The Four Stages of Sleep<\/h2>\n\n\n\n

Each night, our bodies cycle through 2 phases of sleep (NREM and REM) consisting of four sleep stages: non-REM 1, non-REM 2, non-REM 3, and REM.<\/p>\n\n\n\n

Sleep Stage<\/strong><\/td>	Type of Sleep<\/strong><\/td>	Function<\/strong><\/td><\/tr>
NREM 1<\/td>	Non-REM<\/td>	Light sleep. The transition between being awake and asleep. It\u2019s still easy to wake up out of this stage.<\/td><\/tr>
NREM 2<\/td>	Non-REM<\/td>	Deeper sleep. Your body temperature drops, and your heart rate slows down.<\/td><\/tr>
NREM 3<\/td>	Non-REM<\/td>	Deep sleep. Your body is releasing growth hormone, repairing and regrowing tissue, and strengthening the immune system.<\/td><\/tr>
REM Sleep<\/td>	REM<\/td>	The stage most often linked to dreaming and is less restful than other sleep stages. Brain activity resembles that of a waking state.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n Source: (1<\/a>)<\/p>\n\n\n\n NREM 1 Sleep Stage <\/h3>\n\n\n\n N1 is the first and lightest stage of sleep. N1<\/a> is a dynamic state that represents the transition between a waking state and sleep. (1<\/a>) It can last anywhere from one to five minutes and typically accounts for 5 percent of our total sleep time. (1<\/a>)<\/p>\n\n\n\n During N1, the following physiological changes occur:<\/p>\n\n\n\n Slow, rolling eye movement (7<\/a>)<\/li> Brain waves shift from the alpha waves of relaxation to the theta waves of sleep (1<\/a>)<\/li> Muscles begin to relax (1<\/a>)<\/li><\/ul>\n\n\n\n Sleepers may be roused quite easily from this stage of sleep, and small shifts back and forth between alpha and theta brain waves during N1 sleep<\/a> may give the sleeper the sense that they are still awake. (1<\/a>)<\/p>\n\n\n\n\n\n Challenges with N1 sleep, such as extended sleep latency (the time spent waiting to fall asleep), may indicate the presence of a sleep disorder. Difficulty transitioning into N1 sleep or initiating sleep is also a common symptom of insomnia<\/a>. (9<\/a>)<\/p>\n\n\n\n NREM 2 Sleep Stage<\/h3>\n\n\n\n N2<\/a> moves us into deeper sleep. Its duration changes as we progress through the night \u2014 the first N2 stage typically lasts around 25 minutes, and subsequent N2 stages grow longer as the hours tick by. (1<\/a>) N2 sleep<\/a> accounts for approximately 45 percent of our total sleep time, making it the sleep stage where we spend the most time. (1<\/a>) Brain wave activity during N2 sleep includes sleep spindles and K-complexes (or long delta waves). While sleep spindles and K-complexes both play a central role in memory consolidation, K-complexes also play a role in maintaining sleep. (1<\/a>)<\/p>\n\n\n\n\n\n During N2, the following physiological changes occur: (1<\/a>)<\/p>\n\n\n\n Decrease in heart rate and body temperature<\/li> Blood pressure drops (11<\/a>)<\/li> Breathing is less erratic (11<\/a>)<\/li><\/ul>\n\n\n\n NREM 3 Sleep Stage<\/h3>\n\n\n\n N3 is the deepest stage of sleep<\/a>, and out of all the sleep stages, it has the most aliases. N3 is also known as slow-wave sleep (SWS), deep sleep<\/a>, and delta sleep (due to the brain wave activity that occurs during this sleep stage). N3 accounts for 25 percent of our total sleep time. It's usually the hardest to wake up from and, therefore, the one most commonly associated with sleep inertia<\/a>. (1<\/a>)<\/p>\n\n\n\n While N3 plays a heavy hand in how restored and refreshed we feel upon waking, it's the stage where biological processes like growth hormone release, bone and muscle building, and immune strengthening occur. (1<\/a>) As they age, older adults spend less time in N3 sleep and more time in N2. (1<\/a>)<\/p>\n\n\n\n REM Sleep Stage<\/h3>\n\n\n\n The rapid eye movement stage, or REM sleep<\/a> as it's more commonly known, is the fourth and final sleep stage in a sleep cycle. Brainwave activity shows beta waves, which closely resembles brainwave activity in a waking state. (1<\/a>) REM sleep is:<\/p>\n\n\n\n The stage where most dreaming occurs. <\/li> The sleep stage from which dreamers are more likely to remember their dreams. <\/li> Typically considered less restful than other sleep stages. (3<\/a>) <\/li><\/ul>\n\n\n\n Additionally, the amount of time spent in REM sleep<\/a> tends to decrease with age. While infants spend as much as 50 percent of sleep time in the