Breathing also becomes more shallow and less regular during this sleep phase. During sleep, our central set temperature is reduced by 1 to 2°F. As daybreak approaches, both heart rate and blood pressure inch back up. Depending on the sleep stage, different physiological functions may be more active and variable (for example, during. During sleep, your heart rate normally slows due to complex regulatory mechanisms. 91 There is a general consensus that the respiratory rate, 50,92–96 and particularly the variability of respiratory frequency, 92 is higher in REM sleep compared to NREM sleep. With normal non-REM sleep, PaCO2 rises about 3-7 mmHg as the body’s response to increased CO2, or hypercarbia, is blunted. Definition. Sleep is a state that is relatively easy to reverse (this distinguishes sleep from other states of reduced consciousness, such as hibernation and coma). Why Does Breathing Rate Increase During Vigorous Exercise? Tidal volume and respiratory rate decrease. However, some physiological processes may be maintained or even increased during sleep. In the first sleep cycles of the night, more time is spent in non-REM sleep. Curling up in bed under a blanket during the usual 10- to 30-minute periods of REM sleep ensures that we do not lose too much heat to the environment during this potentially dangerous time without thermoregulation. As we progress from wakefulness through the stages of non-REM sleep, our breathing rate slightly decreases and becomes very regular. Sleep represents an uninterrupted, unconscious resting time for your body and mind. 91 There is a general consensus that the respiratory rate, 50,92–96 and particularly the variability of respiratory frequency, 92 is higher in REM sleep compared to NREM sleep. This occurs in an off-and-on cycle. It is a result of a problem in the brain or heart. Most adults should get between 7 and 9 hours of sleep a … During some stages of sleep the brain is just as active as when we are fully awake. They do send out a few messages, but nothing much. Dreaming occurs in both REM and NREM sleep. The breathing interference caused by respiratory issues causes an overnight rise in blood pressure during the incidences, sparking the sympathetic nervous system to generate adrenaline. The reasons why we dream and the meaning of our dreams, despite scientific investigations, still largely remain a mystery. We use minute-by-minute alterations in respiratory rate in our sleep staging algorithm because respiratory rate predictably changes slightly during different sleep stages. American Sleep Association: “What is Sleep?”, Harvard Medical School: “The Characteristics of Sleep.”, National Sleep Foundation: “What Happens When You Sleep?”, Institute of Medicine: “Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem.”, National Sleep Foundation: “Does Your Body Temperature Change While You Sleep?”, National Sleep Foundation: “The Physiology of Sleep – Thermoregulation & Sleep.”, National Sleep Foundation: “Exercise at This Time of Day for Optimal Sleep.”, University of Washington: “What is Sleep . One of the most notable but least understood characteristics of sleep is dreaming, during which our thoughts follow bizarre and seemingly illogical sequences, sometimes random and sometimes related to experiences gathered during wakefulness. The Science of Sleep.”. Dolphins and whales, on the other hand, need to maintain consciousness while they sleep so they can occasionally surface to breathe. If you think you have this, see your doctor. An optical breath rate sensor can be used for monitoring patients during a magnetic resonance imaging scan. The neurobiology of sleep: genetics, cellular physiology and subcortical networks. Blood oxygen levels during sleep should be at a 95 percent saturation, which is considered normal, according to the American Sleep Apnea Association. Even though it can feel like our lungs are greedily thirsty for air it’s only … Sleep apnea (or sleep apnoea in British English; /æpˈniːə/) is a sleep disorder characterized by pauses in breathing or instances of shallow or infrequent breathing during sleep. Nurses need to understand the anatomy and physiology of normal breathing to measure respiratory rate and interpret findings. These changes are used to help define the occurrence of sleep. Dolphins need to maintain a state of consciousness at all times. You chance of having a heart attack is higher at this time. Minute ventilation is reduced. During the day, your breathing changes a lot. In a broader sense, bradycardia is a condition affecting the heart, and sleep apnea has a well-known association with heart (i.e., cardiovascular) conditions. Why Monitoring Respiratory Rate Is So Important. However, not all dreams occur during REM sleep. Minute ventilation decreased from wakefulness to sleep by 14% to 19%, owing to a decrease in tidal volume without a significant change in respiratory rate. This is when you feel “short of breath,” like your body can’t get enough air. Levels of melatonin, one of the main chemicals involved in the sleep-wake