How does sleep affect learning We can trace these neural changes back to transient sleep events, such as spindles for memory Nov 29, 2024 · While you can’t completely undo the effects of chronic sleep deprivation, consistent high-quality sleep can gradually restore cognitive function and memory. So the question is how does a young person incorporate the “big three” into his very busy daily life? Jul 20, 2023 · Case studies provide a closer view of how sleep can affect both mental health and the learning process. But if your child has sleep problems, this can affect how well your child learns. May 29, 2024 · Sleep deprivation causes fatigue, low energy and excessive sleepiness, which can affect your ability to do things you love and simply complete day-to-day tasks. A concrete challenge posed at the beginning of the lesson helps you to understand what you’re learning in real-world terms. e. Not only do mental stressors affect sleep quality, but they also impact performance overall. These emotional disturbances can interfere with the learning process, making it harder to engage with material and retain information. Aug 30, 2022 · The findings suggest that sleep affects learning and behavior through specific brain changes. Mind What You Eat 6. The findings, published in the Journal of Neuroscience, may help explain how humans form memories and learn, and could eventually aid the development of assistive tools for people affected by neurologic disease or injury. 2007). Sleep should not be seen as a luxury, but rather as essential to brain and body health. Jun 22, 2022 · Why do we sleep? Scientists have debated this question for millennia, but a new study adds fresh clues for solving this mystery. , in press). How does sleep affect learning capabilities? Sleep has a profound impact on Mar 12, 2022 · But does sleep affect our learning ability, and does it change as we age? Your Brain Is Busy Strengthening Connections While You Sleep. Oct 18, 2023 · Good sleep can help with your child’s concentration, memory and learning. Introducing Sleep. Individuals with ADHD have been shown to have altered sleep-dependent procedural memory consolidation, leading to impairments in skill-learning. Dr Debra Babcock Jun 9, 2017 · This study demonstrates that very traumatic acute events can affect sleep for weeks. Mar 8, 2019 · Although the memory was implicit, it could affect the people’s behavior, Andrillon and his colleagues have found that learning in sleep can go beyond simple conditioning. Read our Sleep Deprivation and Deficiency page for more information on how lack of sleep affects performance of daily activities, including driving and schoolwork. So, can you learn while sleeping? Examine how sleep affects learning, how different sleep stages affect your brain, and what skills are best to enhance while you snooze. Oct 23, 2024 · One thing, however, has become obvious based on research: sleep deprivation clearly impairs learning. 0 years, 18 women) were tested once after normal sleep (8 hr time in bed for 2 nights) and once after 2 nights of sleep restriction (4 hr/night) on a probabilistic selection task where learning behaviour was How does a lack of sleep affect our brains? In contrast to the benefits of sleep, frameworks exploring the impact of sleep loss are relatively lacking. By understanding how sleep affects learning, individuals can take steps to improve their sleep habits and optimize their learning potential. Evidence from various human and rodent studies supports the importance of sleep in learning and memory. Jul 18, 2023 · Getting enough hours of high-quality sleep fosters attention and concentration, which are prerequisites for most learning. We discuss neuronal-network and regional forebrain activity during sleep, and its consequences for consciousness and . Oct 1, 2021 · The second approach examines how sleep deprivation affects learning. Research indicates that adequate sleep enhances recall abilities significantly. So, if you’re a student looking to boost your academic performance, start with enhancing your sleep routine. Dr Debra Babcock My baby cries when he lies flat. Not getting enough sleep affects how kids think. cadian rhythms can affect inhibition, while sleep inertia affects visual attention. D. Dec 20, 2024 · Sleep disturbances can negatively affect mood and emotional well-being, which can further impact dyslexia symptoms. For little ones, who are just starting to learn how to control their behavior and pay attention in preschool or other Feb 29, 2024 · These connections in the brain help individuals learn new information and form memories during sleep. Sleep helps your brain work properly. Another possibility is a two-way street between sleep and memory: sleep quality may affect memory and thinking, and the brain changes that cause memory and thinking problems may disturb sleep. Dec 17, 2024 · Lack of sleep can affect your physical and mental health, leading to issues like poor brain function, mood problems, and a weakened immune system. The present study aimed to investigate the relationships between sleep, mental