Have you ever wondered what’s happening in your brain as you go through a typical day and night? This fascinating book presents an hour-by-hour, round-the-clock journal of your brain’s activities. Drawing on the treasure trove of information from Scientific American and Scientific American Mind magazines as well as original material written specifi cally for this book, Judith Horstman weaves together a compelling description of your brain at work and at play. The Scientifi c American Day in the Life of Your Brain reveals what’s going on in there while you sleep and dream, how your brain makes memo- ries and forms addictions, and why we sometimes make bad decisions. The book also offers intrigu- ing information about your emotional brain and what’s happening when you’re feeling love, lust, fear, and anxiety—and how sex, drugs, and rock and roll tickle the same spots. Based on the latest scientifi c information, the book explores your brain’s remarkable ability to change, how your brain can make new neurons even into old age, and why multitasking may be bad for you. Your brain is uniquely yours—but research is showing that many of its day-to-day cycles are universal. This book gives you a look inside your brain and some insights into why you may feel and act as you do. The Scientifi c American Day in the Life of Your Brain is written in the entertaining, informative, and easy-to-understand style that fans of Scientifi c American and Scientifi c American Mind magazines have come to expect. The Scientific American DAY IN LIFE of Your Brain I I I I I N N N N N N N N N THE PSYCHOLOGY www.josseybass.com U.S. $25.95 | CAN $30.95 A 24 - HOUR JOURNAL OF WHAT’S HAPPENING IN YOUR BRAIN as You SLEEP, DREAM, Wake Up, EAT, WORK, Play, Fight, LOVE, Worry, COMPETE, Hope, Make Important Decisions, AGE, and Change BY JUDITH HORSTMAN The Scientific American DAY IN LIFE of Your Brain THE DREAMING EATING ENERGETIC DROWSY ANXIOUS MAD AS HELL SEXY SLEEPING HORSTMAN The Scientific American DAY in the LIFE of YOUR BRAIN “Day in the Life of Your Brain takes us on a breezy, fact-fi lled, and eye-opening journey through the neural machinery that navigates us through every moment. Read it and learn.” —Daniel Goleman, best-selling author, Emotional Intelligence “Day in the Life of Your Brain is a fabulous accomplishment. It is practical, fun, easy to read, and fi lled with interesting, useful information. I highly recommend this book.” —Daniel G. Amen, M.D., best-selling author, Change Your Brain, Change Your Life “Day in the Life of Your Brain is a terrifi c read—fun and chock-a-block full of fascinating facts and ideas. Judith Horstman takes us on a romp through the day and the night, telling us what our brains are doing on an hourly basis. It also provides some wonderful and solid advice. I learned from it, and you will too!” —John E. Dowling, Ph.D., Gund Professor of Neurosciences, Harvard University; author, Creating Mind: How the Brain Works “This book is a fascinating read. It capitalizes on the natural fl ux of experiences throughout our day to boldly illustrate the relevance and penetration of the new brain science in helping us understand ourselves more fully.” —Zindel V. Segal, Ph.D., professor of psychiatry, University of Toronto; author, The Mindful Way Through Depression JUDITH HORSTMAN is an award- winning journalist whose work has appeared in publications ranging from USA Today to the Primer on the Rheumatic Diseases (twelfth edi- tion). Horstman’s work has also appeared in publications by Harvard, Stanford, and Johns Hopkins universities, numerous magazines, and on the Internet. She has been a Washington correspondent, a Fullbright scholar, a journal- ism profesor, and is the author of four books. DREAMING EATING ENERGETIC DROWSY ANXIOUS MAD AS HELL SEXY SLEEPING Praise for The Scientifi c American Day in the Life of Your Brain Illustrations © istockphoto.com ffirs.indd iffirs.indd i 6/26/09 12:31 PM6/26/09 12:31 PM The SCIENTIFIC AMERICAN Day in the Life of Your Brain ffirs.indd iffirs.indd i 6/26/09 12:31 PM6/26/09 12:31 PM ffirs.indd iiffirs.indd ii 6/26/09 12:31 PM6/26/09 12:31 PM Day in the Life of Your Brain Judith Horstman The SCIENTIFIC AMERICAN ffirs.indd iiiffirs.indd iii 6/26/09 12:31 PM6/26/09 12:31 PM Copyright © 2009 by John Wiley & Sons, Inc., and Scienti c American. All rights reserved. 