Like most famous patients in the history of neuroscience, Henry Molaison—or HM, as he was known among scientists—was famous because his brain was defective. Unlike the other patients, his case was not an accident but the deliberate work of a surgeon.

In 1953, a neurosurgeon suctioned out two slivers from brain Henry’s skull, hoping to cure him of epilepsy. The surgery helped the seizures, if not completely, but it made Henry unable to form any new memories. (Sound familiar? He was also the inspiration for the movie Memento.) It essentially froze him in time, with a strange memory deficit that ends up illuminating more about how memory works than any other single case in history.

The neurosurgeon who unwittingly made this contribution to memory science was Luke Dittrich’s grandfather. Dittrich has now written a remarkable book titled Patient HM. Henry may have appeared in countless books and articles about the brain already, but Dittrich unearths so many troubling new revelations.

His grandfather, William Beecher Scoville, was a brilliant and brash neurosurgeon, as concerned about scientific experimentation as Henry’s well-being when he drilled into Henry’s skull. Henry’s brain wasn’t the only one he experimented on. Dittrich talked to WIRED about his grandfather, the culture of experimentation on mentally ill patients, and the legacy of Henry’s brain, which is now stored in slices at the University of California, Davis.

WIRED: I studied neuroscience in college, and the story of HM was almost impossible to forget. In all that time we talked about HM and memory science though, I remember zero discussion about the ethics of his surgery.

Dittrich: That’s the thing. The textbook story of patient HM is in a lot of ways half the story. He’s clearly somebody who is illuminating in terms of understanding how our memory works, but his case is also illuminating when it comes to questions of research ethics.

I think it’s very poorly understood how much the operation that my grandfather performed on HM—even though it wasn’t strictly a psychosurgery procedure because HM didn’t suffer from any sort of psychiatric disorder—that still grew out of that whole era. It was in some ways this culmination of a whole period human experimentation.

Your grandfather was a big champion of lobotomies, and he performed dozens of these psychosurgeries on asylum patients in attempt to cure them of their psychiatric disorders. We don’t think of epilepsy as a psychiatric problem, so how did HM’s case fit in?

There is a fairly straight line there. The operation he performed on HM he had performed previously on patients in the back wards of asylums. And it wasn’t until Brenda Milner [a memory researcher from McGill] met them years later that anyone was aware of how it affected their memories.

That shocked me. I always thought HM was this singular patient, who had this one drastic surgery that no one would ever dare try again, now that we know the consequences.

One of the most troubling operations my grandfather performed—maybe in some sense even more than the one the performed on Henry—was the one he performed on the patient DC almost a year after he operated on Henry. It was more or less an identical procedure but DC was another psychotic asylum dweller, whom my grandfather didn’t really know anything about. But by that time he knew what the risks were.

That speaks to how vulnerable, really, and lacking in agency and advocacy, a lot of people who were operated on by my grandfather and other psychosurgeons were. There were a lot of chilling things I came across in writing my book. One of letters that will always stand out for me was from John Fulton, head of neurophysiology at Yale–who was some ways the intellectual godfather of the lobotomy. When he was trying to encourage a young researcher to go spend time with my grandfather’s and study some of my grandfather’s lobotomy patients, he wrote the superintendents of the asylum had given my grandfather unlimited access to his “psychiatric material.” I had to read it twice to before I realized “psychiatric material” meant human beings. I think that tragic attitude was pervasive at the time.

William Beecher Scoville Courtesy of Luke Dittrich

When we think of lobotomies now, we usually think of the icepick lobotomies. But your grandfather actually developed his own surgical technique—which involved peeling down the skin of the forehead and drilling into the skull—and he looked down on icepick lobotomies. Why is that?

He hoped the lobotomies he developed would be far, far less blunting and more precise than the icepick transorbital lobotomies that were pioneered by Walter Freeman. He viewed it as messy and crude. One of the evocative scenes I uncovered was in that asylum, Institute of the Living, finding out there there had been that surgical showdown between my grandfather and Freeman. One afternoon, they lobotomized four different women—two by Freeman’s method, two by my grandfather’s method. Then they went off to the university club to have cocktails and discuss.