health, working memory, and academic performance. For example, restless leg syndrome or disrupted breathing from sleep apnea can cause frequent awakenings that interrupt the normal sleep cycle, reducing restorative sleep. Late-night study sessions, scrolling through social media, or binge-watching the latest Netflix series might seem like necessary trade-offs for those hours of rest. An insufficient amount of sleep can have a detrimental effect on one’s memory. May 31, 2022 · Insufficient sleep means not getting enough sleep at night, which can cause several problems including decreased brain development, learning problems and more frequent negative emotions. How does sleep affect attention and learning? October 7, 2016 1. Oct 7, 2024 · Poor sleep can lead to difficulty concentrating, problem-solving, and remembering important details, essential for academic success. In other words, a good night’s sleep can lead to better problem-solving and decision-making skills. . Sleep also supports numerous other aspects of cognition, including memory, problem-solving, creativity, emotional processing, and judgment. Sleep enhances memory consolidation. Mar 11, 2019 · Numerous studies have shown that structural and physiological changes that occur in the brain during sleep affect capacity for new learning, as well as the strength of memories formed during the day. Jul 13, 2023 · How Lack of Sleep Affects Learning. Different types of memories are formed in new learning situations. Apr 11, 2016 · How does sleep affect learning? For all of us, memory and learning are consolidated during sleep. Sleep is important to process memories and learn. , 2005). Poor sleep can take many forms, including short sleep duration or fragmented sleep. Sleep promotes the consolidation of experiences and ideas; it plays a pivotal role in memory, and has been shown to enhance attention, problem How Poor Sleep Affects the Brain Without sleep, the brain struggles to function properly. Nature Neuro 6: 697–698. It also can affect how well you think, react, work, learn, and get along with others. How does sleep affect learning? Does practicing a skill/studying right before going to sleep retain more of the information? Does having one night of poor sleep make it harder to learn the next day, or does that only apply with consistently poor sleep? Only few human studies on this issue are available at the moment, but they show promising results. Oct 23, 2020 · Sleep can also affect the production of vital hormones Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. About 75% of the night is spent in the non-REM stages (N1-N3), which progressively lead to deeper and more At a follow-up test 6 mo later, the sleep group exhibited increased cortical activation compared with the subjects who stayed awake on the night after word pair learning. A coherent overview of the resultant interrelationships The systems consolidation account for the role of sleep in memory consolidation is not the only viable notion of how sleep affects the brain. Thus, even partial sleep deprivation can affect memory formation and subsequent Jan 11, 2022 · Academic achievement and cognitive functions are influenced by sleep and mood/emotion. 0 years, 18 women) were tested once after normal sleep (8 hr time in bed for 2 nights) and once after 2 nights of sleep restriction (4 hr/night) on a probabilistic selection task where learning behaviour was How does sleep impact your learning? Mar 24, 2022 · Sleep helps with learning and the formation of long-term memories. The findings confirm that truly task-relevant neural patterns are reviewed during sleep, which enables them to survive after sleep to sharpen motor performance. Aug 7, 2023 · How Does Sleep Affect Your Learning? Sleep affects learning in tremendous ways. Lack of sleep or just poor-quality sleep is common among students of all ages. Nov 15, 2022 · How much does sleep apnea affect memory? Sleep apnea can significantly affect memory. (2011) Sleep restriction over several days does not affect long-term recall of declarative and procedural memories in adolescents. According to the synaptic homeostasis hypothesis, there is a net, and unsustainable, increase in synaptic strength in brain circuits that accumulates during exposure to the events of the day ( 12 ). When your kiddo is tired, their cognitive abilities — memory, creativity, decision-making — are affected. How sleep affects learning Putting our meta-analytic effect sizes into this context, it appears that sleep deprivation before learning has an effect size somewhat larger than the average effect size in experimental psychology, while sleep deprivation after learning has a somewhat smaller than average effect size, although the latter varies as a function of both recovery Despite the differences in human and rodent sleep, the neurobiology regulating sleep/wake states is similar and much has been learned about how sleep affects memory by studying animal models. Learn how different stages of sleep affect various aspects of learning and memory, and why prioritizing sleep is essential for academic success. Apr 