Adventures in immortality

So I'm going to share some adventures I'm having in figuring out what to do with myself after I die. It's morbid, and I still haven't figured out what I'm doing for the next few years of my life, but I suppose better sooner than later? I really have no good excuse for this.

I have every intent of making myself useful after I die, and that means not being embalmed and encased in metal under the earth for god knows how long. I am already an organ and tissue donor, but the question comes up--what about the rest of me? That's when I remembered the weird, wonderful, and surreal experience of Body Worlds.

For anyone who is unaware--become aware. And go see it. Body Worlds is the exhibition of real human bodies preserved via a method called plastination. The institute responsible for Body Worlds has a detailed explanation of plastination on their website, but roughly speaking, it's a bit like fossilization, except with plastic polymers instead of minerals. The plastination process replaces the perishable cells and tissues of the body with a non-perishable polymer, preserving the body in all its incredible detail. Every muscle, every blood vessel, every organ and ligament on display, all from bodies voluntarily donated by people.

I know I'm weird compared to the average person when it comes to being squeamish. I've been elbow-deep in a vat of brains for anatomy lab, dissected more invertebrates than most people know exist, and had a lovely chat about different types of stitches with the doctor sewing up my foot. That being said, I am not unique in my response to Body Worlds. Despite the display of real human bodies and the sheer weirdness of seeing inside other people, most people respond favorably to Body Worlds. Some strange people like me have near-religious experiences.

I remember seeing one display where only the blood vessels were preserved. A woman, her child, and a bird in simulated flight stood in the case, their forms composed of nothing but the finest web of crimson. It was unlike anything I've ever seen. I don't have words to describe the feeling I had.

The long and the short of it is that I'm currently going through the information packet and paperwork to donate my body for plastination. It's perfectly compatible with organ and tissue donation--that happens first. What remains of the bodies is then sent to the Institute for Plastination to be transformed into an anatomical display. This, as far as I'm concerned, is the most meaningful kind of immortality I can achieve; my body serves a purpose after death, saving lives and educating the public about the wonderful mechanism that is the human body. What could possibly be cooler than that?

Of course, it's not just like I can sign a few forms and be guaranteed plastination upon death--there's more to it than that. I'll update with details in later posts, after I've figured out exactly what I'm doing.

Why 3D Makes Your Brain Cry

Far more eloquent and well-learned people than me have weighed in on the 3D fad in movies and video games. I'm going to talk about how your eyes and brain actually process 3D, and why current 3D is just not good enough to replicate the effect with complete fidelity.

The first myth about 3D vision that needs to die a horrible, flaming, burning death is the misconception that closing one eye will destroy 3D vision. Human beings perceive depth in many ways, most of which are monocular--they require only one eye. Closer things are more detailed than faraway things. Parallax, the same visual illusion that makes railroad tracks converge in the distance, is another way to tell depth. Relative size of objects, objects overlapping, perspective, and relative apparent movement--these are all monocular cues of depth perception, and they work just fine with one eye shut.

However, there is a benefit to binocular vision; this kind of seeing in 3D is called stereoscopic vision. When the eyes focus on a particular object--let's say, a tree--the tree is in the center of the retina of both eyes. But because there are two eyes that occupy different horizontal positions in the head, slightly different images of the scene surrounding the tree will be projected on the retinas of both eyes. Some neurons of the striate cortex in the brain, part of the brain's visual processing system, respond and become extremely active when a visual stimulus produces retinal disparity--images on different parts of the retina of each eye. It's not that each eye sees a two dimensional scene, then combines them for a three dimensional scene. It's that each eye sees a slightly DIFFERENT three dimensional scene, and the difference between what the eyes "see" is what produces difference in depth perception.

When watching a 2D movie, each eye sees only monocular cues. There are monocular cues for depth within the flat plane of the screen, but no stereoscopic vision. What almost all 3D technology works on is fooling your eyes into producing retinal disparity. 3D movies project two images onto the screen, and place filters over the images to polarize the light differently. Viewers wear 3D glasses that have polarized lenses to match the polarities of the two different images of light.

For example, let's say that there's two images of a tree on the screen. The left image may be polarized to setting X, and the right image may be polarized to setting Y. The left lens of the glasses is also polarized X, so only the left image goes to the left eye, and the right lens is polarized Y so only the right image goes to the right eye. This is, of course, quite a simplification, but that's the essential idea. Bada bing--you have two different images going to your retinas, and hey presto, those little neurons in the striate cortex are fooled into responding to retinal disparity.

