lection

when brains dream

8 june 2021

Scientists Tony Zadra and Bob Stickgold inform the reader, in their affable When Brains Dream, about the current state of dream research. Though I found their approach a little more functionalist and sanguine than my own introspective sense of dreams might warrant, I learned a lot from their book; and I imagine they are correct a lot of the time, given the parameters they've used to study dream matters.

Zadra and Stickgold present a model of dream function they call NEXTUP, which stands for "Network EXploration To Understand Possibilities." I find this acronym impossible to remember, which may say more about the failures of my own NEXTUP processes than the authors' acronyming skills. Basically, NEXTUP says that a lot of stuff happens during a waking day. The brain can't handle it all, so it needs an hour of processing each night to deal with the experiences of each two hours while awake …

… which at first blush is kind of overwhelming. I mean, very little happens in my brain's typical day except the quandary of whether to eat a peanut-butter or a cheese sandwich for lunch. The idea that I need to spend half as much time in mental shutdown in order to cope with the psychic freight of it all is daunting. But in any case …

… in hypnagogic sleep, which belongs to the "N1" physiological stage just as and after you're falling asleep, the brain works mainly with words and still images to "identify and tag concerns" for later dreaming to deal with. Contrary to popular belief, or at least to mine going in, we dream at all stages of sleep, not just in rapid-eye-movement or REM sleep later in the night. But during REM sleep our dreams turn narrative and multi-sensory, as well as sometimes weird, and our brains make lots of distant associations to bring images and concepts together. This out-of-left-field characteristic of dreaming, activating pathways that the conscious brain wouldn't have time or leisure to invoke, helps us form memories and solve problems.

The memory part raises another issue: why would I want to remember whether I had cheese or peanut butter? Isn't there enough useless junk in a waking day without having to spend all night fixing it in archival form? But Zadra and Stickgold conceive of memory as an creative process: we don't fix memories, we evolve them. Dreaming may well help us forget the chronicles of waking life and retain the "gist," the Platonic ideal of cheese or of peanut butter that makes the next day's choice easier.

Problem-solving is more intuitive; everybody knows how some intractable issue seems easier to tackle in the morning after a night of dreaming about goofy unrelated nonsense. Though here too, it strikes me that empirical, experimental research of the kind that Zadra and Stickgold conduct and report on privileges things like memory processing and problem solving. Dream researchers often measure what the brain does while dreaming by setting puzzles for people or assigning them memory quizzes. When they do better on such tasks after dreaming, the conclusion is that that's what dreaming is for. But other dynamics, harder to measure empirically, may be even more central to dreaming.

By contrast, Zadra and Stickgold downplay the emotional function of dreaming. "Everyday dreams aren't very intense," they say (153); and partly I think this is because emotional content is hard to measure ("some studies don't measure discrete categories of emotions in dreams at all … it can all get quite messy," 152). Instead the authors present a generally positive, rational picture of humanity dreaming away, filing things in useful arrangements, weeding out the clutter, honing the efficiency of our daily algorithms.

Meanwhile, I seem to be pursued, on a nightly basis, by unknown assailants through mysterious cities, getting lost in vast hotels, losing clothes and keys, watching planes crash and fending off chimerical monsters. Or is that just my daytime self concentrating the greatest hits of my dream world into retailable narratives for y'all to read and hear? Maybe I just do five minutes of wild dreaming per night, after 7:55 of "where would be the optimal place to park tomorrow." Zadra and Stickgold make the excellent point that nobody tells their shrink about their boring dreams. So selection bias tells us that dreams are wacky, frightening, and portentous.

And of course some are. Zadra and Stickgold talk about nightmares, obsessively recurrent dreams, lucid dreams, sleepwalking, PTSD flashbacks. These are rare, though, they say, and largely feature as hiccups in the placid functioning of the NEXTUP mechanism. One type of dream they rightly discount is the prophetic dream. Many people report foreseeing disasters, deaths, and the like; but they do so after the fact, and their precognitions share with waking attempts at prophecy an extreme bias. At least one person in every river city on earth will dream tonight that a bridge is collapsing, but the only ones who say anything do so after their local bridge really does collapse three days from now.

Zadra and Stickgold offer tips on how to use your dreams more creatively, and even how, if you set your mind to it, you can cultivate lucid dreaming, the kind where you are aware of being a dreamer and can sometimes wrest your dreams to your liking. I don't think I'm going to use these tips but it is interesting that the unconscious can be so amenable to conscious intervention. When Brains Dream gives the sense that life is more manageable … than we might dream.

Zadra, Antonio, and Robert Stickgold. When Brains Dream: Exploring the science and mystery of sleep. New York: Norton, 2021. RA 786 .Z33

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