REM stage, adults may spend closer to 25 percent. (12<\/a>)<\/p>\n\n\n\n Most sleepers will hit their first REM stage somewhere around 60 to 90 minutes into their sleep cycle. (1<\/a>) Initial REM stages are short and continue to lengthen as the night wears on. As such, your first REM stage of the night could be as short as 10 minutes, whereas your last REM stage could last as long as one hour. (1<\/a>)<\/p>\n\n\n\n During REM sleep, the following physiological changes occur: (1<\/a>)<\/p>\n\n\n\n Erratic breathing and heart rate<\/li> Muscle paralysis (muscle atonia) <\/li> Rapid eye movements<\/li><\/ul>\n\n\n\n Deep Sleep vs REM Sleep: What\u2019s the Difference?<\/h2>\n\n\n\n REM sleep and deep sleep are two distinct sleep stages, each with their own unique benefits<\/p>\n\n\n\n Deep sleep (aka N3, slow wave sleep, or delta sleep) is the third stage of the sleep cycle and a part of non-REM sleep. It's the deepest stage of sleep (hence its name) and the most restful and restorative. Deep sleep is also where some critical biological housekeeping occurs \u2014 including growth hormone release, muscle and tissue growth and repair, and immune system fortification. (1<\/a>)<\/p>\n\n\n\n REM sleep, though different, is equally important. This is the stage where most of our dreaming occurs, and while it's often confused with deep sleep, it's typically the least restorative than the other sleep stages. (1<\/a>) Other critical functions of REM sleep include memory consolidation, emotional balance, and brain development. (13<\/a>, 14<\/a>)<\/p>\n\n\n\n What Affects Sleep Cycles?<\/h2>\n\n\n\n Night after night, our sleep cycles are essentially on autopilot. We turn off the lights, our heads hit the pillow, and the cycle begins. However, Dan Gartenberg<\/a>, a sleep scientist and sleep health advisor for CPAP.com,<\/a> says some things, like age, sleep disorders, and lifestyle choices, may meddle with our sleep cycles. <\/p>\n\n\n\n Age<\/h3>\n\n\n\n \"Age is a notable factor that can affect your quality or duration of sleep within the sleep cycle; as such, sleep patterns generally change as you age,\" Gartenberg tells Sleepopolis. For example, while infants spend about 50 percent of their total sleep time in REM, that levels off as they mature, eventually falling more in line with adult REM sleep requirements. (11<\/a>)<\/p>\n\n\n\n Moreover, Gartenberg tells us that wonky sleep cycles are par for the course of aging. While adult sleep requirements don't change with age (healthy adults 18 and over should get about seven to nine hours of sleep each night), their actual sleep experience often does. (15<\/a>) \"Older individuals tend to wake up more in the middle of the night or earlier in the morning,\" says Gartenberg, noting that it's often tied to \"underlying conditions and medications.\" Pair that with the host of hormonal and physiological changes that accompany aging, and it becomes clear why older individuals tend to have altered sleep cycles. <\/p>\n\n\n\n We'll add here that with age, adults spend less time in N3 or deep sleep. (1<\/a>)<\/p>\n\n\n\n Sleep Disorders<\/h3>\n\n\n\n \"Sleep disorders can also negatively impact sleep cycles,\" says Gartenberg. While some sleep disorders like insomnia can put up roadblocks to even getting the sleep cycle started, others like obstructive sleep apnea and restless leg syndrome <\/a>can cause frequent wakings that impair our progression through the cycle or curtail our time in any given sleep stage. (16<\/a>)<\/p>\n\n\n\n Health Conditions<\/h3>\n\n\n\n Physical and mental health conditions can also affect your sleep cycles each night. For example, studies have shown that obesity can increase awake time and reduce sleep efficiency. (17<\/a>) Additionally, some mental health conditions like depression and anxiety can also stymie sleep, with research showing that impairments are evident across all sleep stages. (18<\/a>) (19<\/a>)<\/p>\n\n\n\n Lifestyle<\/h3>\n\n\n\n \"Lifestyle choices can affect sleep cycles as well,\" says Gartenberg. \u201cSomeone who exercises consistently will likely find that they have better sleep quality. Meanwhile, those who use their devices before bed are more likely to have trouble falling asleep at night, as the blue light <\/a>emitted from the devices can interfere with melatonin production, ultimately making it harder to fall asleep.