7, 2021 · “How can I get better sleep for learning?” Here’s what neuroscience has to say. How Sleep Affects Learning and Memory. Emotional events during waking hours affect sleep, and the quality and amount of sleep influences the way we react to these events impacting our general well-being. Regular sleep disruptions, as well as sleep disorders that affect sleep architecture like sleep apnea, can have serious consequences for physical health and mental health. , sleep duration, nocturnal arousals) and can be used to assess sleep over long periods of time (e. Sleep deprivation can also contribute to emotional issues and behavior problems that may affect academic achievement. Set Your Body’s Aug 10, 2017 · These experiments showed that subtly altering neural firing during sleep disrupted crucial computations and eliminated the learning advantage observed earlier. Voderholzer U, Piosczyk H, Holz J, Landmann N, Feige B, et al. Sleep deprivation affects your ability to learn in two ways. It depends on the person and how severe the sleep apnea is. , 2004; Drosopoulos et al. Table of Contents 1. Sleeping well at night, and long enough, is associated with good health. Decreased connectivity between the May 9, 2024 · Scientists and researchers have studied the relationship between memory and sleep for more than 100 years. In related research, Erin C. Set Your Body’s Sleep Timer 2. In addition to metabolic and cardiovascular risks, SD associates with decreases in cognitive performance. If you haven’t slept, your ability to learn new things could drop by up to 40%. Jet Lag in Athletes Not getting enough sleep can affect how well kids do in school. “You can’t pull an all-nighter and still learn effectively,” Walker says. See full list on healthline. ai – the first-ever evidence-based sleep intelligence platform, transforming wellness, engagement, and business performance To determine whether insufficient sleep alters learning from positive and negative feedback, healthy participants (n = 32, mean age 29. (1997) found that average sleep quality was better related to affect balance than average sleep quantity among college students who slept an average of 7 h a night. 0 years, 18 women) were tested once after normal sleep (8 hr time in bed for 2 nights) and once after 2 nights of sleep restriction (4 hr/night) on a probabilistic selection task where learning behaviour was Mar 26, 2024 · How Is Mental Health Related to Sleep? Brain activity fluctuates during sleep, increasing and decreasing during different sleep stages that make up the sleep cycle. Circadian rhythm sleep-wake disorders can lead to insufficient sleep or abnormal sleep architecture. The non-REM stages of sleep seem to prime the brain for good learning the next day. Mar 27, 2022 · Hampers Memory. Impact of Insomnia and Sleep Disturbances. Let’s explore how poor sleep impacts your brain. Oct 1, 2019 · Second, the relation between sleep and academic performance may be moderated by factors that can affect sleep, such as stress, anxiety, motivation, personality traits, and gender roles. Mind Your Caffeine 5. If you’re excessively sleepy, you’re more likely to make frequent errors on tests and more mistakes at work or while driving. , Ph. conversely, a good night's sleep can promote a positive Infants and children who do not nap shortly after declarative learning show reduced consolidation even after one or multiple days of unrestricted follow-up sleep, and even if initial learning occurs during an interval in which they would not normally nap (in contrast to nap deprivation; i. But the amount and quality of your sleep plays a big part in how well you do in Jun 15, 2022 · The damage from sleep deficiency can happen in an instant (such as a car crash), or it can harm you over time. Sleep following learning spatial memories of a virtual town produced increased activation in the striatum at a recall test 3 days later, when compared with a group deprived of Actigraphy usually involves wearing a small wrist-worn watch-like device that can delineate sleep and waking based on motion; such devices can provide measures of sleep in broad strokes (e. Jun 7, 2021 · Poor sleep makes learning difficult. Sleep deprivation can be total (no sleep allowed), partial (either early or late sleep is deprived), or selective (specific stages of sleep are deprived). lack of sleep can contribute to irritability, frustration, and increased stress levels, making it harder for individuals with dyslexia to cope with the challenges they face. Nevertheless, in the field of sleep and wakefulness, several unanswered questions remain. Reduce stressors. com Feb 15, 2012 · Rather than simply boosting alertness and attention, REM sleep allowed the brain to work creatively on the problems that had been posed before sleep. Keep naps brief, if you take them at all. We collected demographic data from university Jul 17, 2019 · Watch more, Matthew Walker Busts Sleep Myths: https://www. How Does Poor Sleep Affect the Brain? Sleep happens in cycles made up of five stages: wake, N1, N2, N3, and REM. For adolescents, this mostly happens