Except not really. First of all, the polarization only applies to light that's being projected onto the screen. Looking at other objects doesn't make them appear "more 3D than before," and there isn't a screen yet--unless you're sitting right under an IMAX screen--that eats up your entire visual field. You'll still be able to see the theatre, the walls, your fellow moviegoers, and the visual cues, monocular and binocular alike, from these more mundane things won't mesh with the stereoscopic cues you're receiving from the screen. There's no way that giant tree can be that detailed, and also occupying the same space as the guy sleeping through the movie in front of you. Linear stereoscopic glasses even require you to not move your head due to the way they are polarized--turning your head will wreck the illusion.

In addition, stereoscopic glasses do nothing for improving monocular cues of depth. Things like shadows, light, and edges. Ever notice how 3D in movies resembles a pop-up book more than it does real life? The edges are too sharp and clean, and the transitions between objects and backgrounds are too abrupt. This is especially noticeable in live-action movies that have then been adapted for 3D. Our brains in real life combine monocular and binocular cues for the illusion of depth, but that synergy simply doesn't work on the silver screen. Take something like detail. Most movies are shot or animated in very crisp detail, and while the image may "pop" due to stereoscopic glasses, the monocular cue of less detail in the background may not be present. This leads to a "fake" looking 3D experience in which monocular and binocular cues don't match up.

I'm not saying there's anything WRONG with 3D. It's an interesting technology, and it displays some of what we understand about visual processing between the eyes and brain. But in no way does it capture and readily combine all the cues we use in the real world for 3D.

Pixelated Love

So this is a repost from a comment I made on the BioWare forums, but I think it bears reposting. In slightly edited form :)

There is a kind of romance that I find both creepy and downright un-fun in roleplaying video games, almost without exception--the dreaded therapymance. I'm a freaking hero(ine). I'm a Jedi, Sith, Warden, Bhaalspawn, Knight Captain, Spectre, etc. I kick ass, take names, make friends, make enemies, make love, save the known universe, shoot lightning at fools, and do it all with epic style. Nowhere in my job description is "psychologist for crazy people."

NPCs, I will happily be your friend or even lover. I will snipe, spill drinks on the Citadel, snark, eat cheese, sing songs, hunt devils, and consult space hamsters with you. I'll be a shoulder to cry on; I will support and enable your growth as a person to the best of my ability. Because that's what friends do. But I will not be your therapist. I will not sit there and listen to you whine incessantly about your dead spouse, estranged child, daddy issues, mommy issues, dead dog, or toe bunions. I will happily help you find a therapist, but if you can't deal with your problems in a reasonably constructive manner without sobbing on my shoulder every other conversation, I'm kicking you out. You're just not cool enough to be around me. END OF LINE.

I know that simulating social relationships in video games is difficult. I know it's complicated. But for the love of Pete, Biggus Dickus, and Prince Humperdink, can I please have a video game in which I don't need to hold my love interest's hand while they sob about how their daddy didn't love them enough? Is that so much to ask?

Relativity made easy?!? WIGGITY WHAA?

If I told the average person on the street that relativity--as in Einstein's general theory of relativity--was fairly easy to understand, I'd either get a) punched for my arrogant presumptuousness or b) stared at like I was crazy. I have in fact said this to friends before, and thankfully received the latter response instead of the former.

The truth is while the mathematics of general relativity might be beyond most of us, the fundamental concepts are not. And as for special relativity, the math is something a high schooler who has mastered algebra and geometry could handle. Imagine my surprise when after calculus-ridden angular momentum, easily the most mathematically challenging aspect of my physics class, we went to special relativity--and basic algebra.

The difficulty of relativity lies in letting go of common sense. Our brains' common sense perception of the world is evolutionarily useful, but not very good when it comes to physics. For example, my common sense right now tells me that I'm sitting still at my computer, typing against solid keys. Physics tells me I am hurtling through the galaxy at bone-crushing speeds, the only force attaching me to the earth is invisible, and the keys I'm tapping on--and most of everything around me--is empty space. My mind, she is boggled. BOGGLED I SAY.

Here are a couple of the general elements of "common sense" that need to be thrown out the window before one can think clearly about relativity.

