The Tale of the Dueling Neurosurgeons: The History of the Human Brain as Revealed by True Stories of Trauma, Madness, and Recovery

by Sam Kean

  In addition to music, Wearing’s emotional memories provide an anchor. He lost his memory within two years of getting married, and in the thirty years since, he hasn’t lost an iota of passion for his Deborah. Every time—every single time—she visits him at his nursing home, he erupts in joy. If she steps out to the ladies’ room, he might crumble—then erupt again when she returns. And for a few years, as soon as Deborah left for the day, Clive would begin leaving messages on her answering machine, begging to know why she never visited. “Hello, love, ’tis me, Clive. It’s five minutes past four… I’m awake for the first time…” Beep. “Darling?… It’s a quarter past four and I’m awake now for the first time…” Beep. “Darling? It’s me, Clive, and it’s eighteen minutes past four and I’m awake…” However flattering—would that we were all loved so much!—Deborah admitted that she sometimes had trouble faking enthusiasm for yet another “reunion.” But there’s no denying that Clive is tapping into his inner core here—something that he’ll never abandon and that will never abandon him.

  *

  The tenacity of the self is revealed even more clearly in another case of distorted consciousness, that of Tatiana and Krista, conjoined twins born in British Columbia in 2006. Surgeons declined to separate the girls at birth because they have, essentially, a Siamese brain, with their skulls fused together. (The girls face the same direction, with Tatiana on their right. They cannot see each other but can walk just fine, leaning toward each other like two legs of a triangle.) Inside their joint skull, a stretch of axon cables connects their thalami. As far as doctors know, this “thalamic bridge” is unique in medical history, and as Tatiana and Krista get older and more articulate, they’re showing some amazing behaviors. They often speak simultaneously, like two stereo speakers, and each can taste what’s in the other’s mouth. Prick one for a blood test, and the other winces. Put them down to bed, and they fall asleep in unison, and possibly dream together.

  In other words, each girl has access to the other’s consciousness, and neither girl distinguishes clearly between her own thoughts and sensations and those of her sister. Their use of pronouns reflects this ambiguity. They use “I” in odd situations: hand each of them a single piece of paper, for instance, and they’ll announce, “I have two pieces of paper.” And they never say “we,” either, as if their single thalamus unites them. The girls do have other brain anomalies: each has a tiny corpus callosum, and Tatiana’s left hemisphere and Krista’s right hemisphere (i.e., the hemispheres between them) never developed fully. But the thalamic bridge is probably what produces their hybrid consciousness.

  And yet, despite sharing in each other’s consciousness, each girl shows strong signs of individuality. With regard to food, Krista breaks out in hives whenever she eats canned corn; Tatiana doesn’t. And while Krista likes catsup, Tatiana hates it, and tries to scrape it off her tongue whenever Krista eats it. The girls also fight as if two separate people—punching each other, gouging eyes, pulling hair. This can lead to some Three Stooges absurdities, like when one girl slaps the other, then grabs her own face in pain. But they apparently feel distinct enough to attack one another as foreign. One twin sometimes even says, out of the blue, as if affirming it, “I am just me.” Of course, her sister often undermines her a moment later by echoing, “I am just me.” (Shades of The Shining twins there.) But there’s clearly a need, an instinct, to declare their independence.

  Psychologists of a certain bent have always denied that people have a fixed core, a fixed self. And given how much we change roles and shape-shift mentally from one situation to another, depending on the social milieu and whom we’re talking to, these psychologists have a point. Neurologically, though, we do seem to have a core brain circuit that defines and establishes a self. This sense of self weaves together many different strands: autobiographical memories; physical looks; a sense of continuity through time; a sense of personal agency; knowledge of our own personality traits; and so on. But like a tapestry, the self doesn’t depend on the integrity of any one strand alone: K.C. lost his autobiography, the mutilés of World War I lost their faces, Clive Wearing lost all continuity, alien hand victims lost personal agency. And yet all of them retained a sense of self. Like consciousness, the self is less a thing in a place than a process in a population—and that makes the self tenacious, stronger than any of the vicissitudes of life.

