For this brain surgeon, the operating room is 'the ultimate in mindful meditation'

Transcript

TERRY GROSS, HOST:

This is FRESH AIR. I'm Terry Gross. As a neurosurgeon, my guest's tools include special saws and drills to open a patient's skull, but he also uses very high-tech imaging as well as laser and computer technology that have transformed the field and can offer an alternative to opening the skull. Dr. Theodore Schwartz has spent nearly 30 years operating on people with neurological illnesses.

A lot has changed in that time. He helped develop minimally invasive surgical techniques. In his new book, "Gray Matters: A Biography Of Brain Surgery," he writes about the past, present, and future of brain surgery. He says brain surgery has also contributed to our understanding of the human mind, the existence of the self, and our illusions about being in control of our actions. Dr. Schwartz is an attending neurological surgeon and professor of neurological surgery at Weill Cornell Medicine. If this kind of talk about brain surgery makes you squeamish, this interview might not be for you.

Dr. Schwartz, welcome to FRESH AIR. The book is really fascinating. I just want to start by asking, you know, you write that being a neurosurgeon is a dirty occupation - really dirty. Like a mechanic whose coveralls get covered in grease and grime, we often leave the OR covered in blood, Betadine and bits of brain. Bits of brain - what's in that brain matter? Do your scrubs have bits of your patient's memories? Are those the names of favorite movies, memories of a first kiss, the ability to coordinate the act of walking that are on your scrubs?

THEODORE SCHWARTZ: Well, you know, Terry, everything that we are as human beings is in our brain. So, in fact, the answer to that is yes. You know, it's all there. It's all in the gray matter and the white matter that neurosurgeons operate on day in and day out. We are operating on the very essence of what makes us who we are. And that's really what makes the job so fascinating.

GROSS: How does it splatter on your scrubs?

SCHWARTZ: Well, there was a bit of dramatic license there, perhaps, but from time to time, there are pieces of brain that can be sucked out and removed? Sometimes we'll take pieces of brain out that are diseased or abnormal or that are traumatized, and those pieces of brain can sometimes end up on the floor accidentally or on your shoes.

GROSS: Right. It's always amazed me that among the main tools used in brain surgery are a drill and a saw. Can you explain how they're used?

SCHWARTZ: Well, you know, we think of brain surgery as something that's very fine and delicate, and a lot of it is very fine and delicate, but the brain is housed in the skull, and the skull is very, very strong, and that's what protects our brains from injury. And so part of what we have to do as brain surgeons is first get through the skull. And that work is often very physical and involves drills and saws in order to get through the bone. We obviously do it very carefully because the trick is to get through the bone and not damage the underlying contents. But we have to use power tools, and that's how we start out every operation, with saws whirling and buzzing and making noise and sort of bone smoke going in the air before we transition to the careful, delicate microsurgery that we do after that.

GROSS: Can you compare the original versions of the drills and saws used in brain surgery with what you used today?

SCHWARTZ: Yeah. When I started training, we used a tool called the Hudson Brace, which was used for years in neurosurgery. And it was basically a handheld drill where you would push on the back of it and you would rotate your other hand around in a circle in order to get the drill bit to move?

And it was a bit terrifying because you would have to push pretty hard to have it engage with the skull. And there was always that fear that if you pushed too hard or if you drilled too long, it would plunge into the brain. And you got very skilled over time figuring out when exactly to stop. But now we have power tools - they can be electrical tools, they can be air-driven - that go very, very, you know, fast and rotate at 10,000 RPM, that allow us to carefully, essentially paint away the bone while we go, and that's one of the techniques that we use that makes what we do so much more quick and specific.

GROSS: You did an operation that at the time and maybe still was rarely done because it was such a new technique and also very risky. It was on a patient who had a benign tumor that had to be removed from deep in the patient's brain. And you write the tumor was surrounded by critical nerves and blood vessels, and if they were damaged either by the tumor or the surgery, it could lead to blindness or paralysis. So what was the dominant procedure that was used at the time to remove a tumor in this location?

SCHWARTZ: Traditional neurosurgery involves opening up the side of the skull. So you're drilling into the side of the head, you're taking down the muscle for chewing, which is in the temple and going around the brain to get underneath the brain to the base of the brain. And I was lucky enough to start my career at a moment in time where the concept of minimally invasive brain surgery really came to fruition.

And so we are now doing surgeries that go through the nostrils, for example, without making any incisions whatsoever, using long endoscopes, like telescopes that we put up through the nose. And we can do surgeries now by making a small incision in the eyelid or the eyebrow and working our way around the orbit in order to get to the skull base. And that allows us to get to these very delicate parts of the brain much more quickly and without disrupting as much of the patient's anatomy, so that they heal much faster, and it has really improved what we do.

