We spend a major portion of our lives tucked between the sheets, and yet many of us know very little about the “why”s and “how”s of sleep. This video about the science of sleep asks the important and surprisingly tricky question: Why do we sleep? The answer is … wait for it … er, no one is really sure.
There are a lot of theories as to why we have to power down for a third of our days. Joe Hanson, host and creator of It’s OK To Be Smart from PBS Digital Studios, points out that, even if we don’t know precisely what sleep does, we do know that it is absolutely vital: extreme sleep deprivation, for example, has been shown to cause seizures and even death in animals. Some common theories as to why we sleep don’t fully account for its importance in our lives and health. Hanson explains that, for instance, while we do quite a bit of “general biological upkeep” (such as “cellular repair,” “protein synthesis,” and so on) in our sleep, we also perform these activities when we’re awake.
One theory about the purpose of sleep is that sleep allows us to, as Hanson puts it, “flush out all the neurogarbage” that builds up in our brain cells and neurons. (Can I just point out that “neurogarbage” is a fantastic word? I’ve decided that “Neurogarbage” will be the title of my undoubtedly bestselling memoir). Another theory suggests that sleep is the only time that our prefrontal cortexes have a chance to rest.
As Hanson points out, when you think about it from an
evolutionary stand point, sleep doesn’t make a lot of sense — after all, sleep
represents an extended time when animals can’t escape from predators. Certain
animals have evolved to accommodate sleep in weird ways. Dolphins, for
instance, avoid drowning by sleeping with only one half of their brains at a
time. Baby dolphins have to get by on taking short naps while being supported
by their parents. (How cute is that?!)
Although sleep still holds a lot of mysteries, what we do
know is that we all need sleep — regularly and abundantly. The average adult
only gets 6.5 hours of sleep, and the average teen gets about 5 — just over
half of the 8.5 to 9.5 hours of sleep recommended for teens by the American
Academy of Pediatrics. Adults
between the ages of 18 and 64 should be aiming for seven
to nine hours, according to the Sleep Foundation. One barrier for sleep for
many people is exposure to bright light at night. Our circadian rhythms — the
bodily rhythms that tell us when to be asleep and awake — are affected by light
and darkness. When it’s light, our bodies think it’s time to be awake, and when
it’s dark, our bodies hit the snooze button. By constantly being tied to light
sources at night, like computer and phone screens, we can throw off our
circadian rhythms and make it difficult for our bodies to know when to sleep.
As Hanson explains, “Depression, heart disease, diabetes, and cancer have all
been linked to chronic overexposure to artificial light.”
yourself a better night’s sleep, try to put away your electronic devices in
the hours before bedtime, and try to have a regular sleep schedule. Avoiding caffeine
in the afternoons and evenings can also help you to get the zzzs you need.
Watch the whole video below:
Images: Pexels; YouTube (4)