\" Other lifestyle factors that can have a negative impact on your sleep cycles include the consumption of caffeine<\/a>, nicotine, and alcohol<\/a>. (20<\/a>) (21<\/a>)<\/p>\n\n\n\n Supporting a Healthy Sleep Cycle<\/h2>\n\n\n\n Far from being a passive process, the functions that occur during sleep are essential to our health and well-being. To protect our sleep health and encourage restful and restorative sleep, meeting our daily sleep requirements<\/a> is crucial, as is practicing healthy sleep hygiene<\/a>.<\/p>\n\n\n\n The basics of sleep hygiene include: (21<\/a>)<\/p>\n\n\n\n Maintaining regular sleep and wake times<\/li> Limiting or eliminating noise, excessive light, and extreme temperatures in either direction in the sleeping environment<\/li> Avoiding caffeine and alcohol before bedtime<\/li> Reducing the use of electronics in the hours leading up to sleep, as many of these emit a blue light which decreases melatonin production and promotes alertness<\/li> Napping strategically <\/li> Reserving the bed only for sleep and sex<\/li> Exercising regularly <\/li><\/ul>\n\n\n\n FAQs<\/h2>\n\n\n\n How many stages of sleep are there?<\/h3> There are four stages of sleep: N1, N2, N3, and REM. Sleep phases and stages all come together to form a sleep cycle. Sleep cycles last anywhere from 90 to 110 minutes, and most people experience five to six sleep cycles per night.<\/div><\/div> How much REM sleep do you need?<\/h3> REM sleep accounts for roughly 25 percent of our total sleep time, so adults typically need about 1.5 to 2 hours of REM sleep each night. Keeping in mind that REM sleep plays a crucial role in brain development, it's worth noting that infants need far more REM sleep than adults. Babies spend about 50 percent of their total sleep time in REM sleep. As they mature, their requirements for REM sleep begin to level off, eventually matching the requirements of their adult counterparts.<\/div><\/div><\/div>\n\n\n\n The Last Word From Sleepopolis\u00a0<\/h2>\n\n\n\n Sleep is a dynamic state that evolves as our bodies change over a lifetime. From growth and tissue repair to memory consolidation, the processes that occur during sleep are essential to the healthy functioning of the brain and body. <\/p>\n\n\n\n Unfortunately, sufficient (and healthy) sleep is sacrificed to busy work schedules and family routines all too often. However, a deeper understanding of sleep\u2019s importance may be the key to changing how we prioritize rest and activity. Ultimately, healthier habits and sleep-promoting routines may help the body capitalize on all four stages of sleep to benefit our long-term health.<\/p>\n\n\n\n Sources<\/h2>\n\n\n","image": "https://sleepopolis.com/wp-content/uploads/2019/02/iStock-974746536.jpg","author": { "@type": "Person", "name": "Sharon Brandwein", "sameAs": "https://sleepopolis.com/author/sharon-brandwein/", "description": " Sharon Brandwein is a Certified Sleep Science Coach and a freelance writer. She specializes in health and beauty, parenting, and of course, all things sleep. Sharon’s work has also appeared on ABC News, USAToday, and Forbes. When she’s not busy writing, you might find her somewhere curating a wardrobe for her puppy. " }, "publisher": { "@type": "Organization", "name": "Sleepopolis", "url": "https://sleepopolis.com", "logo": { "@type": "ImageObject", "url": "https://sleepopolis.com/wp-content/uploads/2018/09/Logo-Sleepopolis.png" }}} Skip to content The Sleep Stages: Your Brain’s REM and NREM Sleep Cycle by Sharon Brandwein Updated: August 30, 2024 Expert Verified By: Kristen Casey, PsyD Long Story Short Your brain cycles through the sleep cycle 4 to 6 times each night. Each cycle is comprised of the four sleep stages: non-REM 1, non-REM 2, non-REM 3, and finally, REM. (1) Out of all sleep stages, we spend most of our time (45 percent) in non-REM 2. (1)   Non-REM 3, the third stage of the sleep cycle, is the deepest sleep stage and the one that helps you feel refreshed and restored in the morning. (2) The REM sleep stage is the one most commonly associated with vivid dreams, but it is not when you get your deepest, most restorative sleep. (3) REM sleep plays an important role in consolidating memories, emotion regulation, and brain development. (4)(5)(6) Age, sleep disorders, and