IntroductionSleep is an important part of your daily routine—you spend about one-third of your time doing it. Quality sleep – and getting enough of it at the right times - is as essential to survival as food and water. Without sleep you can’t form or maintain the pathways in your brain that let you learn and create new memories, and it’s harder to concentrate and respond quickly.Sleep is important to a number of brain functions, including how nerve cells (neurons) communicate with each other.
In fact, your brain and body stay remarkably active while you sleep. Recent findings suggest that sleep plays a housekeeping role that removes toxins in your brain that build up while you are awake.Everyone needs sleep, but its biological purpose remains a mystery. Sleep affects almost every type of tissue and system in the body – from the brain, heart, and lungs to metabolism, immune function, mood, and disease resistance. Research shows that a chronic lack of sleep, or getting poor quality sleep, increases the risk of disorders including high blood pressure, cardiovascular disease, diabetes, depression, and obesity.Sleep is a complex and dynamic process that affects how you function in ways scientists are now beginning to understand. This booklet describes how your need for sleep is regulated and what happens in the brain during sleep.Anatomy of SleepSeveral structures within the brain are involved with sleep.The hypothalamus, a peanut-sized structure deep inside the brain, contains groups of nerve cells that act as control centers affecting sleep and arousal. Within the hypothalamus is the suprachiasmatic nucleus (SCN) – clusters of thousands of cells that receive information about light exposure directly from the eyes and control your behavioral rhythm.
Some people with damage to the SCN sleep erratically throughout the day because they are not able to match their circadian rhythms with the light-dark cycle. Most blind people maintain some ability to sense light and are able to modify their sleep/wake cycle.The brain stem, at the base of the brain, communicates with the hypothalamus to control the transitions between wake and sleep.
(The brain stem includes structures called the pons, medulla, and midbrain.) Sleep-promoting cells within the hypothalamus and the brain stem produce a brain chemical called GABA, which acts to reduce the activity of arousal centers in the hypothalamus and the brain stem. The brain stem (especially the pons and medulla) also plays a special role in REM sleep; it sends signals to relax muscles essential for body posture and limb movements, so that we don’t act out our dreams.The thalamus acts as a relay for information from the senses to the cerebral cortex (the covering of the brain that interprets and processes information from short- to long-term memory).
During most stages of sleep, the thalamus becomes quiet, letting you tune out the external world. But during REM sleep, the thalamus is active, sending the cortex images, sounds, and other sensations that fill our dreams.The pineal gland, located within the brain’s two hemispheres, receives signals from the SCN and increases production of the hormone melatonin, which helps put you to sleep once the lights go down. People who have lost their sight and cannot coordinate their natural wake-sleep cycle using natural light can stabilize their sleep patterns by taking small amounts of melatonin at the same time each day. Scientists believe that peaks and valleys of melatonin over time are important for matching the body’s circadian rhythm to the external cycle of light and darkness.The basal forebrain, near the front and bottom of the brain, also promotes sleep and wakefulness, while part of the midbrain acts as an arousal system. Release of adenosine (a chemical by-product of cellular energy consumption) from cells in the basal forebrain and probably other regions supports your sleep drive. Caffeine counteracts sleepiness by blocking the actions of adenosine.The amygdala, an almond-shaped structure involved in processing emotions, becomes increasingly active during REM sleep.Sleep StagesThere are two basic types of sleep: rapid eye movement (REM) sleep and non-REM sleep (which has three different stages). Each is linked to specific brain waves and neuronal activity.
You cycle through all stages of non-REM and REM sleep several times during a typical night, with increasingly longer, deeper REM periods occurring toward morning.Stage 1 non-REM sleep is the changeover from wakefulness to sleep. During this short period (lasting several minutes) of relatively light sleep, your heartbeat, breathing, and eye movements slow, and your muscles relax with occasional twitches. Your brain waves begin to slow from their daytime wakefulness patterns.Stage 2 non-REM sleep is a period of light sleep before you enter deeper sleep. Your heartbeat and breathing slow, and muscles relax even further. Your body temperature drops and eye movements stop.
