What I’m Reading: Why We Sleep, Matthew Walker

Author: James McKenzie ’71Ph.D.

Persistent medical issues recently shunted me through a sequence of “ologists” to what felt like the end of the line: someone called, less grandly, a “sleep doctor.” Yawn. I confess to having felt a twinge of grumpy-old-man skepticism. What next? Doctors who specialize in the eyebrow or the bellybutton?

But when sleep-lab data showed me that I stopped breathing more than 35 times an hour — “severe sleep apnea” — I paid attention. Among several other adverse effects of such significant sleep disruption, I had developed 100-percent atrial fibrillation and was retaining blood in both of my heart’s upper chambers. I was inviting a serious stroke.


Regular use of a CPAP (continuous positive air pressure) device became a no-brainer, but I was unprepared for a wonderful side-effect of the annoying medical gizmo that I strap to my face most nights: My dream life blossomed as never before.

Sometimes these dreams are goofy, oddly entertaining fragments. Sometimes they’re frightening or depressing, no doubt reflecting current anxieties or conflicts. But every once in a while, my nose gripped in the contraption’s soft plastic mask, I experience powerful, healing storylines — lengthy sequences connecting important people and events from long ago (I am in my 82nd year) with understandings and perspectives that neither I nor others could have had when we were present together.

I’ve dreamed calm, ordinary conversations about taboo subjects with my 40-years-dead, once terrifyingly abusive father. I’ve encountered priests and other figures from my black-and-white, absolutist Catholic upbringing and my high-school years in a Capuchin seminary. Formerly nightmarish obsessions about damnation that I recall from my teens and early 20s have dissolved into benign stories about sacraments.  

I awake from these rarer, most welcome, vivid dreamscapes feeling a quiet wholeness that lies beyond my ability to describe. Painful events have not been forgotten, erased or “forgiven.” Something far grander is going on, some profound integration. Long-past wounds and confusions  seem rather to have been folded into some new, equally real, complex mosaic that I and others inhabit congenially together. Time and my share of psychological therapy have done their good work over the years, but these while-I-dream events, offer special, unexpected nourishment. Awakening, I savor them as if they have happened. Their effects linger in my recollected life.

I am experiencing what neuroscientist Matthew Walker, in his 2017 book, Why We Sleep, calls “overnight therapy,” an internal “nursing” of my emotional and mental health. The book’s subtitle, Unlocking the Power of Sleep and Dreams, winks at my experience of reading it. Never mind that it suggests the influence of the marketing department. Walker, who directs the Center for Human Sleep Science at the University of California, Berkeley, does conveniently include a two-page, how-to appendix, “Twelve Tips for Healthy Sleep,” from the National Library of Medicine, but more importantly, he is on a global health mission to all humanity.

“A balanced diet and exercise are of vital importance,” he writes, “but we now see sleep as a preeminent force in this health trinity. The physical and mental impairments caused by one night of bad sleep dwarf those caused by an equivalent absence of food or exercise.”

Walker’s writing is accessible and grounded in many hundreds of sleep studies, but the work as a whole shows how this activity to which we all devote roughly one-third of our lives is “so much more than the absence of wakefulness.” He never strays far from either the hard data or the humility and “awe” he still experiences in his own sleep lab while watching the neural synchrony of slow brainwaves in “an astonishing act of self-organization, many thousands of brain cells . . . decid[ing] to unite and ‘sing’ or fire, in time.”

Why We Sleep raids classic and popular cultures to nudge humanity back toward healthier sleep — finding insights in Shakespeare, Charlotte Brontë, Billy Crystal, Pink Floyd, Ken Kesey, and many others. He presses the Roman rhetorician Quintilian into service to explore the connections between sleep and memory. Quintilian observed “a curious fact”: “that the interval of a single night will greatly increase the strength of the memory” so that what could not be recalled the day before pops back up, and “time itself, which is generally accounted one of the causes of forgetfulness, actually serves to strengthen the memory.” He is patient with knowing that “the reason is not obvious” for this curiosity he’s observed.

Two millennia later, sleep research has established an explanation: a memory-sorting function wherein Rapid Eye Movement, or REM, sleep integrates the preferred information the brain has stored from an earlier, deeper non-REM (NREM) sleep, which Walker describes as “a shamanistic state.” The two states combine to make a “quite beautiful cycling architecture of sleep.” The switch occurs about every 90 minutes as the brain tries to “find the ‘sweet spot’ between retention of old information and leaving sufficient room for the new.” It’s all about storage: what’s most necessary for an individual’s emotional and physical health and safety.

The pattern is discernible in Walker’s sleep graph (a “hypnogram”!), one of many readily intelligible diagrams in the book. REM sleep, a more recent mammalian and avian evolution, actually paralyzes the body’s motor functions while the brain plays out dream scenarios which, if the sleeping body were to act upon, could endanger the sleeper or bedmate. (Better not swing at that monster or flap one’s arms in flight.)

Before becoming a global leader in sleep study, Walker studied dementia. I can think of no greater indication of how consequential that redirection of his work has become than to say that at one point he turns the book’s title on its head. “Why did life ever bother to wake up?” he asks, a question from a different specialty, theology. I join Walker in this pondering while I await more healing dream stories, in what time is left to me.

James McKenzie, professor emeritus of English at the University of North Dakota, lives and writes in St. Paul, Minnesota. His occasional essays for Notre Dame Magazine include “The Redeeming Grace of Manual Labor.”