  So in all likelihood, if you’d asked him, Phineas Gage would have told you that he still felt like Phineas Gage. Always had.

  The most important details of Gage’s case involve the psychological changes he underwent, because of damage to the front of his frontal lobes. Unfortunately, this is also the area where hard facts are hardest to come by. No one ever performed any psychological evaluations of Gage, and beyond saying “the prefrontal area,” we don’t even know what regions of his brain suffered damage, either from the tamping iron or from the subsequent swelling and infection. Modern neuroscientists have nevertheless found it irresistible to read between the lines of what Gage’s doctors strictly reported and to equate Gage with modern patients.

  The patient most commonly called a “modern Phineas Gage” is Elliot, whom we met in the emotions chapter. (After a tumor crushed his frontal lobes, Elliot spent hours deciding what restaurant to eat at or how to sort tax documents. He also lost his nest egg in a dubious investment.) Neuroscientists associate Elliot and Gage because they both displayed probably the classic symptom of prefrontal lobe damage—personality changes. People who suffer prefrontal damage rarely die from it, and their senses, reflexes, language, memory, and reasoning survive intact. Indeed, a stranger who chatted with Gage or Elliot for a minute probably wouldn’t have noticed anything amiss. But anyone who knew and cared about them could spot the differences immediately: the mental changes were as obvious as a facial scar. Prefrontal damage might not kill people, but it can kill what we cherish most about them.

  Beyond their altered personalities, however, it’s hard to know how closely Gage’s and Elliot’s stories actually parallel each other. On the one hand, the resemblance seems tantalizing, more than enough for, say, a good lawyer to convince you of the similarities: Neither man could resume his job after his brain damage, and both betrayed a sudden lack of money sense, Elliot in making bad investments, Gage in refusing to part with some pebbles for $1,000. Both showed a lack of embarrassment in social situations: Gage reportedly swore like a pirate and let people dig through his hair for dimes; Elliot confessed every last squalid detail about his life without a hint of shame, right down to his moving back in with his parents in his forties. Both showed an attachment to inanimate objects: Gage carried his tamping iron everywhere; Elliot hoarded newspapers, dead houseplants, and empty cans of frozen orange-juice concentrate. Both men seemed enslaved to their impulses: Elliot’s marrying a hooker sounds an awful lot like Gage’s doctor’s comment about the “animal passions” winning out in his patient. Both men hurt loved ones with their callousness, and both showed possible signs of emotional disturbance: Elliot’s feelings flat-lined, and nothing—not music, not painting, not even politics he despised—could rouse him; Gage, in the aftermath of his accident, remained unflappable, eerily indifferent, as if (as some modern commentators claim) he’d been lobotomized.

  All that said, you can also read Gage’s story another way, in which case the Elliot comparisons seem exaggerated and unfair. We actually know very little about Gage’s mental life overall, and what we do know seems ambiguous, even cryptic, if we read carefully. Take the comment about Gage’s sudden “animal passions.” Sounds impressive, but what does that mean? Did he eat or sleep too much? Demand sex? Howl at the moon? It depends entirely on interpretation. As for his supposed attachment to objects, Gage schlepped his tamping iron around everywhere, sure, but can you blame him? Attachment to the rod that remodeled your brain is surely more rational than hoarding cans of frozen orange juice. As for Gage’s emotions, beyond his indifference right after the accident—which could be due to shock�
��we know nothing, zero, about his emotional life in later years. And while Gage did have trouble sticking to plans and seemed to lose the impulse control that prevents nice people from cursing in public, a saucy “hell” or “damn” in conversation hardly makes him an antebellum Elliot.

  Indeed, some modern historians

  * have argued, forcefully, that while Gage did show signs of frontal lobe damage right after his accident, he also—unlike Elliot—seems to have recovered some of his faculties over the next decade. He never became the Phineas Gage of old (no hope of that), but some of his negative traits either diminished or disappeared, possibly because his brain proved plastic enough to recover lost functions.

