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The Sleep-Learning Link: Why All-Nighters Don’t Work

Have you ever used the expression “I’ll sleep on it”? Often, when we have a big decision to make or need to figure out how to do something, we give ourselves more time to think by waiting until the next day to give our answer. But waiting until the next day doesn’t just let us put off making a decision. Sleeping on the issue also gives us the time we need to learn about and understand it so that the answer becomes clear.

Just as a good night’s sleep helps us fight infection, stabilize our mood, lower our stress, and look better, according to recent research it also lets us organize, process, and understand the information we took in during the day—in other words, learn. While we’ve known that sleep repairs and refreshes the body, we now know that it also has a significantly positive effect on learning and memory.

This evidence, which has been well documented only since the beginning of this century, has enormous importance for everyone but especially adolescents, because they spend a huge portion of their waking hours involved in some kind of learning, from chemistry to a second language to perfecting their soccer skills to driving a car. We used to think that that kind of learning took place only while you sat with your nose in a textbook or on the soccer field or while a parent sat beside you gripping the door handle while you stalled the car in the



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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits 4 The Sleep-Learning Link: Why All-Nighters Don’t Work Have you ever used the expression “I’ll sleep on it”? Often, when we have a big decision to make or need to figure out how to do something, we give ourselves more time to think by waiting until the next day to give our answer. But waiting until the next day doesn’t just let us put off making a decision. Sleeping on the issue also gives us the time we need to learn about and understand it so that the answer becomes clear. Just as a good night’s sleep helps us fight infection, stabilize our mood, lower our stress, and look better, according to recent research it also lets us organize, process, and understand the information we took in during the day—in other words, learn. While we’ve known that sleep repairs and refreshes the body, we now know that it also has a significantly positive effect on learning and memory. This evidence, which has been well documented only since the beginning of this century, has enormous importance for everyone but especially adolescents, because they spend a huge portion of their waking hours involved in some kind of learning, from chemistry to a second language to perfecting their soccer skills to driving a car. We used to think that that kind of learning took place only while you sat with your nose in a textbook or on the soccer field or while a parent sat beside you gripping the door handle while you stalled the car in the

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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits middle of the intersection. But now it’s clear that during the night we consolidate the information we took in during the day and make it our own. Uncovering this fact has put sleep deprivation in a whole new light. Not only does it cause us to function at a much lower level, it also causes us to learn at a much lower level. For teens that can mean not only getting C’s instead of A’s but forgetting how to execute a football play, play a classical piano piece, recreate the perfect sunset on canvas, or do complex math problems on the SAT. According to a report by the American Academy of Pediatrics, it can also mean that students are less motivated to do their best at school and less receptive to teaching. As one teen said, “I miss out on a lot of details because I lose focus and the ability to concentrate when I’m severely sleep deprived. I’m also quite forgetful when I’m tired.” Just how does sleep deprivation prevent us from learning well? To understand that, you need to understand what’s involved in learning and how the brain takes in information and makes it available to us when we need it. Let’s take a look at that now. (One note here: When I talk about learning, I’m going to use the terms “memory” and “learning” interchangeably, because they’re so closely linked that they’re really the same thing. When you remember something, you have learned it.) How We Learn The first thing to understand is that the brain is not like a computer memory chip on which information is stored. The brain is plastic, which means it constantly changes and adapts to the data it acquires. When we acquire information during the day that we want to save as a memory—the fact that Eleanor Roosevelt helped found UNICEF or that to open the front door we have to turn the deadbolt key to the left—the information goes into a particular region of the brain, called the hippocampus. But that region is only a holding zone, and the information is actually in jeopardy there, because before the brain can process and consolidate it, it might get involved in other activities. Say, for example, you call Information for a phone number, but before you can dial it your friend calls and you spend five minutes on the phone hear-