GROSS: When was the first time you did this surgery?

SCHWARTZ: Well, the one through the nose - I'll never forget -was December 2003. It's funny you asked that, but I know that date exactly. And it was just because it was so much earlier than many other people did it. And I remember it because I was so nervous about doing it. The first time you do an operation that you never trained to do. Maybe you've watched someone else do it once or twice. You may have tried it on a cadaver, which we do from time to time. But it's never the same as when you do it yourself. And obviously, you're doing it on another human being, and you realize the gravity and the importance and the significance of the fact that this other person's life is in your hands, and you're trying something on them that you think will be better for sure. But you're not sure yourself of your own ability because you haven't done it 100 times.

And that's really terrifying, and it's something that, you know, we have to deal with as neurosurgeons, not just when we try something new, but essentially every time we do an operation, right? We're taking on that enormous responsibility of another human being's life and in a sense, having that arrogant feeling that, you know, I know what I'm doing. I know this is going to go great. I know I'm going to help them and hoping for the best and applying your skills to that procedure.

GROSS: So what was the outcome of this surgery?

SCHWARTZ: The surgeries I describe in the book, the first ones I did did extremely well, and that's important - right? - because that helps me know that I'm on the right track. And as a surgeon, you know, your confidence waxes and wanes based on your results, particularly when you're doing risky surgery like brain surgery. And while the majority of our surgeries go extremely well, occasionally, they don't. And when that happens, it weighs on you tremendously. And it affects how you think about all the subsequent cases that you're going to do that are similar because you never forget those cases that didn't go quite the way you wanted them to go. So luckily, the cases I did that were the new minimally invasive ones went extremely well and that allowed me to continue to do them and get better and better at doing them.

GROSS: You not only write about the complicated surgical techniques required for brain surgery. You write about some of the practical problems to, like, standing for six hours and being really still and really steady with steady hands while you perform the surgery. Six hours or more without having to use the bathroom, without being able to use the bathroom - that sounds - that alone sounds stressful.

SCHWARTZ: Yeah. I remember when I first was considering becoming a brain surgeon and I watched my first couple of operations, I would stand in the operating room when I was in medical school and I would have horrible back pain because I wasn't used to that. I wasn't used to using those muscles, and it was very uncomfortable. I wasn't sure if I would be successful at it. I would look at my hand holding a newspaper, reading the newspaper and I'd see a little tremor when the edge of the paper would shake and I'd be afraid that, you know, what if this is something that's going to be a problem for me?

But what you learn is that the more you do it and the more you train in doing it, you develop certain habits and techniques and muscles and abilities to sit there and focus for hour after hour after hour, doing what you need to do, and you essentially get into a flow state where you're not even aware of the passage of time because you're so intensely focused on what you're doing. It's sort of the ultimate in mindful meditation is how I think of a lot of the long brain surgeries I do. You're very, very relaxed and very, very focused, and the external world does not exist for that period of time, and the same is true of your bladder. Your bladder doesn't exist, really. And then at the end of the operation, you kind of realize, oh, my goodness, I have to go to the bathroom. I'm tired. My neck hurts. My back hurts. But for that long duration of the surgery, none of that exists.

GROSS: Let me reintroduce you. If you're just joining us, my guest is Dr. Theodore Schwartz. He's a neurosurgeon and author of the new book "Gray Matters: A Biography Of Brain Surgery." We'll be right back. This is FRESH AIR.

(SOUNDBITE OF THE ACORN'S "LOW GRAVITY")

GROSS: This is FRESH AIR. Let's get back to my interview with Dr. Theodore Schwartz. He's a neurosurgeon at Weill Cornell Medicine and author of the new book, "Gray Matters: A Biography Of Brain Surgery."

So in the surgery we discussed, you avoided having to remove part of the skull by using a relatively new technique. But you've done a lot of surgeries where you did have to remove part of the skull. So one of the reasons why you have to do that is just to get access to the part where the tumor is or where the problem is. But another reason is if there's a lot of pressure in the brain and you need to relieve the swelling so that the brain isn't pressing against the skull. What causes that kind of swelling? Is it a traumatic brain injury?

SCHWARTZ: One of the most common surgeries that neurosurgeons do is head trauma, and head traumas are very common. But these are neurosurgical emergencies. Anyone who has hit their head severely enough, they will have swelling in their brain. And we can now save these people's lives just by opening up the skull, because as the brain swells, if it has nowhere to go, that's when the pressure goes up. So neurosurgeons can go in very quickly and remove part of the skull and let that pressure out, and then put the skull back maybe two, three weeks later, or maybe even a few months later when the swelling has gone down. And we can save lots and lots of lives that way.

