Tales from Both Sides of the Brain : A Life in Neuroscience (9780062228819) Read online

  I had to have a measure of neural activity to make sure the appropriate half brain was asleep while the other was awake, so I began by pulling together an electroencephalograph, that is, an EEG. Then I had to learn how to teach a rabbit a trick so that it would learn something. We decided to teach the rabbit to blink an eyelid to a sound. I got that under control. Then I had to learn how to attach recording electrodes on the small rabbit skull in order to pick up the electrical activity, the EEG. I somehow managed to do that. Finally, I had to be able to inject into either the left or right internal carotid artery (the key arteries leading from the heart to the brain) an anesthetic and be convinced the drug stayed lateralized to half of the brain and didn’t leak over to the other half brain and thereby put it to sleep as well. After a lengthy library search on the anatomy of the Circle of Willis, the arterial structure at the base of the brain, I decided it would work in the rabbit. Even though it seemed that blood from both sides of the supplying arteries would mix at the Circle, some studies showed that, due to a special hemodynamics, it didn’t. I went ahead, convinced that hemodynamics would save the day and hoped an anesthetic applied to one carotid would stay long enough in one half brain for me to do the experiment. At last, I was ready to rock and roll.

  My laboratory space for all of this was in the hallway in Sperry’s lab area. Space was tight, as there were many active postdocs toiling away with their own studies. One day I was busy doing a trial run. All the components were in place: the rabbit, the EEG machine recording the neural activity and spitting out the results on paper, and the eight ink pins fluttering back and forth. Then Linus Pauling walks by. Now, everybody knew who Linus Pauling was, particularly in our building, as his office was just around the corner in the chemistry building. He was one of the founders of quantum chemistry and molecular biology and was ranked as one the most important scientists of the twentieth century, making his way in 2000 onto an American stamp. Pauling stops and asks me what I’m doing. After sizing up the situation he says, “You know those squiggles you are ‘recording’ may be nothing other than the simple mechanical consequences of a Jell-O-like substance in a bowl. You ought to test that first.”5

  As he walked on down the hall, I caught the fever. His message was simple: Assume nothing, young man, and test everything. No matter where you turned, people were challenging, questioning, poking, yet encouraging, and yes, supporting the notion that it might work differently, which urges the young scientist on. It was intoxicating. Little did I know that a couple of years later, after winning his second Nobel Prize, Pauling would be suing for libel William F. Buckley Jr., who was about to become my lifelong friend!

  It was in this setting that a little over a year later, I tested the first split-brain patients. I wanted to see what people were like who for medical reasons had had the two hemispheres of their brain were surgically separated: the left brain no longer connected to the right brain. This book is about what that particular medical reality is, means, and taught us. The biographical details about the many scientists both directly and indirectly involved, who are featured in this telling, have been pruned from previous, mostly purely scientific accounts. As I have reflected on my own body of research, I feel it is important to grasp at least one tale of how many seemingly unrelated experiences flow together to make a life, and in this case, my life in science. But I am getting ahead of myself.

  Over that all too short summer, I got the rabbit preparation to work. There was constant kibitzing from others in the lab, but the task I chose was mine to do. The notion of discovering a little bit of the way something worked was palpably exciting. I was seduced. I knew then I had to discuss this with my father. His dream was for me to follow in his and my brother’s footsteps and attend medical school. My father was a force. Breaking away from the padrone’s plan required a conversation.

  ORIGINS

  Dante Achilles Gazzaniga (Figure 2) was born in Marlboro, Massachusetts, in 1905. After attending St. Anselm’s College in Manchester, New Hampshire, he was bound for home to work at the boot factory where his father had worked since emigrating from Italy. The local priest intervened, the same one who had been instrumental in getting him to college. He told my father that if he studied chemistry and physics over the summer, he would arrange for him to go to medical school at Loyola, in faraway Chicago. Oh life was so simple and straightforward in those days. Learn the stuff and you get to go to the next step. And that is what he did. He went to Chicago in 1928, and with the money his mother had saved, he planned to buy himself a microscope. Unfortunately, the money was in the bank, and it was all lost in the 1929 crash.

