Lydia Sedy
English 102 - T/TH 1:00pm
Prof. Sonia Apgar Begert
11 June 15
[Title TBD]
“Sleep, those little slices of death — how I loathe them.” Sleep has been talked about for centuries, and many people, like Edgar Allen Poe, do not take it seriously enough. The student pulling an all-nighter study session or staying up way past midnight to finish a final paper is a common example. According to the National Sleep Foundation (NSF) 2011 Sleep in America poll, two thirds of Americans report they aren’t getting enough sleep during the week, and 60% say they experience a sleep problem close to every night. Does America itself have a sleep problem? According to review on multiple studies and reports, a lack of sleep has been shown to be the cause of major disasters, such as the Challenger Space Shuttle explosion and the nuclear accident on Three Mile Island. Insufficient sleep also causes fatigue, concentration difficulties, and mood changes which can affect a person’s performance in the work field. (Wells and Vaughn, 235).
Americans commonly try to solve their sleep problem by sleeping for greater lengths on the weekends. Half of the responders to the 2008 Sleep in America poll conducted by the NSF, report building up a sleep debt. This is defined as not sleeping enough during the week and then “catching up” on lost hours during the weekend. This behavior was studied by Jaques Taillard, Pierre Philip, and Bernard Bioulac in their article "Morningness/Eveningness and the Need for Sleep” which was published in the Journal of Sleep Research in 1999. This study examines the effects of morning/eveningness on daytime sleepiness. One particular characteristic of Eveningness is building up a sleep debt, as well as going to bed and waking at later times of day. 617 participants completed a variety of questionnaires, out of which the authors found a clear link between daytime sleepiness and sleep debt. Although sleeping more on the weekends might appear to be solving a problem, it is still associated with some of the same issues that regular sleep loss causes.
Some question whether the lack of sleep is caused by an increase in electronic devices. Yu Sun Bin, Nathaniel Marshall, and Nick Glozier sought answers to this inquiry in their study "Sleeping at the Limits: The Changing Prevalence of Short and Long Sleep Durations in 10 Countries” published in 2013 in the American Journal of Epidemiology. The authors analyzed cross-sectional surveys for 10 countries conducted in the past three decades. The authors found that in America, in 1985, of 3,000 survey participants, 11.7% reported regularly sleeping less than 6 hours. By 2007, this number dropped to 9.2% in the over 11,000 survey participants that responded. The authors describe the idea that we are sleeping less might be derived from the fact that people generally sleep less as they get older, skewing our perceptions of actual change. However, this viewpoint contradicts what other studies report, as the 2001-2002 Sleep in America poll conducted by the National Sleep Foundation found that from 1960-2002, self reported sleep duration had decreased, the average respondents sleeping around 8.5 hours in 1960 to 7 hours in 2002. Regardless of when sleep deprivation started becoming more common, it is clear the majority of the population in the United States is not receiving adequate sleep. Because sleep has a profound effect on each person’s life, it is necessary to understand just how important it is. This paper will explore the negative effects of poor sleep habits, specifically on learning and memory, academic performance, and behavioral functioning.
Lᴇᴀʀɴɪɴɢ ᴀɴᴅ Mᴇᴍᴏʀʏ
The most recent area of sleep research, and perhaps the most interesting, explores the connection between sleep and brain processes such as learning and memory. Thanh Dang-Vu, MD PhD, and colleagues conducted an extensive study, reviewing over 200 credible research articles and studies to report sleep’s role in brain plasticity. One well researched area of sleep and brain operation concerns neural development. Dang-vu reports that newborns and young children sleep much more than adults, and a large portion of this time is spent in a phase called REM sleep. Neural activity is characteristically high during REM sleep, and seems to favor neural development. Also, “REM sleep is associated with acetylcholine release, a neurotransmitter that influences neural development and synaptic remodeling” (99). The easiest way to study the importance of REM sleep is to observe what goes wrong without it. In animals that had been deprived of REM sleep (the sleep phase is characteristized by rapid eye movements under the eyelids) they showed long-lasting changes such as anxiety, depression, and reduced pleasure seeking. Measurements of brain regions showed that actual cortex and brainstem sizes were significantly smaller in REM sleep-deprived rats (100). The authors claim that further studies are needed, as differentiating between cause and effect or correlation processes at the molecular and cellular level can be difficult. However, they do state that “Available experimental evidence strongly suggests a role for sleep in brain development” (102).