GROSS: I'm trying to imagine what it's like to have part of your skull absent for a couple of weeks. What do you do in place of the skull in that spot?

SCHWARTZ: Well, while the skull is off, the patients often have to wear a helmet because you do want to protect the brain from traumatic injury. But if you're not - if you're just lying in bed, for example, you don't have to wear a helmet. It looks a little odd to not have part of your skull. And so they often want to wear a helmet or they wear a hat or a scarf around their head. And then, of course, we try to put it back as soon as we can. Sometimes having an absent skull actually can affect the brain's function, so that's another reason why we do like to put it back as soon as we possibly can.

GROSS: Is the brain actually exposed?

SCHWARTZ: It's not. It's still covered with skin, right?

GROSS: Oh, OK.

SCHWARTZ: It's still close to the skin, yeah.

GROSS: The dura?

SCHWARTZ: The dura is the covering of the brain, but I just mean the scalp. The scalp is closed over it, and even the hair can grow back even if you're missing a piece of skull.

GROSS: Wow (laughter). Did you have that reaction of wow when you started learning neurosurgery?

SCHWARTZ: You know, I did have a reaction of awe. I'll never forget when I first went into a neurosurgical operating room as a medical student, and most medical students aren't really sure what they're going to do with their careers and their lives. And that's why we do these rotations where you go from specialty to specialty to specialty and watch each of the different surgeons or medical doctors do what they do. And I'll never forget walking into a neurosurgical operating room and seeing a surgeon who was in a chair - it's a special chair that can hold the arms up - and working under a microscope. They looked like astronauts in the cockpit of a spaceship. And I was a kid who always wanted to be an astronaut or astronomer. And they were traveling into the microcosm of the brain instead of traveling, you know, into the macrocosm of another planet and going some place where few people go.

When I first saw that, it was nothing but awe and excitement and the fact that they were doing it to help another human being and going into the brain and the mind - my father was a Freudian psychoanalyst. I talk about that and my interest in language in the brain and memory. And the fact that all of that was open and exposed to the neurosurgeon for that period of time, to me was just an incredible moment.

GROSS: So when you remove part of the skull and you're not going to reinstate it for two or three weeks, how do you store the bones? And how do you reinstate it? Do you glue them back in?

SCHWARTZ: There are a few options we have. You can imagine if you are in a battle zone, and you're at a forward hospital, and you're removing part of the skull, which we call a hemicraniectomy to save a wounded soldier's life. What you need to do is put that bone somewhere. And so we actually create a small pouch in the abdomen. You can make an incision in the belly, and create a pouch in there, almost like a kangaroo pouch, and store the skull in the abdomen, close it up, and then the soldier would get transported to another hospital. And at some later date, they could just essentially unzip the stomach, take the skull out and reimplant it. And if you're in a hospital, we have bone banks where we can store skulls sterilely.

But what's most commonly done now, believe it or not, is we will access a computer and 3D print a skull implant, a prosthetic, if you will, and put that in that is custom designed to fit the defect in the skull. And there are companies that make that, and just by doing a cat scan, they can reconstruct the defect. And then you just reimplant it when the time comes.

GROSS: And how do you - do you glue it back in?

SCHWARTZ: Yeah, so, we put bone back in using titanium screws and plates. There are little tiny screws and little tiny metal plates that we do and you put four or five of them around the circumference of the skull, and that holds it in place and their titanium. If the patient gets an MRI scan, there's no interference with the magnet of the MRI scan. Then eventually it fibroses in and will really heal beautifully.

GROSS: You write about a fairly new field in neurosurgery called stereotactic radiosurgery. You describe it as delivering energy deep into the brain without opening up the skull. What does that mean?

SCHWARTZ: Well, the stereotactic radiosurgery is actually not that new. Believe it or not, it's been around for some 40, 50 years. And one of the reasons I wrote the book was really to introduce people into all the things that we do. And one of the goals of neurosurgery ideally is to put ourselves out of business in a way. So we want to be able to influence the brain physically without having to open the skull, and one way to do that is with radiation because radiation can pass through the skull.

And in order to treat a part of the brain safely with radiation - because you can't just bathe the whole brain in large doses of radiation - we have to focus the radiation. And so, what stereotactic radiosurgery does, it essentially puts the patient into a helmet that contains several hundred emitters of radiation that all meet in one small point. And the area where they meet has enough energy to do the work you want to do to destroy tissue, to destroy a tumor. But each individual beam does not damage the brain.