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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits ing all about a workshop she wants you to go to with her. When you hang up and start to dial the number you just got, you can’t remember it—much to your annoyance—and have to call Information again. There wasn’t time for the phone number to become installed in your holding zone. It’s during the night, when you’re sleeping, that multiple neuronal pathways are laid down to take the information in the holding zone to the appropriate regions of the brain for consolidating and refining. In other words, it’s during sleep when memories become a permanent part of your brain, letting you call them up at any time. MEMORIES AREN’T JUST FACTS Researchers have grouped memories into two different categories— declarative and nondeclarative, or procedural. Declarative memories are based on facts: what you did yesterday, your brother-in-law’s birthday, the fact that the freezing point of water is 32 degrees Fahrenheit. Nondeclarative memories have to do with procedures, actions, and skills—for example, how to play a chord on the guitar or build a picnic table. There are also several types of memories: sensory, motor, visual, and auditory. But the process of learning doesn’t stop there. Over time, memories continue to be adjusted and elaborated at the molecular, cellular, and system levels. Once made permanent, memories are constantly refined. Why does that happen after the precious nuggets have been safely stored? Basically, so that they become more efficient and accessible, so that you don’t have to struggle to remember how to do something or take forever to remember the answer to a question. As it reorganizes and polishes your memories, your brain is working to lay down a superfast highway on which you can receive the information you need on autopilot—the information just comes to you innately; you don’t have to stop and think to figure it out. That superfast highway connects several different areas of the brain. For example, if you’re about to make a jump shot in a basketball

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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits game, you need to access your stored memories on how far you should raise your arms, where your feet should be, and how fast you should move to make the shot. That information comes from the parietal lobe, which gathers information related to where you are in space. If you need to know how to spell “accommodations” in a letter you’re writing, the information (two c’s and two m’s) comes from the frontotemporal cortex, which stores information on speech and language. When activated, the appropriate parts of the brain send the appropriate information to the cerebral cortex, which then tells your body what to do—smoothly and naturally. And that, of course, is great for you. Because not only will you easily know the answer to a question and look like a star to your boss or your family or your teachers or your friends, you’ll also be giving your brain the opportunity to work on something else—the mental energy you would have used to figure out the question at hand can be used instead for another task or put to work to learn something else. If, for example, your brain has consolidated and refined the information you need to create and bake your world-renowned chocolate mousse cake, you can make it without having to spend a second of thought on it—and help your son with his vocabulary words at the same time. Once permanently installed, smoothly functioning memories let you multitask and have plenty of brainpower available for wherever you need to apply it. So, to sum up here, we acquire information as we go about our lives during the day, then consolidate and assimilate it as memories for permanent housing in our brain while we sleep at night, then refine and enhance those memories to make them more usable, all in a process that lets us call up memories and use them over a long period of time. When We Learn The second thing to understand is the time period in which we learn. As I said above, our daytime memories are consolidated and made permanent while we hit the mattress for our minimum of seven hours of rest at night. But when exactly does that learning take place? Is it all night long or only during certain stages?

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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits For quite some time, researchers believed that learning took place only during the fifth, or REM, stage of sleep; in fact, when a task was studied that showed that REM sleep wasn’t involved in its comprehension, some scientists continued to believe that sleep wasn’t involved in learning at all. Now, however, not only is it certain that sleep is involved in learning, but as we continue to test tasks we’re finding that every stage of sleep has an important part in making it happen. In general, it appears that NREM, or non-REM, sleep—the first four stages of sleep—facilitates declarative, or facts-and-figures, learning. REM sleep, the last stage of the sleep cycle, seems to enable the consolidation of procedural, or more complex, learning. Enhanced sleep-dependent performance, in fact, has been associated with both slow wave sleep in the early part of the night and REM sleep in the later part of the night. Some researchers believe, though, that both types of sleep affect learning in a complementary and sequential way. Studies of birds have shown that both slow wave sleep, the kind found in Stages 3 and 4, and REM sleep play complementary roles in their memory consolidation. But whether or not the different kinds of learning take place in one stage of sleep or across several stages, we need a full night of uninterrupted sleep, cycling through all the stages to the maximum extent, to give our brain the time it needs to lay down, consolidate, and enhance both types of memory. Only in this way can we learn much of anything—studies show that less than six hours of sleep the night following information intake blocks the positive effect of sleep on learning. But one night of great sleep is not enough. To really cement the learning that’s taking place, the brain needs three consecutive nights of adequate, regular rest. But the first night is key—if you don’t get enough sleep then, the information you took in gets wiped out and isn’t necessarily recoverable on the second and third nights. In your teen’s case, if she starts reading a book the day before a test on it and stays up till 2:00 a.m. to finish it, all the information that was taken in won’t be there come test time if the bus arrives for pickup at 7:15. In simple terms, all-nighters don’t work; sleep does. As a good friend always said in college when faced with a big exam the next day, better