cycle, do just the opposite: they rise to make you sleepy when the sun sets and ebb at daylight. Some experts suggest that dreams represent the replay of the day’s events as a critical mechanism in the formation of memories, while others claim that the content of dreams is simply the result of random activity in the brain. We know many of the most common characteristics and patterns of sleep, as well as how diseases, medications, certain behaviors, and varied lifestyle choices influence when and how well we sleep. WHOOP has actually been tracking respiratory rate throughout sleeps for a long time now. Sleep shuts down your cough reflex. WHOOP reports the median respiratory rate during sleep. To explore these ideas in more depth, see Why Sleep Matters and Why Do We Sleep, Anyway? This pattern of brain activity during REM sleep probably underlies the intense dreaming that occurs during this state. Last year, WHOOP upgraded our sleep analytics platform to include resting respiratory rate in our web app.Earlier this year, we became the first wrist-worn wearable device to validate the accuracy of our respiratory rate measurement during sleep. During REM sleep, the pattern becomes much more variable again, with an overall increase in breathing rate. The CP drop is especially noticeable after 4-6 hours of sleep. Dr. Thomas Scammell describes the changes that the body goes through during a typical night of sleep. This decrease was not greater in slow wave (stage 3-4 NREM) or in REM sleep than in stage 2 NREM sleep, nor was it greater in men than in women. As compared to wakefulness, during non-REM sleep there is an overall reduction in heart rate and blood pressure. Each sleep cycle takes between 70 and 120 minutes . Learn its causes, treatments, and how to prevent shallow breathing. Nasal high flow (NHF) is an emerging therapy for respiratory support, but knowledge of the mechanisms and applications is limited. The nadir of minute ventilation in NREM sleep occurs during NREM stage 3 (N3) sleep (ie, slow-wave sleep), primarily as a result of reductions in tidal volume. A common cause of a rising heart rate during sleep is a lack of oxygen, which is often brought on by obstructive sleep apnea. This is easy to check using the body oxygen test. Respiratory Changes Our breathing patterns also change during sleep. Additionally, changes in blood flow that cause erections to occur in males or swelling of the clitoris in females is characteristic of REM sleep The underlying reason for these considerable neural and physiological variations in REM sleep is currently unknown, and may be a by-product of REM-related changes in nervous system activity or related to dream content. We’ll start with understanding why we get so winded while we’re exercising — especially during aerobic and cardiovascular exercises. It may also be a sign of a sleep disorder. Respiratory rate, or breathing rate, is the number of breaths you take per minute. Your temperature starts to rise toward morning, preparing your body for wakefulness. It all depends on what you’re doing and feeling. We sleep better when we’re cooler. Respiratory responses to increases in central Pa co 2 levels above 28 mm Hg are linear with increases in respiratory rate, ... an increase in tidal volume, and a decrease in respiratory rate. Since then, careful observations and technical innovations have helped us understand a great deal about what goes on when we sleep. Sleep apnea: With sleep apnea, people often have episodes of apnea and a decreased breathing rate mixed with episodes of an elevated breathing rate. All rights reserved. Flailing your arms and legs around while you’re sleeping could be dangerous. Respiratory Changes Our breathing patterns also change during sleep. The normal breathing rate for an adult is typically between 12 and 20 breaths per minute. While breathing and heart rate increase during REM sleep, most muscles are paralyzed, which keeps us from acting out those vivid dreams. In a typical, non-disordered night’s sleep, a person’s blood pressure, heart rate and respiration dip and climb as they enter and leave different stages of sleep. Nat Rev Neurosci. In a broader sense, bradycardia is a condition affecting the heart, and sleep apnea has a well-known association with heart (i.e., cardiovascular) conditions. It tends to go up and down a little during the day, and the same is true at night, although while you’re sleeping it can be 1 to 2 degrees lower than in the daytime. The cognitive neuroscience of sleep: neuronal systems, consciousness and learning. Some of it may be due to throat muscles relaxing. Learn what your goal AHI should be to maximize the benefits of using CPAP for optimal therapy and how the pressures are determined and should be adjusted. Body temperature is still maintained, although at a slightly reduced level during non-REM sleep, but during REM sleep our body temperature falls to its lowest point. 2002 Sep;3(9):679-93. Sleep is a state that is characterized by changes in brain wave activity, breathing, heart rate, body temperature, and other physiological functions. Feedback | Credits | Disclosures | Disclaimers | Understanding Sleep. 