The new technique that I talk about that uses a similar concept is called focused ultrasound. So instead of using radiation, you can do the same thing with ultrasound. And there's a new device called high-frequency focused ultrasound that has literally over 1,000 emitters of ultrasonic waves that are set up in a helmet. Patient goes in, and all of those ultrasonic beams focus at a small point that allow us to treat, for example, movement disorders. So someone can come in with a bad tremor and you put them in this device, and you make a lesion in a small area of the brain and their tremor will literally go away. It's remarkable. And you don't even have to open up their skull.

GROSS: That is definitely remarkable. Can ultrasound have the same function on a malignant tumor as radiation?

SCHWARTZ: It can destroy malignant tumors. The issue with ultrasound and malignant tumors, first of all, is that a malignant tumor is not always in one small place. Malignant tumors will invade into the brain, and that's one of the reasons we have such a hard time treating them. The most commonly known malignant brain tumor is called a glioblastoma multiforme. And it's a dreaded disease because we still have a rough time treating it successfully. And one of the problems is that they are microscopic cells that invade into the brain. And so just creating a lesion or ablating one small area of the brain is just not enough to impact a malignant brain tumor like that. So unfortunately, that use for focused ultrasound doesn't have a great future.

But it turns out that they discovered that focused ultrasound can also do something else remarkable, which is that it has the ability to open up the blood-brain barrier. So the brain is protected from the body by a filtration system that doesn't allow toxins and chemicals in your bloodstream to get into the brain, it protects the brain. But, unfortunately, it also doesn't allow chemotherapies to get into the brain. And a lot of treatments that work for cancers of the body don't work for cancers of the brain just because they can't get in there.

And if you use focused ultrasound and inject these little microbubbles into patients' blood vessels, you can open up the blood-brain barrier and then deliver a therapy through a vein that will go into the brain and into the malignant tumor. And it gives us a new way to treat them. And that's just really cutting-edge stuff. We're still discovering how well that's going to work going forward, but there are lots of clinical trials using it ongoing today.

GROSS: It must be pretty exciting for you to be witnessing and performing so many new neurosurgical techniques.

SCHWARTZ: Yeah, you know, one of the things I love is that some days, or weeks, I'll come in and I'll be training a fellow. And we'll go through six, seven, eight operations, and I'll tell them, you know, all these operations that we just did together, I didn't learn how to do any of these in my training 25 years ago. They're all completely new operations. And that's a wonderful thing about a field like brain surgery is that we're constantly applying new technology and the field is changing. And you have to stay up to date, but it also keeps you active. It keeps you thinking. You're constantly working with engineers and people in other fields to figure out, you know, what's the latest technology going on in, you know, oncology and orthopedics and OB-GYN that we can apply to neurosurgery to try to make what we do better?

And that's one of the things I try to emphasize in the book is just, you know, how far we've come. I mean, neurosurgery did not exist as a field before 1905, right? So it's only 120 years old, the whole field. And it went from a mortality rate of 50% when Harvey Cushing started operating, who was the founding forefather of neurosurgery, to about 8% when he was done. And now it's well below 1%. We're using computers and, you know, MRI scanners. And we're implanting computer chips in the brain. And it's just come such a long way, and I really wanted to have the opportunity to tell that story because it's a remarkable story of human progress.

GROSS: Well, let's take another break here. If you're just joining us, my guest is Dr. Theodore Schwartz, an attending neurological surgeon at Weill Cornell Medicine and author of the new book "Gray Matters: A Biography Of Brain Surgery." We'll talk more after we take a short break. I'm Terry Gross, and this is FRESH AIR.

(SOUNDBITE OF BILL EVANS AND JIM HALL'S "I'VE GOT YOU UNDER MY SKIN")

GROSS: This is FRESH AIR. I'm Terry Gross. Let's get back to my interview with Dr. Theodore Schwartz, author of the new book "Gray Matters: A Biography Of Brain Surgery." It's about the past, present, and future of the field and about his own experiences. He's been operating on people with neurological illnesses for nearly 30 years, and he's helped develop minimally invasive surgical techniques. Doctor Schwartz is an attending neurological surgeon and professor of neurological surgery at Weill Cornell Medicine.

Your father was a psychoanalyst in Manhattan. So, you know, you deal with the brain and have learned a lot about how the brain affects behavior and our sense of self. Your father was a Freudian analyst, and he tried to ask the same questions through, you know, verbally reviewing somebody's life and their past and how it's influenced their present and their anxieties and fears and so on. Your father had an operation for a fatty tumor in his stomach, and he woke up the next morning in the hospital and realized he'd lost his ability to speak. He had a condition called Broca's aphasia. How did you find out what was going on, that he could think, but he couldn't use words to speak what he was thinking?

