By Sara Fullerton
Until Thomas Edison’s invention of the lightbulb in 1897, people’s activities were largely dictated by the natural world, which offered them light or dark at no choice of their own. In his review of Matthew Walker’s book “Why We Sleep,” New York Times writer David Kamp reflected that the light bulb was, “As much a profound upending of the natural order as it was a huge technological advance.” Where pre-lightbulb rhetoric about sleep described it as something sacred, like “nature’s soft nurse,” Edison rewrote it as mere “heritage from our cave days” and a “criminal waste of time.”
Modern thinking is riddled with ill thoughts about sleep. Inadequate sleep has become a status symbol, indicating one’s intellectual capacity, productivity and strength. The capitalist world is driven by the sentiment “Money never sleeps.” Since there is nothing externally quantifiable happening while we sleep, it is deemed valueless.
TEDx speaker Jessa Gamble has explained that our species originated near the equator, so we evolved to be most optimally suited to conditions of about 12 hours of light followed by 12 hours of darkness. Sleep, though, is far from being something to fill the gap that darkness creates.
Russell Foster is a circadian neuroscientist, which means he studies the internal clocks that exist in almost all living beings, and guide our cycles of wakefulness and sleep. These “body clocks” evolved to be responsive to predictable outside conditions, but they also transcend them. They do not rely on external cues to function.
A series of bunker studies were conducted from 1964-1989 on 447 human volunteers, each of whom would live in the bunkers for spans of about two months. These bunkers are deemed timeless environments, in that they isolated subjects from any external cues of temporality, and participants were able to self-select when they wanted lights on or off.
Results showed that humans did follow activity patterns that closely matched a 24-hour day even without external cues. It seems clear that any evolutionary function that takes up an average of about a third of each of our lifetimes must be more than a waste of time. A look into the brain during sleep reveals that many cognitive structures are activated more during sleep than wakefulness.
Neurological studies have demonstrated that sleep enhances problem-solving capacities, creativity, and sorts and makes meaning of memories. Sleep is a multifaceted physical process. It is not initiated by any single brain structure, but is the product of many interactions. The optimal night’s rest contains about five cycles of sleep, switching between REM and non-REM states.
REM sleep is characterized by rapid eye movement and a less deep state of sleep. Non-REM sleep is a deeper state that generally precedes REM sleep. During non-REM sleep, the brain dumps out all the superfluous memories that are not necessary to store and retain. The REM state then creates a hospitable environment for functions of problem-solving and creativity because it hones in on the memories that remain, and strengthens the neural connections associated with them.
Both of these processes working in union are necessary to achieve the process of “synaptic remodeling,” which is essential for functions of learning, memory, problem-solving and creativity. This “synaptic remodeling” results in better emotional intelligence, better mood and more clarity of mind.
This all makes intuitive sense. We know by experience how incompetent we feel when we’re sleep deprived. We have all faced a problem that feels massive and impassible at night, and is somehow less daunting the next morning. Many of the world’s languages have a phrase for “sleep on it,” indicating just how universal this phenomenon is. It makes perfect sense in light of foundational structures like Maslows’ hierarchy of needs, too. When our most basic needs are not taken care of, we cannot be attentive to much else.