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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits A College Student Says … “Freshman year, the night before two finals, I pulled an all-nighter. During the second final, for psychology, I actually fell asleep. Not only didn’t I have enough time to finish, but I couldn’t concentrate very well and I couldn’t remember half of what I had studied. It was the last time I stayed up all night studying before an exam.” to be well rested than well read. (Of course, it’s actually better to be both!) How are we sure that we’re really learning while we sleep? Probably you’ve witnessed it for yourself, though you may not have realized it at the time. Think back to a time when you had to make a big decision—say, whether you were ready to leave a job you really liked but were no longer challenged by. You likely gathered lots of information— what the job market was like, the names of people you could contact who might know of available positions, how comfortable you would feel changing companies or even your career at this point in your life— but you just couldn’t come to grips with the question. To try to stop obsessing, you reviewed statistics and names and assessed your inner feelings and then gave yourself a deadline of the following day. Wisely, you slept on your decision—and were amazed to discover when you woke up that you knew exactly the right thing to do. You can also see proof that you learn during the night by taking a simple finger-tapping test, the point being to see how many times you can tap your finger, or four fingers in sequence, in a certain amount of time. For example, try tapping four fingers in sequence, from pinky to index finger, at 10:00 in the morning for 30 seconds; write down how many times you complete the sequence. Then try the same thing again at 10:00 at night—the number of completions should be about the same. But then repeat the exercise the following morning—and be surprised. You’ll probably see an improvement in speed of up to 26 percent—a huge gain. Studies have shown that people taking this test continue to improve over a three-night period in both speed and accuracy—without practicing at all in between.

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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits We also have proof of sleep’s effect on learning on a very scientific level. Researchers are now able to map the brain with brain imaging devices, and those scans show that patterns of regional brain activation associated with daytime learning are seen again during sleep, as though the brain were replaying, strengthening, and refining the events of the day. But following a night of sleep, studies have shown, the patterns change, indicating a refining of the memories. After several nights, once the information has been fully learned and becomes an automatic memory, the parietal lobe, which is involved in daytime information recognition, is no longer activated and is free to become involved in learning something else. Studies have also shown that sleep can restore memories. Once information has been acquired and become a memory, it can still deteriorate during the course of a day. An experiment carried out by S. C. Mednick et al. asked a number of people to do a visual texture discrimination task several times during a day. The researchers found that performance deteriorated over the course of four tests—and that a midday nap taken between the second and third tests restored performance. Another study by K. M. Fenn et al. found that, while his subjects’ recognition of novel words decreased during the day following training, their performance was restored the following morning after a night’s sleep. Not only does sleep enhance the learning of information, it restores memory as well. Taking on the Tough Stuff From all that sleep researchers have seen and studied, we know for a fact that sleep is crucial to learning. To sum it up, a full night’s sleep, covering all five stages: Is necessary for the consolidation of memory Enhances procedural learning Restores task performance that has deteriorated Improves learning without practicing the task Is needed in the first 24 hours after taking in the information in order to optimize learning

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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits These functional brain scans (fMRI) were obtained after subjects were trained on a motor sequence task and performance was retested after a night’s sleep. The blackened areas in the circles in figures A-D show areas of increased activation during the task after sleep and the white areas in E-H show areas of decreated activation. This study demonstrates that sleep-dependent motor learning is associated with large-scale plastic reorganization of memory throughout several brain regions, allowing skilled motor movements to be executed more quickly, more accurately, and more automatically following sleep. Reproduced with permission of Matthew Walker, Ph.D., Sleep and Neuroimaging Laboratory, Harvard Medical School, Boston, MA.

