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

Although it is a bit nuanced, insomnia is different than sleep deprivation.

An individual who is sleep deprived has sufficient ability to sleep but is not giving herself sufficient time to sleep (i.e. she doesn’t want to sleep).

An individual suffering from insomnia has sufficient time to sleep but an insufficient ability to sleep (i.e. she simply cannot sleep).

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

Ladies, there is such a thing as beauty sleep. According to a research study, healthy and  young participants were photographed after (1) obtaining 8 hours of normal sleep and (2) after one night of total sleep deprivation (all-nighter). Independent observers then rated the 2 sets of pictures on 3 different factors: tiredness, healthy looking, and attractiveness. Results show that when you are sleep deprived, you are rated as more sickly, less healthy, and less attractive. Get your beauty sleep to get your crush’s attention!

Axelsson, J., Sundelin, T., Ingre, M., Someren, E. J., Olsson, A., & Lekander, M. (2010). Beauty sleep: experimental study on the perceived health and attractiveness of sleep deprived people. Bmj, 341, C6614-C6614. doi:10.1136/bmj.c6614

Although you may think that sleeping in on the weekend will make up for the sleep loss during the week, that is not true! Unfortunately, you cannot accumulate a sleep debt and hope to pay it back. Sleep, in terms of memory, is an all-or-nothing event. If you do not sleep within the first 24 hours after learning new information, you lose the chance to cement those new memories in your brain.

Stickgold, R., Whidbee, D., Schirmer, B., Patel, V., & Hobson, J. A. (2000). Visual Discrimination Task Improvement: A Multi-Step Process Occurring During Sleep. Journal of Cognitive Neuroscience, 12(2), 246-254. doi:10.1162/089892900562075

Newborn infants are highly polyphasic sleepers.  They sleep a lot during the day and the night, in short bouts, and with a very irregular schedule. This can be very tiring for mothers, who are monophasic sleepers . Mothers, like all adults, need 8-9 hours of sleep at night. Because of this, the newborn’s sleep cycle and the parents’ sleep cycles are not compatible, explaining why new mothers are so cranky in the morning.

Parmelee, A. H. (1961), Sleep Patterns in Infancy A Study of One Idant from Birth to Eight Months of Age. Acta Pædiatrica, 50: 160–170. doi:10.1111/j.1651-2227.1961.tb08035.x

Williams, R. L., Agnew, H. W., & Webb, W. B. (1964). Sleep patterns in young adults: an EEG study. Electroencephalography and Clinical Neurophysiology, 17(4), 376-381. doi:10.1016/0013-4694(64)90160-9

Severe sleep deprivation is responsible for both heightened emotions and hallucinations/delirium.

The amygdala, a structure of the brain responsible for generating emotions,  shows greater activity levels in sleep deprived individuals. As a result, when reacting to the same emotional experience, a sleep deprived individual is more likely to be emotionally over-reactive compared to a well-rested individual. So, it is possible that this sleep deprived individual might respond more to a joke that actually isn’t all that funny.

The reason for the heightened amygdala reactivity is because, in sleep deprived individuals, the connection between the amygdala and  medial frontal cortex, which inhibits the amygdala, is cut off.

As observed with Peter Tripp, former world record holder of the longest period of uninterrupted wakefulness, sleep deprivation can result in hallucinations. When he was seeing things, it was like he was having a dream even though he was awake. During his hallucinations, his brain wave patterns started to resemble that of dream sleep. 

Yoo, S., Gujar, N., Hu, P., Jolesz, F. A., & Walker, M. P. (2007). The human emotional brain without sleep — a prefrontal amygdala disconnect. Current Biology, 17(20). doi:10.1016/j.cub.2007.08.007

Gulevich, G. (1966). Psychiatric and EEG Observations on a Case of Prolonged (264 Hours) Wakefulness. Archives of General Psychiatry, 15(1), 29-35. doi:10.1001/archpsyc.1966.01730130031005

You should think of sleep as being due tonight. Do you need sleep before learning in the morning? Yes, if you want to soak up new information! Without sleep, your brain’s memory circuits cannot absorb information effectively. Therefore, do not pull that all-nighter!

The hippocampus of the brain plays an important role in receiving new memory. Studies have shown that people who are sleep deprived have very little brain activity in this region, which impairs their ability to receive new information and commit that information to memory. These individuals also revealed a 40% deficit in their capacity to make new memories.

Those who got a full night of sleep, on the other hand, had more sleep spindles, which helped refresh the hippocampus by moving memories from here to the long-term storage site in the cortex.

Yoo, S., Hu, P. T., Gujar, N., Jolesz, F. A., & Walker, M. P. (2007). A deficit in the ability to form new human memories without sleep. Nature Neuroscience, 10(3), 385-392. doi:http://dx.doi.org/10.1038/nn1851

Mander, B. A., Santhanam, S., Saletin, J. M., & Walker, M. P. (2011). Wake deterioration and sleep restoration of human learning. Current Biology, 21(5), R183-R184. doi:10.1016/j.cub.2011.01.019

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