  FIGURE 2. Dante Achilles Gazzaniga dropped everything he was doing in Los Angeles to join the U.S. Navy and serve during World War II. He offered soldiers surgical care at bases in the New Hebrides and New Caledonia.

  (Courtesy of the author)

  In Chicago, he lived around the corner from where the infamous Valentine’s Day Massacre occurred, carried out by the gangster Al Capone. He even heard the shots on Clark Street. My father would sometimes get clam chowder at a local dive right by the alleyway where the shooting took place and sneak out packages of oyster crackers, which were a main part of his diet. To support himself and pay tuition, he played semipro football, as he was tall and strong, and he also ran an elevator, in which he did much of his homework. Somehow he got it done and I have thought about how different our experiences were, as I had enjoyed a paid research assistantship in luxurious Pasadena, California.

  After four years of Chicago, he headed off to the train station with a plan: get on the first train heading to a sunny place. Successful in this goal, he stepped off in Los Angeles, where he did an internship at the famous County Hospital in 1932–33. Headed to the Rose Bowl game with his buddies, he was trotting down the hospital’s front steps on New Year’s Day 1933 when he first met my mother, who was on her way in to work. Three and a half months later, they were married. At one point in my mother’s lively life, she was the secretary to the famed Aimee Semple McPherson, the evangelist who founded the Foursquare Church and captured the imagination of Los Angeles with her sermonizing at the Angelus Temple she’d built. It may well have been that my mother’s famous father, Dr. Robert B. Griffith, had landed her the job in the media-conscious town. He was the first plastic surgeon in Los Angeles and a hugely talented and successful physician. Among his patients were Hollywood stars including Mary Pickford, Charlie Chaplin, cowboy star Tom Mix, and Marion Davies.

  My mother’s father, whom I never met, was also known in local circles as a great chess player (masters level) and was a very good friend of Herman Steiner, the longtime chess columnist for the Los Angeles Times. They were both on their way back to Hollywood from a chess match in 1937 when they were hit head-on by a drunk driver. My mother found out that her father died in a car crash by reading the newspaper. I recently saw a picture of my grandfather for the first time and noticed some similarity in our facial features, though the chess gene didn’t find its way to me. (My brother Al got that.)

  Life in Los Angeles was fast-paced and colorful, but it was the Depression, and jobs were tight, even for physicians. Unable to find a job in Los Angeles, my father found work as a doctor for the men building the Colorado River aqueduct, which channeled water all the way through Arizona to California. It was a vast project. Nonetheless, in his spare time in the desert, my father had other projects going. He prospected and set up mining claims all over the place but gave them all up to the government years later when he signed up to join the World War II effort. My father always had multiple activities going at the same time and he worked at all of them. All of his children adopted the trait.

  My father’s cousin, who was a doctor in North Adams, Massachusetts, drowned. The family called my father to move back, so he, my mother, and their new baby, my oldest brother, Donald, climbed into the family car, a DeSoto sedan, and made the trip to North Adams in the summer of 1934. They were put up in a house a ways out of town.
During snowstorms when my father was stuck in town, my mom, the original California girl, was isolated in the sticks hovering in front of an open oven with the baby to keep warm. Meanwhile, my father was hanging out and playing cards with the boys in town. That didn’t wear well. The following February, in the depths of a western Massachusetts winter, my mother’s cousin sent her a sprig of orange blossoms from sunny California. That put her over the edge. My father didn’t like the weather, either, so they moved back to Los Angeles after about nine months. He hooked up with the Ross-Loos Medical Group, which was just starting up, and became one of the founding partners. That medical group became the first HMO in American history and served as the model for the now-huge Kaiser Permanente.

