In 1953, a young man named Henry Gustav Molaison, of Hartford, Connecticut, lost his memory and helped to invent neuroscience. Henry Molaison's amnesia was the result of a highly risky "psychosurgical" procedure, an operation designed to cure the debilitating epilepsy he had suffered since childhood. In an attempt to remove the part of the brain that was causing Henry's fits, two holes were drilled in the front of his skull and a portion of his brain, the front half of the hippocampus on both sides, and most of the almond-shaped amygdala, was sucked out. The procedure, hopeful at best, went badly wrong and Henry, then aged 27, was left with no ability to store or retrieve new experiences. He lived the subsequent 55 years of his life, until his death in 2008, in the permanent present moment.
Henry Molaison's tragedy was, however, perhaps also the single most significant advance in understanding the function of memory made in the past century. Until his operation, it had been believed that memory was a property of the whole brain. The accident of his surgery proved a large part of its capacity to be localised in this one area. The "cleanness" of Henry's amnesia made his brain the perfect subject for study of cognitive function in many other ways, too. After his operation, living first with his parents and later with carers, he became known to science as "HM" to protect his identity. It was through these initials that a young postgraduate researcher called Suzanne Corkin, now professor of behavioural neuroscience and head of the Corkin Lab at the Massachusetts Institute of Technology, got to know him.
Their relationship seemed a little bit like fate. When Corkin came across Henry's case in medical journals from the late 1950s, she discovered that their lives had already overlapped in curious ways. She had grown up a couple of miles from him, in Connecticut, and as a child had lived over the road from the surgeon who had operated on Henry's brain; the surgeon's daughter had been her childhood friend. In 1962, as part of her research, Corkin interviewed Henry. Over the next 46 years they spent many days in each other's company, though for Henry, of course, it was always the first time. Corkin has now written a compelling memoir of that bond between scientist and subject, Permanent Present Tense, a relationship which Henry once described neatly: "It's a funny thing – you just live and learn. I'm living and you're learning."
Corkin's book is both a case study and a biography, partly written with the mission to show that HM was much more than a filing cabinet of test scores and brain images; he was Henry, "an engaging, docile man, with a keen sense of humour, who knew he had a poor memory and accepted his fate … and hoped that research into his condition would help others live better lives." The striking thing about Henry's memory loss was how specific it was. He forgot all of his experiences after the operation within 30 seconds, but he retained a good deal of the texture of life he knew up until the age of 27. His personality remained intact, he still had above average IQ and language skills, though for more than 50 years he was able to acquire only the tiniest fragments of self-knowledge.
Speaking to Corkin by phone at her lab in Boston, I ask if she has missed Henry since his death. She laughs a little. "I feel that in a way he is not gone," she says. "Partly because I have been writing this book but also because when he died he donated his brain to MIT. So we continue to study him. He has gone but is still very present for us every day."
There is an estranging moment at the end of Corkin's book, where in the hours after his death Henry's brain is removed from his skull and Corkin gets to look at the physical object she has been probing with her questions for most of her adult life. She describes that moment with a mixture of high scientific excitement and human loss. When she looked at the "tofu-like" mass of that organ, did the neuroscientist have a sense of it being the man she had known?
"Well," she says, "he will always be a real person for me. I tried to understand his brain when he was alive and now he is dead it is just another way of getting to know him better." After being preserved in formaldehyde, Henry's brain was sent to a lab in San Diego, where it has been sliced into 2,401 fine sections, on slides, as a permanent neurological research resource, soon to be available online. "Some people say Henry has been translated into 2,401 objects," Corkin says, "but I don't see him like that."
One of the fascinating, unsettling impulses in reading Henry's life is that sense of identity being a bundle of all of the stories we tell ourselves about ourselves. Henry loved to relate the few clear memories of his childhood, over and over, though he lacked a context for them and the face he surprised himself with in the mirror each morning did not quite connect with them. Corkin heard those stories many times over the years; every time she left the room for a minute and returned to Henry he introduced himself as if they had never met before, and told the stories again. Some were the family lore of how his father had moved north from Louisiana; others involved going roller skating as a child in the park, taking banjo lessons, driving with his parents along the Mohawk Trail.
"The interesting and important thing scientifically about these stories was that he would give you the gist of them, but they were never linked to a specific time and place," Corkin says. "You and I can say what we did on our last birthday. But Henry could never remember what else happened. There were no connections, no associations for him in that way."
