PERMANENT
PRESENT TENSE
PERMANENT
PRESENT TENSE
The Unforgettable Life
of the Amnesic Patient, H.M.
SUZANNE CORKIN
BASIC BOOKS
A Member of the Perseus Books Group
New York
Copyright © 2013 by Suzanne Corkin
Published by Basic Books,
A Member of the Perseus Books Group
All rights reserved. No part of this book may be reproduced in any manner whatsoever without written permission, except in the case of brief quotations embodied in critical articles and reviews.
For information, address Basic Books, 250 West 57th Street, 15th Floor, New York, NY 10107-1307.
Books published by Basic Books are available at special discounts for bulk purchases in the United States by corporations, institutions, and other organizations. For more information, please contact the Special Markets Department at the Perseus Books Group, 2300 Chestnut Street, Suite 200, Philadelphia, PA 19103, or call (800) 810-4145, ext. 5000, or e-mail [email protected].
Book Design by Cynthia Young
Set in Adobe Garamond Pro
Library of Congress Cataloging-in-Publication Data
Corkin, Suzanne.
Permanent present tense : the unforgettable life of the amnesic patient, H.M. / Suzanne Corkin.
pages cm
Includes bibliographical references and index.
ISBN 978-0-465-03349-2 (e-book) 1. H. M., 1926–2008. 2. Amnesiacs—Biography. 3. Epilepsy — Surgery — United States — History. I. Title.
RC394.A5C58 2013
616.85'2320092—dc23
[B]
2013002391
First Edition
10 9 8 7 6 5 4 3 2 1
In Memory of Henry Gustave Molaison February 26, 1926–December 2, 2008
Contents
List of Insert Figures
Prologue: The Man Behind the Initials
1. Prelude to Tragedy
2. “A Frankly Experimental Operation”
3. Penfield and Milner
4. Thirty Seconds
5. Memories Are Made of This
6. “An Argument with Myself”
7. Encode, Store, Retrieve
8. Memory without Remembering I: Motor-skill Learning
9. Memory without Remembering II: Classical Conditioning, Perceptual Learning, and Priming
10. Henry’s Universe
11. Knowing Facts
12. Rising Fame and Declining Health
13. Henry’s Legacy
Epilogue
Acknowledgments
Notes
Index
List of Insert Figures
1. Four lobes of the cerebral cortex. Courtesy of André van der Kouwe, Jean Augustinack, and Evelina Busa.
2a. Medial temporal-lobe structures. Courtesy of André van der Kouwe, Jean Augustinack, and Evelina Busa.
2b. Hippocampus, entorhinal, and perirhinal cortices. Courtesy of André van der Kouwe, Jean Augustinack, and Evelina Busa.
3. Henry’s MRI. S. Corkin et al., “H.M.’s Medial Temporal Lobe Lesion: Findings from Magnetic Resonance Imaging,” Journal of Neuroscience 17 (1997): 3964–79.
4. Mooney Face-perception Test. B. Milner et al., “Further Analysis of the Hippocampal Amnesic Syndrome: 14-Year Follow-up Study of H.M,” Neuropsychologia 6 (1968): 215–34.
5a. Visual stepping-stone maze. B. Milner et al., “Further Analysis of the Hippocampal Amnesic Syndrome: 14-Year Follow-up Study of H.M,” Neuropsychologia 6 (1968): 215–34.
5b. Tactual stylus maze.
6. Route-finding task.
7. Limbic system. This image is a work of the United States Government (NIH) and is in the public domain falling under Image License B defined under the Image License section of the Disclaimer page.
8. The typical neuron. L. Heimer, The Human Brain and Spinal Cord: Functional Neuroanatomy and Dissection Guide (New York: Springer-Verlag, 1983). With kind permission of Springer Science+Business Media.