Brain wave activity slows but is marked by brief bursts of electrical activity. You spend more of your repeated sleep cycles in stage 2 sleep than in other sleep stages.Stage 3 non-REM sleep is the period of deep sleep that you need to feel refreshed in the morning. It occurs in longer periods during the first half of the night.
Your heartbeat and breathing slow to their lowest levels during sleep. Your muscles are relaxed and it may be difficult to awaken you. Brain waves become even slower.REM sleep first occurs about 90 minutes after falling asleep. Your eyes move rapidly from side to side behind closed eyelids. Mixed frequency brain wave activity becomes closer to that seen in wakefulness. Your breathing becomes faster and irregular, and your heart rate and blood pressure increase to near waking levels.
Most of your dreaming occurs during REM sleep, although some can also occur in non-REM sleep. Your arm and leg muscles become temporarily paralyzed, which prevents you from acting out your dreams. As you age, you sleep less of your time in REM sleep. Memory consolidation most likely requires both non-REM and REM sleep.Sleep mechanismsTwo internal biological mechanisms–circadian rhythm and homeostasis–work together to regulate when you are awake and sleep.Circadian rhythms direct a wide variety of functions from daily fluctuations in wakefulness to body temperature, metabolism, and the release of hormones. They control your timing of sleep and cause you to be sleepy at night and your tendency to wake in the morning without an alarm. Your body’s biological clock, which is based on a roughly 24-hour day, controls most circadian rhythms.
Circadian rhythms synchronize with environmental cues (light, temperature) about the actual time of day, but they continue even in the absence of cues.Sleep-wake homeostasis keeps track of your need for sleep. The homeostatic sleep drive reminds the body to sleep after a certain time and regulates sleep intensity. This sleep drive gets stronger every hour you are awake and causes you to sleep longer and more deeply after a period of sleep deprivation.Factors that influence your sleep-wake needs include medical conditions, medications, stress, sleep environment, and what you eat and drink. Perhaps the greatest influence is the exposure to light. Specialized cells in the retinas of your eyes process light and tell the brain whether it is day or night and can advance or delay our sleep-wake cycle.
Exposure to light can make it difficult to fall asleep and return to sleep when awakened.Night shift workers often have trouble falling asleep when they go to bed, and also have trouble staying awake at work because their natural circadian rhythm and sleep-wake cycle is disrupted. In the case of jet lag, circadian rhythms become out of sync with the time of day when people fly to a different time zone, creating a mismatch between their internal clock and the actual clock.How Much Sleep Do You Need?Your need for sleep and your sleep patterns change as you age, but this varies significantly across individuals of the same age. There is no magic “number of sleep hours” that works for everybody of the same age. Babies initially sleep as much as 16 to 18 hours per day, which may boost growth and development (especially of the brain).
School-age children and teens on average need about 9.5 hours of sleep per night. Most adults need 7-9 hours of sleep a night, but after age 60, nighttime sleep tends to be shorter, lighter, and interrupted by multiple awakenings. Elderly people are also more likely to take medications that interfere with sleep.In general, people are getting less sleep than they need due to longer work hours and the availability of round-the-clock entertainment and other activities.Many people feel they can 'catch up' on missed sleep during the weekend but, depending on how sleep-deprived they are, sleeping longer on the weekends may not be adequate.DreamingEveryone dreams. You spend about 2 hours each night dreaming but may not remember most of your dreams. Its exact purpose isn’t known, but dreaming may help you process your emotions.
Events from the day often invade your thoughts during sleep, and people suffering from stress or anxiety are more likely to have frightening dreams. Dreams can be experienced in all stages of sleep but usually are most vivid in REM sleep. Some people dream in color, while others only recall dreams in black and white.The Role of Genes and NeurotransmittersChemical signals to sleepClusters of sleep-promoting neurons in many parts of the brain become more active as we get ready for bed. Nerve-signaling chemicals called neurotransmitters can “switch off” or dampen the activity of cells that signal arousal or relaxation. GABA is associated with sleep, muscle relaxation, and sedation. Norepinephrine and orexin (also called hypocretin) keep some parts of the brain active while we are awake.
