The waking dream

Yesterday's post, about the generally bizarre nature of dream content, prompted a friend and loyal reader of Skeptophilia, the amazing writer A. J. Aalto, to send me a link to a study done a while back in Switzerland that showed that our dream content sometimes forms a continuum with our waking experience.

The author and lead researcher, Sophie Schwartz of the Department of Neuroscience at the University of Geneva, did a clever study where volunteers were instructed to play the computer game Alpine Racer II, wherein the player stands on a movable platform that tracks his/her movements, while an avatar skis downhill on the computer screen.  To be successful in the game, the player has not only to exhibit balance, coordination, and motor skill, but to focus visually on the task and ignore any distractions.  Schwartz then had the players record their dream content, comparing it to people who had only watched the game, and control volunteers who had done an unrelated activity.

Schwartz writes:

After training on the Alpine Racer, 30% of spontaneous mentation collected at different times during pre-sleep wakefulness and light NREM sleep (up to 300 sec after sleep onset) contained imagery (of any modality, 24%) or thoughts (6%) related to the skiing game.  Wamsley et al. also found that imagery directly related to training on the game (unambiguous representations of the Alpine Racer or of skiing) declined across time.  This time-course was paralleled by a tendency for game-related incorporations to become more abstracted from the original experience.  These findings do not only provide empirical evidence for spontaneous memory replay during wakefulness and light NREM sleep (stages 1 and 2), but they show that reports of subjective experience offer valuable information about cognitive processes across changing brain states.

Schwartz acknowledges that the high rate of incorporation of skiing imagery into the players' dreams probably had to do with the degree of attention the game required:

High levels of incorporation of Alpine Racer are most plausibly related to the strong motivational and attentional involvement of the player during the game.  Consistent with this interpretation, a few participants who only observed those playing Alpine Racer also incorporated elements of the game into their sleep-onset mentation, at rates similar to the participants who were actively engaged in the game.  These effects and their time-course suggest that novelty may be a critical factor for the selection of material to be mentally replayed.  Moreover, many baseline night reports incorporated thought or imagery related to the game (compared to a control set of sleep-onset mentation reports), indicating that the mere anticipation of the task could trigger prospective memory processes that emerged at sleep onset.  It is tempting to speculate that hypnagogic imagery may contribute to the integration of recent experiences with long-term memories and future goals.

This is consistent with my wife's memories of being in graduate school and spending an inordinate amount of time avoiding doing her research by playing Tetris.  She realized she should probably stop when she started having dreams of brightly-colored blocks falling from the sky, and fortunately was able to curb her Tetris addiction before her adviser had to stage an intervention.

For myself, I can't say that I see a lot of incorporation of waking experience into my dreams.  Much of my dream content seems to fall squarely into the category of "What the fuck?", such as a recent dream wherein I was filling our bathtub with styrofoam peanuts, except they kept melting and running down the drain, which made even less sense when I looked up and realized that the bathtub wasn't in my house, it was in the middle of the Sahara Desert.

None of which, I can assure you without hesitation, was a continuation of anything I'd been doing that day.

I've also noticed a tendency in my more reality-based dreams to have more content with strong emotional charge than that with any connection to recent events.  I've been teaching for thirty years, and I still have frequent teaching-anxiety dreams -- that my students aren't listening or are misbehaving, that I get confused or off track during a lecture and can't remember what I'm supposed to be doing, even that I'm wandering around the halls in the school and can't find my classroom.  I also have dreams of losing loved ones or pets, dreams of witnessing violence, dreams of being trapped -- all of which have a powerful emotional content.

But I haven't noticed much tendency for my dream content to exhibit Schwartz's continuance from the waking state.  In fact, I can recall many times when I expected to dream about something -- when I've been involved all day in a project, or (especially) when I've watched a scary or emotionally powerful movie -- and it almost never happens.

So once more, we're back to dreams being mysterious, and any explanations we have regarding dream content being incomplete at best.  Which, of course, is part of their fascination.  I'll definitely be giving this topic more thought, once I've figured out what to do with all of these melted styrofoam peanuts.

Live your dream! Unless it's the one where you're naked on the bus.

Last night I had the strangest dream, but it wasn't about a girl in a black bikini (sorry if you're too young to get that reference).  One of my coworkers was going to be interviewed on public television by Yoko Ono.  I won't mention who the interviewee was, but trust me, if there was a list of people who were likely to be interviewed by Yoko Ono, this person would be near the bottom.  So anyway, I was being driven to this event by our school psychologist, but we were going to be late because he had the sudden overwhelming need to find a grocery store so he could buy a bag of potato chips.