  Clearly, my father was full of spunk and a bit of a maverick. His roundabout course to professional success was objectively evident to me, but did he see it that way? I didn’t know what to expect when I broached the news about my new plan. “Dad, I think I want to go to Caltech rather than medical school.” There. It was laid out clean and clear. My dad looked at me with deep medical authority and said, “Mike, why would you want to be a Ph.D. when you can hire one?” He was truly puzzled. My father was committed to medicine like few others and was there to serve the sick. I can remember more vacations either canceled or shortened than enjoyed because patients always came first.

  Nonetheless, after a moment, Dad smiled and wished me luck. After all, there was still the small matter of being accepted into Caltech. The description of what a student had to be like in order to even be considered by Caltech bore no relation to me. As I have already mentioned, the place was chock full of mighty smart cookies and most of them could run circles around me. I had come to learn, however, that a large number of students were there for another reason: They had somehow proven to their future mentors that they knew how to do stuff. This usually came about by serving in summer fellowships just like I had done. This would be my only hope of getting in.

  THE UNDERGRADUATE LIFE

  Sperry came to bat for me. He had been impressed with my rabbit work and overall energy, and the following spring, my senior year at Dartmouth, the Caltech biology department conditionally accepted me to graduate school. Clearly, I had to show my stuff the first year.

  It had been a challenging four years at Dartmouth. Little did I know, however, that due to my membership in the infamous Animal House (Figure 3), my social life there would become a more noteworthy achievement than anything I had ever accomplished academically. A science geek among the more notorious animals, I played out my days as “Giraffe.” I was the nerd of the fraternity, preferring to spend more of my time working in the laboratory of the psychologist William B. Smith than drinking in the Alpha Delta Phi House basement.

  FIGURE 3. The Alpha Delta Phi (Animal) house at Dartmouth College. A few years back, some of us former “animals” met for a reunion. It didn’t take long for us to decide that the place should be bulldozed.

  (Courtesy of Joseph Mehling, Dartmouth College)

  Smith had a passion for research. He had built a small lab on the top floor of McNutt Hall, where we developed methods to measure eye movements. We worked together long into the night. Research was all new and exciting for me, and the first tantalizing glimpses of the search for one of Mother Nature’s mysteries had me hooked. Yet, at the time, before that momentous summer at Caltech, it simply seemed as if it were another thing to do in order to get into medical school. I did make some of my dearest friends at Animal House, and the tone of the place motivated me to get on with life!

  So, during my senior year, while my Dartmouth days were winding down and my serious itch for Caltech had taken hold, I became captivated by the question “What would happen to humans with a corpus callosum section?” (Section here refers to surgery cleaving the brain’s biggest nerve bundle.) It was clear after my Caltech summer with the rabbits’ brains and the heavy emphasis on basic research that I would move toward both. At the time it was inconceivable to think that humans might show the dramatic disconnection effects that were being shown in animals. No one really thought that a human being with an object placed in his or her left hand would be unable to find an object to match with the right hand. That just seemed nutty.

  In the tradition of Francis Bacon, it was time to count the horse’s teeth. This possibly apocryphal story captures what science is all about:

  In the year of our Lord 1432, there arose a grievous quarrel among the brethren over the number of teeth in the mouth of a horse. For thirteen days the disputation raged without ceasing. All the ancient books and chronicles were fetched out, and wonderful and ponderous erudition such as was never before heard of in this region was made manifest. At the beginning of the fourteenth day, a youthful friar of goodly bearing asked his learned superiors for permission to add a word, and straightway, to the wonderment of the disputants, whose deep wisdom he sore vexed, he beseeched them to unbend in a manner coarse and unheard-of and to look in the open mouth of a horse and find answer to their questionings. At this, their dignity being grievously hurt, they waxed exceeding wroth; and, joining in a mighty uproar, they flew upon him and smote him, hip and thigh, and cast him out forthwith. For, said they, surely Satan hath tempted this bold neophyte to declare unholy and unheard-of ways of finding truth, contrary to all the teachings of the fathers. After many days more of grievous strife, the dove of peace sat on the assembly, and they as one man declaring the problem to be an everlasting mystery because of a grievous dearth of historical and theological evidence thereof, so ordered the same writ down.6

  The teeth, in my case, were the human patients at the University of Rochester who had undergone surgery similar to what had been done on the animals at Caltech. In the early 1940s, this famous group of patients had had the corpus callosum sectioned in order to limit epileptic seizure activity to one half of the brain. This process split and disconnected the two hemispheres of the brain.