Other neurotransmitters that shape sleep and wakefulness include acetylcholine, histamine, adrenaline, cortisol, and serotonin.Genes and sleepGenes may play a significant role in how much sleep we need. Scientists have identified several genes involved with sleep and sleep disorders, including genes that control the excitability of neurons, and 'clock' genes such as Per, tim, and Cry that influence our circadian rhythms and the timing of sleep.
Genome-wide association studies have identified sites on various chromosomes that increase our susceptibility to sleep disorders. Also, different genes have been identified with such sleep disorders as familial advanced sleep-phase disorder, narcolepsy, and restless legs syndrome. Some of the genes expressed in the cerebral cortex and other brain areas change their level of expression between sleep and wake. Several genetic models–including the worm, fruit fly, and zebrafish–are helping scientists to identify molecular mechanisms and genetic variants involved in normal sleep and sleep disorders. Additional research will provide better understand of inherited sleep patterns and risks of circadian and sleep disorders.Sleep studiesYour health care provider may recommend a polysomnogram or other test to diagnose a sleep disorder. A polysomnogram typically involves spending the night at a sleep lab or sleep center.
It records your breathing, oxygen levels, eye and limb movements, heart rate, and brain waves throughout the night. Your sleep is also video and audio recorded. The data can help a sleep specialist determine if you are reaching and proceeding properly through the various sleep stages. Results may be used to develop a treatment plan or determine if further tests are needed.Tracking Sleep Through Smart TechnologyMillions of people are using smartphone apps, bedside monitors, and wearable items (including bracelets, smart watches, and headbands) to informally collect and analyze data about their sleep.
Smart technology can record sounds and movement during sleep, journal hours slept, and monitor heart beat and respiration. Using a companion app, data from some devices can be synced to a smartphone or tablet, or uploaded to a PC. Other apps and devices make white noise, produce light that stimulates melatonin production, and use gentle vibrations to help us sleep and wake.Tips for Getting a Good Night's SleepGetting enough sleep is good for your health. Here are a few tips to improve your sleep:Set a schedule – go to bed and wake up at the same time each day.Exercise 20 to 30 minutes a day but no later than a few hours before going to bed.Avoid caffeine and nicotine late in the day and alcoholic drinks before bed.Relax before bed – try a warm bath, reading, or another relaxing routine.Create a room for sleep – avoid bright lights and loud sounds, keep the room at a comfortable temperature, and don’t watch TV or have a computer in your bedroom.Don’t lie in bed awake. If you can’t get to sleep, do something else, like reading or listening to music, until you feel tired.See a doctor if you have a problem sleeping or if you feel unusually tired during the day. Most sleep disorders can be treated effectively.Hope Through ResearchScientists continue to learn about the function and regulation of sleep. A key focus of research is to understand the risks involved with being chronically sleep deprived and the relationship between sleep and disease.
People who are chronically sleep deprived are more likely to be overweight, have strokes and cardiovascular disease, infections, and certain types of cancer than those who get enough sleep. Sleep disturbances are common among people with age-related neurological disorders such as Alzheimer’s disease and Parkinson’s disease. Many mysteries remain about the association between sleep and these health problems.
Does the lack of sleep lead to certain disorders, or do certain diseases cause a lack of sleep? These, and many other questions about sleep, represent the frontier of sleep research. Where Can I Get More Information?For information on other neurological disorders or research programs funded by the National Institute of Neurological Disorders and Stroke, contact the Institute's Brain Resources and Information Network (BRAIN) at:BRAINP.O. Box 5801Bethesda, MD 20824(800) 352-9424Prepared by:Office of Communications and Public LiaisonNational Institute of Neurological Disorders and StrokeNational Institutes of HealthBethesda, MD 20892NIH Publication No.
17-3440cNINDS health-related material is provided for information purposes only and does not necessarily represent endorsement by or an official position of the National Institute of Neurological Disorders and Stroke or any other Federal agency. Advice on the treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient's medical history.All NINDS-prepared information is in the public domain and may be freely copied. Credit to the NINDS or the NIH is appreciated.