In talking to Henry and testing his recall over all those years, Corkin discovered only two exceptions to that rule. One was a plane ride that Henry took as a teenager, as a present for graduation from junior high school. The other was an occasion he stole a cigarette from his father and smoking it made him sick, and he got into trouble with his parents. Both of these stories Henry could describe in quite obsessive emotional detail distinct from anything else he talked about. Again, this offered insights into the way memory functioned. In the case of the plane ride there was the anticipation of it, the buying of the tickets, all of the detail of the flight itself, sights and sounds, and then the telling of it to others once it was over.
"It was clear that he had encoded all that information and stored it across many parts of his brain," Corkin says. "All memories are not stored in one specific spot. Strong memory is a creative process that takes in sights and sounds and textures and emotions, so a really important memory will link with all of these areas of the brain. And when we recall it there is a creative process of putting it all together. Similarly with the smoking incident, that appears to have been very emotional also. So: a very negative experience and a very positive one."
It was out of these things, on a daily basis, that Henry seemed to work out who he was. The metaphor of well-trodden neural pathways and formative experiences which have been laid down seems particularly physically expressive here.
Henry was not capable of learning new information, though his knowledge of past events, the Wall Street Crash, Pearl Harbor and so on, was clear. Only a very few tiny details of TV programmes he watched repetitively ever stuck. He could, however, learn and retain new motor skills, which led to important understanding of the difference between conscious memory and unconscious. The latter category would include learning how to play tennis or ride a bicycle, or even play the piano – things that the brain encodes and transmits to the muscles through conditioning, memories which we come to think of as intuitive.
In all of this revelation, Henry opened up as many questions of the mystery of memory as he answered. MRI scans have helped unpick some of this, but shouldn't be relied on too heavily, Corkin says. She places more faith in the new science of optogenetics, which has begun to understand memory processes at the level of "a specific circuit and the neurotransmitters and brain chemicals that modulate long-term memory. The future of memory research will focus on being able to activate or deactivate these circuits in the hippocampus," Corkin says, "and see how they promote or impair memory function."
Partly through the physical example of Henry, she has no truck with any more esoteric ideas of mind. "The mind is the brain in my view. Your mind is not in your big toe. The brain is a very physical structure, it is like your arm, but it has grey matter and white matter and a huge number of cells we are just beginning to understand called glia. All your mind is contained in there."
As we talk, I wonder if Henry was able to feel things like guilt or regret, emotions with a temporal component. She suggests not, though "he knew that he'd had a brain operation. He knew not many people had had the operation before him. He never used the word 'experiment', but I think he had the sense of himself as that word. Of the original operation, he once said: 'I think they possibly did not make the right movement at the right time.'"
She did not remind Henry of this too often, however, in the same way that it was too painful, after his parents passed away, to have to let him know, as if for the first time, that they were dead. The amnesia was both a prison and a liberation in this sense. His operation had given Henry by default the kind of concentration on the present to which Buddhist meditation might aspire. "He was never sad or depressed," Corkin says, "though I don't think any of us would want to change places with Henry. He had a tragic life and he made the best of it. He showed the world you could be saddled with a tremendous handicap and still make an enormous contribution to life. I found his resilience inspirational."
In all their meetings Henry betrayed only the most fleeting traces of recognition of Corkin. For all of her objective rigour, it seems she clung to those intimations of connection. "If I said my name was 'Suzanne', he would say 'Corkin'," she explains, "but he didn't really know who I was. If I said: 'What do I do?', he would say 'doctoress', which was a name he used only for me, so that was heartwarming." It helped that they had grown up in the same places. Corkin did one test with him where she intermingled his family photos with her own. In one of Corkin's pictures of her mother holding her sister, Henry recognised the park in which they stood.
It is gratifying to Corkin to know that the public memory of Henry Molaison will long outlive them both. His unique brain will continue to be studied for years to come. Of all the hundreds of things she learned from Henry, I wonder, what are the images of him that come first to the top of her own mind in that curious process of remembering?
She offers three, all pointedly emotional. In the first, during an interview, Henry had gone to the bathroom with a nurse and when he returned she gave him her usual question: have we spoken before, Henry? On this occasion, for whatever reason, he said: "Yes, we were speaking just now." Her second memory is of the last time she saw him, when he was demented and uncomprehending; she stood by him and said who she was, and she had a sense that he turned toward her with a trace of a smile.
The final memory is the oddest of all. "It is when we put his brain on a plane to San Diego," she says. "It was strapped into a seat of its own. I watched the plane take off on its trip across the country and I had this swelling of emotion, remembering Henry and his plane ride. It was the perfect goodbye."
• This article was amended on 16 July 2013. The original referred to Molaison's brain having been sliced into 4,201 fine sections. That should have been 2,401 sections, and has been corrected.