  The surgery was performed by the neurosurgeon William P. Van Wagenen, who had noticed that an epileptic patient who had developed a tumor in the corpus callosum was having fewer seizures. He wondered if severing the corpus callosum would stop the spread across the brain of the electrical impulses that elicited the seizures. So he sectioned the corpus callosum in a series of twenty-six patients with severe uncontrollable epilepsy. Seemingly well examined by a young and talented neurologist, Andrew J. Akelaitis, these patients had a remarkable decrease in the number of seizures they experienced, without any major behavioral or cognitive changes following surgery. Disconnect the two hemispheres and nothing appeared to change! Everyone was happy. That finding sat in the literature for ten years. Karl Lashley, the leading experimental psychologist of the era and Sperry’s postgraduate advisor, had seized on this finding to push his idea of mass action and the “equipotentiality” of the cerebral cortex; he claimed that discrete circuits of the brain were not important, only its cortical mass.7 Quoting Akelaitis’s work, he concluded that cutting the massive nerve bundle that connected the two halves of the brain appeared to have no effect on interhemispheric transfer of information and quipped that the function of the callosum was to keep the hemispheres from sagging.8

  The Akelaitis patients, as they were called, seemed like the perfect patients to confirm or refute whether the Caltech animal work done by Sperry and his graduate student Ron Myers applied to the human brain. It was then known from the animal work that after splitting the cerebral hemispheres, the monkey’s left hand didn’t know what the right hand was doing. Could that possibly be true for humans? While it seemed crazy, I was convinced it had to be. I wanted to retest the Rochester patients.

  I figured out who might know about those patients in Rochester and made a call. It worked and through the offices of Dr. Frank Smith, who at the time of the surgeries in the early 1940s had been a resident and operated on the very patients in question, I was going to be allowed to see the patients, if I could find them.

  I designed many experiments that were differ
ent from those done by Akelaitis and exchanged letters with Sperry about the ideas and the plan. I applied to the Mary Hitchcock Foundation at Dartmouth Medical School and received a small grant (two hundred dollars) to rent a car and to pay for my stay in Rochester. I drove out to Rochester and went straight over to Smith’s office to begin sorting through his files to find possible names and phone numbers. While I was there, he called to say that he had had a change of heart and he basically asked me to bug off. Even though my car was loaded with borrowed tachistoscopes, pre-computer-age devices that display images on a screen for a specific amount of time, and other paraphernalia from the Dartmouth psychology department, I departed as requested. The effort to reveal the effects of a human corpus callosum section was left for a later time.

  A few months later, however, I was back on the road, and rather than being disappointed, I was excited. I was headed to Pasadena. For five glorious years, Caltech was to be my home.

  DISCOVERING CALTECH

  It was a grand adventure to go from the Animal House to the so-called J. Alfred Prufrock house, across the street from the Caltech biology building (Figure 4). Helping me to get settled was one of Sperry’s senior graduate students at the time, Charles Hamilton, who soon became my best friend there, and had urged me to live at the Prufrock house. By the time I got there, it had a huge reputation for smarts, for parties, for just about everything. Chuck’s roommates, who already graced the rented two-story home, included Howard Temin, who went on to win the Nobel Prize for his groundbreaking work on viruses, and Matt Meselson, who coauthored with Franklin Stahl one of the most famous experiments in all of molecular biology.* When I moved in, Sidney Coleman and Norman Dombey, two theoretical physicists—one studying with Richard Feynman, the Nobelist and celebrated populizer of science, and one studying with Murray Gell-Mann, another Nobelist, who coined the term quark—were living there. Coleman went on to a distinguished career at Harvard and became known as the “physicist’s physicist.”