I won't go any further into it, because at that point it started to get a little weird.

It is an open question why people dream, but virtually everyone does.  During the REM (rapid eye movement) stage of sleep, there are parts of the mind that are as active as they are during wakefulness.  This observation led brain scientists to call this stage "paradoxical sleep" -- paradoxical because while the body is usually very relaxed, the brain is firing like crazy.

Well, parts of it are.  While the visual and auditory centers are lighting up like a Christmas tree, your prefrontal cortex is snoozing in a deck chair.  The prefrontal cortex is your decision-making module and reality filter, and this at least partly explains why dreams seem so normal while you're in them but so bizarre when you wake up and your prefrontal cortex has a chance to reboot.

[image courtesy of the Wikimedia Commons]

The content of dreams has been a subject of speculation for years, and all available evidence indicates that the little "Your Dreams Interpreted" books you can buy in the supermarket checkout lines are unadulterated horse waste.  Apparently there is some thought that much of our dream content is involved with processing long-term memories; but equally plausible theories suggest that dreaming is a way of resetting our dopamine and serotonin receptors, or a way of decommissioning old neural pathways (so-called "parasitic nodes").  Probably, it aids in all three.  Whatever it is, however, it's important -- all mammal species tested undergo REM sleep, some for as much as eight hours a night.

Anyone who's a dog owner probably knew that already, of course.  Both of my dogs dream, as evidenced by their behavior while they're asleep.  My coonhound, Lena, has squirrel-chasing dreams, which makes sense because while she's awake two of her three operational brain cells are devoted to constant monitoring of our backyard squirrel population.  She'll be lying there, completely sacked out, then suddenly she'll woof softly under her breath, and her paws will twitch as if she were running after her prey.  Every once in a while she apparently catches one, because she'll go, "Rrrrrrr," and shake her head as if tearing a squirrel apart.

Grendel, on the other hand, tends to have happy, sweet dreams.  He'll twitch and sigh... and then his tail starts wagging.  Which is a top contender for the cutest thing I've ever seen in my life.

As far as human dreams go, it's interesting that there is a fairly consistent set of content types in dreams, regardless of your culture or background.  Some of the more common ones are dreams of falling, being chased, fighting, seeing someone who has died, having sexual experiences, being in a public place while inappropriately dressed, and being unable to attend interviews by Yoko Ono because of searching for potato chips.

A few well-documented but less common dreamlike experiences include lucid dreams (being aware that you're dreaming while it's happening), hypnagogic experiences (dreams in light sleep rather than REM), and night terrors (terrifying dreams during deep sleep).  This last-mentioned is something that is found almost exclusively in children, and almost always ceases entirely by age twelve.  My younger son had night terrors, and the first time it happened was truly one of the scariest things I've ever experienced.  At 11:30 one night he started shrieking hysterically, over and over.  I jumped out of bed and ran down the hall like a fury, to find him sitting bolt upright in bed, trembling, eyes wide open, and drenched with sweat.  I ran to him and said, "What's wrong?"  He pointed to an empty corner of the room and said, "It's staring at me!"

I should mention at this point that I had just recently watched the movie The Sixth Sense.

When I finished peeing my pants, I was able to pull myself together enough to realize that he was having a night terror, and that there were in fact no spirits of dead people staring at him from the corner of his bedroom.  When I got him calmed down, he went back into a deep sleep -- and the next morning remembered nothing at all.

I, on the other hand, required several months of therapy to recover completely.

Whatever purpose dreams and other associated phenomena serve, there is no evidence whatsoever that they are "supernatural" in any sense.  Precognitive dreams, for instance, most likely occur because you dream every night, about a relatively restricted number of types of events, and just by the law of large numbers at some point you'll probably dream something that will end up resembling a future event.  There is no mystical significance to the content of our dreams -- it is formed of our own thoughts and memories, both pleasant and unpleasant; our fears and desires and wishes, our emotions and knowledge; so they are at their base a reflection of the bits and pieces of who we are.   It's no wonder that they are funny, scary, weird, complex, erotic, disturbing, exhilarating, and perplexing, because we are all of those things.

So, next time you're in the midst of a crazy dream, you can be comforted by the fact that you are having an experience that is shared by all of humanity, and most other mammals as well.  What you're dreaming is no more significant, but also no more peculiar, than what the rest of us are dreaming.  Just sit back and enjoy the show.  And give my regards to Yoko Ono.