There was something very chilling to me about the whole scene. I don’t want to engage in too much presentism. They were operating during very desperate times. To be mentally ill at that time was to not have a very promising future period. Many surgeons passionately believed they would be able to find the magic bullet for mental illness by operating. I don’t think that entirely excuses everything that they did, but I do try to bear in mind the context.

The book is titled Patient HM but in some ways it’s really about your family— your grandfather’s career as surgeon and his wife’s—your grandmother’s—mental illness, which your family never really discussed.

It became increasingly clear in this odd way that my grandmother’s mental illness inspired my grandfather to be this passionate lobotomist, to pursue psychosurgery with a fervor and an energy that he probably wouldn't have otherwise. That passion for psychosurgery ultimately lead to that surgery that he performed on HM. There were these weird connections. Somehow my grandmother’s mental illness was relevant to memory science.

It was difficult. I was suddenly doing investigative journalism on my own family and digging up and dragging skeletons out of closets that were going to be hurtful to people I care about. It was an odd position to be in.

Are your parents still alive? Have they read the book?

My mom and dad are alive. I remember the first I told her I got the book deal—and my mom is the most loving supportive person, my biggest fan—the words out of her mouth were, “Oh no.” I think she realized even then it was going to be difficult. It was going to shine a spotlight on aspects of the family that she was uncomfortable with. I discovered a lot of things she had no idea about—like my grandfather may have performed a lobotomy on his own wife.

William Beecher Scoville Courtesy of Luke Dittrich

That’s one of the most chilling moments in the book.

Again, it’s possible. It’s not confirmed. That’s the thing that’s been most difficult personally to grapple with—certainly for my mom much more than me because I had a distance from my grandparents. She doesn’t. They’re her parents. I can say that it reshapes my memories of them together. Their stories shift underfoot. I’m still processing the possibility, and I think my mother is as well.

In a coincidence that might have seemed implausible in a novel, Sue Corkin, the neuroscientist who becomes famous for studying HM, was your mother’s childhood best friend and grew up across the street from your grandfather’s house. She did not want to participate in the book at all. Did that affect your mother’s relationship with her?

It was an awkward, strange experience. My first stab at reporting on HM was shut down after I approached Sue and she sent me that confidentiality contract that would give her control over what I wrote, which I couldn’t sign for obvious reasons.

In the beginning, I thought my personal relationship with Sue Corkin might have helped, but it did not. I do think it was strain on my mom’s relationship with her. But they perhaps were less close in the last few years of Sue’s life, which is sad because Sue passed away. It was difficult for my mom because they were very close and very old friends. I think they went to school together from third grade to senior year of college. It’s a long friendship, and they knew each years beyond that and were quite close. I think my working on the book did drive a wedge between them, unfortunately.

It seemed like Sue Corkins, who had written her own book about HM, was very protective of his legacy, and by extension, hers.

Howard Eichenbaum—a great Boston University neuroscientist—who had a chance to do a little bit work with HM but does most of his work with rats, told me he “can always order some more rats.” But there is only one HM. His brain becomes then this kind of scientific golden goose, so you don’t want to lose that access.

One of shocking moments during my reporting was when Sue Corkin told me she had shredded data about HM. It was unclear how much data was left and what was going to be done with it. It struck me baffling and heartbreaking. I would hope this might spur the researchers who do have their own smaller collection of HM to pool it. I think there is something so terrible of his data not being archived somewhere. Whatever’s left should be preserved.

Henry always seems like a bit of a cipher—in part because of his own memory deficit and in part because he is unable to tell his own story. Our memories are our identity. What’s it like writing a book around someone who is so difficult to describe?

He’s frozen in time, so he inevitably as a character becomes more of a cipher. But he was at the center of these very vivid characters and brilliant people in orbit around him for a half century or more. I did my best to bring him to life through transcripts. Some of my favorite parts of the book are the extended transcripts of Henry talking. There’s something mesmerizing about his manner of speaking. I would have loved to have met him.