Sleep, from apnea to zzz’s

The behavioral biologist Paul Martin loves sleep. His “Counting Sheep” is a paean to the slumbering world and a jeremiad about why we all need more of it. People who don’t sleep enough have bigger bellies, less friendly demeanors and weaker immune systems than people who get Martin’s recommended eight hours a night of shut-eye. The sleep-deprived crash their cars more often too.

Martin cites data estimating that sleepiness results in about 22% of car accidents, measured partly by the number of collisions not preceded by skid marks. The switch to daylight saving time makes people tired and causes the number of car accidents to spike each year. Somnolent doctors -- and there are plenty -- not only make bad operating decisions but also crash their cars frequently going home, creating more work for their colleagues.

Sleepy children are sometimes diagnosed with attention-deficit disorder and given Ritalin, which makes sleeping harder. Sleepy adolescents do worse on standardized tests and take more risks because fatigue makes people cocky. Sleepy adults are more likely to shake their babies and perhaps kill them.

Fortunately, more sleep reverses all of these problems while letting us enter a netherworld of dreams and imagination. Martin recommends setting your alarm clock back half an hour, if not tossing it completely, and he recommends writing down your dreams so you can revel in them. He also recommends napping: “Spending 20 minutes a day in a nap room is just as worthy and rational as spending 20 minutes a day in a gym.”

Martin’s main agenda is to reverse the cult of the comatose in a country in which not sleeping is associated with virility and dedication. He wants the fresh-eyed people around the water cooler to have the early-morning moral high ground in the office, not the trolls who lug themselves in while bragging of hardly sleeping the night before. “Those who stumble through life on only five or six hours of poor-quality sleep a night are admired for their stamina, in the way that people were once admired for their capacity to drive cars while drunk,” he writes.

But he also wants to educate us about this mysterious third of our lives, and his book is extraordinarily wide-ranging. “Counting Sheep” takes on snoring, sleep apnea, nighttime erections and the proper body temperature for maximizing the quality of sleep. He even has self-help suggestions for insomniacs and recommendations for people who want to learn how to dream lucidly, a state in which the dreamer is semiaware and able to move about his imagination.

Martin’s section on the four stages of sleep is particularly fascinating and clearly explained. Sleep begins with what’s called the hypnagogic stage, in which our brains resemble a state similar to that seen in people meditating. Gradually we move toward REM sleep, the last and most intense of the stages that make up the 90-minute cycles that our minds travel through as we sleep. As many people know, we dream most heavily in this stage, with the whole body except for the eyes paralyzed. But this paralysis is just a small step away from mayhem. Cutting the nerve endings that control the paralysis of cats during REM sleep sends them dashing about, pouncing on imaginary prey.

Martin provides detailed scientific explanation of his arguments and admits where the biology is shaky. For example, he admits that no one really knows why we dream. Martin’s hypothesis is that we do so mainly to process memories. People engaged in intensive learning have particularly intense REM cycles. People, or rats, deprived of REM sleep for a night do not transfer what happened that day into their long-term memories. But Martin doesn’t claim to be surer than the science reasonably allows.

Unfortunately, Martin’s book is often repetitive and it doesn’t have a clear narrative. The book also occasionally lapses because of its outrage. For example, Martin posits that people who regularly get little sleep might essentially just fake wakefulness during the daytime because their brains show some of the increased synchronicity of neural activity that marks the early stages of sleep. “Their distinguishing feature may be that they are simply more tolerant of being tired,” he writes. Martin puts that down as a bad thing and moves on. But isn’t that tolerance at least somewhat of a good thing if it allows people to limit the time spent nodding off from their work and lives?

Still, Martin is extremely convincing in his overall argument and compensates for his slips by throwing in wonderful quotes and stories throughout. Groucho Marx once said that he stayed awake by subtracting sheep. Dolphins sleep with only one-half of their brain at any given time, so that they can always bob to the surface for oxygen. An 1851 invention called the “Alarum Bedstead” tried to wake people up first with a bell, then by stripping their bedsheets, then by tilting their mattress sideways at a 45-degree angle.

“Counting Sheep” probably wasn’t intended to be read straight through. Instead, thumb through chapters periodically. To make the author happiest right now, go buy the book and carefully place it on your nightstand. Then crawl into bed and take a nap. *