9. Mirror tracing task.
10. Rotary pursuit task.
11. Bimanual tracking task.
12. Coordinated tapping task.
13. Sequence-learning task.
14. Reaching task.
15. Basal ganglia. Image by John Henkel, FDA staff writer, via Wikimedia Commons.
16. Eyeblink conditioning task. Courtesy of Diana Woodruff-Pak.
17. Gollin Incomplete Figures Test. B. Milner et al., “Further Analysis of the Hippocampal Amnesic Syndrome: 14-Year Follow-up Study of H.M,” Neuropsychologia 6 (1968): 215–34.
18. Pattern priming. J. D. Gabrieli et al., “Intact Priming of Patterns Despite Impaired Memory,” Neuropsychologia 28 (1990): 417–27.
19a. William Beecher Scoville.
19b. Brenda Milner. Photograph courtesy of Neuro Media Services
20. Five-year-old Henry.
21. Henry the animal lover.
22. Henry’s high school graduation photo, 1947.
23. Henry, 1958.
24. Henry with his parents.
25. Henry, 1975.
26. Henry ready for testing at MIT. Photograph by Jenni Ogden, 1986.
27. Henry at Bickford Health Care Center.
28. Henry’s drawing of the floor plan of his home. S. Corkin, “What’s New with the Amnesic Patient H.M.?” Nature Reviews Neuroscience 3 (2002): 153–160.
29. Henry’s spoon.
Prologue
The Man Behind the Initials
Henry Molaison and I sat opposite each other, a microphone on the narrow table between us. Parked next to him was his walker, and the white basket attached to the front held a book of crossword puzzles; he always kept one close by. Henry wore his usual attire—pants with an elastic waist, a sport shirt, white socks, and sensible black shoes. His large face, partly covered by thick glasses, wore a pleasant, attentive expression.
“How are you feeling today?” I asked him.
“I feel okay,” Henry replied.
“That’s good. You look great.”
“Well, thank you.”
“I understand that you have a little trouble remembering things.”
“Yes, I do. I do have—well, a lot of trouble remembering things, you know. And one thing I found out that I fool around with a lot is crossword puzzles. And, well, it helps me in a way.”
Henry and I talked a bit about his crossword puzzles, a frequent topic of conversation. Then I asked, “How long have you had trouble remembering things?”
“That, I don’t know myself. I can’t tell you because I don’t remember.”
“Well, do you think it’s days or weeks? Months? Years?”
“Well, see, I can’t put it in exactly on a day, week, or month, or year basis.”
“But do you think it’s been more than a year that you’ve had this problem?”
“I think it’s about that. One year or more. Because I believe I had an—this is just a thought that I’m having myself—that, well, I possibly have had an operation or something.”
Our conversation took place in May 1992, nearly forty years after Henry’s capacity to form long-term memories disappeared as a result of a risky surgical intervention. In 1953, he underwent a bilateral medial temporal-lobe resection, an experimental brain operation intended to alleviate the severe epilepsy he had faced since childhood. Since his first seizure in 1936, his condition had grown worse, making it increasingly difficult for him to participate in normal activities. The operation did control his seizures, but with an unanticipated and devastating consequence—an extreme amnesia that robbed Henry of the ability to form new memories and, in doing s
o, determined the course of the rest of his life.1
Amnesia is the inability to establish lasting memories that are later available for conscious retrieval. The word’s origin is in the Greek amnesia, meaning forgetfulness or loss of memory, but the deficit goes beyond forgetting. Amnesic patients such as Henry are stripped of their ability to turn their immediately present experiences into lasting memories. This condition, which may be permanent or temporary, typically stems from an insult to the brain, such as encephalitis, stroke, or head injury. Amnesia can also arise from a rare psychiatric disorder, psychogenic amnesia, which has no identified neurological cause. In Henry’s case, the amnesia resulted from the surgical removal of pieces of his brain, and it was permanent.