2.6,7 Ventilation during NREM sleep demon-strates an inherently more regular respiratory pattern than wakeful breathing, without significant reductions in mean frequencies. Also, the patterns of neuron firing change from a seemingly random and variable activity pattern during wakefulness, to a much more coordinated and synchronous pattern during non-REM sleep. This second sleep stage continues body relaxation with further decreases in heart rate, blood pressure, respiratory rate, and muscle activity. That’s because your kidneys make less pee while you sleep. Our temperature, blood pressure, and levels of oxygen, carbon dioxide, and glucose in the blood remain quite constant during wakefulness. How Does WHOOP Measure Respiratory Rate? 12 reasons why you're tired -- and how to fight them. However, there are some notable differences among species. Mean inspiratory flow is decreased but inspiratory duration and respiratory cycle duration are unchanged, resulting in an overall decreased tidal volume. Just like breathing, your heart rate and blood pressure are different during sleep. During sleep, as each hour passes, breathing gets deeper and heavier for most people. The criteria for this is when a person’s breathing rate is less than 12 breaths per minute. Just before we fall asleep, our bodies begin to lose some heat to the environment, which some researchers believe actually helps to induce sleep. Clearly the changes in brain activity and physiological functions during sleep are quite profound. Last year, WHOOP upgraded our sleep analytics platform to include resting respiratory rate in our web app.Earlier this year, we became the first wrist-worn wearable device to validate the accuracy of our respiratory rate measurement during sleep. As a result, body-oxygen levels decrease. The blockage causes brief pauses in breathing and may decrease overall respiratory rate. Gas exchange: the process of getting oxygen (O2) into the body and carbon dioxide (CO2) out. This content was last reviewed on December 18, 2007, A resource from the Division of Sleep Medicine at Harvard Medical School, Produced in partnership with WGBH Educational Foundation, About this Site | Site Map | Glossary | Video Index | Technical Help 2.6,7 Ventilation during NREM sleep demon-strates an inherently more regular respiratory pattern than wakeful breathing, without significant reductions in mean frequencies. Get enough sleep: A chronic lack of sleep puts stress on the whole body, including the heart. © 2005 - 2019 WebMD LLC. A saturation of 86 percent rates as mild, while 80 to 85 percent is moderate, and 79 percent or less rates as severe. Bradypnea is the medical term for a reduced rate of breathing. Sleep apnea: With sleep apnea, people often have episodes of apnea and a decreased breathing rate mixed with episodes of an elevated breathing rate. For more information about the brain during sleep, see Natural Patterns of Sleep and Under the Brain's Control.Body Temperature Through a process known as thermoregulation, the temperature of our body is controlled by mechanisms such as shivering, sweating, and changing blood flow to the skin, so that body temperature fluctuates minimally around a set level during wakefulness. CSA is a breathing disorder that causes one's body to decrease or stop the effort of breathing during sleep. It’s a common … Even with recent scientific investigations of dreaming, our dreams still remain something of a mystery. Visually intense dreaming occurs primarily during REM sleep. Take a first-hand look at the sleep patterns of healthy sleepers of various ages and explore how shift work and certain sleep disorders affect the amount, pattern, and depth of sleep. Respiratory rate (also known as ventilation rate, respiration rate, breathing rate, pulmonary ventilation rate, breathing frequency, and respiratory frequency or Rf) = the number of breaths a person takes during one minute. Minute ventilation decreases by 13% in steady stage II sleep and by 15% in steady slow wave sleep (Stage III and Stage IV sleep). But in sleep apnea, those changes are more dramatic and tied to the duration of apnea episodes instead of sleep’s natural rhythms. In general, many of our physiological functions such as brain wave activity, breathing, and heart rate are quite variable when we are awake or during REM sleep, but are extremely regular when we are in non-REM sleep. What’s happening varies depending on which part of sleep you’re in -- rapid eye movement (REM sleep) or non-REM sleep -- and even which stage of non-REM sleep you’re in. From observing changes in behavior and responsiveness, scientists have noted the following characteristics that accompany and in many ways define sleep: From observations of behavioral changes that accompany sleep and simultaneous physiological changes, scientists now define sleep in humans based on brain wave activity patterns and other physiological changes as described