
A night’s sleep lost leads to a glut of aftereffects. That heavy gait, that groggy mind, that inability to tell words on a page from alphabet soup–all too familiar. Therefore, it baffles me that we don’t biologically know why we sleep, just that it certainly feels good. Three explanations were posited by Dr. Russell Foster during his TED Talk: sleep as a means of energy conservation, sleep as a means of physical restoration, and sleep as a means of handling memories and brain processes. Although all hypotheses are probably true to some degree, the last one seems to me the largest and most viable reason.
First, the idea that sleep is a means of energy conservation is supported by meager evidence. For instance, our bodies only save about one hundred calories per night’s worth of sleep–an amount equal to approximately one slice of bread. Even under the hunting-gathering conditions of our past, this seems to me a second-rate exchange for the dangers associated with being unconscious for eight hours.
However, there’s still problems with this. Firstly, we actually decrease our total protein production while we sleep. To me, it seems counterproductive for the body to decrease the number of essential building blocks available to it if the goal is repair work. Furthermore, stage 3 non-REM sleep is shown to be most beneficial to our physical health, and adults spend less than half our sleep time here. Contrastingly, we spend upwards of 50% in stage 2 non-REM sleep. Stage 2 non-REM sleep is responsible for memory consolidation and information processing, leading neatly to Foster’s final suggestion.
From experience, we know when we’re sleep deprived we’re fault to a number of follies like forgetting details, forgetting how to perform tasks, and being less creative in our problem solving; yet when we get a good night’s rest, our problem solving skills increase three times due to REM sleep, and our ability to retain information from the day before increases due to the time spent in stage 2 non-REM sleep. These characteristics are crucial in defining humans from other animals. From an anthropologic and historical sense, our intellect and ingenuity have led us to survive and thrive as a species for so long, and, thusly I’d say have a lot to do with our need for sleep.
I pulled the information for this post from this website. Although the authorship is ambiguous (you have to go to the “contact” page) it seems reliable as there are a number of reputable books and websites listed as the sources. Additionally, the information was presented in a clear cut manner as opposed to being superfluous, showing me the author had a somewhat put together concept of the subject material.
Sources:
Russel Foster: Why do we sleep? [Video file]. (2013, June). Retrieved April 8, 2016, from http://www.ted.com/talks/russell_foster_why_do_we_sleep#t-653233
Mastin, L. (n.d.). Why Do We Sleep? – Physical Restoration. Retrieved April 08, 2016, from http://www.howsleepworks.com/why_restoration.html
Mastin, L. (n.d.). Why Do We Sleep? – Energy Conservation. Retrieved April 8, 2016, from http://www.howsleepworks.com/why_energy.html
Mastin, L. (n.d.). Why Do We Sleep? – Memory Processing and Learning. Retrieved April 8, 2016, from http://www.howsleepworks.com/why_memory.html