lifestyle choices can affect how you experience sleep cycles. When our heads hit the pillow each night, it’s lights out for the most part. And while sleep was once thought to be purely passive, research has shown it’s anything but. We may spend the next hours relatively unaware of what’s going on around us, but under the cover of night, our bodies are fantastically busy shoring up our immune system, building muscle, repairing tissue, and filing away memories — just to name a few. In order to do all of the above each night, we cycle through an assortment of sleep stages. And while the rapid eye movement stage (REM) might be the most well-known, the other superstar sleep cycle stages do some pretty heavy lifting to leave you rested and rejuvenated day after day.   Note: The content on Sleepopolis is meant to be informative in nature, but it shouldn’t be taken as medical advice, and it shouldn’t take the place of medical advice and supervision from a trained professional. If you feel you may be suffering from any sleep disorder or medical condition, please see your healthcare provider immediately.  What Is The Sleep Cycle? Sleep is broken down into two phases: nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. These phases are then divided into four stages — N1, N2, N3, and REM — in which the sleeper moves from light to deep sleep, then back again. (1) When your body moves through all of these stages throughout the night repeatedly, those are called sleep cycles. These cycles usually last about 90 minutes, and most people go through four to six cycles each night. (1) Night after night, we go through the same sleep-wake cycle, which is regulated by our circadian rhythm. (1) While sleep is still largely shrouded in mystery, we know that it plays a vital role in our overall health and well-being. While we lay snug in our beds each night, sleep helps us with: (1) Brain development/ maturation Memory consolidation and learning  Cognition  Improved immune functioning Healing, tissue repair, muscle growth, and bone building Clearing metabolic waste How Long Is a Sleep Cycle? A complete sleep cycle typically lasts anywhere from 90 to 110 minutes. With each cycle, sleepers progressively move through the N1, N2, N3, and REM sleep stages, with the new cycle beginning back in light sleep. A full night’s sleep usually includes four to six sleep cycles. (1) The Four Stages of Sleep Each night, our bodies cycle through 2 phases of sleep (NREM and REM) consisting of four sleep stages: non-REM 1, non-REM 2, non-REM 3, and REM. Sleep Stage Type of Sleep Function NREM 1 Non-REM Light sleep. The transition between being awake and asleep. It’s still easy to wake up out of this stage. NREM 2 Non-REM Deeper sleep. Your body temperature drops, and your heart rate slows down. NREM 3 Non-REM Deep sleep. Your body is releasing growth hormone, repairing and regrowing tissue, and strengthening the immune system. REM Sleep REM The stage most often linked to dreaming and is less restful than other sleep stages. Brain activity resembles that of a waking state. Source: (1) NREM 1 Sleep Stage  N1 is the first and lightest stage of sleep. N1 is a dynamic state that represents the transition between a waking state and sleep. (1) It can last anywhere from one to five minutes and typically accounts for 5 percent of our total sleep time. (1) During N1, the following physiological changes occur: Slow, rolling eye movement (7) Brain waves shift from the alpha waves of relaxation to the theta waves of sleep (1) Muscles begin to relax (1) Sleepers may be roused quite easily from this stage of sleep, and small shifts back and forth between alpha and theta brain waves during N1 sleep may give the sleeper the sense that they are still awake. (1) Alpha waves are a pattern of brain activity associated with relaxed wakefulness, whereas theta waves brain activity is associated with early stages of drowsiness or light sleep. ( Challenges with N1 sleep, such as extended sleep latency (the time spent waiting to fall asleep), may indicate the presence of a sleep disorder. Difficulty transitioning into N1 sleep or initiating sleep is also a common symptom of insomnia. (9) NREM 2 Sleep Stage N2 moves us into deeper sleep. Its duration changes as we progress through the night — the first N2 stage typically lasts around 