BRAVE NEW BRAIN. The Scientifi c American

Transcription

1 The Scientifi c American BRAVE NEW BRAIN HOW NEUROSCIENCE, C E BRAIN-MACHINE A INE INTERFACES, NEUROIMAGING, PSYCHOPHARMACOLOGY, EPIGENETICS, THE INTERNET, AND OUR OWN MINDS ARE STIMULATING AND ENHANCING THE FUTURE OF MENTAL POWER JUDITH HORSTMAN

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3 The SCIENTIFIC AMERICAN BRAVE NEW BRAIN

4 ii Brave New Brain

5 CHAPTER TITLE iii The SCIENTIFIC AMERICAN BRAVE NEW BRAIN Judith Horstman

6 Copyright 2010 by John Wiley & Sons, Inc., and Scientific American. All rights reserved. Published by Jossey-Bass A Wiley Imprint 989 Market Street, San Francisco, CA No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, , fax , or on the Web at Requests to the publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, , fax , or online at com/go/permissions. The contents of this work are intended to further general scientific research, understanding, and discussion only and are not intended and should not be relied upon as recommending or promoting a specific method, diagnosis, or treatment by physicians for any particular patient. The publisher and the author make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of fitness for a particular purpose. In view of ongoing research, equipment modifications, changes in governmental regulations, and the constant flow of information relating to the use of medicines, equipment, and devices, the reader is urged to review and evaluate the information provided in the package insert or instructions for each medicine, equipment, or device for, among other things, any changes in the instructions or indication of usage and for added warnings and precautions. Readers should consult with a specialist where appropriate. The fact that an organization or Web site is referred to in this work as a citation and/or a potential source of further information does not mean that the author or the publisher endorses the information the organization or Web site may provide or recommendations it may make. Further, readers should be aware that Internet Web sites listed in this work may have changed or disappeared between when this work was written and when it is read. 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 , outside the U.S. at , or fax 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 Horstman, Judith. The Scientific American brave new brain / Judith Horstman. 1st ed. p. cm. Includes bibliographical references and index. ISBN (cloth) 1. Brain. 2. Brain Metabolism. 3. Brain Physiology. 4. Neurophysiology. I. Scientific American. II. Title. QP376.H '2 dc Printed in the United States of America FIRST EDITION HB Printing

7 CONTENTS Acknowledgments Preface xiii xi Introduction 1 1 Your Changeable Brain: Neurogenesis, Neuroplasticity, and Epigenetics 7 The Birth of Brain Cells: Neurogenesis 10 Changes in Your Brain: Neuroplasticity 11 Changes in Your Genes: Epigenetics 13 Keeping Your New Brain Cells 14 No Pain, No Gain 16 Brain Training Programs: Help or Hype? 17 What s Next? And What About My Brain? 19 2 Boosting Your Brain Power 21 The Brave New Pharmacy 22 Juicing the Brain: The Smart Drugs 24 The Caveats: Are These Really Smart Pills and Are They Safe? 26 Six Drug-Free Ways to Boost Your Brain 29 Boosting Your Brain with Meditation 31 Meditation Means Changing Your Brain 33 What s Next? And What About My Brain? 35 v

8 vi Contents 3 Manipulating Your Memory 37 Memories Are Made of This We Hope 38 How Memory Works the Short Version 39 Alzheimer s Disease: The Memory Epidemic 41 What We Know Now About Dementia 43 Marijuana to Ward Off Alzheimer s? Wow. Like, Cool. 44 Making Memories Stick Around 45 Erasing Bad Memories: A Morning-After Pill for the Brain 48 The Toll of Mental Illness and Anxiety 50 What s Next? And What About My Brain? 52 4 Digital You: What the Digital Explosion Is Doing to Your ibrain 55 Are You Born Digital or a Digital Immigrant? 56 The Brains of Digital Natives 57 The Bad, the Good, and the Unknown Effects of Technology 59 The Future Is Closer Than You Think 61 Uses of the Digital You 63 What About My Body? Balancing the ibrain and Your Sensory Self 64 Beyond Digital: The Serious Need for Play 66 What s Next? And What About My Brain? 67 5 Looking Inside Your Brain: The Magic of Neuroimaging 71 Smile, Say Cheese? Not Exactly: How an MRI Works 74 Picture This: Psychopath, Pedophile, Autistic Toddler 76 Scanning the Other Half of Your Brain: Why White Matter Matters 77 The Limits of Brain Scans 79 The Five Flaws of Brain Scans 80 What s Next? And What About My Brain? 83