Another important area of Dang-vu and colleagues’ study concerns sleep and memory. The authors found that neural activities seemed to be repeated during sleep. This is called memory consolidation, and results when memories or fragments of neural activity are reactivated, analyzed, and incorporated into long-term memory. They report that REM sleep was increased after intense learning periods or textbook study, as experienced by college students. Different studies have gone so far as to explain which phases of sleep most effect certain learned memories. For example, REM sleep seems to be involved with stories or prose, whereas spatial memory is improved following early sleep phases. Also interested in this subject is Pierre Maquet, MD, PhD, a professor at The University of Liège in Belgium and the Director of research at the Belgian National Funds for Research and Science. His article, “The Role of Sleep in Learning and Memory” was published in 2001 in Science. Dr. Maquet reports that brain activities carefully recorded during REM sleep matched the brain activity during wakefulness. In fact, performance on specific tasks was improved after REM sleep. Reactivations of brain activities appear to be beneficial to storing memories, and sleep poses a favorable time for this consolidation. Maquet goes deeper into the subject, stating that for consolidation to be possible, smaller processes like protein synthesis and gene transcription must occur. He reports that a correlation was found between the early sleep phase and the amount of cerebral protein synthesis in monkeys. Another study on rats found that when a protein-inhibitor was introduced into their brains, learning was impaired. Although many of the studies still need to be repeated and further research conducted, the evidence points to the significant importance of sleep in both memory and learning.
Another article report on a study focused on the need for continuous sleep in mice. The mice were introduced to new objects, and then tried to sleep. Their sleep was interrupted once every minute, for four hours. In previous studies, waking mice can cause stress and add other factors to the situation that affect the results. In this study, a light-sensing protein was introduced into the brain, so that by stimulating the cells, the mice were “awakened” without causing extra stress. This more accurate experiment found that mice who got interrupted sleep could not remember the objects they had seen before, and treated them just like new objects (Saey, 9). Although the study is particularly on mice and not humans, it exposes that there is a biological need for sleep.
Another expert in the field, Michael Gradisar, PhD, an Associate Professor at Flinders University in Australia, joined the conversation along with three other colleagues with his study “Adolescent Sleep and Working Memory Performance” which was published in Sleep and Biological Rhythms in 2008. The authors narrowed their study to examine working memory performance, and especially its correlation with insufficient sleep in adolescents. Working memory is defined as “the ability to temporarily store and manipulate information while performing complex cognitive tasks” (147). One task required students to remember a sequence of numbers and then later “operate” on the numbers, for example, by changing the order in which they appeared. The authors found that students who had slept less did not perform as well on the tests, specifically the more complex tasks that involved manipulating information. Students who got the optimal eight to nine hours of sleep took less time to fall asleep and had less daytime sleepiness, which also contributed to better results on the tasks. Clearly sleep has some significant involvement in neural development, memory consolidation, and the ability to manipulate information.
