If sleeping more means doing less—whether that involves cutting back on extracurricular activities, dropping a job, or not going out—many are unwilling to make the concession. There seems to be a societal stigma that sleep is associated with laziness. But, the truth is that getting enough sleep is crucial for being strong and healthy enough to do all those things we need or love to do. Not sleeping enough is weak.

Jenni, O. G. (2005). Children’s Sleep: An Interplay Between Culture and Biology. Pediatrics, 115(1), 204-216. doi:10.1542/peds.2004-0815b

There are two types of sleep: NREM (non-rapid eye movement) sleep and REM (rapid eye movement) sleep.

During REM sleep, our eyes are shut, of course. However, underneath our eyelids, our eyes are making these strange movements. They primarily shift left and right, and occasionally they’ll move up and down.

Aserinsky, E., & Kleitman, N. (1953). Regularly occurring periods of eye motility, and concomitant phenomena, during sleep. Science, 118, 273-274. doi:http://dx.doi.org/10.1126/science.118.3062.273

Why and how does coffee make you feel so great (at first)?

Well, it’s important to know that there are two processes that determine when a human is awake and when a human is asleep: Process-C (drive to be awake) and Process-S (drive to be asleep). Process-C is your Circadian rhythm. Process-S, on the other hand, works to make you sleepy by building up a chemical pressure in your brain. The longer you are awake, the more you build up the chemical (namely, adenosine) and the sleepier you feel.

So, how does coffee fit into this equation? The caffeine found in coffee binds onto the receptors of adenosine, convincing the brain that there isn’t as much adenosine buildup as there actually is. Thus, you don’t feel as sleepy you as would be without coffee.

Borbély, A. A. (1982). A two process model of sleep regulation. Human Neurobiology, 1(3), 195-204. Retrieved from https://search.proquest.com/docview/616860359?accountid=14496

Huang, Z., Qu, W., Eguchi, N., Chen, J., Schwarzschild, M. A., Fredholm, B. B., . . . Hayaishi, O. (2005). Adenosine A2A, but not A1, receptors mediate the arousal effect of caffeine. Nature Neuroscience, 8(7), 858-859. doi:10.1038/nn1491

You’re probably feeling crummy from both the caffeine crash and the sleep deprivation!

Caffeine doesn’t get rid of the adenosine in your brain; it simply binds onto its receptors. So, when the caffeine is inevitably broken down, your body feels the pressure of all the adenosine you had at the time you drank coffee PLUS all the adenosine that has built up since then. It’s no wonder you feel incredibly sleepy when you experience a caffeine crash.

To add to that, by the time the caffeine wears off, your Process-C (drive to be awake) is likely at its lowest level and your Process-S (drive to be asleep) is at its peak. The great distance between those two processes make for a sleep deprived individual.

Borbély, A. A. (1982). A two process model of sleep regulation. Human Neurobiology, 1(3), 195-204. Retrieved from https://search.proquest.com/docview/616860359?accountid=14496

Huang, Z., Qu, W., Eguchi, N., Chen, J., Schwarzschild, M. A., Fredholm, B. B., . . . Hayaishi, O. (2005). Adenosine A2A, but not A1, receptors mediate the arousal effect of caffeine. Nature Neuroscience, 8(7), 858-859. doi:10.1038/nn1491

Birds have the ability to engage in unihemispheric sleep, or sleep with half of their brain. But, they can only do so during NREM sleep. When the left half of the brain is asleep and the right half of the brain is awake, for example, the right eye is closed and the left eye is open.

Humans sort of have unihemispheric sleep. On the first night of sleeping in an unfamiliar place, one half of the brain goes into a much deeper sleep than the other half. But, both eyes are closed. Not as cool, but what are you going to do, ya know?

Rattenborg, Niels C.; Lima, Steven L.; Amlaner, Charles J. (1999). “Half-awake to the risk of predation”. Nature. 397 (6718): 397–398.

Tamaki, Masako, et al. “Night watch in one brain hemisphere during sleep associated with the first-night effect in humans.” Current biology 26.9 (2016): 1190-1194.

After a night of poor sleep, you’d think that you should catch up on sleep by sleeping in the next day. But, by sleeping in, you won’t feel tired the following night, and you’ll stay up late again and wake up late again.

In order to develop a better sleep schedule, it is best to go to bed at the same time and wake up at the same time regardless of the day of the week and how bad a night of sleep was.

Edinger, J. D., Wohlgemuth, W. K., Radtke, R. A., Marsh, G. R., & Quillian, R. E. (2001). Cognitive Behavioral Therapy for Treatment of Chronic Primary Insomnia. Jama, 285(14), 1856-1864. doi:10.1001/jama.285.14.1856

According to a 1992 study, bad dreams are more likely to occur following a stressful event.