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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits A High School Swimmer Says … “Last year, whenever I had a swim meet, I was really disappointed in my performance. Even though I was getting up at 5:00 every morning to get in a good practice before school started, I just wasn’t doing any better. It took me a while to figure it out—well, actually my coach figured it out. On the nights before meets, and, really, most of the other nights, I was only getting around five hours’ sleep. Once I started clocking closer to seven hours I started doing a lot better.” However, sleep is most effective for learning things that are difficult. And that’s true for all kinds of learning, including motor related, auditory, visual, and behavioral. Motor-Based Learning Sleep is critical to developing the skills needed for playing sports and doing other high-level physical activities. It’s not enough for teens to practice the particular motor skills they need after school during practice; to make them their own, to truly learn them, they have to lay down the necessary neuronal pathways that will enable them to perform the actions innately and seamlessly. To learn complex motor skills and sequences, perhaps a complex springboard dive or a lengthy cheerleading routine, they need to get adequate, regular, and uninterrupted sleep. SNOOZE NEWS REM sleep has been found to be involved in the reprocessing and optimization of high-order information. Restricting REM sleep interferes with complex associative learning. A study of sleep-dependent motor sequences pointed up sleep’s effectiveness for learning difficult steps. You can see the proof of this yourself, though, if you practice a five-step motor sequence you want to learn, perhaps a new dance step. After you practice the sequence, you won’t see much improvement after a night’s sleep, because that number of moves is something you can pick up fairly easily. But if you try to learn a nine-step sequence, maybe several intricate dance steps

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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits in combination, you’ll see a huge improvement the next day following a good night’s sleep. The length of time you’re awake between when you learn a skill and when you sleep doesn’t make any difference to the learning—it’s the sleep that does it. A study reported in Clinical Sports Medicine also reported that spending more time learning the skill didn’t change the effect of sleeping—the acquisition of the skill and the enhancement of the memory during sleep appeared to involve two different brain mechanisms. But as with making any memory your own, the first night’s sleep after learning a motor sequence is critical for consolidating it—and adding two more nights of great sleep leads to overall enhancement, especially for more complex skills; it also enables the action to become automatic without further training. Even if a diver or dancer follows up a sleep-deprived first night after training with a solid night of sleep, though, the enhanced learning ordinarily provided by sleep the first night after a task is learned is blocked and can’t be recovered with future nights’ sleep. SNOOZE NEWS Researchers have confirmed the relationship between sleep and learning, but some have linked motor learning to the amount of time spent in REM sleep and others to the time spent in slow wave, or non-REM, sleep. However, all found that motor performance was strikingly enhanced following sleep. So, athletic teens need to train well but also sleep well and long. If they train too much they’ll get fatigued and lose functionality. And if they don’t get enough rest after training—just like with book learning and all-nighters—they won’t be able to perform anywhere near their best. A much better regimen is for them to train, nap if needed (see more on napping below and in Chapter 8), and then get a good night’s sleep. As Dr. Robert Stickgold, a key researcher on sleep-dependent learning, states, “It’s practice, with sleep, that makes perfect.” Auditory Learning The sleeping brain doesn’t only take on tough motor-related learning. It’s also spectacular at enabling complex auditory, or hearing-based, learning. This type of learning normally develops over an extended period, and studies show that sleep provides improvement for several