during REM sleep - which is a phase in the sleep cycle that happens after deep sleep. Jun 15, 2020 · So for both too little and too much sleep, the important number may be the hours of quality sleep. How Does Sleep Apnea Affect Memory? Sleep apnea, a condition where breathing stops and starts during sleep, disrupts the brain’s ability to consolidate memories. Here are four ways lack of sleep can put up roadblocks to learning. Limits planning and organization skills. However, for those looking to boost your […] 6 days ago · Sleep is a vital component of a healthy routine, and its impact on learning is undeniable. Both Nov 20, 2020 · To determine whether insufficient sleep alters learning from positive and negative feedback, healthy participants (n = 32, mean age 29. Inadequate sleep appears to affect the brain's ability to consolidate both factual information and procedural memories about how to do various physical tasks. Poor balance and coordination Oct 14, 2024 · However, sleep is a critical part of the learning process, and a few ways exist to enhance your learning by using strategies while you sleep. Researchers like Wu are spending many of 6 days ago · The Sleep-Performance Connection: How Lack of Sleep Affects School Performance As students, parents, and educators are well aware, sleep is essential for overall health and well-being. However, many students today are not getting the quality sleep they need, and this lack of sleep can have significant effects on their academic performance. Learn more about the link between sleep and your memory. You strain to recall the concept you learned last week. Sleep Stages and Types of Memory. Sep 1, 2002 · Sleep can be addressed across the entire hierarchy of biological organization. The goal of this study was to use an experimental design to examine the effect of both of these sleep patterns on cognitive performance in healthy adults. m. A lack of sleep can have a negative impact on the ability to think clearly, form memories, learn well, and function optimally during the day. For example, ongoing sleep deficiency can raise your risk of some chronic health problems. 3. “Children who had insufficient sleep—less than nine hours per night—at the beginning of the study had less grey matter or smaller volume in certain areas of the brain responsible for attention, memory, and inhibition control, compared to those Mar 1, 2023 · Without enough sleep, children and teens can have problems with attention, memory, and problem-solving. Jan 18, 2018 · Not only does a lack of solid sleep affect performance, it can also lead to mood disorders, anxiety, and depression. Building on previous research Jul 16, 2018 · How does sleep affect the memory of facts, names, places, faces? Definition: The part of memory that is concerned with storing factual information such as names, places, faces, etc. Naps should be no more than an hour and not taken after 3 p. “But it turns out that sleep is a period during which the brain is engaged in a number of activities necessary to life—which are closely linked to quality of life,” says Johns Hopkins sleep expert and neurologist Mark Wu, M. [Google Scholar] 18. youtube. In addition, several other factors affect learning. Getting better sleep. Exercise Early in the Day How to Get Better Sleep for Learning 1. Sleep strengthens neural connections associated with new information, making retrieval easier later. Mental health benefits . The hypothalamus, a peanut-sized structure deep inside the brain, contains groups of nerve cells that act as control centers affecting sleep and wakefulness. Sleep and mental health can affect cognition and academic performance. Article available in: Arabic, Dari, Dinka, Hakha Chin, Persian, Simplified Chinese, Swahili, Tamil, Vietnamese. Prolonged wakefulness can be due to acute total sleep deprivation (SD) or to chronic partial sleep Associations of reduced sleep with poorer school performance beg the question of how prelearning and posttraining sleep affect the learning process. Sleep improves learning and retention through a process of Oct 1, 2019 · A study by MIT researchers underscores the importance of sleep consistency when it comes to academic performance, reports Jamie Ducharme for TIME. Undergraduate medical students in their first year are particularly vulnerable to sleep Apr 5, 2024 · Healthy individuals cycle through all four stages of sleep multiple times a night. It can be the key to turning those B's into A's! Effects of Sleep Deprivation on Academic Performance Apr 29, 2022 · How Does Sleep Affect Learning Ability? Kids and teens who get less than 8 hours of sleep at night are more likely to get lower grades than their well-rested classmates. Importantly, the effects of sleep deprivation (SD) do not simply reflect the absence of sleep and May 18, 2017 · How does sleep deprivation affect the human brain? Walker and colleagues review neuroimaging studies on the consequences of sleep deprivation on cognition and emotion — with specific focuses on Nov 20, 2020 · To determine whether insufficient sleep alters learning from positive and