1) Absolute frame of reference. This one's pretty easy to chuck, even with Newtonian mechanics. If you're standing still on a platform and someone passes by on a train going 50 miles per hour, you perceive the person on the train moving with you standing still. They perceive themselves standing still, and you zipping by.

2) Instantaneous light. You have to think of light as something that has a finite speed--just a really fast finite speed. It's difficult since when we see a light turn on, it's instantaneous. But as a way to disabuse yourself of this notion, watch live news when the correspondent is half a world away from the anchor. There should be a slight delay in their responses to each other. That's not lag--it's because comm signals travel at the speed of light, and the time it takes the signal to get from one to another is actually perceptible to us.

3) Gravity as falling. Gravity is much more than just the force that glues us to the earth. A broader conception of gravity helps enormously with understanding relativity.

4) Absolute time. This misconception is harder to remove. A crude but effective analogy is to think of time zones. The 3:00 PM of a person living in Madagascar is not the same 3:00PM as a person living in Beijing. Now take that concept and apply it not only to hours on the clock, but also to units of time. Your one second is not the same as my one second.

Disabusing oneself of these "common sense" notions of the world is essential to understanding relativity.

DO WANT

For no particular reason, here's a list of video games that I really want now.

1) The Old Republic. I am no MMO gamer. In fact, I have a lot of trouble getting into MMOs, and I find them boring and repetitive. But a fully voiced MMO, of the Old Republic era of Star Wars, designed by BioWare? If this can't convince me to play an MMO, nothing short of a heavenly mandate will.
2) Kirby's Epic Yarn. ADORABLE. 'Nuff said.
3) Epic Mickey. Will it be as epic as Kirby running around being his adorable fluffy self? Who knows? But I'm a Disney fan and have been since about age five, so unless the game sucks--which it won't considering who's designing it--I'll enjoy it immensely.
4) Ninokuni. Studio Ghibli meets video games. There are not words to describe how awesome this could be, unless you tack "epic" onto its title too.
5) The Legend of Zelda: Skyward Sword. Ugh, that HUD from the E3 demos looks fugly. But it's a Zelda game, and it involves flying. I'm not completely sold, but it takes some effort to keep me from playing a Zelda game.
6) Dragon Age 2. I've got my reservations about this game. A lot of them, actually. How will a decade long story be implemented? Will the voice actors be good? Will the dialogue wheel make me say something I really didn't want to about a fourth of the time? But I feel like among all the game developers, BioWare have earned my trust enough where I can give them the benefit of the doubt for now.
7) Portal 2. Portal was like crack. A 2-3 hour condensed dose of gaming goodness that left a horrible crash when I realized that was it. It was all over. Now I can get my fix again :)

Of course, I would happily give up all those games if I could get an old-school BioWare style RPG set in the world of Avatar: The Last Airbender. But that only exists in my fantasies XD

The Neuroscience of Christopher Nolan's Inception: Part 2

As a movie, I very much enjoyed Inception, and I'm currently prodding my family to see it again with me. But I'm not addressing the movie's merits as a movie.

Now that I've seen the thing and no longer have to rely on conjecture, I have a few more things to say on elements of the movie, mostly based off of areas that I misinterpreted given the limited information before the movie's release. Obviously, spoilers follow.

1) The difficulty of inception: I've already covered why planting an idea in someone's head really isn't all that hard. Interestingly enough, the movie's version of inception is more complex. It involves planting an idea and making sure that person believes the idea is his/her own. Cobb's argument for the difficult of inception is that people can always trace the source of their ideas if they were from another person. Which is, unfortunately, patently untrue. Tracing the source of an idea involves remembering where it came from. Neuroscience tells us that our memory is reconstructive. We don't remember events or facts in perfect detail--instead, the brain reconstructs events in a fashion that makes sense to it. This is why eyewitness reports, despite being prized by juries, are factually less reliable than other evidence. The ability of any individual to trace the exact genesis of an idea is pretty wishy-washy.

2) Knowing what you don't know you know: The concept of subconsciously knowing things that you're consciously unaware of is older than Freud, and actually has some truth to it. Certain kinds of learning do not require conscious knowledge of learning. Muscle memory is an excellent example of this, illustrated by the famous patient H.M., who had a disastrous surgery for epilepsy that left him unable to form new memories, and presumably an inability to learn new things. However, H.M. consistently improved at motor tasks like tennis, even though every time the researchers handed him a tennis racket, he claimed he had no idea how to play. Another good example of being consciously unaware of knowledge comes from split-brain patients, who have had the connection between the right and left hemispheres of the brain severed. The two halves of the brain then act almost independently, without sharing information with one another. From split-brain studies, it appears that for an individual to be consciously aware of a stimulus, the stimulus has to be processed somewhere down the line by the left side of the brain--the side responsible for language. It might be a stretch, but it seems like conscious knowledge of something depends on our ability to put it into words.