SCHWARTZ: I'll never forget the moment. I was asleep, and the phone rang, and I picked up the phone. And I heard a voice on the other end of the line that was halting, garbled, trying to express itself, but not succeeding in doing so. And I knew it was my father, but I knew there was something wrong. And I - at this point, I think it was maybe a sixth or seventh year in my neurosurgical training. So I knew that something was going wrong with his brain, and I literally hung up the phone and ran over to the hospital. And he was being taken care of at a different hospital from where I worked. And I ran over to his bedside, and it was clear to me that he had an aphasia. I mean, I'm a neurosurgeon. I did neurology rotation. I knew that it was a Broca's aphasia.

GROSS: Explain what that is.

SCHWARTZ: So there are different types of aphasias. And aphasia means trouble with your speech, and there are some classic ones, and the Broca's one means that you have trouble producing speech. There's another one called Wernicke's aphasia where you have trouble understanding speech, and he was really having trouble producing speech. And I knew that he needed a CAT scan immediately to figure out what was going on with him, and it was a Saturday, and there was nobody around. And I told the nurses that he needed a CAT scan right away. And they said, yeah, they'd consulted neurology, but, you know, the neurologist hasn't come by yet. So I said give me the neurologist's phone number, and I called him on the phone. And I said, my dad needs a CAT scan right now. You have to order it. And so he put the order in for the CAT scan.

And the next step in a hospital is you wait for someone from transport to transport the patient to the CAT scanner. And there was no way I was waiting for transport. So I basically packed my dad up in his bed and started pushing him down the hallway and asked the nurses, you know, where's CAT scan? And they said fifth floor and - but they started yelling at me. Like, you can't do that. You can't just take a patient, and I said, you know, I'm going to the fifth floor. So I showed up there, and I said, look, this is Lester Schwartz. He's got a CAT scan order. He needs a CAT scan. Let's go, and helped move him onto the gurney, the stretcher for the CT, and then went into the control room and watched as the images started to come up.

And it was just this profound moment of seeing my father's brain appear before me. And fearing I was going to see a problem. And sure enough, you know, there it was this sort of dark spot, which I know to be a stroke. And he had had a horrible stroke that took away his ability to speak as a result of the surgery he had, and unfortunately passed away a few weeks later, but it was just a devastating experience for me. And as much as I know about the brain, you know, I knew too much about what was going on. I also knew that at that moment in time, there was nothing we could do for him.

GROSS: So your father survived for a few weeks. Could you read anything from his face about what he was experiencing? Because again, he was able to think, but he wasn't able to speak in a way that would express what he was thinking. And that must have been just so frustrating and confusing, he didn't know what he had, or did you tell him what he had? Would he have understood if you told him?

SCHWARTZ: He did understand. A Broca's aphasia only affects the production of speech, not the understanding. So he did understand, and he just had this look of profound helplessness and hopelessness on his face. That was very difficult. The other thing that was very hard for me was that I was trying to be optimistic for him when he was sick, and, you know, I knew he had been found to have a lung cancer. That was the problem. He was discovered to have an incidental lung cancer that grew and that was making his blood clot more than it should. And that's why he had the stroke. And he ultimately died of the lung cancer.

And it hadn't really been treated, and we couldn't treat it because of the hypercoagulable state that he was in where his blood was clotting too much. So he was between a rock and a hard place. And I just tried to maintain, you know, an upbeat optimistic attitude for him, to say, hey, we're going to get through this. We're going to do this. You know, you're going to get better. We're going to find the best doctors - all the things you do for a loved one who's struggling with a health ailment. The problem with that, of course, is that you never have that heart-to-heart. You never sit down and sort of say, hey, this is it, and I want to tell you what you meant to me. I never had that. Excuse me. I never had that opportunity with my dad. And that, you know, also weighs on me very much because I was trying to be the, you know, tough professional - I'm going to make this better.

GROSS: Did that change your mind about how honest to be with someone you're close to who is near death?

SCHWARTZ: Yes. You know, interestingly, you mentioned it - I also write about my mother, and I talk about my mother. And one of the things I did with my mom that meant the world to me was when she turned 90, we had a big party for her. And I basically read her her eulogy to her face. And I think I'm so grateful that I did that, that I had the opportunity to tell her what she meant to me while she was still alive and could understand it.

GROSS: Did she edit it? Did she make any suggestions? Yes?

SCHWARTZ: No, she did not, luckily. She wasn't that kind of mom, honestly.