9 CONTENTS vii 6 Rewiring the Brain Electric 87 The Electrical Revolution: A History of Hot-Wiring Your Head 88 The Current Brain Research: Magnets to Implants 90 Discovering Depression s Sweet Spot 95 Could Implants Help Alzheimer s Patients? 96 What s Next? And What About My Brain? 97 7 Your Bionic Brain: The Merging of Brain with Machines 101 Spare Parts 102 Bionic Brain Research Today 104 The Britannica in Your Brain and More 106 Artificial Retinas: Giving Sight to the Blind 107 An Artificial Hippocampus? 108 Putting Thoughts into Action 110 How and Why Your Brain Is Better Than a Computer for Now 112 What s Next? And What About My Brain? The Possible Dreams: Stem Cells, Gene Therapy, and Nanotechnology 117 The Future of Stem Cells 120 Retinal Stem Cells from Adults Show Promise 122 The Promise of Gene Therapy 123 Nanomedicine 125 What s Next? And What About My Brain? Neuroethics: Facing the Dark Side 129 Stem Cells: Still Fighting After All These Years 132 Liar, Liar: Can Brain Scans Reveal the Truth? 133 Responsibility: My Sick Brain Made Me Do It (The Devil Made Me Do It?) 134 Privacy, Bias, and Self-Incrimination 136

10 viii Contents Psychotreatment: Should We Force Psychopharmacological Therapies? 137 Mental Doping on the Rise: They Jail Athletes, Don t They? 137 Issues Yet to Come: A Future of Busy Lawyers The Past Is Prologue: To the Future 141 Sources 143 Illustration Credits 153 Glossary 155 About the Author 161 Index 163

11 To the future, and to all of our children and grandchildren who will make it so, especially (and always) Alcina, Ariadne, Isabela, Blue, Raj, and Lulu

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13 ACKNOWLEDGMENTS I must first thank the writers and editors of Scientific American and Scientific American Mind for the excellent articles on which so much of this book is based; they are acknowledged in detail in the Sources. I am most grateful to the renowned neuroscientists and experts who graciously gave of their time to help me sort out what might be in the quite near future, and who have contributed much to neuroscience, especially R. Douglas Fields, Joseph LeDoux, Richard Davidson, Philip Kennedy, and Hank Greely, an expert on the legal, ethical, and social issues surrounding this brave new world of neuroscience. The captivating concept for this book came from the creative and hard - working team at Jossey - Bass, who are much appreciated. For the second time, I want to give heartfelt thanks to executive editor (and my editor) Alan Rinzler and senior editorial assistant Nana Twumasi, who have contributed so much to the shaping and creation of this book; Carol Hartland, production genius; Bev Miller, much more than a copyeditor; ace freelance researcher Brianna Smith; Paula Goldstein, who designed the book s interior; and all the marketing people who put my book in your hands: Jennifer Wenzel, Erin Beam, P. J. Campbell, Karen Warner. At Scientific American, Diane McGarvey and Lisa Pallatroni were responsible for finding and approving years of archived material. Thank you. My family, good friends, and fellow writers have once again listened to me agonize endlessly and rant on about the difficulties of writing about the brain. Many thanks to you all, in particular to first readers Kelly A. Dakin (who corrected many of my errors and added xi

14 xii Acknowledgments valuable content), Ann Crew, Ferris Buck Kelley, Frank Urbanowski, and literary agent Andrea Hurst (for sending this book my way) and the wonderfully productive and generous writing community of Sacramento.

15 PREFACE Yesterday s science fiction is today s science. Yes, that s a clich é you ve been hearing for decades. That s because it s true. In fact, many of today s discoveries in neuroscience and the accompanying technology have surpassed some science fiction. There have been massive changes in our basic understandings of neuroscience and our tools, and yet we are just beginning to grasp the intricate workings of the human brain your brain. Scientific American has been looking to the future for more than a century. For example, it projected and predicted the future of brain research in Scientific American special editions in 1999 ( Your Bionic Future ) and again in 2003 ( Better Brains ). And in just the past two years, neuroscientists doing cutting - edge research have been written about in or have written for Scientific American and Scientific American Mind. This book is based on many of those articles. We trolled recent years for issues and articles key to what s happening today in brain science, particularly how today s world and the many advances in research and technology are changing our brains every day, and what we can expect in the coming decades. Among the contributors whose work is represented here are outstanding scientist writers at the forefront of brain research. We ve added new research as well some so new that it was not yet in press when this book was being written. And as you are holding this book in your hands, research is leading to even more new xiii