackwell's experience had occurred a different way; suppose his fusiform gyrus had been stimulated by one of his seizures, away from a hospital, away from anyone who could immediately reassure him that what he was seeing wasn't real, with no one there who could simply turn the electrodes off and make the illusion vanish.  Is it any wonder that some people report absolutely convincing, and bizarre, visions of the paranormal?  If your brain firing pattern goes awry -- for whatever reason -- you will perceive reality abnormally.  And if you are already primed to accept the testimony of your eyes, you very likely will interpret what you saw as some sidestep into the spirit world.  Most importantly, your vehement claims that what you saw was real cannot be accepted into evidence by science.  Ockham's Razor demands that we accept the simpler explanation, that requires fewer ad hoc assumptions, which is (sorry) that you simply had an aberrant firing pattern occur in your brain.

Third, this study has significant bearing on the stories of people who claim to have had "spiritual visions" while under the influence of psychoactive drugs.  One in particular, DMT (dimethyltryptamine), present in such ritual concoctions as ayahuasca, is supposed to create a "window into the divine."  A number of writers, particularly Terence McKenna and Rick Strassman (the latter wrote a book called DMT: The Spirit Molecule), claim that DMT is allowing you to see and communicate with real entities that are always there, but which only the drug allows you to experience.  Consider McKenna's account of his first experience with the chemical:

So I did it and...there was a something, like a flower, like a chrysanthemum in orange and yellow that was sort of spinning, spinning, and then it was like I was pushed from behind and I fell through the chrysanthemum into another place that didn't seem like a state of mind, it seemed like another place.  And what was going on in this place aside from the tastefully soffited indirect lighting, and the crawling geometric hallucinations along the domed walls, what was happening was that there were a lot of beings in there, what I call self-transforming machine elves.  Sort of like jewelled basketballs all dribbling their way toward me.  And if they'd had faces they would have been grinning, but they didn't have faces.  And they assured me that they loved me and they told me not to be amazed; not to give way to astonishment.

A generation earlier, Carlos Castañeda recounted similar sorts of experiences after ingesting datura root and psilocybe mushrooms, and like McKenna and Strassman, Castañeda was convinced that what he was seeing was absolutely real, more real in fact than the ordinary world around us.

My response, predictably, is: of course you saw weird stuff, and thought it was real.  What did you expect?  You monkey around with your brain chemistry, and you will obviously foul up your perceptual apparatus, and your ability to integrate what's being observed.  It's no more surprising that this happens than it would be if you spilled a cup of coffee on your computer, and it proceeded to behave abnormally.  If you short out your neural circuitry, either electrically (as Parvizi did) or chemically (as McKenna and others did), it should come as no shock that things don't work right.  And those altered perceptions are hardly evidence of the existence of a mystical world.

In any case, Parvizi's accidental discovery is a fascinating one, and will have wide-reaching effects on the study of perceptual neuroscience.  All of which supports what a friend of mine, a retired Cornell University professor of human genetics, once told me: the 21st century will be the century of the brain.  We are, she said, at a point of our understanding of how the brain works that corresponds to where geneticists were in 1912 -- we can see some of the pieces, but have no idea how the whole system fits together.  Soon, she predicts, we will begin to put together the underlying mechanism -- and at that point, we will be starting to develop a complete picture of how our most complex organ actually works.