As a chronic insomniac, I’m always a little disturbed when I learn about the lingering cognitive effects of a bad night sleep:
In a study at the Walter Reed Army Institute of Research in 2003, for example, scientists examined the cognitive effects of a week of poor sleep, followed by three days of sleeping at least eight hours a night. The scientists found that the “recovery” sleep did not fully reverse declines in performance on a test of reaction times and other psychomotor tasks, especially for subjects who had been forced to sleep only three or five hours a night.
In a similar study in 2008, scientists at the Karolinska Institute in Stockholm found that when subjects slept four hours a night over five days, and then “recovered” with eight hours a night over the following week, they still showed slight residual cognitive impairments a week later, even though they reported no sleepiness.
In a recent study for The Archives of Internal Medicine, scientists followed 153 men and women for two weeks, keeping track of their quality and duration of sleep. Then, during a five-day period, they quarantined the subjects and exposed them to cold viruses. Those who slept an average of fewer than seven hours a night, it turned out, were three times as likely to get sick as those who averaged at least eight hours.
My problem with these studies is that they make me less likely to fall asleep. To understand why, let’s play a simple game with only one rule: Don’t think about white bears. You can think about anything else, but you can’t think about that. Ready? Close your eyes, take a deep breath, and banish the animals from your head.
You just lost the game. Everyone loses the game. As Dostoevsky observed in Winter Notes on Summer Impressions: “Try to avoid thinking of a white bear, and you will see that the cursed thing will come to mind every minute.” In fact, whenever we try not to think about something that something gets trapped in the mind, stuck in the recursive loop of self-consciousness. Our attempt at repression turns into an odd fixation.
This human frailty has profound consequences. Dan Wegner, a psychologist at Harvard, refers to the failure as an “ironic” mental process. Whenever we establish a mental goal – such as trying not to think about white bears – the goal is accompanied by an inevitable follow-up thought, as the brain checks to see if we’re making progress. The end result, of course, is that we obsess over the one thing we’re trying to avoid.
What does this have to do with sleep? For me, insomnia is my white bear. My conscious goal is to fall asleep, which then causes my unconscious to continually check up on whether or not I’m achieving my goal. And so, after passing out for thirty seconds, I’m jolted awake by my perverse brain. It’s rather frustrating.
And this is why I can’t help but grit my teeth when I hear about how important a good night sleep is. I know it’s important, OK? I don’t need more reasons to try to fall asleep, because the more I want to fall asleep – the more intensely I’m trying to achieve my goal – the less likely I am to actually pass out. I’ll lie awake, haunted by thoughts of white bears and cognitive deficits.