Aᴄᴀᴅᴇᴍɪᴄ Pᴇʀꜰᴏʀᴍᴀɴᴄᴇ
There is a notable correlation between sleep and academic performance. Mickey Trockel, MD, Michael Barns, PhD, and Dennis Egget, PhD explore this in their study, “Health-Related Variables and Academic Performance Among First-Year College Students: Implications for Sleep and Other Behaviors” which was published in 2000 in the Journal of American College Health. The authors explore the effects of many health-related variables on the grade point averages of random students, using a specialized survey and obtaining grades from the registrar's office. Variables included sleep habits, work hours, exercise, spiritual health, nutrition, and social support. Trockel and his team found that “The relationship between sleep habits and higher GPA appears to be the most significant finding of this study and provides strong support for the hypothesis that sleep habits account for some of the variance in 1st-year college students’ GPAs” (129). Although this study does not prove a cause-and-effect relationship, correlations between sleep habits and GPA are plainly evident. Another study used 172 student responses to an online questionnaire, and again obtained student GPAs from the registrar’s office to prevent bias. The authors found a negative correlation between sleep latency, or trouble falling asleep, and cumulative GPA. A quarter of the students reported taking half an hour or longer to fall asleep, which the authors warn is one of the criteria for Delayed Sleep Phase Syndrome (DSPS), “with which students [report] low GPAs” (Chiang et al, 84-85).
Most college students would agree they frequently deal with sleep deprivation due to exams, finals, or other college related activities. Some even go so far as to say their best work is produced late at night, when they would normally be sleeping. Experts in the field are interested in how these behaviors affect academic performance, among them Dr. Jane Gaultney, an associate professor in the department of psychology at the University of North Carolina. In her study, “The Prevalence of Sleep Disorders in College Students: Impact on Academic Performance” which appeared in the Journal of American College Health in 2010, she found that the amount of sleep students got before school was significantly correlated with higher grades. One section of the survey considered a response to the question, “I generally sleep badly.” Student who strongly agreed with the statement were found to have a significantly lower GPA. Other aspects of sleep related to higher grades included consistent sleep and uninterrupted sleep (93-94). Gaultney warns us that the correlation is small and results should be taken cautiously, however, the relationship between sleep and academic performance is repeatedly found in several other studies. For example, another study examined 148 college students’ sleep habits and self-reported grade-point averages. It is interesting to note that fewer long sleepers (9 or more hours a night) reported their GPA than did the short sleepers (less that 6 hours each night). Also, no correlations were found for age or gender and GPAs. However, the authors did find that long sleepers had significantly higher GPAs (mean of 3.24) than did short sleepers (mean of 2.74) (Kelly, Kelly, and Clanton, 84). Another expert in the field who has made valuable contributions to the argument is Amy Wolfson, Ph.D., the vice president for academic affairs at Loyola University, previously having been a professor of Psychology at the College of the Holy Cross. She partnered with Mary Carskadon, Ph.D, who is a professor in the department of Psychiatry and Human Behavior at Brown Medical School, as well as the director of the Bradley Hospital Sleep and Chronobiology Research Lab. Their extensive study, “Sleep Schedules and Daytime Functioning in Adolescents” appeared in the 1998 edition of Child Development. Wolfson and Carskadon surveyed 3,120 students at four different schools in Rhode Island. The survey considered sleep time, bedtime, and risetime during school-nights and weekends, and the effects on school performance. The authors found that students reporting B’s or better had more total sleep time and generally earlier bedtimes. Student’s reporting C’s or worse reportedly slept less and went to bed later.
Bᴇʜᴀᴠɪᴏʀᴀʟ Fᴜɴᴄᴛɪᴏɴɪɴɢ
Another area that has been studied extensively is sleep’s role in behavioral functioning. Wolfson and Carskadon’s previously mentioned study also included aspects of behavioral functioning. Their survey asked questions about sleep/wake behaviors such as arriving late to class, falling asleep during certain activities in the daytime, or having trouble falling asleep at night. Students who did not receive the adequate amount of sleep (>8 hours a day and <60 minutes of weekend sleep debt) showed significantly more of these problems. Another area of the study examined depressive mood and asked about feeling unhappy, depressed, or hopeless. A similar trend was found: students who slept less experienced more depressive moods, as well as greater sleepiness throughout the day. In all of the categories, it was found that students who accumulated weekend sleep debt showed similar results to those who overall slept less (878-883). This suggests that maintaining consistent sleep times throughout the week is just as important as getting the right length of sleep.
