Sleep and Academic Performance

Worse than being sleepless in Seattle is to be sleepless before a final in either math or a foreign language class. Lack of sleep when attempting to calculate complicated math problems or figuring out demanding translations can markedly affect performance. 

Both disciplines require ‘higher executive functions’ which include planning, extended attention, and working memory. These skills are accessed through the prefrontal cortex of the brain, which is very sensitive to poor and insufficient sleep. Come into a math test after an all-nighter of cramming and your score could easily dip 14%; for language arts, 7-8 %. Sleep can distinctly give a student an edge in performance. 

A study published in the Journal of Scientific Reports tracked the online sleep schedule diaries of 61 Harvard College students for 30 days. They identified regular sleepers who followed a sleep schedule, and irregular sleepers who changed their waking and sleeping schedules. 

Regular sleepers showed higher academic achievement over tasks requiring analytical skills. They were in sync with their circadian rhythm and took advantage of their most productive times. The irregular sleepers often varied their work times and sleep schedules resulting in substantially more exposure to light at night, interrupting their internal circadian clock, and causing unreliable release of melatonin, a sleep hormone that regulates sleep and wakeful attentiveness. 

According to Andrew Phillips, PhD., the lead researcher  and biophysicist at the division of Sleep and Circadian Disorders at the Brigham and Women’s hospital in Boston: “Our results indicate that going to sleep and waking up at approximately the same time is as important as the number of hours one sleeps.”

While unpredictable sleep patterns might rob academic performance, lengthy periods of sleep deprivation can make all sorts of bad things occur.  A 2007 Study detailed how consistent sleep loss eventually caused immune systems to collapse, substantial inability to concentrate, and impaired memory. In humans, lack of sleep prevents neurons, the major component of the mind, from rejuvenation. Eventually the brain will lose its ability to function at optimum levels.

 The National Sleep Foundation recommends teenagers get 9 hours, yet only about 15% do. To make this point  more strongly, a study by Tim Althoff, published by Stanford Medicine, followed  the sleep regimen of 30,000 people over 18 months, representing more than 3 million nights of sleep analyzed, and  tracked their abilities to perform web searches requiring higher order thinking skills. After one night of insufficient sleep (defined as less than 6 hours) participants suffered a 1.2% decrease in cognitive performance. Two consecutive nights of insufficient sleep resulted in a 4.8% decline.

How does sleep work and what should one expect in a good sleep? One of the leading sleep experts, Meir Kryger, a MD at the Yale School of Medicine and  specialist over the last 40 years in sleep medicine, describes in his book, ‘The Mystery of Sleep’ (2018) that sleep cycles through a series of 90-minute stages. The first two stages Kryger labels ‘slow wave’ sleep, in which the neocortex (the portion of the brain which accounts for the feeling of being refreshed after a good night’s sleep) powers down. Then it shifts into REM (the ‘rapid eye movement’ state), which Kryger calls the ‘enigmatic state’. In REM most of the muscles are paralyzed, except the diaphragm, allowing the sleeper to keep breathing,  then the brain begins to emit electrical storms producing dreams, about 3-5 per night for the average sleeper. Interspersed among these sleep cycles are ‘arousals’, in which the sleeper might even appear to be awake. Healthy sleepers experience ‘arousals’ about 5 times per hour—the arousals are never remembered by the sleeper.   

Getting sleep that will promote good academic performance is multidimensional. Regularity is just as important as duration. Understand that your sleep might be filled with ‘arousals’ and forgotten dreams, and that’s normal. But don’t try to cheat on sleep because academically you will likely bear the consequences.