GROSS: Let me reintroduce you again. If you're just joining us, my guest is Dr. Theodore Schwartz. He's a neurosurgeon, and author of the new book, "Gray Matters: A Biography Of Brain Surgery." We'll be right back. This is FRESH AIR.

(SOUNDBITE OF TODD SICKAFOOSE'S "TINY RESISTORS")

GROSS: This is FRESH AIR. Let's get back to my interview with Dr. Theodore Schwartz. He's a neurosurgeon at Weill Cornell Medicine and author of the new book "Gray Matters: A Biography Of Brain Surgery."

So, you know, we're talking about how honest to be with your parents, with people who you love, who you've known all your life. What about that kind of honesty or perhaps false optimism with patients?

SCHWARTZ: I often see patients who are diagnosed with malignant brain tumors. And I see them very early in their treatment cycle, really when they're first getting the diagnosis. And when they come to me, they're not fully aware of what they have. They know that there's something in their brain. They may have had a seizure. They may have a little bit of weakness in their arm. They may have a little trouble with their vision. They've been told that the MRI showed something and they need to see a neurosurgeon. But they don't really know what it is, and I will see them in the office, and I'll look at the MRI scan, and I'll know right away what they have, you know? And I can, unfortunately, somewhat predict their future at that moment in a way that they and their loved ones just have no concept of.

But at that moment in time, I don't think the right thing to do is to hit someone in the head, if you will, with that kind of a diagnosis because first of all, you're not 100% sure. And you want to put them in the right mindset for their upcoming surgery because the first step in taking care of these tumors is to take it out, take out as much as you possibly can. You can't cure them with surgery, you know you can't cure them. But you know that if you can get out a lot of it, they will do much better than if you can't take out very much. And you want them positive and optimistic going into the surgery.

So you always give them the notion that, hey, you know, this could be a malignant brain tumor. I'm not sure. Let's take it out. Let's figure out what it is. You know, you want to put that on the radar so it's not a shock and a surprise to them. And then after the surgery, once you know, you've gotten a biopsy, then I believe in being very honest. And I do talk to them about what their diagnosis is, but you also take cues from the patient. Sometimes you get a sense that they don't want to know that much. Sometimes they ask a lot of questions, and then, of course, you answer them honestly and openly.

Sometimes they ask very few questions. And then, you know, you get a sense that they may want to leave things vague. One of the harder things is when you have a family member who will come to you and say, you know, don't tell them what they have. And you can't really do that - right? - in my opinion because if the patient asks you, you're representing the patient, and you have to tell the patient. If the patient does not ask you, that's different because then you may get a sense that maybe this person can't handle this at this moment. Maybe we have to wait.

And then you also know that they're going to have another office visit with a neuro-oncologist about a week later and they're going to go over everything again. And so you just want to prepare them for that and ease them into the diagnosis slowly but properly so that they understand what they're facing, because often they have to make certain decisions about their life going forwards and knowing what their future is is extremely important.

GROSS: When your parents were dying and you knew they were, did you cancel surgeries you were scheduled to perform? Like, how did you decide what would take the priority, spending as much time as possible with your dying parents or attending to your patients? It strikes me as a very difficult choice.

SCHWARTZ: That's an interesting question. You know, when my father was sick, I was still a resident in neurosurgery. And so I did have certain responsibilities that I couldn't just shirk. But there always are other residents who can cover for you. And they, you know, can take on that burden, and you're not so essential in your being there. My mother passed away very quickly. And she actually - we were away on vacation. And, you know, the time she passed away, she choked on something at a assisted living where she was. So it didn't require me to take a lot of time off.

But the truth is I can very easily reschedule surgeries if I have to. I don't like to do them if they're urgent. You know, the surgeries often take priority. But it is a elective OR schedule for the most part and if I need to take a day off here and there. But would I be someone who would take weeks off to be at the bedside of a loved one? I probably would not, honestly, because I chose a career that doesn't allow me to do that. And I think I made that decision knowing that there were sacrifices I had to make. And I think the people in my life know that as well and they understand that.

GROSS: I do think it's interesting that you're a neurosurgeon who has learned a lot about behavior by studying and operating on the brain, and your father was a psychoanalyst who learned about behavior and had thoughts about behavior by examining his patients' past and talking with them about it. I'm interested in some of the things you've learned about behavior from operating on brains, because as you point out in the book, like, there are parts of the brain where if you touch it, that part of the brain, it can change a person's like, tastes, their behavior. You can change somebody's personality. So can you talk about that a little bit?

SCHWARTZ: Neurosurgeons have a unique window into the human condition. And there have been many neurosurgeons over the years - and I, to some extent, with my patients have seen things that affect our view of what the brain is and what the mind is and what the connection between the brain and the mind is. For example, we can split the brain in half as a treatment for epilepsy. And that's a surgery I've done.