This studied examined the percentage of subjects who experienced a bad dream after the 1989 Bay Area earthquake. Those who lived closest to the epicenter and experienced the most stress had the most nightmares. Those who lived furthest from the epicenter and did not feel as stressed experienced the fewest nightmares.

Thus, the intensity of stress is positively associated with the number of nightmares.

Wood, J. M., Bootzin, R. R., Rosenhan, D., Nolen-Hoeksema, S., & Jourden, F. (1992). Effects of the 1989 san francisco earthquake on frequency and content of nightmares. Journal of Abnormal Psychology, 101(2), 219-224. doi:http://dx.doi.org/10.1037/0021-843X.101.2.219

Your hunger is controlled by 2 hormones: leptin and ghrelin. Leptin decreases your appetite and communicates to the brain the you’re full. Conversely, ghrelin increases your appetite and communicates to the brain that you’re hungry.

When you’re sleep deprived, leptin levels drop and ghrelin levels rise, making you feel hungrier than usual.

While we will admit it is clever joke, the condition is not called “insom-nom-nom-nom-nom-nia.”

Spiegel, Karine, et al. “Brief communication: sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite.” Annals of internal medicine 141.11 (2004): 846-850.

Remember Process-S and Process-C from Day 1? Well, we’re about to go into a bit more detail.

Think of Process-C, the circadian rhythm, as a sine curve that naturally rises and falls throughout the 24-hour period. Think of Process-S as a curve that continues to rise relentlessly as you remain awake but falls as you sleep. The greater the distance between the 2 curves, the more tired you feel.

So, when you’re pulling an all-nighter and not sleeping like you’re supposed to, Process-C (your drive to be awake) is at its lowest point and Process-S (your drive to be asleep) continues to rise. At this point, you feel completely exhausted.

But, as the morning comes along, the Process-C curve begins to rise as your circadian rhythm naturally increases your drive to be awake. Even though Process-S is still rising into the morning, thanks to Process-C, the distance between the two curves is not as great as it was at night, and you don’t feel as tired as you did.

But, just wait until your Process-C naturally falls again later in the day.

Borbély, A. A. (1982). A two process model of sleep regulation. Human Neurobiology, 1(3), 195-204. Retrieved fromhttps://search.proquest.com/docview/616860359?accountid=14496

Although Sigmund Freud suggested that dreams play out our repressed wishes–a wish that our heart makes, if you will–his theory is scientifically invalid.

According to Freud, individuals have repressed wishes that, in their raw form, are too scary for our sleeping minds to handle. This “latent content” is censored through a filter. Our dreams then depict “manifest content” that we can recall. While Freud claimed he could reverse-engineer this process and reveal our our heart’s wishes and the truth behind our dreams, this scientific theory cannot be proven correct or incorrect because it is not testable. Additionally, different psychoanalysts provide different interpretations of the same dream, pointing to the subjectivity of Freud’s “science.”

Fosshage, J. L., & Loew, C. A. (1987). Dream interpretation: a comparative study. New York: PMA Publishing corp.

All puns aside, sleepwalking is a type of parasomnia. Like other parasomnias, sleepwalking typically occurs as your body is trying to wake up from deep slow-wave sleep (Stages 3 and 4 of NREM sleep). The autonomic nervous system, which controls automatic bodily functions like your breathing, is suddenly jolted. Your brain is forced to wake up from its deep sleep but gets stuck in the middle of that and wakefulness. As a result, your brain is in deep sleep, but your body is acting out behaviors as if you were awake.

You may be wondering what’s going on in your brain when you’re sleepwalking. The cerebellum and motor cortex are highly active while the prefrontal cortex (responsible for logical reasoning) shows extremely low activity levels–lower than the levels seen during REM sleep.

Bassetti, C., Vella, S., Donati, F., Wielepp, P., & Weder, B. (2000). SPECT during sleepwalking. The Lancet, 356(9228), 484-485. doi:10.1016/s0140-6736(00)02561-7

Narcolepsy occurs when you have an overwhelming appetite for sleep during the day time. It can be described as an inability to resist sleep. The 4 key symptoms are excessive daytime sleepiness (unable to stay awake), sleep paralysis (inability to talk or move), hypnagogic hallucinations (vivid, scary dreams that result from falling immediately into a  severe form of REM sleep), and cataplexy (a sudden loss of muscle tones causing you to partially or totally collapse).

It is not narcolepsy if you fall asleep during a boring lecture and you’re sleep deprived.