SCOTT SIMON, host:
Fifty years ago this month, the Journal of Neurology, Neurosurgery and Psychiatry published the findings of a remarkable case. A young man who had undergone an experimental brain operation had lost his ability to retain new memories. He could remember things from his life before the operation but any new face or fact, he completely forgot within minutes. Researchers at that time studied him. And it turns out their discoveries opened the modern era of memory research, what's involved every time we say I remember. That young man is now in his 80s. And as Brian Newhouse reports, scientists are still learning from him.
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BRIAN NEWHOUSE: If you close your eyes and just listen for a moment, you may find yourself going somewhere, back in memory. Back maybe to a farm or a park or a lake. Other sounds may make those memories sharpen or change. Add still more and you may start to see particular faces or even smell wood smoke. Remember?
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NEWHOUSE: This is the power of memory, the system that captures pictures, smells, sounds, events, directions - endless amounts of information every day and then seconds or decades later calls it up for us. Memories - what we've learned and what we've done - in a large sense make us who we are. To appreciate this, think if your ability to form any new memories were suddenly cut off.
Who would you be? By studying people who've lost their memories, scientists have learned enormous amounts about how learning and memory work in healthy brains. And what they used to think was relatively straightforward they've since found it's fascinatingly complex, thanks in large part to one man.
He's the most famous patient in the study of the human brain today. He's written up in textbooks and dozens of scientific papers. The modern era of memory research essentially began with him, yet very few people know his name or have ever seen him, despite the efforts of journalists, filmmakers and TV networks, all of whom have asked to photograph, film or interview him. Outside the circle of his family and caregivers, he's known only by his initials, H.M. His guardians recently agreed to release audio recordings made of him in the early 1990s talking to scientists. This is the first time a wide audience has been able to hear his voice.
Dr. BRENDA MILNER (McGill University) : When you're not at MIT, what do you do during a typical day?
H.M. (Patient): See, that's what I don't - I don't remember things.
Dr. MILNER: Uh-huh.
H.M. was a very pleasant normal young man, but he had suffered from very severe epilepsy all his life, really. It made him unable to hold down his job as an assembly worker. It made him very late in finishing high school, although he was quite intelligent.
NEWHOUSE: Brenda Milner is a British-born neuroscientist at McGill University in Montreal who first met H.M. in the mid-1950s.
Dr. MILNER: He had huge major and minor seizures, you know, huge convulsions, and also many, many lapses of consciousness every few minutes. He was in a very, very hopeless condition with his epilepsy.
NEWHOUSE: Dr. Milner came to know H.M. after Connecticut neurosurgeon William Beecher Scoville performed an experimental operation to help relieve H.M.'s seizures. Dr. Scoville thought if he could remove the part of H.M.'s brain where the seizures originated, it might stop them.
Dr. MILNER: And this operation was carried out when - in '53, 1953, September - when H.M. was 27. The operation did have an enormously beneficial effect on the epilepsy so that H.M. has maybe now one big seizure a year, and so the clinical hunch about the epilepsy was justified. But at obviously a horrendous price.
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Dr. MILNER: Who is the president of the United States now?
H.M.: That I don't - I couldn't tell you. I don't remember exactly at all.
Dr. MILNER: Is it a man or a woman?
H.M.: I think it's a man.
Dr. MILNER: His initials are G.B. Does that help?
H.M.: No, it doesn't help.
(Soundbite of piano)
NEWHOUSE: The horrendous price that H.M. paid was a severe case of amnesia. Not the amnesia of Hollywood, where a person forgets everything about his past, but in H.M. it's his ability to acquire new memories, to commit to memory even the simplest events of his day or the world around him, and then to effectively retrieve those memories. Put a finger above your ear. If you were able to push that finger into your head about two inches, you'd be in the area called the medial temporal lobe. There's one on each side of the brain. In the 1950s, Dr. Scoville theorized that these were the general areas involved in H.M.'s epilepsy. But in trying to alleviate H.M.'s seizures, Dr. Scoville removed most of the medial temporal lobes, including much of the hippocampus. This unintentional experiment showed that the hippocampus and medial temporal lobes are where the brain converts short term memory into long term memory.
Dr. MILNER: Do you know what you did yesterday?
H.M.: No, I don't.
Dr. MILNER: How about this morning?
H.M.: I don't even remember that.
Dr. MILNER: Could you tell me what you had for lunch today?
H.M.: I don't know, to tell you the truth.