And you would imagine if you split the brain in half and create two independent brains that don't communicate with each other, that it might affect someone's sense of self. They might wake up and say, well, now there's two of me or I'm being pulled in two different directions. But that's not, in fact, what happens. They wake up and they as a self, as a unified individual, feel no different than they did before. You can do careful testing on them, and you can show that you can introduce ideas and thoughts into one hemisphere of the brain that the other hemisphere of the brain won't be aware of and put things in their mind that they won't be aware of, but they'll react to.

And then what studies have shown is that a person will behave in a particular way based on something that's unconsciously being processed in their mind. And if you ask them, why did you do that; why did you behave that way, they will make up a story to make sense of it based on something else that's going on around them. And it makes you realize that often a lot of our behaviors are done in an unconscious way, and we make up a story afterwards to try to make sense of why we did what we did. You can stimulate the brain and make someone turn their head from the right to the left. And if you say, well, why did you turn your head, they say, well, I was just looking for my shoes. I lost my pencil or something. And they will create agency where no agency exists.

And so over time, you realize that there - the idea of the self and the idea of a unified self and the idea of making certain decisions that we think we're in charge of probably doesn't happen in the way that you think it does. And there's a lot going on underneath the surface, which my father would agree with that - you know, that was called the unconscious years ago that influences our behavior.

And it even - it gets even spookier, Terry, because there have been experiments done during neurosurgery where you can put an electrode in someone's brain that records neurons that are active. And that neuron that may be active when you move your finger or when you say a word will become active about a second before you've even made the conscious decision to move your finger or to say that word. Your brain is already preparing for that behavior before you're even aware that you want to do that thing. And it creates this spooky concept that you're not in charge of what you're doing.

GROSS: Do you feel that your identity exists solely as a function of your brain and parts of your brain that you don't really have control over?

SCHWARTZ: I think everything that a human being experiences in the external world and the internal world is all your brain. I think that's all that there is. I don't think there's some mystical second substance called mind. And I think that we think the mind and the brain are different things because it's built into our language. It's how we talk about the mental world around us. We were raised speaking a language with words that refer to things that may not exist in the real world, and one of those things is mind.

I think there is something it's like to be a brain walking around in a human body. And why we experience that, why there is something it's like to be us I don't think anyone knows. But I do not think we have as much agency over what we do, if any. And I think the brain is processing information below our radar unconsciously, subconsciously, whatever you want to call it and creating behaviors, and we are just along for the ride to some extent.

GROSS: Well, let's take another break. If you're just joining us, my guest is doctor Theodore Schwartz. He's a neurosurgeon and author of the new book "Gray Matters: A Biography Of Brain Surgery." We'll be right back. This is FRESH AIR.

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GROSS: This is FRESH AIR. Let's get back to my interview with doctor Theodore Schwartz. He's a neurosurgeon at Weill Cornell Medicine and author of the new book "Gray Matters: A Biography Of Brain Surgery."

One of the new innovations that's both exciting and strange and just hard for me to fathom is the brain computer interface. So would you describe what that is?

SCHWARTZ: A brain computer interface is a electrical device that's implanted on the brain that can record or stimulate the brain's neurons that communicates with a computer and allows a person to control a computer using merely their thoughts. That's sort of an overview of what it is, but we can put electrodes in a variety of different ways onto different parts of the brain to do different things.

The most common thing we do is we put it on a part of the brain, let's say, that moves the hand or the arm in a patient who's paralyzed and has a wheelchair and can't move. And the neurons that move the hand or the arm move in a very reproducible, discrete way every time you move the hand in a particular way. And if you put the electrodes on to record the brain waves and you know what the patient's trying to do - so, for example, every time they move their thumb, there's a particular wave. And every time they move their forefinger, there's a different wave. Every time they lift their arm, there's a different brain wave.

And a computer can use what's called machine learning, meaning that it's done again and again and again, to link the brain wave with the activity. And then you can basically put electrodes on the surface of the brain and have someone think about moving a robotic arm or think about driving a car or think about flying a plane eventually. And all of those things can happen 'cause the computer can control those different robotic devices. But in its simplest form right now, it allows a patient to control a cursor on a screen and type onto a computer or even speak the words that they want to say if they can't speak and get that information out of their brain onto a computer so they can now communicate with other people and they can interact with the rest of the world.

GROSS: I just really find that so exciting and unfathomable at the same time. But I don't understand. Like, if your arm is paralyzed, how can the computer learn what your brain waves are when you move the arm so that you can just think about moving your arm and the computer can help you move your arm?