A prominent voice in this area of sleep research is Avi Sadeh, a professor of Psychology as well as the director of the Laboratory for Children's Sleep-Wake Disorders and the director of the Adler Center for Research in Child Development and Psychopathology at Tel Aviv University in Israel. Sadeh partnered with Reut Gruber, Ph.D, a clinical child psychologist and a professor of psychiatry at McGill University, and Amiram Raviv, Ph.D., who is also a professor of Psychology at Tel Aviv University. This extensively qualified team combined to explore how sleep affects neurobehavioral functioning (NBF) in school-aged children. Their first study was “Sleep, Neurobehavioral Functioning, and Behavior Problems in School-Age Children” which was published in Child Development in 2002. Neurobehavioral functioning is referred to as “specific cognitive, attention, and performance skills” (405). The authors assessed 135 healthy children, from second to sixth grade ages. The student’s sleep habits were assessed by wearing a small actigraph on their wrist while they slept, which records sleep activities throughout the night. A series of six tests, measuring motor speed, reaction time, omission/commission errors, and digit learning was then conducted twice each day. Correlations between sleep quality and test performance suggest that children who got poor quality sleep had greater problems with attention, reaction, and behavior regulation. Fragmented sleep was especially associated with problems in maintaining attention and behavior regulation.
Sadeh, Gruber and Raviv conducted another more narrowed study, “The Effects of Sleep Restriction and Extension on School-Age Children: What a Difference an Hour Makes” which appeared in the same journal in 2003. Their aim was to look particularly on the effects of a minimal difference in sleep time on NBF, ranging from 30 minutes to one hour. This is more accurate as it reflects regular changes that may result in a child's day to day life. They found that extension of sleep led to improved memory function and improved performance on a complex reaction test, which tested the student’s ability to differentiate between images and respond to a particular one. These behaviors are important because, as Sadeh and colleagues report, they have been correlated with certain classroom behaviors (453).
Richard Millman, MD, who has served as the Vice Chairman for Operations of three hospitals accredited by the American Academy of Sleep Medicine, also found information on behavioral functioning and sleep. He reviewed over 150 credible sources researching and discussing sleep in his article, “Excessive Sleepiness in Adolescents and Young Adults: Causes, Consequences, and Treatment Strategies”, which was published in Pediatrics in 2005. His goal was to explore changes in adolescents sleep patterns, explain the effect of insufficient sleep on a number of functions, and report common sleep disorders and solutions. Dr. Millman found extensive support that daytime sleepiness (caused by less total sleep time or fragmented sleep) has negative effects on performance and cognitive abilities, such as decision making and judgement, lack of attention, and the tendency to fall asleep in class.
A most interesting study on sleep and behavior was conducted by Samantha Clickinbeard, PhD, and colleagues, titled "Sleep and Delinquency: Does the Amount of Sleep Matter?" published in the Journal of Youth & Adolescence in 2011. This study examines delinquent behavior in adolescents and the amount of hours they slept. The authors state that their findings should be repeated before considered absolute, but they did find that children who slept less were involved in more property delinquency. The authors also acknowledge that the correlation between sleep and delinquency might not be causational, and that the sleep problems themselves may be a cause of other issues with self-control. However, the link between sleep loss and more delinquency is there, and definitely raises an important find for parents and teachers alike.
Sleep is evidently involved in many important processes. The most recent discoveries include the importance in neural development, especially in young children, consolidation of memories and the ability to manipulate learned information. Many studies explore the resulting impact on academic performance, and generally find that studies whose sleep is of greater quality and length perform better. Another important field concerns behavior regulation, showing the correlation of insufficient sleep and classroom behaviors, and even delinquency. Clearly, sleep is indeed important to proper biological functioning, and should especially be dealt with seriously at any academic, learning or performance activity. It might not always be convenient, but sleep has profound effects on our lives.
[Works Cited list left off for brevity]
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