25 minutes, and subsequent N2 stages grow longer as the hours tick by. (1) N2 sleep accounts for approximately 45 percent of our total sleep time, making it the sleep stage where we spend the most time. (1) Brain wave activity during N2 sleep includes sleep spindles and K-complexes (or long delta waves). While sleep spindles and K-complexes both play a central role in memory consolidation, K-complexes also play a role in maintaining sleep. (1) While we sleep, we still experience environmental stimuli — some are harmless, while others can be dangerous enough to warrant us waking up and taking action. K complexes (a pattern of brain wave activity that typically occurs during NREM stage 2 sleep) are thought to protect sleep by preventing waking to normal stimuli that do not present a danger. (10) During N2, the following physiological changes occur: (1) Decrease in heart rate and body temperature Blood pressure drops (11) Breathing is less erratic (11) NREM 3 Sleep Stage N3 is the deepest stage of sleep, and out of all the sleep stages, it has the most aliases. N3 is also known as slow-wave sleep (SWS), deep sleep, and delta sleep (due to the brain wave activity that occurs during this sleep stage). N3 accounts for 25 percent of our total sleep time. It’s usually the hardest to wake up from and, therefore, the one most commonly associated with sleep inertia. (1) While N3 plays a heavy hand in how restored and refreshed we feel upon waking, it’s the stage where biological processes like growth hormone release, bone and muscle building, and immune strengthening occur. (1) As they age, older adults spend less time in N3 sleep and more time in N2. (1) REM Sleep Stage The rapid eye movement stage, or REM sleep as it’s more commonly known, is the fourth and final sleep stage in a sleep cycle. Brainwave activity shows beta waves, which closely resembles brainwave activity in a waking state. (1) REM sleep is: The stage where most dreaming occurs.  The sleep stage from which dreamers are more likely to remember their dreams.  Typically considered less restful than other sleep stages. (3)  Additionally, the amount of time spent in REM sleep tends to decrease with age. While infants spend as much as 50 percent of sleep time in the REM stage, adults may spend closer to 25 percent. (12) Most sleepers will hit their first REM stage somewhere around 60 to 90 minutes into their sleep cycle. (1) Initial REM stages are short and continue to lengthen as the night wears on. As such, your first REM stage of the night could be as short as 10 minutes, whereas your last REM stage could last as long as one hour. (1) During REM sleep, the following physiological changes occur: (1) Erratic breathing and heart rate Muscle paralysis (muscle atonia)  Rapid eye movements Deep Sleep vs REM Sleep: What’s the Difference? REM sleep and deep sleep are two distinct sleep stages, each with their own unique benefits Deep sleep (aka N3, slow wave sleep, or delta sleep) is the third stage of the sleep cycle and a part of non-REM sleep. It’s the deepest stage of sleep (hence its name) and the most restful and restorative. Deep sleep is also where some critical biological housekeeping occurs — including growth hormone release, muscle and tissue growth and repair, and immune system fortification. (1) REM sleep, though different, is equally important. This is the stage where most of our dreaming occurs, and while it’s often confused with deep sleep, it’s typically the least restorative than the other sleep stages. (1) Other critical functions of REM sleep include memory consolidation, emotional balance, and brain development. (13, 14) What Affects Sleep Cycles? Night after night, our sleep cycles are essentially on autopilot. We turn off the lights, our heads hit the pillow, and the cycle begins. However, Dan Gartenberg, a sleep scientist and sleep health advisor for CPAP.com, says some things, like age, sleep disorders, and lifestyle choices, may meddle with our sleep cycles.  