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About the Author
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Preface: Falling in Love with Science
I don’t recall when I first fell in love with science, but I remember the day when I said, “’Til death do us part.” I was counting raspberry bushes. They grew wild around the abandoned strip mines of Appalachia. As an ecology student at West Virginia University in Morgantown, I clambering around an old mine’s precarious slopes with twenty other eager undergraduates. We shot line transects and counted the bushes, orienting our test sites by the compass, while measuring roped-off segments ten-meters square for careful counting and mapping.
The day was hot and sticky. The prickly bushes tore our clothes and gouged our flesh. Black coal dust clogged our lungs. Sunburned and sweaty, we learned that wrestling truth from reality was difficult . . . and fun! Field science infatuated me that day, but my pledge of lifelong devotion to the scientific process came a few days later, when we pooled data from several teams. We made graphs of numbers of raspberry bushes, north and east, upslope and down. The graphs sang to me. Their meaning popped off the page and danced around my desk. In axes, points, clusters, and lines, the numbers of raspberry bushes revealed the history of the mine. In the days long before ecology became a household word, those bars, dots, lines, and curves mirrored the fifty-year history of the mine, disclosing how the site had been worked, when it had been abandoned, where the acid mine drainage had polluted most, and how nature had attempted—with wild raspberries—to bandage the land so it could heal from within. The data painted a picture more beautiful to me than any art museum masterpiece.
From that day on, I never questioned my choice of a career. It was science for me, in some form, and I’ve tried quite a few. In the bacteriology labs at West Virginia University, I grew on agar culture plates the acidophilic microorganisms that can survive in acid mine drainage when nothing else can. At Oak Ridge National Laboratories, I zapped protozoans with ultraviolet light to see if they would die. They did. At West Virginia University Medical Center, I worked under a grant from the U.S. Army, screening the effects of possible new malarial drugs on blood samples run through a labyrinth of tubes, reaction vessels, and colorimeters. (Computers do all that now.) In Colorado, I mixed reagents for thyroid tests in a medical lab. I stuck thermometers down prairie dog burrows in Rocky Mountain National Park, and I set up anemometers in mountain meadows.
Then I got into science teaching and educational reform because I wanted every young person to fall in love with science just as I had. Writing curriculum and designing educational materials led me into topics ranging from medical genetics to land use planning. In the early 1990s, I read a sentence that riveted my attention. The neuroscientist Richard Restak wrote, “The [human] brain is the only organ in the known universe that seeks to understand itself.”1 That sentence stopped me dead in my tracks. Here was the science of science itself—an organ of tissue and blood attempting to understand its own functioning. To my mind, that was bigger than malaria drugs, bigger than burrowig animals, bigger even than my raspberry bushes. I couldn’t wait to find out what neuroscientists were doing with their brains as they attempted to comprehend . . . their own brains! So I started digging though the scientific literature and eventually I wrote a book called 101 Questions Your Brain Has Asked About Itself But Couldn’t Answer . . . Until Now. The book was moderately successful, garnering a “Best Book” honor from the American Association for the Advancement of Science in 1999. The book is now in its second edition and continuing to make a contribution, I hope.
For me, however, one hundred and one questions formed only the tip of the iceberg. The more questions I asked and the more I read and learned, the more I wanted to know. I became fascinated with research on how the brain and senses interact—thus this book’s title, Brain Sense. “Brain sense” is a field that many tillers are plowing: the neurologists who study the interaction of peripheral and central nervous system; the brain mappers who chart the regions of the brain that handle specialized functions and the nerve networks that connect those regions; the biochemists who probe the molecular receptors that initiate the impulses of the chemical senses; the biophysicists who explore how light and sound waves can sometimes translate themselves into sensory perceptions; the physicians and surgeons who seek to treat the maladies that befall the senses and the brain; the engineers and biomechanicists who try to understand how perception works so they can construct devices ranging from prosthetics to virtual reality simulators; the cognitive psychologists who want to understand how we learn; the behavioral psychologists who hope to explain why we do the things we do; and the clinical psychologists who strive to cure the intellectual, social, and emotional sequelae of sensory perception gone awry.
The organization of this book follows traditional lines. There’s a part on each of the five major senses: touch, smell, taste, vision, and hearing. The book begins with touch because, in my opinion, it’s the least appreciated of all the senses and perhaps the most vital. We explore the chemical senses next, because taste and smell work in similar ways. Next come sight and sound, the senses that we rely on the most and can trust the least. In the individual chapters about each sense, I’ve tried to include some stories about how ordinary people live when their sensory capacities are diminished or lost. I’ve also included as much of the latest in scientific research as I could jam onto each page. There is so much going on in brain-sense research, I can scarcely scratch the surface here, but I hope that the studies I’ve chosen for inclusion impart some sense of the endless fascination of that work. Throughout these chapters, you’ll notice two recurring themes. The first is brain plasticity. Plasticity means that the brain changes throughout life. Once, we thought of the adult brain as fixed and unchanging (except for the deterioration that comes with age), but research in the last two decades has shattered that notion. The brain is constantly rewiring itself, reshaping its own structure, recruiting new circuits to perform its work when old ones are damaged or lost. It even re-creates memories each time it retrieves them. The implications of brain plasticity for understanding our senses, our consciousness, and the essence of what it means to be human are nothing short of staggering.