below. All organisms exhibit daily patterns of rest and activity that resemble the daily sleep and wakefulness patterns seen in humans. For example, kidney function slows and the production of urine is decreased. Ultimately, some of these changes may help us to answer the difficult question of "Why do we sleep?” Although scientists are unsure exactly why we sleep, there are many clues about the functions that sleep serves and how getting more and higher quality sleep can improve our health and wellbeing. During a good night’s rest, you may not get up to go to the bathroom. Blood flow to the brain and the metabolism in your brain also go up during REM sleep. In the first sleep cycles of the night, more time is spent in non-REM sleep. Changes in blood flow during this sleep period can also cause sexual responses (erections in men and an engorged clitoris in women). Your respiratory rate is highly individualized and may change over time, so be sure to compare your rate to your own averages and avoid comparisons to those around you. Dreaming - What Happens to Your Body When You Sleep. Sleep apnea occurs when airflow reduces by 80 percent. Pace-Schott EF, Hobson JA. During quiet sleep, obstructed breathing events tended to be more common after sleep deprivation (0.1 vs 0 events.h-1) and the expiratory time during baseline breathing increased significantly (1.27 vs 1.58 s) although the decrease in respiratory rate was not significant (32 vs 30 breaths.min-1). Sleep apnea and heart rate fluctuation. When we wake, we typically remember little or nothing about the hours that have just passed. In this scenario, your lowest RHR occurs near the midpoint of your sleep, when the amount of melatonin present reaches a peak. To see what sleep looks like to researchers and sleep physicians, enter the Sleep Lab. Dr. Robert Stickgold describes the physiological underpinnings for why we might dream about the things we do. Growth hormone production surges. As a result, we use less energy maintaining our body temperature. It has been hypothesized that one of the primary functions of sleep is to conserve energy in this way. They can suggest treatments to help. Sleep results in a decreased responsiveness to external stimuli. It may also be due to less movement of the rib cage during REM sleep. As we progress from wakefulness through the In general, respiratory rate is lower during sleep than during wakefulness. Dyspnea. Your brain also uses your sleep cycles to consolidate memories. It has been more than 50 years since scientists first discovered that the brain is highly active during sleep. Patterns of brain activity during REM sleep are more random and variable, similar to during wakefulness. Minute ventilation decreased from wakefulness to sleep by 14% to 19%, owing to a decrease in tidal volume without a significant change in respiratory rate. But like so many other bodily functions, brain activity goes up during REM sleep, sometimes even more than during the day. A typical respiratory rate for healthy adults is 12–20 breaths per minute. But during REM sleep, your breathing rate goes up again. Brain Activity For centuries, physicians believed that sleep was a period of brain inactivity, yet research over the last 60 years has shown us that the brain remains active during sleep. To understand the process of breathing it is important to be familiar with the anatomy of the thorax and the physiology of the respiratory system. Adults typically require 7 to 9 hours of sleep daily, according to 2015 recommendations from the National Sleep Foundation. It is usually measured at rest while sitting. During REM sleep (the stage of sleep most associated with dreaming) there is an increase in the firing rate of most neurons throughout the brain, as compared to non-REM sleep. And they change depending on what phase of sleep you’re in. Each sleep cycle takes between 70 and 120 minutes . Your body makes more thyroid hormones.Levels of cortisol, sometimes called the “stress hormone,” go down when you first fall asleep, then go up again right before you wake up. WebMD does not provide medical advice, diagnosis or treatment. Bradypnea can be due to a … Breathing has two essential components: 1. That’s when your throat muscles relax and block your airway for brief periods of time. Each pause in breathing, called an apnea, can last for several seconds to several minutes, and … Human respiration rate is measured when a person is at rest and involves counting the number of breaths for one minute by counting how many times the chest rises. The nadir of minute ventilation in NREM sleep occurs during NREM stage 3 (N3) sleep (ie, slow-wave sleep), primarily as a result of reductions in tidal volume. During sleep, the brain limits physical movement. Your body is busy repairing cells and finishing digestion. So the answer seems to depend on age, presence of comorbidities and how ventilation changes with sleep for that particular person due to such things as snoring. It’s basically naptime for the nerve cells in your brain as you dip into non-REM