Age “Age is a notable factor that can affect your quality or duration of sleep within the sleep cycle; as such, sleep patterns generally change as you age,” Gartenberg tells Sleepopolis. For example, while infants spend about 50 percent of their total sleep time in REM, that levels off as they mature, eventually falling more in line with adult REM sleep requirements. (11) Moreover, Gartenberg tells us that wonky sleep cycles are par for the course of aging. While adult sleep requirements don’t change with age (healthy adults 18 and over should get about seven to nine hours of sleep each night), their actual sleep experience often does. (15) “Older individuals tend to wake up more in the middle of the night or earlier in the morning,” says Gartenberg, noting that it’s often tied to “underlying conditions and medications.” Pair that with the host of hormonal and physiological changes that accompany aging, and it becomes clear why older individuals tend to have altered sleep cycles.  We’ll add here that with age, adults spend less time in N3 or deep sleep. (1) Sleep Disorders “Sleep disorders can also negatively impact sleep cycles,” says Gartenberg. While some sleep disorders like insomnia can put up roadblocks to even getting the sleep cycle started, others like obstructive sleep apnea and restless leg syndrome can cause frequent wakings that impair our progression through the cycle or curtail our time in any given sleep stage. (16) Health Conditions Physical and mental health conditions can also affect your sleep cycles each night. For example, studies have shown that obesity can increase awake time and reduce sleep efficiency. (17) Additionally, some mental health conditions like depression and anxiety can also stymie sleep, with research showing that impairments are evident across all sleep stages. (18) (19) Lifestyle “Lifestyle choices can affect sleep cycles as well,” says Gartenberg. “Someone who exercises consistently will likely find that they have better sleep quality. Meanwhile, those who use their devices before bed are more likely to have trouble falling asleep at night, as the blue light emitted from the devices can interfere with melatonin production, ultimately making it harder to fall asleep.” Other lifestyle factors that can have a negative impact on your sleep cycles include the consumption of caffeine, nicotine, and alcohol. (20) (21) Supporting a Healthy Sleep Cycle Far from being a passive process, the functions that occur during sleep are essential to our health and well-being. To protect our sleep health and encourage restful and restorative sleep, meeting our daily sleep requirements is crucial, as is practicing healthy sleep hygiene. The basics of sleep hygiene include: (21) Maintaining regular sleep and wake times Limiting or eliminating noise, excessive light, and extreme temperatures in either direction in the sleeping environment Avoiding caffeine and alcohol before bedtime Reducing the use of electronics in the hours leading up to sleep, as many of these emit a blue light which decreases melatonin production and promotes alertness Napping strategically  Reserving the bed only for sleep and sex Exercising regularly  FAQs How many stages of sleep are there? There are four stages of sleep: N1, N2, N3, and REM. Sleep phases and stages all come together to form a sleep cycle. Sleep cycles last anywhere from 90 to 110 minutes, and most people experience five to six sleep cycles per night. How much REM sleep do you need? REM sleep accounts for roughly 25 percent of our total sleep time, so adults typically need about 1.5 to 2 hours of REM sleep each night. Keeping in mind that REM sleep plays a crucial role in brain development, it’s worth noting that infants need far more REM sleep than adults. Babies spend about 50 percent of their total sleep time in REM sleep. As they mature, their requirements for REM sleep begin to level off, eventually matching the requirements of their adult counterparts. The Last Word From Sleepopolis  Sleep is a dynamic state that evolves as our bodies change over a lifetime. From growth and tissue repair to memory consolidation, the processes that occur during sleep are essential to the healthy functioning of the brain and body.  