NEWHOUSE: H.M.'s condition has also helped scientists understand how and where the brain processes different types of memory. Scientists now know that some brain structures are involved in things like phone numbers we keep only for a few seconds, while others deal with the day's appointments. And still others determine which childhood experiences will stay with us until we die. Now, when you can't remember what you did yesterday or had for lunch today, how do you build a life? Unfortunately, there's been no silver bullet for H.M. Holding a job or even having friends, normal things for most of us with working memories, have been beyond him. H.M. is now in his early 80s and living in a Connecticut nursing home. And he is still what doctor's call profoundly amnesic.
Dr. Brenda Milner studied and tested H.M.'s memory for years after his surgery. In the early 1960's she asked Suzanne Corkin, a young American neuroscientist working in her lab, to help. Dr. Corkin, now at MIT in Cambridge, Massachusetts, has interview H.M. many times since then.
Dr. SUZANNE CORKIN (MIT): He is in my PhD thesis and I have followed his progress for the last 43 years. And he still doesn't know who I am.
NEWHOUSE: Despite H.M.'s difficulties with creating new memories, his old ones from his childhood are intact, especially about major world events.
Dr. MILNER: What happened in 1929?
H.M.: The stock market crashed.
Dr. MILNER: It sure did.
NEWHOUSE: H.M.'s clear memory of events before his surgery showed that although the hippocampus was necessary to make new long term memories, it wasn't needed to retrieve old ones. In the mid-1950's the surgeon Dr. Scoville was mortified to discover that his operation had ruined so much of H.M.'s memory, even though it did relieve H.M.'s epilepsy and probably saved his life. Afterward, Dr. Scoville campaigned widely against the procedure. So H.M. is what scientists call an N(ph) of one. He is the only patient whose had this operation. That makes H.M. unique in science today. But that's not the only thing, or even the most important. Again, Dr. Corkin.
Dr. CORKIN: One thing that still fascinates us today is the fact that in real life, in spite of his profound amnesia, he is able to learn a meager amount of semantic information, knowledge about public figures, people who became famous after his operation. The fact that he can remember anything at all is just enough to make the experimenter fall right off her chair.
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Dr. MILNER: How about 1963? Someone was assassinated.
H.M.: He'd been a president.
Dr. MILNER: That's right.
H.M.: And he was assassinated.
Dr. MILNER: What was his name?
H.M.: He had been, like you said, he had been a president.
Dr. MILNER: His initials are JFK.
Dr. MILNER: That's right. What was his first name?
Dr. CORKIN: The other day, I was talking to a nurse in his nursing home, just asking her a few questions about him. And after we talked, she went into his room and she said, Oh, I was just talking to a friend of yours from Boston, Dr. Corkin. And H.M. said, Suzanne?
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Dr. CORKIN: Now, this is really astonishing. Now, he doesn't know who I am. He doesn't know what I do or what my connection is with him. But he has learned to associate my first name and my last name. And that was another surprise for all of us.
NEWHOUSE: Somehow the man who couldn't form new memories had found a way to learn new things. It was a remarkable discovery that radically altered our understanding of how learning and memory work. Before H.M., doctors believed there was a single memory store through which all information moved and was processed, and that it all resided in one spot in the brain, what you might call a single address.
Now, based on what they've learned from H.M., doctors understand memory to be much more dynamic than that. They found that the brain has several different memory systems. We use what's called declarative memory any time we say I remember, and then recall that we had cereal for breakfast, or that the capital of Illinois is Springfield, or that these two notes on the piano are C and D.
(Soundbite of piano)
NEWHOUSE: The other kind of memory is non-declarative. It's what we use to tie our shoes, ride a bike, or how to play the C-scale smoothly without thinking of the individual notes.
Again, Dr. Corkin.
Dr. CORKIN: We believe that when you remember something it's really an active process. You're not tuning into a few cells in your brain where a particular memory is stored. What you're really doing is creating a memory based on information that you have stored in many parts of your brain. Now, since H.M.'s operation, we know that there are multiple long term memory systems in the brain that have different addresses. I think his case inspired clinicians and scientists all over the world to find their H.M. and to make amazing discoveries. So it's sort of an ongoing adventure of the human mind and the human brain.
NEWHOUSE: Despite those discoveries, scientists admit they still don't know how it all works, how memories are culled from different parts of the brain and fused together. What they have learned, though, is that the brain's processes are far more intricate than they ever thought. And much of the credit for that goes to patient H.M. Even though H.M. can't look back over a lifetime of rich memories, his spirit seems untouched by that deficit in his brain.
Dr. CORKIN: What do you think you'll do tomorrow?
H.M.: Whatever is beneficial.
Dr. CORKIN: Good answer. Are you happy?
H.M.: Yes. Well, the way I figure it is, what they find out about me helps them to help other people.
NEWHOUSE: For NPR News, this is Brian Newhouse.
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