Photo Credits

COVER (clockwise from top left) Yukim/Getty Images; Walter Zerla/Getty Images; GK Hart/Vikki Hart/Getty Images; James Holmes/Science Source BACK COVER Getty Images TITLE Juliana Sohn CONTENTS 2–3 Ted Spagna/Science Source/Getty Images FOREWORD 4 RubberBall Productions/Getty Images 7 Dorling Kindersley/Getty Images MAINTENANCE FOR THE MIND 9 Photo illustration by Timothy Goodman for TIME 12 University of Rochester Medical Center/AP 15 (from left) Oliver Rossi/Getty Images; Steve Coll/Getty Images; Mike Powell/Getty Images SLEEP RULES 17 (clockwise) Elena Elisseeva/Brand X/Getty Images; Hero Images Inc./Corbis; iStock by Getty Images 18 (clockwise) Pixhook/Getty Images; Ed Freeman/Stone/Getty Images; iStock by Getty Images 19 (clockwise) Erik Isakson/Blend Images/Getty Images; Kate Brady/Getty Images; Juanmonino/Getty Images SLEEP YOURSELF THIN 21 Alamy; (dream) Getty Images (2) 23 Zack Blanton/Getty Images BEDTIME BATTLES 25–27 Juliana Sohn (2) 29 Ale Ventura/PhotoAlto/Getty Images TEENAGE BRAIN 31 Image Source/Alamy 32 Tim the Oyster Guy 35 Hero Images/Gallery Stock DOCTOR’S ORDERS 37 Kathy Quirk-Syvertsen/Getty Images 39 Science Source Photo Library/Corbis 40–41 John Lund/Tom Nenpark/Getty Images DREAM THERAPIST 43 James Steinberg/theispot.com TUNING OUT BAD DREAMS 47 Photo illustration by Lincoln Agnew for TIME 51 Lou Brooks/theispot.com 52 Louie Psihoyos/Corbis 55 Alan Hobson/Science Source/Getty Images SLEEP LIKE A PRO 57 David Plunkert/theispot.com 59 Rob Carr/Getty Images 60 The Image Bank/Getty Images 62 Anne-Michelle Gallero for TIME; (vitruvian man) VladSt/Getty Images 65 Bettmann Corbis SLEEPING PILLS 67 Jacques Loic/Getty Images 68–69 Jekaterina Nikitina/Gallery Stock 70 GIPhotoStock/Science Source 73 Dieter Spannknebel/Getty Images A SIMPLE PLAN FOR REST 75 Christopher Bissell/Getty Images 77 (phone) Getty Images; (app) courtesy of SleepRate WAKE UP to YOUR CREATIVITY 79 Phillip Toledano for TIME 80 Pete Turner/Getty Images 81 Fritz Henle/Science Source 82 MGM/Kobal Collection 83 Jannis Werner/Demotix/Corbis A WORLD OF SLumber 84–85 Jon Woo/Reuters/Corbis 86 Corey Rich/Aurora Photos 87 Maggie Steber/National Geographic Creative/Corbis 88–89 Nicolaus Czarnecki/ZUMA Wire/Corbis 90 Raquel Maria Carbonell Pagola/LightRocket/Getty Images 91 Erika Larsen/Redux 92–93 Erin Patrice O’Brien 94–95 Damir Sagolj/Reuters/Corbis CREDITS 96–97 Gregg Segal/Gallery Stock

The numbers in this section reference the page numbers of the print version of this text.