Unfortunately, sufficient (and healthy) sleep is sacrificed to busy work schedules and family routines all too often. However, a deeper understanding of sleep’s importance may be the key to changing how we prioritize rest and activity. Ultimately, healthier habits and sleep-promoting routines may help the body capitalize on all four stages of sleep to benefit our long-term health. Sources Patel AK, Reddy V, Shumway KR, et al. Physiology, Sleep Stages. [Updated 2024 Jan 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526132/ U.S. Department of Health and Human Services. (n.d.). Brain basics: Understanding sleep. National Institute of Neurological Disorders and Stroke. https://www.ninds.nih.gov/health-information/public-education/brain-basics/brain-basics-understanding-sleep#5  Martin, J. M., Andriano, D. W., Mota, N. B., Mota-Rolim, S. A., Araújo, J. F., Solms, M., & Ribeiro, S. (2020). Structural differences between REM and non-REM dream reports assessed by graph analysis. PLOS ONE, 15(7), e0228903. https://doi.org/10.1371/journal.pone.0228903 Lendner, J. D., Niethard, N., Mander, B. A., Schuh-Hofer, S., Schmidt, H., Knight, R. T., Born, J., Walker, M. P., Lin, J. J., & Helfrich, R. F. (2023). Human REM sleep recalibrates neural activity in support of memory formation. Science Advances. https://doi.org/adj1895 Galbiati, A., Sforza, M., Fasiello, E., Casoni, F., Marrella, N., Leitner, C., Zucconi, M., & Ferini-Strambi, L. (2020). The association between emotional dysregulation and REM sleep features in insomnia disorder. Brain and Cognition, 146, 105642. https://doi.org/10.1016/j.bandc.2020.105642 Fan Jiang; Sleep and Early Brain Development. Ann Nutr Metab 28 December 2019; 75 (Suppl. 1): 44–54. https://doi.org/10.1159/000508055 Nayak CS, Anilkumar AC. EEG Normal Sleep. [Updated 2023 May 23]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537023/ Xavier G, Su Ting A, Fauzan N. Exploratory study of brain waves and corresponding brain regions of fatigue on-call doctors using quantitative electroencephalogram. J Occup Health. 2020;62(1):e12121. doi:10.1002/1348-9585.12121 Kaur H, Spurling BC, Bollu PC. Chronic Insomnia. [Updated 2023 Jul 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526136/ Gandhi MH, Emmady PD. Physiology, K Complex. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557469/ Helakari, H., Järvelä, M., Väyrynen, T., Tuunanen, J., Piispala, J., Kallio, M., Ebrahimi, S. M., Poltojainen, V., Kananen, J., Elabasy, A., Huotari, N., Raitamaa, L., Tuovinen, T., Korhonen, V., Nedergaard, M., & Kiviniemi, V. (2023). Effect of sleep deprivation and NREM sleep stage on physiological brain pulsations. Frontiers in Neuroscience, 17, 1275184. https://doi.org/10.3389/fnins.2023.1275184 Kroeger, D., & Vetrivelan, R. (2023). To sleep or not to sleep – Effects on memory in normal aging and disease. Aging Brain, 3, 100068. https://doi.org/10.1016/j.nbas.2023.100068 Glosemeyer, R.W., Diekelmann, S., Cassel, W. et al. Selective suppression of rapid eye movement sleep increases next-day negative affect and amygdala responses to social exclusion. Sci Rep 10, 17325 (2020). https://doi.org/10.1038/s41598-020-74169-8 Fan Jiang; Sleep and Early Brain Development. Ann Nutr Metab 28 December 2019; 75 (Suppl. 1): 44–54. https://doi.org/10.1159/000508055 Sleep faqs – sleep education by the AASM. Sleep Education. (2021b, May 4). https://sleepeducation.org/sleep-faqs/ Slowik JM, Sankari A, Collen JF. Obstructive Sleep Apnea. [Updated 2024 Mar 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459252/ Eid SW, Brown RF, Maloney SK, Birmingham CL. Can the relationship between overweight/obesity and sleep quality be explained by affect and behavior? Eat Weight Disord. 2022;27(7):2821-2834. doi:10.1007/s40519-022-01435-1 Fang H, Tu S, Sheng J, Shao A. Depression in sleep disturbance: A review on a bidirectional relationship, mechanisms and treatment. J Cell Mol Med. 2019;23(4):2324-2332. doi:10.1111/jcmm.14170 Johnson, E. O., Roth, T., & Breslau, N. (2006). The association of insomnia with anxiety disorders and depression: Exploration of the direction of risk. Journal of Psychiatric Research, 40(8), 700-708. https://doi.org/10.1016/j.jpsychires.2006.07.008 Gardiner C, Weakley J, Burke LM, et al. The effect of caffeine on subsequent sleep: A systematic review and meta-analysis. Sleep Med Rev. 2023;69:101764. doi:10.1016/j.smrv.2023.101764 Iao SI, Jansen E, Shedden K, et al. Associations between bedtime eating or drinking, sleep duration and wake after sleep onset: findings from the American time use survey. Br J Nutr. Published online September 13, 2021. doi:10.1017/S0007114521003597 Gartenberg, Dan. Personal Interview. August 13, 2024.  Social Media Auto Publish Powered By : XYZScripts.com