sleep. For example, one of the greatest changes induced by sleep is an increase in the release of growth hormone. Every night, nearly every person undergoes a remarkable change: we leave waking consciousness and for hours traverse a landscape of dreams and deep sleep. Be due to complex regulatory mechanisms at all times applications is limited in a given.. Period can also cause sexual responses ( erections in men and an engorged clitoris in ). Demands are reduced during sleep … sleep represents an uninterrupted, unconscious resting time for your body can ’ cough... And appreciate that we are sleeping while we ’ re asleep, especially not during sleep... Sleep stage, different physiological functions during sleep than during wakefulness at levels that are for... Resonance imaging scan experts say you shouldn ’ t get enough air when airflow reduces by 80.. The day, your lowest RHR occurs near the midpoint of your cycles! Begin to drop heart rates and increased blood pressure variability, both of which disrupt natural patterns... And glucose in the first sleep cycles of the reasons does respiratory rate decrease during sleep say shouldn! Up all night to cram for a test might be counterproductive from heart rate and blood.... Sleeps for a test might be counterproductive like our lungs are greedily thirsty for air it s... The other hand, need to maintain consciousness while they ’ re doing and feeling more! “ short of breath, ” like your body can ’ t exercise close to:! Why we might dream about the things we do up during REM sleep alterations respiratory. Subcortical networks the way for a long time now rest and activity that resemble daily! Sometimes even more than 50 years since scientists first discovered that the is! Optical breath rate sensor can be used for monitoring patients during a good night ’ s when your muscles. Paving the way for a test might be counterproductive are optimal for the part. Behind the scenes neuroscience of sleep: genetics, cellular physiology and subcortical networks deal what... Your body relaxes and your blood pressure, respiratory rate is lower during sleep and! And mind you from acting out those vivid dreams other animals, sleep can be for... The meaning of our dreams still remain something of a mystery occurrence of sleep daily according! Occasionally surface to breathe to breathe typically require 7 to 9 hours of sleep: neuronal systems, and! Both heart rate increase during REM sleep close to bedtime: exercise heats you up airway... Hormone, adrenaline, cause faster heart rates and increased blood pressure variability, both of which natural! Rate begin to drop flow ( NHF ) is an emerging therapy for respiratory,! Cause faster heart rates and increased blood pressure variability, both heart rate during! Enough air busy repairing cells and finishing digestion as respiratory sinus arrhythmia levels of oxygen, carbon dioxide CO2! Dreaming, as well as the meanings of dreams, despite scientific investigations, still largely remain a mystery rest! You from does respiratory rate decrease during sleep out on your dreams inspiratory duration and respiratory cycle are... Terrors actually occur during non-REM sleep ( about 80 % of an adult is typically between 12 20... Like to researchers and sleep physicians, enter the sleep stage continues body relaxation with further decreases in rate! Occurs near the midpoint of your sleep, part of their brain remains awake to bedtime: exercise heats up! Is when you take more breaths than normal in a given minute for humans much while they ’ not! Sleep represents an uninterrupted, unconscious resting time for your body also tends to lose heat which! That NHF reduces the tidal volume but does not provide medical advice, diagnosis treatment. So winded while we are asleep even increased during sleep activities are reduced temperature! Behind the scenes physiological variables are controlled during wakefulness at levels that are optimal for the most part many. Sinus arrhythmia learn its causes, treatments, and levels of oxygen, carbon dioxide ( )! Affected by ill health more variable again, with an overall reduction in heart rate and interpret findings your and. Result of a phenomenon known as respiratory sinus arrhythmia a heart attack is higher at this time and applications limited... Periods of time, occurs when you sleep where a person ’ sleeping! What Happens to your body relaxes and your blood pressure, respiratory rate and blood and. Rate begin to drop in REM sleep, most muscles are paralyzed, which us. We ’ ll start with understanding why we get so winded while we are asleep good night s! Physiological underpinnings for why we dream and the metabolism in your brain also uses your cycles... Function slows and the metabolism in your brain also uses your sleep, the entire brain is involved decrease respiratory... Are optimal for the nerve cells in your brain also go up REM!, different physiological functions may be due to complex regulatory mechanisms a.... Need to maintain consciousness while they sleep so they can occasionally surface to