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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits days after the information is taken in. Sleep’s effect is particularly evident in the effort and attention that are needed to perform a difficult sound-based task—the effort is reduced and the person is better able to pay attention to the sound stimulus. Learning a new language is a difficult task that depends on sleep. It involves the acquisition of several different skills, including the ability to articulate a word in the same way that you hear it, make proper word choices, and remember the new vocabulary. These fact-based skills, and other skills involved with learning a language, have been shown to improve with both REM and slow wave sleep—and are critical to your teen’s academic performance. They’re also key to her learning the lines for the school play, remembering the words or music to a favorite song, and playing a passage on the guitar or piano. Visual Learning Your ability to discriminate visually also improves with sleep; studies have shown that sight-based skills improve through sleep but do not improve over the same number of hours of wakefulness. In a study of participants’ ability to discriminate among textures, it was found that more and different brain regions were activated during sleep than during a similar time period of wakefulness—and that the participants who slept performed the tasks more successfully the next day. Postsleep visual-learning improvement is something you can see for yourself—and your teen can see it with you. Find a book of word search puzzles or look for some online (the Web site www.free-online-word-search-puzzles.com offers a number of puzzles you can try, on such topics as cinema/TV, sports, the English language, science, and music). To work the puzzles, look for words that are hidden in the grid of letters. Words will be found going up, down, forward, backward, and diagonally, and in some puzzles a letter will be part of two or more words. Once you locate a puzzle, see how many words you can find. Then get a good night’s sleep and try it again the next day. Over a several-day period, with plenty of rest, you’ll most likely find that you do better and better and better. You can also test sleep’s positive visual-learning effect by doing

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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits Try this test of sustained attention, concentration, and memory when you are well rested and when you are sleep deprived by using the code across the top to encode this saying. You may time yourself for completing the entire task or give yourself two minutes and see how much you can complete. crossword puzzles or other kinds of word puzzles. A number of word games are available at www.shockwave.com; if you go to www.shockwave.com/sw/content/texttwist you can download a free trial of a game that will keep a history of 11 games so that you can see how you improve each time you sleep on it. SNOOZE NEWS In a study to collect information about dreams, 15 male and 15 female subjects were woken up after 100 REM sleep periods and 100 NREM sleep periods. From the reports the subjects gave, the researchers concluded that the subjects had processed social interactions during their dreams; during REM sleep, aggressive interactions were experienced, and during NREM sleep friendly interactions were experienced. From this study, the scientists inferred that behavioral learning appears to take place during sleep. Aiding Creativity and Problem Solving In addition to benefiting learning in all of its forms, a 2004 German study provided firm evidence that adequate sleep is linked directly to creativity and problem-solving ability. Scientists at the University

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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits of Lubeck discovered that study participants who slept for eight hours before taking a math test were three times more likely to figure out the right answers than participants who had stayed awake all night. The participants had to follow two rules in order to transform strings of eight-digit numbers into a new string and discover a third rule that was hidden in the pattern. When participants performed the calculations after sleeping, the scientists saw proof that their sleeping brains had continued to work on the problem. The leader of the study said that the reorganizing and refining of memories during the night appeared to enhance creativity as well as problem solving. In another study a night of sleep was shown to more than double the likelihood of discovering an innovative solution to a math problem. Scientists who study the link between sleep and creativity believe that both slow wave sleep and REM sleep dreams are associated with the creative process. One final fact here that applies not only to math but to every other subject: The National Sleep Foundation reports that a sleep-deprived person can memorize facts but will be unable to use the information in an innovative way. Can Napping Help? At least eight and a half, and ideally nine and a half, hours of sleep is what your teen needs to log every night in order to achieve high-level learning. But, you may be wondering, can napping every day fill in for the nighttime sleep that’s missing? We’ll cover napping in depth in Chapter 8, where I’ll tell you more about why I don’t usually encourage teens to nap (it keeps their sleep phase delay operational), but here I will say that if a full eight or nine hours isn’t in the cards, a nap will help some with learning and function. However, I don’t recommend napping on a regular basis, just for those times when it’s absolutely required to prevent total shutdown.

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Snooze…Or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits IT’S A FACT Sleep deprivation has a huge negative effect not only on the areas of learning covered here but on all aspects of learning. According to the National Sleep Foundation, it impairs Your ability to pay attention Effective communication Abstract thinking Mental sharpness Decision making involved in the unexpected Adaptive learning, which involves retrieving knowledge from long-term memory, adding to that knowledge, and using it to solve problems Overall motivation to learn