Want to get A's? Then get some Z's
This semester, 12 students joined Dr. Sue Chaplin in a one-credit freshman seminar, "Sleep – Why We Need It." The seminar covered a wide variety of topics: brain anatomy; biological rhythms of activity; sleep disorders; and effects of sleep on aging, performance, mood, memory and immune function.
Highlights of the weekly class sessions were seminars by Dr. Roxanne Prichard, Psychology Department, on sleep patterns of college students, and Dr. Michel Cramer Bornemann, of Hennepin County Medical Center's Minnesota Regional Sleep Disorders Center, on clinical features of sleep disorders.
In response to the question of what their roommate should know about sleep, the students generated the following list of questions and answers that they hope will be useful to everyone as they prepare for final exams and the holiday frenzy:
Q. Do you remember something better if you "sleep on it"? What is the relationship between sleep and memory?
A. A study on memory in which 48 participants had to memorize 20 to 40 pairs of words showed that amount of sleep is critical for memory. According to an article in Current Biology, participants who were sleep-deprived remembered significantly fewer of the memorized words than those who got adequate sleep. During sleep, the brain processes and organizes the new information that was learned or studied that day. The quality of sleep during the night is important too. Deep sleep early in the night is essential for "declarative memory," which promotes recognition and recall. Dream (REM) sleep later in the night is essential for "procedural memory," which promotes analytical thinking and problem solving. It sounds paradoxical, but getting about seven to eight hours of sleep the night before a final actually will boost your memory and your performance on the exam.
Q. How does sleep affect performance?
A. Sleep-deprived individuals are less creative, have trouble focusing on multiple tasks and making quick, logical decisions, are less efficient, more irritable and have slower reaction times. In several studies of elementary to high school students, those who routinely had a short night's sleep and irregular sleep patterns had lower GPAs and experienced more depression than students who routinely got from seven to nine hours of sleep each night, the average sleep requirement for most humans. Individuals kept awake for 19 hours scored substantially lower on performance-and-alertness tests than those with a blood alcohol level of 0.08, which is legally drunk. Getting the optimal amount of sleep can boost performance by as much as 30 percent. Test yourself on the BBC Science and Nature Web site.
Q. Why is it so hard to wake up for those 8 a.m. classes?
A. Young adults tend to be night owls. You work better at night, but then want to sleep in late the next day. This happens because your circadian rhythm has shifted since childhood, giving you a "second wind" right when you used to go to bed as a kid. Because of this, you are sluggish in the morning and unable to be at your best for 8 a.m. classes. On the weekends, you tend to stay up later and get up later, which shifts your biological rhythm even further away from the cycle that an early morning class schedule demands. What can you do? Try to wake up with bright lights during the early morning, because bright lights can help set the biological clock to early arousal, shut off loud electronics and bright lights late in the evening to help reduce the stimulus to shift the biological clock to a late arousal, and force yourself to get on a schedule and stick to it over the weekend as well.
Q. My roommate stays up much later than I do. How can I get to sleep when people around me are working or recreating?
A. Even if you can get to sleep in a room full of light and noise, you may not get the quality of sleep you need. Light can penetrate closed eyelids and affects the hormones secreted by the brain that keep you asleep (melatonin). Therefore, even though you are asleep, your brain continuously is receiving signals that it should be awake. As you go through the stages of sleep and enter dream (REM) sleep, you can be aroused more easily and noise or light may awaken you, making it difficult to get back to sleep. What's the solution? Wear a sleep mask that covers your eyes and blocks out the light when you go to bed. Wear ear plugs that muffle the noise. Of course, you'll need to set the alarm closer to your bed so you can hear it in the morning!
Q. My roommate drinks Mountain Dew or Red Bull to get fired up to do homework late at night but then can't get to sleep until 3 or 4 a.m. How does caffeine affect sleep?
A. Everyone knows that caffeine is a stimulant. It increases heart rate, blood flow to the brain and makes you feel more alert. It's absolutely vital for late-night study sessions, but it greatly impacts the quantity and quality of sleep following its consumption. When caffeine is consumed before bedtime, falling asleep can be difficult, total sleep time is reduced, the normal stages of sleep are altered, restlessness during sleep is increased and, therefore, the quality of sleep is greatly reduced. Caffeine is absorbed rapidly, reaching peak levels in the blood within 15 to 45 minutes with effects on the brain in 30 to 60 minutes; however, its effects can persist for several hours, depending on an individual's ability to metabolize it. Half-life in women taking contraceptives, for example, may be as long as 13 hours, and in babies up to 30 hours. It is recommended that you avoid consuming caffeine at least five to seven hours before bedtime. So, the next time you slam that "Dew" at midnight to give you that extra boost to finish your paper or study for your exam, remember what the "Dew" does.
Q. Should I take naps to make up for lost sleep?
A. It depends. If you have trouble falling asleep at night, you should avoid taking daytime naps. Daytime sleep, especially if it is longer than 30 minutes or occurs late in the afternoon, could actually cause nighttime insomnia. Naps are a good idea when you cannot manage to get one continuous period of sleep at night that is long enough to enable you to be fully alert all day long. Thirty percent of Americans nap more than four times a week. It is common for you to feel sluggish around midday because your biological rhythm of alertness takes a dip right then. Usually, people think of this as an effect of a big lunch, but your natural sleep pattern is actually biphasic. You have a significant drop in core body temperature and alertness at night, and a smaller but similar drop in the middle of the day. It is then that a nap makes sense, especially if you have slept poorly the night before.
Q. Why do some people sleep walk or talk in their sleep?
A. Sleepwalking occurs when individuals are in a deep sleep, not dreaming, even though it seems that they may be acting out their dreams. It tends to occur in children and adolescents
, but only in 4 percent of adults. Sleepwalking ranges from simple motions of sitting up in bed to complicated activities of dressing, walking around, and even driving a car. Without supervision, the sleepwalker may end up getting hurt, and find themselves with unexplained cuts or bruises the next day. Talking during sleep is actually a fairly common sleep disorder and seems to run in families. It occurs in one out of 20 adults and roughly half of all adolescents. Both of these phenomena occur more frequently when a person is rapidly transitioning between deep sleep and dream sleep, which might happen when the individual is sleep deprived or is intoxicated. When the individual is aroused only partially, they are "awake" enough to use basic motor functions but are unaware of what they are doing and will have no memory of the event. So the next time you wake up late at night when you hear your roommate yelling, " !&#% you, Santa Claus!" don't be offended because they have no idea what they are doing.
Q. Why do I get sick after staying up to cram for exams?
A. Sleep is vital for the body to recover from illness and repair itself. Sleep deprivation has been shown to cause headaches, upset stomach, increased sensitivity to pain, as well as some symptoms of common illnesses, like colds. During sleep, the immune functions are heightened and mutated body cells or foreign cells are detected and removed. Staying up late to cram for a test results in decreased quantity and quality of sleep, which directly impacts the efficiency of the immune system. Sleep deprivation is interpreted by the body as a stressor, and the release of stress hormones actually decreases the number of different types of immune system cells. The longer the period of stress, the greater the decrease in immune system function. So, if you want to stay healthy for the holidays, get some sleep during final exams.