negative feedback, healthy participants (n = 32, mean age 29. Aug 26, 2024 · Moreover, sleep deprivation has a negative impact on emotional regulation, which in turn affects learning. By prioritizing sleep and creating a sleep-conducive environment, individuals can: How does sleep affect students’ learning? November 2022; Comprehensive Child Studies 4(3):212-225; after midnight, do not get enough sleep during the entire school week and . Dec 22, 2009 · Sleep disorders can negatively affect what happens when you sleep. Lack of sleep affects a part of the brain called the hippocampus, which is key for making new memories. How does sleep affect us? Sleep is a critical part of everyday existence. How does sleep affect attention and learning? Good sleep is critical for helping little ones maintain their attention and focus throughout the day, and for helping children to regulate their emotions and their behavior. The SRI does not require a main daily sleep episode and therefore can be used among populations with higher sleep variability such as college students. Sleep has been found to affect the learning, thinking, and memory of individuals with and without ADHD. Avoid Bright Light at Night 4. Jan 12, 2017 · A lack of sleep can negatively affect your ability to secure memories and learn new information. Only 11 percent of American college students sleep well, and 40 percent of students feel well rested only two days per week. For example, Pilcher et al. May 31, 2021 · Several studies have found sleep quantity and/or quality to be related to the affective components of subjective well-being. In ad- dition to that, circadian rhythms and homeostasis regulate reaction time, visual attention May 22, 2017 · The first learning assessment started (approximately) 30 min after awakening in the morning and subjects filled out a questionnaire rating the sleep quality of the night before (that is, assessing Apr 1, 2014 · For instance, the dopamine D2-like receptor agonist pramipexole enhances the consolidation of memories that had been associated with low reward during learning before sleep but does not affect memories associated with a high reward (Feld et al. Mar 22, 2023 · Although sleep affects a range of waking behaviors, the majority of studies have focused on sleep loss with relatively little attention on sustained periods of adequate sleep. A large part of this population does not experience adequate sleep, leading to chronic sleep restriction and/or disrupted sleep–wake cycles. Dec 21, 2020 · Sleep plays a crucial role in learning, memorizing, retaining, recalling, and solving problems creatively. Hanlon, Assistant Professor of Medicine, and colleagues have studied the relationship between sleep loss and food choices, finding that sleep-deprived study participants had higher levels of chemical signals that can make high-fat, high-calorie foods more pleasurable than when not sleep-deprived and that following The Takeaway . In a study by De Koninck and colleagues, polysomnographic analysis before and after an intensive language course indicated that changes in sleep structure take Jun 1, 2020 · The index is scaled such that an individual who sleeps and wakes at the same times daily scores a 100, and an individual who sleeps and wakes at random scores 0. Because you can’t focus as well, it’s more difficult to pick up information, so you can’t Understanding child development is an essential factor in being a parent. 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. Childhood psychosocial stressors, such as family conflict, can also exert long-term effects on the relationship between stress and sleep outcomes through early adulthood (Hanson & Chen, 2010). Dec 16, 2024 · Sleep is essential for cognitive development; it helps the brain integrate new and existing knowledge, making learning long-lasting rather than transient 8,9,10. The general consensus today is that memory consolidation – the process of preserving key memories and discarding excessive information – takes place during both the non-rapid eye movement (NREM) and rapid eye movement (REM) stages of your sleep cycle. The brain has a harder time concentrating when it doesn’t get enough sleep, which makes it more difficult for it to remember new information. In an fMRI study, reduced top-down cognitive control was evident in sleep-deprived compared to control participants (Yoo et al. Teachers, parents and students usually have very different perspectives on what sleep is and why we need it. Sleep disturbances in early Before the 1950s, most people believed sleep was a passive activity during which the body and brain were dormant. Jan 1, 2018 · Not only does emotion impact sleep, but there is also evidence that sleep plays a key role in regulating emotion. , [13,19]). is a category of declarative memory known as the semantic memory. Whether you’re a student, teacher, or business professional, everyone has experienced too few hours of sleep only to struggle through class or work the following day. Here are 12 tips for getting Mednick S, Nakayama K, Stickgold R (2003) Sleep-dependent learning: a nap is as good as a night. Because they don’t have time to recuperate, neurons in the brain become overworked and less capable of optimal performance in various types of thinking. It can temporarily weaken the part of the brain that manages organization, planning, and problem-solving. Conversely, engaging in memory-intensive tasks or learning new information can influence sleep patterns, highlighting the complex interplay between sleep and cognitive function. What should I do? April 12, 2016 0. Lack of sleep can lead to increased irritability, mood swings, and difficulty managing stress. Insomnia and other sleep disturbances are more than just a nuisance; they can severely affect your academic outcomes. 