Henry was a young man of twenty-seven when he had the operation. Now sixty-six, he relied on a walker to prevent falls. But to him, only a short time had passed. In the decades after his operation, he lived in a permanent present tense: he could no longer remember the faces of people he met, places he visited, or moments he lived through. His experiences slipped out of his consciousness seconds after they happened. My conversations with Henry vanished from his mind immediately.
“What do you do during a typical day?”
“See, that’s tough—what I don’t . . . I don’t remember things.”
“Do you know what you did yesterday?”
“No, I don’t.”
“How about this morning?”
“I don’t even remember that.”
“Could you tell me what you had for lunch today?”
“I don’t know, tell you the truth. I’m not—”
“What do you think you’ll do tomorrow?”
“Whatever’s beneficial,” he said in his friendly, direct way.
“Good answer,” I said. “Have we ever met before, you and I?”
“Yes, I think we have.”
“Where?”
“Well, in high school,”
“In high school?”
“Yes.”
“What high school?”
“In East Hartford.”
“Have we ever met any place besides high school?”
Henry paused. “Tell you the truth, I can’t—no. I don’t think so.”
At the time of our interview, I had been working with Henry for thirty years. I first met him in 1962, when I was a graduate student. We had not met in high school, as Henry firmly believed, but by pure coincidence our lives had overlapped. I grew up in Connecticut, near Hartford, a few miles from the houses where Henry lived. When I was seven, I became close friends with a girl who lived across the street from my family. I remember her father zooming up our street in his fire-engine-red Jaguar, and on weekends, dressed in mechanic’s overalls, tinkering with the car’s machinery underneath.
My friend’s father was a neurosurgeon. As a child, I had no idea what a neurosurgeon did. Years later, when I was a graduate student in the Department of Psychology at McGill University, this man reentered my life. While reading articles on memory in medical journals, I came across a report by a doctor who had performed a brain operation to cure a young man’s intractable epilepsy. The operation caused the patient to lose his capacity to establish new memories. The doctor who coauthored the article was my friend’s father, William Beecher Scoville. The patient was Henry.
This childhood connection to Henry’s neurosurgeon made reading about the “amnesic patient, H.M.” more compelling. Later, when I joined Brenda Milner’s laboratory at the Montreal Neurological Institute, Henry’s case fell into my lap. For my PhD thesis, I was able to test him in 1962 when he came to Milner’s lab for scientific study. She had been the first psychologist to test Henry after his operation, and her 1957 paper with Scoville, describing Henry’s operation and its awful consequences, revolutionized the science of memory.2
I was trying to expand the scientific understanding of Henry’s amnesia by examining his memory through his sense of touch, his somatosensory system. My initial investigation with him was focused and brief, lasting one week. After I moved to MIT, however, Henry’s extraordinary value as a research participant became clear to me, and I went on to study him for the rest of his life, forty-six years. Since his death, I have dedicated my work to linking fifty-five years of rich behavioral data to what we will learn from his autopsied brain.3
When I first met Henry, he told me stories about his early life. I could instantly connect with the places he was talking about and feel a sense of his life history. Several generations of my family lived in the Hartford area: my mother attended Henry’s high school, and my father was raised in the same neighborhood where Henry lived before and after his operation. I was born in the Hartford Hospital, the same hospital where Henry’s brain surgery was performed. With all these intersections in our backgrounds and experiences, it was interesting that when I would ask him whether we had met before, he typically replied, “Yes, in high school.” I can only speculate as to how Henry forged the connection between his high-school experience and me. One possibility is that I resembled someone he knew back then; another is that during his many visits to MIT for testing, he gradually built up a sense of familiarity for me and filed this representation among his high-school memories.
Henry was famous, but did not know it. His striking condition had made him the subject of scientific research and public fascination. For decades, I received requests from the media to interview and videotape him. Each time I told him how special he was, he could momentarily grasp, but not retain, what I had said.