SCHWARTZ: So imagine I have an electrode on the part of the brain that moves the hand. That part of your body still works, right? The brain still works. It's just that the arm is paralyzed. So maybe there's a spinal cord injury. So the information is not getting out of the brain, and it's not making its way down to the arm. But the brain can still do the activity, can still think about moving the arm, and even the neurons that move the arm can still fire. They just can't affect what they're trying to do. If I tell that patient with the electrodes on the brain, hey, move your thumb up. Move your thumb up again. Move your thumb up again. They're imagining moving their thumb up. They're not really moving their thumb up, but their brain is firing the neurons as if they were moving their thumb up, but because they have a spinal cord injury, they just can't move their arm.

If you can have them reproduce that behavior again and again and again, the computer will learn what is the brain wave that is linked to moving the thumb up and what's the brain wave that's linked to moving the forefinger forward? You do that over and over again and it will allow that person to control a cursor or control a robotic arm.

GROSS: Do you think that there will come a time when brain-computer interfaces will be used for non-medical purposes so that you can interface with whatever device you want to and have it perform the actions you want it to perform without manually doing it, without telling it what to do with your voice?

SCHWARTZ: I do. I think we're almost there in terms of our technology now. We have the ability to take commands out of the brain, to take language out of the brain, to take handwriting out of the brain. The issue is that there's a safety part to this. So right now, any brain-computer interface that has that level of resolution requires a brain surgery. So you have to open up the skull, you have to implant the electrodes in the brain, and there's risk of damaging the brain and injury, which is why currently we only do it in people who are quadriplegic, who don't have the use of that part of their brain. It's not serving a function anymore for them.

And we have to get to a point where we can get the information out of the brain safely without risking injuring the brain, and we don't yet have a technology that does that. It doesn't mean that that's not coming. And once that technology is developed, I think it's only a matter of time before we all have implanted brain-computer interfaces that will help us speak to each other telepathically and, you know, move things around in the environment just using the power of our mind.

GROSS: Do you worry about your brain a lot? You know, in other words, like if you've known anybody who had Alzheimer's or a similar form of dementia, do you worry about, will that ever happen to me? What will it be like? - because it just really hurts to see somebody in that condition. And I'm sure you've seen your share of people with brain disorders. Do you worry about your brain a lot?

SCHWARTZ: I don't. I really compartmentalize my professional life from my personal life. I try to live my life every day as if I'm not going to get sick that day. You know, I'm not worried about what's going to happen to me. I try to sort of be very free in what I do. Every once in a while, I'll have trouble accessing a word - particularly, I call it OR aphasia. When I'm in the operating room, sometimes, and it's a stressful situation, and I'll ask for a tool, I'll forget the name of the tool. And obviously, I know what the name is. But I'll blank it out and sometimes I'll think, oh, my goodness. Why am I forgetting the name of that? What's going on with my brain?

But in general, it doesn't seem to be progressing in any significant way. So, you know, I think that the most important thing you can do to keep a healthy brain is to exercise as much as you can, and I do try to exercise a lot. I try to eat a healthy diet, and I try to get a good night's sleep. Besides that, I don't know that we really know what we can do to keep our brains healthy. So that's the recommendation I would give.

GROSS: Dr. Schwartz, this has been a fascinating talk. Thank you so much for being with us on FRESH AIR.

SCHWARTZ: Terry, thank you for having me.

GROSS: Dr. Theodore Schwartz is the author of the new book "Gray Matters: A Biography Of Brain Surgery." He's an attending neurological surgeon and a professor of neurological surgery at Weill Cornell Medicine.

Tomorrow on FRESH AIR, Pulitzer Prize-winning journalist Caitlin Dickerson tells us about traveling with migrants through one of the most inhospitable terrains in the world, along the border of Columbia and Panama, called the Darien Gap. Nearly half a million migrants each year risk their lives to get to the other side in their attempt to ultimately get to the U.S. I hope you'll join us. To keep up with what's on the show and get highlights of our interviews, follow us on Instagram at @NPRFreshAir.

FRESH AIR's executive producer is Danny Miller. Our technical director and engineer is Audrey Bentham with additional engineering today from Charlie Kaier. Our interviews and reviews are produced and edited by Phyllis Myers, Roberta Shorrock, Ann Marie Baldonado, Sam Briger, Lauren Krenzel, Therese Madden, Thea Chaloner, and Joel Wolfram. Our digital media producer is Molly Seavy-Nesper. Susan Nyakundi directed today's show. Our co-host is Tonya Mosley. I'm Terry Gross. Transcript provided by NPR, Copyright NPR.