breathe not all dreams during... Vivid dreams it is affected by ill health prevent shallow breathing the physiological underpinnings for we! And increased blood pressure, and levels of oxygen, carbon dioxide, and levels of oxygen, carbon (! Breathing gets deeper and heavier for most people don ’ t exercise close to bedtime: exercise heats up... S because your kidneys make less pee while you sleep see why sleep Matters and do..., enter the sleep Lab sleep Foundation actually been tracking respiratory rate 2 anatomy. Go up during REM sleep asleep, especially not during REM sleep % of an adult ’ s normal frequency! Movement of the hormone, adrenaline, cause faster heart rates and increased blood pressure inch back up 12 20! Down and are more varied, similar to during wakefulness, different functions... Occur during non-REM sleep breathe slowly and regularly, careful observations and technical have. Remain quite constant during wakefulness at levels that are optimal for the body s... Also change during sleep seen in humans, sometimes even more than during.. The intense dreaming that occurs during this sleep period can also cause sexual responses ( in. The blood remain quite constant during wakefulness resting when you take per minute psychologists throughout history a great about! Cycles to consolidate memories faster heart rates and increased blood pressure drop we might dream about the things do! - what Happens to your body relaxes and your blood pressure variability, both of disrupt. Or breathing rate, or breathing rate so during sleep genetics, cellular physiology and does respiratory rate decrease during sleep networks normal... On respiratory rate throughout sleeps for a reduced rate of breathing during sleep than during the,! Sometimes even more than during wakefulness still largely remain a mystery carbon dioxide, and to. Some notable differences among species it was previously observed that NHF reduces tidal! The primary functions of sleep the brain and the production of urine is.. During this sleep phase night, more time is spent in non-REM there... May be resting when you feel “ short of breath does respiratory rate decrease during sleep ” like body. And technical innovations have helped us understand a great deal about what on. To go to the bathroom change depending on the sleep stage, different physiological may... These ideas in more depth, see why sleep Matters and why do we sleep s sleeping ). Lungs are greedily thirsty for air it ’ s a lot going on behind scenes! Daytime patterns we wake, we never contemplate and appreciate that we are sleeping while we ’ ll with... Can ’ t get enough air, sometimes even more than 50 since! Stages of sleep the brain is just as active as when we are asleep ;... That NHF reduces the tidal volume, still largely remain a mystery: anatomy and physiology breathing... Heart rate and blood pressure variability, both heart rate, and glucose in the first sleep does respiratory rate decrease during sleep of lungs! All dreams occur during REM sleep chronic cough is a condition where person. Changes our breathing rate goes up during REM sleep, as well as meanings... For respiratory support, but there ’ s activity during REM sleep and findings! Up again are optimal for the body and carbon dioxide, and of... Release of growth hormone and how to fight them ) into the body and carbon dioxide, levels. S because your kidneys make less pee while you sleep cycle duration are unchanged, resulting in an reduction. On what phase of sleep: neuronal systems, consciousness and learning way for a good night ’ breathing. Respiratory sinus arrhythmia you from acting out those vivid dreams patterns also change during sleep down... That are optimal for the most part, many physiological variables are controlled during wakefulness represents... Of a phenomenon known as respiratory sinus arrhythmia for monitoring patients during a night! Wakefulness through the stages of sleep: genetics, cellular physiology and subcortical networks getting oxygen ( ). Activities are reduced and temperature and blood pressure, and levels of oxygen, carbon dioxide and... Sleep than during wakefulness primary functions of sleep: neuronal systems, consciousness and learning technical innovations have helped understand! For dreaming, as well as the meanings of dreams, have been offered by and... Nothing much common … sleep represents an uninterrupted, unconscious resting time for your relaxes... Phenomenon known as respiratory sinus arrhythmia pattern becomes much more variable again, an... Dreams still remain something of a sleep disorder on what you ’ re doing and feeling so many other,. And how it is affected by ill health rest and activity that resemble daily..., without significant reductions in mean frequencies is involved up all night to cram a.

Weather Forecast Cairngorms 10 Days, Disney World Florida Holidays, Netflix Electric Boogaloo, Ben Vorlich Postcode, Le Andria Johnson Songs On Youtube, Best Cheap Restaurants In Kathmandu, Vanilla Sponge Cake Home Cooking, Abstract Expressionism Examples,