The Canadian Broadcasting Corporation recorded our 1992 conversation for two radio programs, one devoted to memory, the other to epilepsy. A year earlier, Philip Hilts had written an article about Henry for the New York Times, and later made him the focus of a book, Memory’s Ghost.4
Scientific papers and book chapters were written about Henry, and his case is one of the most frequently cited in the neuroscience literature. Open any introductory psychology textbook and you are likely to find somewhere in its pages a description of a patient known only as H.M., next to diagrams of the hippocampus and black-and-white MRI images. Henry’s disability, a tremendous cost to him and his family, became science’s gain.
During his life, the people who knew Henry kept his identity private, always referring to him by his initials. When I gave lectures about Henry’s contributions to science, I always encountered intense curiosity about who he was, but his name was revealed to the world only after his death in 2008.
Over the course of decades, during which I worked with Henry, it became my mission to make sure that he is not remembered just by brief, anonymous descriptions in textbooks. Henry Molaison was much more than a collection of test scores and brain images. He was a pleasant, engaging, docile man with a keen sense of humor, who knew that he had a poor memory and accepted his fate. There was a man behind the initials, and a life behind the data. Henry often told me that he hoped that research into his condition would help others live better lives. He would have been proud to know how much his tragedy has benefited science and medicine.
This book is a tribute to Henry and his life, but it is also an exploration of the science of memory. Memory is an essential component of everything we do, but we are not consciously aware of its scope and importance. We take memory for granted. As we walk, talk, and eat, we are not aware that our behavior stems from information and skills that we previously learned and remembered. We rely constantly on our memory to get us through each moment and each day. We need memory to survive—without it, we would not know how to clothe ourselves, navigate our neighborhoods, or communicate with others. Memory enables us to revisit our experiences, to learn from the past, and even to plan what to do in the future. It provides continuity from moment to moment, morning to evening, day to day, and year to year.
Through Henry’s case, we gained insights that allowed us to break memory down into many specific processes and to understand the underlying brain circuits. We now know that when we describe what we h
ad for dinner last night, or recite a fact about European history, or type a sentence on a keyboard without looking at the keys, we are accessing different types of memory stored in our brains.
Henry helped us understand what happens when the ability to store information is missing. He retained much of the knowledge he had acquired before his operation, but in his daily life afterward, he depended heavily on the memories of those around him. His family members, and later the staff at his nursing home, remembered what Henry had eaten that day, what medications he needed to take, and whether he needed a shower. His test results, and medical reports, and the transcripts of his interviews, helped preserve information about his life that he could not retain. Of course, none of these resources could substitute for the capacities Henry had lost. For memory does more than just help us survive—it influences our quality of life and helps shape our identity.
Our identity is composed of narratives we construct based on our personal history. What happens if we can no longer hold our experiences in our brain long enough to string them together? The link between memory and identity lies at the heart of our apprehensions about aging and cognitive decline. Losing our memory to dementia seems an unimaginable misfortune, yet this is what all of adult life was like for Henry. As his present moved forward, it left no trail of memory behind it, like a hiker who leaves no footprints. How could such a person ever have a clear sense of who he was?
Those of us who knew Henry recognized a clear personality—gentle, goodhearted, and altruistic. Despite his amnesia, Henry had a sense of self. But it was skewed, weighted heavily toward his general knowledge of the world, his family, and himself before 1953. After his operation, he was able to acquire only the smallest fragments of self-knowledge.
We can describe memory in all the ways we confront it in our lives. But how do our experiences translate into mechanisms in the brain? Memory is not a single event, not a snapshot fixed in celluloid with the click of a shutter. We have learned—initially from Henry—that memory does not reside in one spot in the brain. Instead, memory engages many parts of the brain in parallel. We can think of remembering as a trip to the supermarket to buy all the ingredients for beef stew. We select the meat, vegetables, stock, and spices from different parts of the store and then combine them in a large stew pot at home. Similarly, calling up the memory of one’s last birthday entails pulling information stored in different parts of the brain—the sights, sounds, smells, and tastes—and organizing these stored traces in a way that allows us to relive the experience.
Permanent Present Tense Page 1
