Whenever a person is tired, a common line they would say is “I want to sleep.” Students would often stick to caffeine to finish papers and projects that they lose sleep. It is important to remember that sleep is essential for a human’s health and well-being and it is also said that humans actually spend one-third of their lives sleeping (National Institute of Neurological Disorders and Stroke, 2017). After a long day, we know that we lie down on our beds and close our eyes and that is what causes us to sleep but what exactly is sleep? Sleep is defined as “a natural state of rest characterized by a reduction in voluntary body movement and decreased awareness of the surroundings” (Morris & Maisto, 2016, p. 127). As we sleep, we move through unique stages of sleep, each distinguished by changes in brain waves. REM or rapid-eye movement is a stage wherein there is rapid movement of the eye and increased dreaming and non-REM stage of sleep alternates with REM stages during the sleep cycle.
The branch of psychology that deals with all there is to know about sleep is called sleep psychology and it took years for it to advance to where it is now. Even during ancient civilization, ideas about sleep already existed. A Greek philosopher or physician named Alcmaeon was the first to make a theory about sleep he said that sleep is produced by the withdrawal of the blood away from the surface of the body to the larger “blood flowing” vessels and that we awake when the blood diffuses to the body again (Huffman, 2003). Ideas about sleep changed and theories came up during the Renaissance period as some thought that toxins build up in the body and drain away slowly during sleep while others argued that people sleep after and inhibitory reflex causes the body to shut off.
These ideas would not be debunked for a long time, not until scientists understand the connection of the brain to sleep and wakefulness. The Age of Enlightenment had scientists like Marquis d’Hervey de Saint-Denis and Alfred Maury and they studied and interpreted their dreams. It was once accepted to take the visitors to the bedroom, as practiced by Louis XIV of France but during this time, the bedroom slowly became a private and intimate room. Moreover, sleeping for more than 8 hours was deemed as being lazy (Division of Sleep Medicine at Harvard Medical School, 2008). The first text to analyze sleep from a physiological perspective was entitled “Le problème physiologique du sommeil” and it was published in 1913 by Henri Pieron (“A Brief History of Sleep Psychology,” 1999). Constantin von Economo discovered in 1916 that the hypothalamus is the center of sleep and wake activity (Thomas, 2017). In the 1920s, Dr. Nathaniel Kleitman began work in Chicago examining the regulation of sleep and wakefulness and of circadian rhythms.
He distinguishes the cerebral cortex as the source of consciousness, mental ability, and voluntary movement. He is now known as the “Father of American sleep research.” In 1924, the EEG or electroencephalogram was invented and this paved the way to see the brain’s electrical waves during sleep and wakefulness. During this time, stimulants like ephedrine and amphetamines were also being used to stimulate wakefulness in narcolepsy patients. German biologist Erwin Bunning creates the term “biological clock” in 1935 after recognizing the role that inheritance plays in controlling the circadian rhythm. Scientists Loomis, Harvey, and Hobart discovered the five stages of sleep: alpha, low voltage, spindles, spindles plus random, and random in 1937 and the sleep structure is described. In 1939, after years of sleep studies, Kleitman published his book called Sleep and Wakefulness. The understanding of the neuroscience of sleep was made possible after more work found the role of the brain stem in skeletal muscle relaxation during sleep. In 1953, Dr. Kleitman and one of his students, Dr. Eugene Aserinsky, made an important discovery for sleep psychology when they discovered rapid eye movement or REM during sleep (Aserinsky and Kleitman, 1953). The next year, another student of Dr. Kleitman discovered that sleep is cyclical in nature and that night-time sleep comprises several repeating cycles (Dement and Kleitman, 1957). Melatonin, a hormone that plays an important role in the regulation of sleep and wakefulness, was discovered in 1958.
In 1959, French physician Michel Juvet differentiated REM from NREM and in the same year, Franz Halberg made the term “circadian” and studied it for the first time in humans, thus becoming the father of chronobiology. Michel Juvet is also responsible for discovering that the pons regulated REM sleep in 1962. Henri Gastaut characterized sleep apnea in 1965 after recording brain activity, breathing, heart rate, and other physiological measures at the same time and this led to the new discipline of “sleep medicine.” The 1970s was remarkable for it witnessed the setting up of the first sleep research center in Stanford and the rise of reliable sleepiness measures like multiple sleep latency test (MSLT). In the 1980s, the relationship between sleep and learning was studied, and the direct physiological necessity of sleep to life was finally confirmed. By the end of the decade, the book on sleep research called “Principles and Practice of Sleep Medicine” by Kryger and Dement was published. Sleep research at the end of the 20th century is made up of many different areas from infant sleep to shift work and its effects on sleep and so on. Over 200 sleep disorders centers and laboratories are accredited in the US alone and they are made to recognize and treat all disorders of sleep (“A Brief History of Sleep Psychology”, 1999).
During the 2000s, research and advice from physicians regarding the importance of sleep became a constant reminder to the people. Right now, research regarding sleep disorders are still ongoing to establish its environmental, genetic, and physiological features. Because of the fast-growing field that is sleep psychology, sleep psychologists are in demand for their knowledge on how to treat certain sleep disorders. Sleep medicine is a unique specialty that combines the work of different health professionals from pulmonologists with expertise in sleep apnea to neurologists, psychiatrists, and psychologists. The field has grown so much that the demand for trained sleep psychologists far exceed the supply. Sleep disorders are very widespread and they cause significant impairment of function so that is where sleep psychologists come in and help people.
The demand for sleep psychologists will only grow, according to Daniel Buysse, the former president of the American Academy of Sleep Medicine, as more therapies for sleep disorders pile up. Sleep technologists are also important in sleep science. They perform tests on sleeping patients to record their brain activity, heart, and nerve functions and breathing. Moreover, they make the reports used to diagnose and treat patients so their job is as important as the sleep psychologist. Sleep medicine will only continue to grow as technologies and medicines improve for sleep disorders and careers in this field will flourish to help more people.