If you haven't played the game during the alpha stage, then you'll have some trouble progressing - as its challenges are quite hard, even for experienced players. So in this beginner's guide for The Long Dark, we're going to give you some tips that will help you make this dangerous journey and endure your adventures in the snowy wilds.
Set the Right DifficultyThe Long Dark offers four levels of difficulty. If you’re a new player, you'll want to skip the Interloper one, which is the hardest. But if you really want to learn something, then don’t take the easiest setting, either. Instead, go for Stalker difficulty. It is perfectly balanced, and can really give you a sense of realistic survival. Find Shelter and Get WarmYour game starts in the Northern Canadian wilderness, and your first task is to get warm clothes and shelter. Your starting clothes are not very good, so you must find a place to hide from the cold as soon as possible.Don’t stray away into the wilderness too much, but try to follow the main path or the highway, as this will surely lead you to a safe place.
On your way, you can start picking up sticks from the ground that will serve as the fuel.As soon as you find a cabin or a house, immediately start looking for clothes and food inside. But be careful with your food and always check it for staleness. If it’s below 50%, then it is advisable not to consume such stale foods as they may provoke sickness.Change your clothes and use any bed for sleeping. This will help you get warm and protect you from freezing. Beware of the Wild AnimalsBefore leaving your shelter, make sure that you have a torch with you. For now it’s your only protection from the wolves and bears. You can craft a torch using three simple components: wood, cloth and lamp oil.
How To Sleep In Long Dark
You should be able to find all of them in your shelter.Another way of getting rid of wild animals is to throw them a decoy, which is basically a piece of meat that you can carry around. The wolves will most definitely smell it on you, so drop it as soon as you hear barking in the distance. This way they will chase the food rather than you.One more trick you can use to avoid wolves is to crouch.
It will make you almost invisible to them, even in cases when they appear really close to you. But don’t get too close, as there is a chance that they will attack you no matter what.In time you will need to find a real weapon, such as a rifle. It is way more effective against wild animals. You might also want to get yourself a hunting knife that can be used for skinning animals. Learn Navigation and Weather PredictionNavigating the map and predicting weather are probably two of the most important skills for survival in The Long Dark.
It will help you find the best locations for setting up your base and hide in there in case you get caught in a blizzard.The best places for setting up your base on the map are following:. Trapper's Homestead: A decent location that has fine loot inside, including a rifle. (Mystery Lake: South-West). Camp Office: Located in the central area of a Mystery Lake, which makes it perfect for fishing. Quonset Gas Station: Located in an area infested with wolves, but has tons of valuable loot inside. (Coastal Highway: East).
Farmhouse: Find it in the central part of the Pleasant Valley. It not only has good loot, but also a basement that can be used for storage purposes.Try not to leave your base too early in the morning, as usually the weather is extremely cold at that time of the day.
If you see that there is snow falling and wind blowing, then return immediately to your base - in such cases, the blizzard is inevitable.If you do get caught in blizzard, then try to find any other shelter that is close to you. Don’t try to reach your base if you know that you’re too far away. Just light up your lantern and get to the closest building you may have passed during your exploration. Hunt For SurvivalWhen you have all the clothes, equipment, and your own base, you can start hunting for wild animals. Now you’re the predator, so learn as much as you can about hunting.First, look up into the sky and check for a pack of crows circling above a certain area.
This will indicate that there is a dead animal nearby, which you can use for meat or skin.Secondly, don’t forget to check for footprints. You will see them in the snow.
In time you will be able to distinguish them pretty well, and even follow your prey.Lastly, learn fishing. You can craft hooks and lines easily using metal scraps and cured guts. If you are located on a lake, then look out for fishing huts.
Often these huts already have fishing equipment inside them, so you don’t really need to craft anything. Make a hole in the ice and catch some fish, which is an excellent source of food.-This is pretty much it for the basics of the survival game in The Long Dark. With the new Story Mode, the game should deliver all kinds of fresh challenges. So keep your eyes open and come back soon for more The Long Dark guides at GameSkinny!