  After his stints in Barnum’s museum and a New Hampshire horse stable, Gage took off for Chile in 1852, probably following a gold rush. He was seasick the whole voyage. Once ashore, he found work driving a carriage and shuttling passengers along the rugged, mountainous trails between Valparaiso and Santiago. Considering his brain damage, his success in this job—he did it for seven years—beggars belief. He likely drove a team of six horses, which demanded no little dexterity, since he had to control each horse separately. Rounding a bend without tipping the coach over, for instance, required slowing down the inner three horses a touch more than the outer three, simply by tugging on their reins with varying amounts of pressure. (Imagine driving a car while steering all four wheels independently.) Furthermore, the trails were crowded, forcing him to make quick stops and dodges, and because he probably drove at night sometimes, he would have had to memorize their twists and turns and fatal drop-offs, all the while keeping an eye out for banditos. He also likely cared for his horses and (contra the claim that he lacked all money sense) collected passenger fares. Not to mention that he presumably picked up a soupçon of español in Chile. You wonder how many of Gage’s passengers would have climbed in had they known about their one-eyed driver’s little accident a few years before, but he seems to have handled himself fine, far better than Elliot ever did.

  That Gage carved out a life for himself in Chile doesn’t mean that his brain recovered fully. It merely suggests that his brain recovered somewhat. As we’ve seen, the brain’s neural circuits can rewire themselves in certain circumstances, and perhaps Gage retained enough of his frontal lobes (especially on the right side) to compensate for his lost social and executive skills. At the very least, Gage didn’t deteriorate into the drunken sociopath that many modern accounts make him out to be.

  One factor that may have helped Gage thrive (and that may explain why Elliot didn’t) was the routinized nature of Gage’s work. He likely arose each day before dawn to prep the horses and carriage, then spent the next thirteen hours driving the same road from Valparaiso to Santiago and back. As noted, victims of frontal lobe damage often have trouble finishing tasks, especially open-ended tasks, because they get distracted or overwhelmed. But all Gage had to do was keep driving forward until it was time to turn around, and every day unfolded pretty much the same way. This introduced structure into his life and probably helped him avoid a life of dissolution. Gage might not have been Gage anymore, but he wasn’t a wastrel.

  Still, he couldn’t outrun his brain damage entirely—and when it did catch up to him, the end was swift. Increasingly poor health forced him to quit Chile, and in 1859 he caught a steamer to San Francisco, near where his family had moved. After a few months of rest, he found work as a farm laborer and seemed to be doing better, until a punishing day of plowing in early 1860 wiped him out. He had a seizure the next night over dinner. More followed.

  Gage tried gamely to continue working during this spell, but he suddenly became restless and capricious, and began drifting from farm to farm, always finding a reason to quit his current job. Finally, at 5 a.m. on May 20, while resting at his mother’s home, he had a fit more violent than any before. In fact the fits never really stopped after that, and Gage entered a state called status epilepticus—a continuous seizure. He died on May 21, age thirty-six, having survived his accident by almost a dozen years. His family buried him two days later, presumably with his beloved tamping iron. To the inestimable loss of the world, there was no San Francisco Broca to preserve his brain.

  Gage’s story might have ended there—an obscure small-town tragedy, little more—if not for Dr. John Harlow. Harlow had lost track of Gage after Gage shipped off to Chile in 1852. (Amid other distractions, Harlow got caught up in politics, and he later won a seat in the Massachusetts state senate.) Nevertheless, Gage’s story kept nagging Harlow; he couldn’t shake the thought that his former patient had more to teach the medical world. So when Harlow learned the address of Gage’s mother in 1866 (through some unspecified “good fortune”), he wrote to California straightaway for news.

  Although panged that they’d not arranged for an autopsy, Harlow exchanged some letters with the Gages and milked them for details of Gage’s life. He then prevailed upon Gage’s sister, Phebe, to have the grave opened in late 1867 to salvage Gage’s skull. The exhumation sounded like quite a to-do, with Phebe, her husband, their family doctor, the city mortician, and even San Francisco’s mayor, one Dr. Coon, all present to peek inside the coffin. Gage’s family hand-delivered the skull and tamping iron to Harlow in New York a few months later. After interviewing the family and studying the skull, Harlow wrote a detailed case report on Gage in 1868, including most of what we know about his psychological transformation. His work on Gage complete, Harlow donated the skull and tamping iron to an anatomical museum at Harvard University, where they remain today.