National Institutes of Health. (n.d.). What Are the Signs and Symptoms of Narcolepsy? Retrieved April 13, 2017, from https://www.nhlbi.nih.gov/health/health-topics/topics/nar/signs

Jetlag occurs when we fast-forward or drag back in time our circadian rhythm. It’s a disruption of our circadian rhythm as a result of our crossing time zones. For that reason,  we struggle to function in the new time zone because there is a mismatch between our internal circadian clock and external time (new time zone) . So, you can be sleepy in the day in the new location because you are biologically supposed to be sleeping. Or, you can’t sleep at night because it’s daytime in your biological circadian rhythm time zone.

Arendt, J., & Marks, V. (1982). Physiological changes underlying jet lag. British Medical Journal (Clinical Research Ed.), 284(6310), 144–146.

While one occasion of waking up at 3 AM and not being able to fall back asleep does not constitute insomnia, there is a type of insomnia that describes that type of poor sleep.

Sleep maintenance insomnia is a type of insomnia that describes difficulty staying asleep throughout the night or difficulty going back to sleep after waking up during the night or early morning hours.

Ellis, G. (2014, Jul 08). Recent studies link sleep issues, diabetes. Philadelphia Tribune Retrieved from https://search.proquest.com/docview/1549956226?accountid=14496

Dwight is partially correct.

If a dream is defined more broadly as any sort of mental activity reported immediately upon waking up from sleep, then dreams can occur at every stage of the sleep cycle, not just REM sleep. This includes during the transition from wakefulness to sleep (hypnagogic dreams) and during the transition from sleep to wakefulness (hypnopompic dreams).

However, what most people constitute as “dreaming” does occur during REM sleep.

Foulkes, W. D. (1962). Dream reports from different stages of sleep. The Journal of Abnormal and Social Psychology, 65(1), 14-25. doi:10.1037/h0040431

During REM (dream) sleep, some areas of our brain are activated and some are de-activated. The following are the activated parts:

• Motor cortex – deals with voluntary motor control
• Cingulate cortex and amygdala – deals with emotions
• Occipital cortex – deals with visual processing
• Hippocampus – deals with memories

Based on this knowledge, we know that dreams draw on our memories and can be filled with movement, emotions,  visual components.

On the other hand, the lateral prefrontal cortex, which deals with rational, high-level decision making, is deactivated. Based on this piece of information, we can understand why dreams are so illogical and irrational.

McCarley, R. W., & Hoffman, E. (1981). REM sleep dreams and the activation-synthesis hypothesis. The American Journal of Psychiatry, 138(7), 904-912. doi:http://dx.doi.org/10.1176/ajp.138.7.904

The mechanisms of REM sleep not only allow you to dream but also allow you to do so safely. There is a signal that is sent down your brain stem and through your spinal cord to inhibit all nerves connected  to your skeletal muscles. Experiencing REM sleep paralysis,  you cannot move. This evolution turns out to be good for us! If you ever act out in your dream (such as jumping out the window), you body cannot physically do those things because of REM sleep paralysis.  In this way, the mind paralyzes the body so that the mind can dream safely!

Hishikawa, Y., & Shimizu, T. (1994). Physiology of REM sleep, cataplexy, and sleep paralysis. Advances in Neurology, 67, 245-271.

No need to buy the light-blocking curtains. Jean Jacques d’ Ortous de Mairan’s 1729 experiment already demonstrated that the 24-hour circadian rhythm is not dictated by the dark/light cycle and sunlight. It is caused within the biology of organisms. If we take ourselves out of the outer world, we will still continue that rhythmic behavior. And, the French geophysicist showed this by  conducting an experiment on the leaf movements of a heliotrope plant over 24-hour periods. As the day time arrives, the plant unfolds its leave; yet, when darkness comes, the leaves collapses. Initially, everyone thought this behavior was governed by external forces (i.e. sunlight). However, Jean discovered that the leaves still exhibit this same behavior when he placed the flower away from the sun in a dark room. His experiment proved that circadian rhythm still persists in absence of external cues like light.  

(de Mairan, 1729)

Our circadian rhythm is the rhythm that is generated and controlled from within us. It is the biological clock that resides in our brains. It is endogenous. Circadian rhythms help us regulate our sleep and wake cycle. In addition, it regulates our eating and drinking habits, body temperature, and hormone release. The human circadian rhythm is approximately 24 hours AND 10 minutes. All living species (including bacteria surviving more than 24 hours) function on a  circadian rhythm.

Kleitman, N. (1963). Sleep and wakefulness. Chicago: University Press.