I'd never heard of acetylcholine, but now that I know what it does, I'm abjectly grateful. Acetylcholine is the sovereign chemical in your dream life, the logic that fuels illogic. When you dream you're flying, or have just stepped onstage naked, or are taking tea with a badger, it's because brainstem neurons "[flipped] a switch that completely altered the brain's balance of neurotransmitters" writes Andrea Rock in her captivating "The Mind at Night: The New Science of How and Why We Dream" (Basic, 2004).

Flip that switch, and the "daytime" chemicals sign off shift. Goodbye to norepinephrine (which helps focus our attention) and serotonin (which helps regulates mood, judgment, and memory). And hello to acetylcholine, which hyper-stimulates the visual, motor, and emotional parts of our brains — and triggers our rapid eye movement (REM) stage of deep sleep and dreaming. "The acetylcholine-soaked brain operates under entirely different rules from its waking state," Rock explains.


In short, no norepinephrine and serotonin, no reality check. This explains why we have over-the-top anxiety dreams, erotic dreams, nightmares, nonsensical jump cuts — and why we have trouble remembering them. Freud and Jung, of course, came at the subject from a psychological, not biochemical, perspective. To them, dreams unveiled the id's primal desires, spurred by the "day residue" of unfulfilled wishes.

I personally think dreams have spiritual, psychological, and neurobiological roots: Why pick one? But Rock cleaves soft science from hard. Indeed, her first chapter presents Eugene Aserinsky, a University of Chicago grad student who, in the 1950s, discovered REM by taping electrodes on his 8-year-old son and watching him sleep. Then it's on to Harvard psychiatrist J. Allan Hobson, who in the 1970s did pioneering studies on neurochemistry during REM sleep (he's the guy who hit on acetylcholine's powers). Rock covers other subtopics, too, like children's dreams plus the connection between dreaming and mental illness.


Long ago, when things weren't good with a boyfriend, I had a recurring dream in which my knees were disfigured with deep cuts and bruises. My friend Ellen half-joked my knees were my needs, which weren't being met. It turns out there's a long history of dreaming in puns, one of the many pearls I fished from "Dreams: A Reader on the Religious, Cultural, and Psychological Dimensions of Dreaming" (Palgrave Macmillan, 2001), edited by Kelly Bulkeley. Some ancient Egyptians, for instance, believed that if a man dreamt he was eating donkey meat ('at) it meant he would become great (s'at).

The anthology brims with cultural context, from Buddhist to Islamic to various tribal dream traditions. Such wonderfully obscure takeaways: In Brazil's Kagwahiv tribe, if you dream about a party, it means you'll be successful at hunting the white-lipped peccary. Also, westerners "have" a dream, but South Asians "see" a dream, believing it's gifted to them by a deity rather than self-created. They see the dream — and the dream sees them.

"Dreams and Experience in Classical Antiquity" (Harvard University, 2009) asks this novel question: How did people used to dream? Columbia University historian William V. Harris reveals that moderns are better at recounting dreams because we "have much greater tolerance for the disjointed and the inconclusive." But the ancient Greeks and Romans "abhorred incomplete stories" and thus "favoured the improvement and hence distortion of dream-descriptions" in the records that have survived.


As a result, our dreams read more episodic and theirs more cohesive. Does modernity promote disjointedness? Or did the ancients tidy up their retelling? No one knows, but Harris does exhaustive research in art and literature (citing Aristotle, Empedocles, Galen, and more) and finds that people more frequently had "epiphany" dreams back then, in which a god gave the dreamer sage advice. But we're more likely to dream of zoos than Zeus.

Anyone can thumb a dream-symbol dictionary and find that, say, a parakeet means a lack of initiative (huh?). But Stase Michaels says these sources offer a "cookie-cutter approach to images" because we each hold our own personal trove of symbols. In "A Little Bit of Dreams: An Introduction to Dream Interpretation" (Sterling Ethos, 2015), she offers a five-step analytical approach that's highly customizable. It includes examining the emotions of the dream, creating a storyline, and linking the narrative to your life. I used it on several recent dreams. It was illuminating.

Michaels also offers unexpected reassurance: To all you readers who've dreamed of having sex with someone you despise (it's very common), check out her remarkable explanation: "[B]ecause prolonged animosity toward another is unhealthy (emotionally and psychologically), the psyche manufactures an intense, pleasant experience to jump-start a change in attitude about that person."

She also said that the brain sorts between what is completed and what needs attention. And dreams, through exaggerated metaphor, highlight the latter — i.e., there's a reason I didn't dream of a tiny scratch on my knee. I later broke up with that boyfriend. As Delmore Schwartz wrote, in dreams begin responsibilities.


Katharine Whittemore is a freelance writer based in Northampton. She can be reached at katharine.whittemore@ comcast.net.