3) The nature of reality: The ending didn't really come as a surprise to me. It would be strange if a Christopher Nolan mind-screw of a movie gave us an unambiguous ending. However, the questions it raises are more complicated than the simplistic "are we brains in a vat" version. As I said in an earlier post, the difference between REM brain activity and awake brain activity comes down to the involvement of the prefrontal cortex, and the availability of sensory input. The way the dream machine worked in the movie seemed to preserve prefrontal cortex functioning for everyone in the dream: Cobb, his team, and Fisher. Otherwise, there is no way they would be able to plan, reason, and keep track of the elaborate heist.

Now, part of the reason why we can distinguish dreams from reality is their sheer weirdness. Without the prefrontal cortex to make sense of the activity of the sensory association areas of the brain, dreams flat out don't make much sense when we wake up. However, the dreams of Inception are fundamentally different from "normal" dreams. First of all, they are constructed by not the individual's sensory association cortices, but by an architect who pulls everyone into a shared dream. Secondly, the prefrontal cortex is active during Inception's dreaming. At this point, I'm venturing into the realm of conjecture, but it seems reasonable that a dream in which the prefrontal cortex is active and making sense of things would indeed be very difficult to distinguish from reality.

Overall, though, I did really like the film. And while a lot of Inception's claims either contradict or muddle what science has discovered about sleep and dreams, I have to give the movie props for constructing its own internal logic about dreams, and sticking to it. Hopefully, I'm off to see it again :)

The Neuroscience of Christopher Nolan's Inception

A Google search for "dream interpretation" brings up over eleven million results. Pop psychology certainly loves this bit of Sigmund Freud's psychoanalytic theory. For Freud and his intellectual successors, dreams were a psychological gold mine. They offered a unique glimpse into the unconscious mind while the conscious mind slept. And Freud was hardly alone in his fascination with our nightly visions: almost every human culture has ascribed some kind of importance to dreams. Joan of Arc supposedly predicted her own death in dreams. The "inexplicable cultural phenomenon" (MST3K guys' words, not mine) that is Twilight occurred to author Stephanie Meyer in a dream. And now director Christopher Nolan takes us into a world of dreams with drugs and a strange machine that sends Leonardo DiCaprio into an individual's dreaming mind.

His purpose? To steal ideas. Inception is based around the premise that individuals can share dream states, and that bizarre machine we've seen in snatches of trailers seems to be the key. So how realistic is all this?

First, a quick crash course on the neuroscience of sleep and dreams. Sleep, typically considered a passive state where nothing's happening, is actually a time of great changes in brain activity. When we sleep, we go through cycles of approximately ninety minutes a piece, with multiple stages of sleep per cycle (conveniently numbered in chronological order). Stage 1 and 2 sleep are relatively shallow--in fact, if participants in sleep experiments are awakened during this period, they might not even remember being asleep. Stages 3 and 4 are what scientists call "slow-wave sleep," after the large slow delta waves that show up on EEGs measuring brain activity. If awakened from this very deep sleep, people are typically confused and groggy.

Yet these four stages have nothing to do with dreaming. In fact, it's only after going through stages 1-4 that we reach the dreaming state of sleep--REM sleep. REM, which stands for rapid eye movement, refers to the state of sleep in which the brain is insanely active. Brain activity of a person in REM sleep bears a lot of resemblance to that of a person who's awake. If startled from REM, people will be alert, responsive, and almost always report that they've been dreaming. However, REM itself doesn't account for much of the time we're asleep. With about four to five sleep cycles per night and about a half hour of REM sleep per cycle, we only enter REM for about two to two and a half hours per night.