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No warranty may be created or extended by any promotional statements for this work. Neither the publisher nor the author shall be liable for any damages arising herefrom. Jossey-Bass books and products are available through most bookstores. To contact Jossey-Bass directly call our Customer Care Department within the U.S. at 800-956-7739, outside the U.S. at 317-572-3986, or fax 317-572-4002. Jossey-Bass also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. Library of Congress Cataloging-in-Publication Data The Scientifi c American day in the life of your brain / Judith Horstman.—1st ed. p. cm. Includes bibliographical references and index. ISBN 978-0-470-37623-2 (cloth) 1. Neurosciences. 2. Brain. 3. Human behavior. 4. Body and mind. I. Horstman, Judith. II. Scientifi c American, inc. III. Title: Day in the life of your brain. RC341.S346 2009 616.8—dc22 2009013923 Printed in the United States of America   HB Printing 10 9 8 7 6 5 4 3 2 1 ffirs.indd ivffirs.indd iv 6/26/09 12:31 PM6/26/09 12:31 PM ffirs.indd iffirs.indd i 6/26/09 12:31 PM6/26/09 12:31 PM v Acknowledgments xiii Preface xv Introduction 1 You Gotta Know the Territory: A Short Tour of Your Brain 4 Your Neurotransmitters 6 Charting the Day: Your Body Clocks 8  e Best of Times? 9 COMING TO CONSCIOUSNESS Awake and Aware 5 A.M. TO 8 A.M. 13 5:00 a.m. Waking to the World 14 Your Inner Alarm Clocks 14 Your Brain Chemicals 15 Larks and Owls 16 Coming to Our Senses 19 An Orchestra of Sensory Harmony 20 Touch and Movement: Feeling Our Way 22 Varieties of Touch 23 Contents ftoc.indd vftoc.indd v 6/26/09 12:30 PM6/26/09 12:30 PM vi Contents 6:00 a.m. Coming to Consciousness 25  e Seat of Consciousness 26 Emotion, Memory, and Consciousness 27 It’s Always About Networking 28 Little Gray Cells and Big White Matter: Myelin in Your Brain 29 Prime Time for Heart Attack and Stroke 31 7:00 a.m. Those Morning Emotions 33 Reason Needs a Neurochemical Boost 34 Can Meditation Help Master  ose Emotions? 36 Is  ere a God Spot in Your Brain? 37 Practice Makes Compassion 39 8:00 a.m. Finding Your Way 41 Why His Brain May Not Ask Directions 42 How We Know Where to Find Our Lost Keys 44 ENGAGING THE WORLD Getting Out and About 9 A.M. TO NOON 47 9:00 a.m. Encountering Others 48  at Face,  at Familiar Face 48 Friend or Foe? Read My Face 49 Mirror, Mirror: Copycat Neurons in the Brain 51  e Broken Mirror: Autism Insights from Mirror Neurons and Face Perception 52 10:00 a.m. Peak Performance—or Stress? 55 Stress in the Brain 55  e Alarm  at Doesn’t Stop: Why Chronic Stress Is So Bad 56 Stress Destroys Neurons 56 Stress Ups the Risk of Alzheimer’s Disease 57  e Very  ought of It Is Enough 58 Multitasking—Again? 59  e Limits of Multitasking 60 ftoc.indd viftoc.indd vi 6/26/09 12:30 PM6/26/09 12:30 PM  vii How Your Brain Helps Your Job Kill You 61 You Can Lull Your Brain Away from Stress 62 Flow Versus Stress 63 11:00 a.m. Decisions, Decisions, and More Decisions 65  e Brain’s CEO 65 “Chemo Brain” Can Ambush Your CEO 66 Choosing Economically 67 Making an Emotional Moral Choice 68 Choosing Wearies Your Brain 69  e Brain Has a Section for Regret 70 Noon The Hungry Brain 72 How Hunger Works in Your Brain 72 We’re Losing Our Scents 73 Still Hungry? When Hunger Goes Awry 74 Why Calories Taste Delicious 75 Addicted to (Fill in the Blank) 76 Self-Control Sucks Your Energy 78 Yes,  ere Is Such a  ing as Brain Food 79 THE GUTS OF THE DAY Getting Down to Business 1 P.M. TO 4 P.M. 83 1:00 p.m. The Tired Brain 84 Partial Recall: Why Memory Fades with Age 84 Can You Help Your Brain Stay Young(er)? 85 Predicting Alzheimer’s Disease 86 How Forgetting Is Good for the Brain 86 Asleep at the Wheel—Almost? It Could Be Narcolepsy 88 1:54 .. Just Time for a Six-Minute Power Nap 89 ftoc.indd viiftoc.indd vii 6/26/09 12:30 PM6/26/09 12:30 PM [...]