Gorgeous papercraft by Estonian artist Eiko Ojala for a New York Times article on how sleep serves as the brain’s janitor:
A series of new studies … may at last be shedding light on just what it is that would be important enough. Sleep, it turns out, may play a crucial role in our brain’s physiological maintenance. As your body sleeps, your brain is quite actively playing the part of mental janitor: It’s clearing out all of the junk that has accumulated as a result of your daily thinking.
Nothing new, of course, since we already know that REM sleep helps us regulate the negative emotions that accumulate during our waking hours, but there’s more. And yet, the NYT article continues, this is cause for alarm:
Modern society is increasingly ill equipped to provide our brains with the requisite cleaning time. The figures are stark. Some 80 percent of working adults suffer to some extent from sleep deprivation. According to the National Sleep Foundation, adults should sleep seven to nine hours. On average, we’re getting one to two hours less sleep a night than we did 50 to 100 years ago and 38 minutes less on weeknights than we did as little as 10 years ago. Between 50 and 70 million people in the United States suffer from some form of chronic sleep disorder. When our sleep is disturbed, whatever the cause, our cleaning system breaks down. At the University of Pennsylvania’s Center for Sleep and Circadian Neurobiology, Sigrid Veasey has been focusing on precisely how restless nights disturb the brain’s normal metabolism. What happens to our cognitive function when the trash piles up?
At the extreme end, the result could be the acceleration of neurodegenerative diseases like Alzheimer’s and Parkinson’s.
It’s a pernicious cycle. We work longer hours, become more stressed, sleep less, impair our brain’s ability to clean up after all that hard work, and become even less able to sleep soundly.
No wonder we suffer from “social jet lag.” And yet:
There is, however, reason to hope. If the main function of sleep is to take out our neural trash, that insight could eventually enable a new understanding of both neurodegenerative diseases and regular, age-related cognitive decline. By developing a diagnostic test to measure how well the glymphatic system functions, we could move one step closer to predicting someone’s risk of developing conditions like Alzheimer’s or other forms of dementia: The faster the fluids clear the decks, the more effectively the brain’s metabolism is functioning.
Pair the full article with this excellent read on the science of our internal time, then see what happens while you sleep and how it affects your every waking moment.