  Harlow persisted in tracking Gage down and documenting his story in part because he assumed that posterity would forget about Gage otherwise. But in the two decades following Gage’s accident, neuroscience had changed considerably. Europe was suddenly frothing over with debates about brain localization, and although most Europeans didn’t take American science seriously, the singularity of Gage’s injuries—You are sure, Yan-kee? Ze rod went zhrough his skull?—proved too fascinating to ignore. Over the next few decades neuroscientists began debating Gage’s case in earnest.

  In reality, the dearth of hard details about Gage probably secured his fame, since it left infinite room for interpretation and bickering. Gage became—and remains today—something of a Rorschach blot for neuroscientists, an indication of the passions and obsessions of each passing era. Phrenologists explained some of Gage’s symptoms, like his cursing, by noting that his “organ of veneration” had been blown to bits. Roberts Bartholow cited Gage in defense of his experiments on the exposed brain of Mary Rafferty, for if Gage could survive having his skull reamed, Bartholow argued, how was he to know that a little electricity would kill? Neurosurgeons, oddly, saw Gage as an inspiration. Whatever did or didn’t change inside him, Gage proved that people could at least survive extensive loss of brain tissue. This reassured surgeons during an era of appallingly high death rates, and justified the surgical approach to treating certain brain disorders.

  Above all, Gage got dragged into that all-time classic debate in neuroscience—over localization and the supposed seat of our humanity. Many antilocalizationists actually seized upon Gage as evidence of a unified and nonlocalized brain, a counterweight to the likes of Tan and Lelo. They emphasized, first of all, that despite the widespread damage, Gage had retained most of his mental faculties: he could still reason, remember, recognize faces, and learn new skills. Furthermore, due to a misunderstanding, the antis thought that the tamping iron had actually destroyed the rear frontal lobes—the very regions that Broca and other localizationists were passing off as speech and motor centers. Since Gage never lost those skills, the antis argued that localization theory must be bunk.

  Localizationists parried. While they conceded that Gage had retained most of his mental faculties, those talents might simply be located in other lobes. What’s more, they dug up an experiment from 1849 in which a doctor had drilled a hole in a cadaver’s skull to determine the path of the tamping iron through Gage’s head. Th
is sounds a bit like Henri II’s doctors battering the skulls of decapitated criminals with the lance butt, but this experiment actually yielded useful information: it proved that the rod had almost certainly missed Gage’s speech and motor centers, rendering that objection mute. Most important, localizationists noted that—whatever else got spared—Gage’s personality had changed, drastically. The human mind isn’t just memory plus language plus reasoning plus sensory data, all working independently: those modules have to come together and find a common expression. They do so in the frontal lobes, which serve as a hub to integrate those isolated talents. And when that hub was destroyed, Gage lost something essentially human. He was no longer Gage.

  The localization arguments eventually carried the day. There was simply too much evidence that the damage to Gage’s frontal frontal lobes had remade his personality. And from there it was but a small step to one of the founding doctrines of modern neuroscience: that brain and mind are interlocked. Somewhere inside our gray and white matter, we can indeed find mere flesh that, if sparked a certain way or drenched in a certain soup, can produce generosity, patience, kindness, persistence, common sense—or a lack of any of those things. Gage’s case alone didn’t drag neuroscience to this conclusion. But after him, scientists had real proof that the glories of the human mind arise directly from the intricacies of the human brain. No matter what parts of his life remain murky or debatable, Gage remains probably the most important case in the history of neuroscience because his story pointed us toward that truth.

  Gage’s story retains its grip on us for other reasons as well. Stories probably mean more to neuroscience than to any other scientific field—and as we’ve seen throughout this book, they’re not always the easiest stories to take. Some are in fact downright difficult to sit through, striking a little too close to home. Unlike with other fields, any one of us could make a vital contribution to neuroscience someday, through no fault of our own. Our names (or at least initials) might be immortalized in textbooks, and like many other facets of neuroscience, that’s both amazing to think about and scary.