... overall brain is often described in three parts, from the bottom up, just the way your brain evolved over millennia The primitive brain the brain stem or hindbrain—that sits at the top of the spine is the oldest part of your brain It takes care of basic business such as breathing, heartbeat, digestion, reflexive actions, sleeping, and arousal It includes the spinal cord, which sends messages from the brain. .. emotional brain part, the amygdala, rules There are many more connections from the amygdala to the thinking brain than the other way around Most exciting is the finding that your brain is teaching old neurons new tricks and even making new neurons When some sections of the brain go dark, other parts of the brain can learn to take over part of those functions In fact, many who have half their brain removed... represents the fascinating and entertaining state -of -the- art brain science that we can use in our daily lives Judith Horstman flast.indd xvi 6/26/09 12:30 PM The SCIENTIFIC AMERICAN Day in the Life of Your Brain flast.indd xvii 6/26/09 12:30 PM flast.indd xviii 6/26/09 12:30 PM Introduction Your brain is the most important organ in your body Without it, nothing else would work—and you wouldn’t be aware of. .. It’s the repository of memory, mind, and feeling; the conductor of the orchestra that’s your body; the seat of consciousness that is you Every day this three pounds of “thinking meat” navigates you through the ordinary and extraordinary events of being human— from waking to sleep, and everything in between It guides your body through motions of intricacy and delicacy, ranging from the most gross to the. .. three pounds of “thinking meat.” The book is structured by the clock, beginning at 5:00 a.m as we (or some of us) awake, and ending at 4:00 a.m., in the last moments of sleep You might find yourself comparing the activities of your own brain as you read xv flast.indd xv 6/26/09 12:30 PM xvi Preface As scientists continue to study the brain, we’ll know even more about how our brain works and influences... happening in your brain as you go through a typical day and night? These questions (and more) were the spark for this book: an hourby-hour journal of a day in the life of your brain and how it affects you as you go about your day The editors at Jossey-Bass conceived the idea and took it to Scientific American magazine, a treasure trove of fine articles about these very issues I was brought to the project... tegmental area At the very top of the brain is the wrinkly and crevassed cerebrum the part we usually see when we picture a brain and what is sometimes called the crown jewel” of the body The actual crown is cintro.indd 5 6/26/09 12:31 PM 6 Introduction the nickel-thin layer of the cerebral cortex (or neocortex) that covers the cerebrum This is the most recently evolved part of the brain the part, some... (SCN): two tiny bundles of ten thousand neurons, each no bigger than a letter on this page, nestled deep in your brain, very near the optic nerves As the morning light strikes your retina, photoreceptor cells there signal to the neurons in the SCN to begin firing The SCN toggles a biological switch setting off a process that tells the pineal gland to shut off the flow of melatonin, start the waking process,... why? The hour-by-hour sections of this book explain what’s going on during some of our most ordinary and extraordinary everyday events You Gotta Know the Territory: A Short Tour of Your Brain Your brain is about three pounds of flesh, nerves, and fluid that looks like an oversized walnut but is much softer Nestled in the protective shell of your bony skull, it has the squiggly consistency of gelatin The. .. differently from the other In an oft-cited overgeneralization, the right hemisphere is associated with creativity and the left hemisphere with logic For reasons unknown, the messages between the hemispheres and the rest of our body criss-cross, so that the right brain controls our left side, and vice versa Your emotional brain the inner brain or limbic system—is tucked deep inside the bulk of the midbrain and . American DAY IN LIFE of Your Brain THE DREAMING EATING ENERGETIC DROWSY ANXIOUS MAD AS HELL SEXY SLEEPING HORSTMAN The Scientific American DAY in the LIFE of YOUR BRAIN Day in the Life of. compelling description of your brain at work and at play. The Scientifi c American Day in the Life of Your Brain reveals what’s going on in there while you sleep and dream, how your brain makes memo- ries. insights into why you may feel and act as you do. The Scientifi c American Day in the Life of Your Brain is written in the entertaining, informative, and easy-to-understand style that fans of Scientifi