1. Nov 8, 2024 · Feeling drowsy after a bad night’s sleep is just the tip of the iceberg. Several experiments have been designed to understand if sleep can affect motor learning in post-stroke patients [130–132], based on the observation of a sleep-dependent memory consolidation of different motor tasks in healthy subjects [133, 134]. "If sleep is disturbed or sleep is deprived altogether," says Nokia, "things we have Jan 10, 2024 · By: Keshav Saigal In the whirlwind of deadlines, exams, and extracurricular activities that define our lives throughout high school and college, sleep is often sacrificed. Each stage plays a role in brain health, allowing activity in different parts of the brain to ramp up or down and enabling better thinking, learning, and memory. Thus, insufficient sleep can impair acquisition and retrieval when sleep reduction results in sleepiness, irritability, distractibility, inattention, and lack of motivation. May 23, 2017 · A new study looks at the effects of disturbed deep sleep on the neuroplasticity in the brain's motor cortex and the ability to learn new movements. Additionally, studies have established that not getting the required level of sound slumber can affect both the memory and language development in … Sep 30, 2020 · Moreover, learning procedures affect sleep. g. Learning and sleep Interesting results from a study examining learning efficiency and sleep have shown that learning can affect the structure of sleep. Dec 13, 2023 · These can affect sleep quantity and quality, especially if your athletic schedule is inconsistent. Not getting enough sleep or enough high-quality sleep can lead to problems focusing on tasks and thinking clearly. , several weeks or months). com/watch?v=oDRrRuPqALs&list=PL7qClh5XAo-2Darr200WTwpHskBLfx_Vw&index=3 Why We Sleep is out How does poor sleep affect language learning and use? When is a medical referral needed? This uncertainty prompted us to ask whether individuals with sleep disorders are at higher risk for language learning deficits than healthy sleepers. You’ll likely already be aware of the fact that a lack of sleep affects the brain and causes more instability with emotions. Napping won’t make you smart or assure success, but it can help improve your memory and solve problems. Jeff Grossman. It can also contribute to weight management problems, growth issues and increased frequency of illnesses. From educational environments to the workplace, practical examples show how sleep problems can negatively impact mental performance and well-being, while highlighting the benefits of adopting healthy sleep habits. While most studies of the effect of sleep deprivation on memory address the effects of overnight-sleep deprivation, there is also evidence supporting that 3–4 h-sleep restriction can also affect memory performance (Rauchs et al. “If you can just get the same amount each night, compared to someone who averages the same amount as you but gets less consistent sleep, you’re going to do better,” says Prof. Impaired sleep can significantly derail your learning journey, impacting both your grades and general health. Sleep Stages and Their Specific Effects on Memory Lack of sleep can certainly contribute, perhaps indirectly, to emotional dysregulation (as may be particularly evident, anecdotally, in cranky children in need of sleep). and sleep suppressing learning (deep NREM sleep). Therefore, prioritizing sleep after learning is crucial for optimal memory function. Aug 26, 2024 · Poor sleep quality can negatively impact all stages of memory processing, from encoding to retrieval. Sleep problems are prevalent among individuals with ADHD and can impact their cognitive and behavioral domains. Adjust Your Circadian Clock in the Evening 3. Studies investigating the effects of different sleep–wake schedules on academic achievement showed that impaired sleep quality and quantity are associated with decreased learning ability and Mar 10, 2024 · Sleep deprivation (SD) is a common condition and an important health concern. Making sleep a priority is important for parents who want their children to succeed in school. Introduction The link between sleep and cognitive processes, such as memory and learning, continues to be one of the most intriguing and perplexing theories. Today, prolonged wakefulness is a widespread phenomenon. pulwx ydaxl qyj uahxc pztub fee fzvlwq nff caayc bha