The second theme is what I’ve come to think of as a negotiable reality. We believe in our senses, and we trust that they are providing us with objective, complete, and accurate data about the world around us. We are wrong. Our brains construct our reality, molding every input to what we expect, what we imagine, what we wish for. Our brains have minds of their own. They shape light waves into expected images, sound waves into patterns ranging from noise to music.
Our sense of touch is malleable, variable, 2and refinable. We taste and smell what we believe we will taste and smell. In precisely the same environment, you and I will neither see, hear, taste, touch, nor smell the same things—nor will we draw the same conclusions about the information our senses have collected. Our personal worlds are constructions built by our brains using the raw materials of the senses—raw materials that are greatly modified during the construction process.
That idea of a negotiable reality is the reason for the last part of this book, “Beyond the Big Five,” which looks briefly at some of the other “senses” or sensory experiences that don’t fit with the big five but are too intriguing to ignore, such as the mingling of the senses known as synesthesia, the experience of déjà vu, the phantom sensations and phantom pain often experienced by people who have amputations, the possibilities and probabilities of extraordinary sensory perception, and the brain’s sense of time kept by a body clock far more precise than most of us realize.
I hope that people who know a lot about the brain and the senses will read this book. I hope that people who know very little about those topics will read it, too. For those readers who are interested in the brain and the senses but don’t know much about the brain’s structure and function, I’ve included an appendix at the end of the book, “The Brain and the Nervous System—A Primer,” which provides a short course in neuroscience and explains many of the terms and concepts used in this book. It also includes diagrams showing the locations of many of the brain regions discussed in the book. Before long, you’ll know your occipital lobe from your parietal, and you’ll be well on your way to comprehending your own “brain sense.”
From beginning to end, this book is many things. It’s part memoir because it’s my opportunity to reminisce about some things I’ve learned from science and f rom life. It’s part investigative reporting because I’ve delved into the work of some cutting-edge researchers who are designing clever experiments to gain answers to questions that we didn’t even know how to ask a decade ago. It’s part biography because I want you to know—as I have come to know—what real scientists are like as they work in real labs on real questions that have never before been answered. It’s part textbook because basic knowledge about how our senses work is important to everyone. It’s part history because we can’t appreciate where we’re going if we don’t value where we’ve been. It’s part newspaper because it contains some of the late-breaking stories that are making headlines on a daily basis. It’s part travel journal because I invite you to fly with me as I visit working neuroscientists in Washington, Minnesota, Michigan, and Massachusetts. It’s part personality profiles because the scientists I met and talked with are intriguing people, doing interesting work and living full and satisfying lives. I want readers of this book to see scientists as I have seen them—not as geeky weirdos in lab coats, but as warm, humorous, engaging human beings who thrive on the search for knowledge as they toil among the “raspberry bushes” of their chosen research specialty.
Most of all, this book is a tribute to courage and to some of the wonderful people who shared their stories with me: the tour guide who faced death as her ship sank in Antarctica; the hairdresser who lost her sense of smell to brain injury;
the woman who had a mastectomy but continues to feel her breasts; theyoung poet, born deaf, who had a cochlear implant; the synesthete who sees letters in colors; the electronic genius who engineers phone lines and ignores his tinnitus; the teenager who was born without the sense of touch and the mother who has loved him totally and unconditionally through all he has achieved.
Finally, this book is a love letter to science and scientists. I’ve been wedded to science all my life, and my fascination with the questions, methods, and inferences of scientific research has never diminished. Science isn’t the only way to see, to know, to understand, but it’s the one that won my heart. Come meet the love of my life.
Table of Contents
Preface: Falling in Love with Science ix
Part 1 Touch
1 Life Without Touch 3
2 In from the Cold 9
3 On Which Side Is Your Bread Buttered? 15
4 Pain and the Placebo Effect 21
5 Nematodes, Haptics, and Brain-Machine Interfaces 29
Part 2 Smell
6 It's Valentine's Day...Sniff! 39
7 Do Odors Dance in Your Nose? 45
8 Life Without Scent 53
9 The Sweaty Scent of Sex 59
10 Express Train to Happiness 65
11 The Bitter Truth 75
12 Coconut Crazy 83
13 Cooking Up Some Brain Chemistry 89
14 How to Knit a Baby Taste Bud 95
15 Expecting What You Taste and Tasting What You Expect 101
Part 4 Vision
16 The Big Picture 109
17 Color and Memory 117
18 Sizing Things Up 123
19 On the Move 130
20 Vision and the Video Game 137
Part 5 Hearing
21 Hearing, Left and Right 147
22 Listening and Language 154
23 My Eats Are Ranging 160
24 Music and the Plastic Brain 166
25 Cochlear Implant: One Man's Journey 174
Part 6 Beyond The Big Five
26 Synesthesia: When Senses Overlap 183
27 If This Looks Like Déjà Vu, You Ain't Seen Nuthin' Yet 190
28 Feeling a Phantom 197
29 Probabilities and the Paranormal 206
30 Time 212
Appendix The Brain and the Nervous System-A Primer 219
Recommended Resources 263