That's two hours, give or take a half hour, that we're dreaming and conscious. That's right--conscious. Strike one against Inception, which assumes, as common sense would have it, that dreamers are unconscious. Startlingly, it turns out that we're actually not down and out for the count while we're dreaming, and our brains are aware of what's going on. For example, say you're having a dream about running along the beach. The parts of your brain responsible for motor control become active, as if you were actually running. The visual association cortex of your brain--the part responsible for making sense of information from your eyes--is extremely active, literally "seeing" the beach. Even your eye motions are not random--they resemble the eye movements of a conscious person scanning a scene for information. Your heart rate and blood flow to the brain increases, as does your brain's oxygen consumption.

So why, if you're actually conscious, do dreams make so little sense when you wake? How do you get the crazy dream-scapes seen in the trailers of Inception? One possible explanation is the lack of activity in certain parts of the brain during REM. The prefrontal cortex, located behind your forehead and eyeballs, shows low activity during REM. The prefrontal cortex's job is to make sense of things, plan, execute higher order functions like logic and reasoning, among other functions. The lack of activity in this part of the brain while dreaming may explain why dreams are very vivid, but don't make a whole lot of sense upon waking, as Leo informs Ellen Page in the movie trailer.

Here's where the premise of Inception begins to get a bit implausible. There are indeed common patterns among mental states. Generally speaking, individuals show consistent patterns of brain activation depending on what their mental state is. Someone looking at faces has brain activation in the fusiform face area, on the underside of the brain. Someone listening to music shows activation in the temporal lobe, responsible for hearing and sound. In theory, it would be plausible for two people's brains to share the exact same pattern of brain activation at a given moment in time. We obviously have no technology nowadays that would achieve such a feat, whatever movies like Inception or Avatar might imply, but it is theoretically possible.

However, Leo would be in trouble if he had the exact same brain activation pattern as the dreaming person. Remember that prefrontal cortex? The bit of your brain that makes logical sense of things? His prefrontal cortex would have to remain active in order for him to pull off a heist inside someone else's mind. Otherwise, he'd just be sucked into the dream with no particularly coherent sense of time or planning, just like the rest of us when we dream. So whatever technology he's using would have to replicate the mental patterns of the dreaming person in the sensory areas of his brain, but leave Leo's own prefrontal cortex unaltered.

But let's assume for the moment that Leo can share a dream state with another person, and still keep his own sense of planning, logic, and reason active. What will he find in another person's dreams? Deep dark corporate secrets? Not likely. The premise of Inception is that it's easier to steal secrets from someone's dreaming mind, when the mind is supposedly more vulnerable. However, there's no evidence that REM has anything to do with unconscious desires or deep dark secrets. There is evidence that in animals, REM sleep helps with learning new information, though the evidence is somewhat thinner with humans. Learning is correlated with the amount of REM sleep in humans, but there's no telling if one causes the other. Bottom line is this--Leo might have spent all that time and effort getting into someone's dreaming mind to find nothing useful there.

Even if there is something useful there, there is still the fundamental problem that dreamers are conscious. In neuroscience terms, consciousness roughly refers to awareness of thoughts, perceptions, emotions, and memories. When experimenters wake sleeping participants from REM sleep, they are alert and perceptive. When asked to describe their dreams, they show signs of consciousness, giving details of how their dreams looked, what they felt, what they did within the dream, etc. Even if their prefrontal cortices were inactive and their dreams are strange and disjointed, participants were still conscious in their dreams, even if it was different from wakeful consciousness.

Bottom line is this--Leo would most likely go through all that trouble with futuristic technology to enter someone else's dream state, only to find a dream that has none of the information he wants, and a very much conscious dreamer capable of reacting to events in the dream, including his intrusion. But that's just half of the equation. What about inception, his ultimate challenge of planting an idea in a dreamer's mind rather than taking it?

The film synopsis and marketing so far have made a huge deal of the difficulty of inception, but neuroscience and psychology tell us that planting an idea inside someone's head without them noticing is actually surprisingly easy, even when that person is awake. Hysteria about subliminal messages and brainwashing aside, it is possible to "prime" people subliminally in visual experiments. Priming involves rapidly flashing a word, too quickly for it to be consciously processed. If primed with one word, participants will tend to pick related words, like picking the word bedroom over the word elephant if primed with the word "house." This is just one example of the subtle but real ways in which ideas can be influenced without the person's conscious awareness.

In conclusion, Leo would really have an easier time of getting what he wanted if he stuck to good, old-fashioned conversation with a person while conscious. The premise of Inception is not entirely unrealistic, but it certainly is extremely impractical, even if the strange dream-sharing technology in the film did exist.