by Sam Kean
As for sex, human beings often respond differently to brain damage than monkeys do. Seizures that send volleys of electricity into the limbic system, for example, can actually depress sexual appetite, leading to impotence and Dead Sea–level libidos: some epileptics have never had an orgasm in their lives. (In contrast, rabies infections can lead to spontaneous ejaculations—up to thirty per day.) Temporal lobe lesions can flip people’s sexual orientations from gay to straight (or vice versa), or redirect their sexual appetites toward inappropriate things: common side effects of Klüver-Bucy include zoophilia, coprophilia, pedophilia, and -philias so idiosyncratic they don’t have names. In 1954 three scientists published a report about an epileptic named L.E.E., a thirty-eight-year-old carpenter who, ever since boyhood, had been sneaking into bathrooms not with nudie magazines but with safety pins. After withdrawing the safety pin from his pocket—the shinier the better—he stared at it with increasing titillation for a minute, then became glassy-eyed. He hummed, sucked his lips, and went rigid; his pupils dilated. It’s unclear if L.E.E. actually climaxed this way, but he didn’t care. He claimed that his shuddering, groaning, mini-seizures actually trumped orgasms, providing much more pleasure. (And titillation wasn’t the only benefit of his fetish. When he demonstrated it for military recruiters during World War II, they couldn’t reject him fast enough.) Still, the fetish strained his marriage: by his thirties he couldn’t get an erection during foreplay, and his wife was threatening to walk out. Only when surgeons removed a three-inch shank from his temporal lobe did he find any relief; afterward, he and the missus enjoyed connubial bliss.
In truth, though, L.E.E. got lucky: all too often, removing temporal lobe tissue to stop one problem only introduces another. Most commonly, if the offending tissue suppressed someone’s sex drive, removing it can cause his libido to skyrocket, and he’ll get horny—beyond horny. One surgical patient started getting erections that lasted several hours, and within seconds of ejaculating he would roll over onto his wife for more sex; no amount of coitus could sate him. As you can imagine, this isn’t easy for spouses to take, and some have even pulled their loved one’s brain surgeons aside and requested a temporal lobectomy for themselves, so they can “keep up.” Parents have it rough, too. Children as young as three (who have their temporal lobes removed to control intractable epilepsy) might start flashing their genitals and thrusting their little hips. One twenty-four-year-old lobectomy patient started begging sex from strangers, neighbors, and family members, and if they weren’t ready to go, she’d start masturbating wherever. Hospitalized once for a seizure, she escaped from her room within half an hour. Her doctors found her beneath the sheets of an elderly man who’d just had a heart attack, her head bobbing up and down—combined hypersexuality and hyperorality. (As one commentator said, “One person’s syndrome was another’s lucky day.”) Interestingly, she never remembered her “episodes” afterward.
Aside from our vision, motor, and sex centers, one final region that interacts with our limbic circuits is the frontal lobes, which help soothe and placate our more primal emotions. That’s not to say that the frontal lobes quash emotions completely. A mysterious rustling in a dark forest will always sound alarms in the amygdala and send a pulse of fear through us. But instead of letting that fright overwhelm us, the frontal lobes, which are more discriminating and less reactive, help defuse and master it somewhat. This frontal-lobe influence also allows humans to have a more nuanced repertoire of emotions than other animals, who usually fall back on inflexible and stereotyped reactions.
All that said, we shouldn’t congratulate ourselves just yet about being such smart, rational Vulcans. We’ve all been overwhelmed by fear or anger at times. And as the story of a man named Elliot shows, even the vaunted “higher reasoning” of our frontal lobes owes a heavy debt to raw emotion.
Elliot was good people. A caring husband who’d married his high school sweetheart; a father of two; head accountant at work; a solid member of his Iowa community. But in 1975, at age thirty-five, he started getting excruciating headaches, so piercing he couldn’t think. Brain scans confirmed the worst: a baseball-sized tumor lodged above and behind his eyes. Actually, the tumor itself wouldn’t have done much harm, except that in the enclosed space of the skull, it was crushing his frontal lobes. When surgeons opened him up, in fact, they had to remove whole swaths of damaged tissue from the prefrontal area, a region in the very forefront of the brain that contributes to planning, decision-making, and personality traits. A much different Elliot woke up from surgery.
This Elliot couldn’t do something as simple as choose where to eat dinner. Before picking a restaurant he had to weigh the prices, menu, atmosphere, proximity to home, and quality of the waitstaff—then drive to every single option to see how busy it was. And after all that, he still couldn’t decide. In fact, no matter what the decision was, Elliot went round and round, dithering and dallying and never making up his mind. Imagine every piddling choice in your life—what tie to wear (stripes or Snoopy? Hmmm); what side dish to choose (soup or salad? Hmmm); what radio station to listen to (smooth jazz or classic country? Hmmm)—being subject to such intense and futile scrutiny.
Elliot fared no better professionally. Although punctual before, this Elliot needed hounding every last morning to get his butt to work. He might spend hours shaving or washing his hair, because he simply didn’t care about arriving on time, or at all. Not that he was much use at work. Even though his math skills remained intact, he couldn’t manage his time and got distracted by meaningless tasks. He might fritter away a whole morning deciding how to file some documents, for instance. By color? Date? Department? Alphabetically? Hmmm. Hour after hour of shuffling and reshuffling ensued, with Elliot entirely indifferent to both the hours he was wasting and his boss’s glares. The inability to see the big picture is a common consequence of prefrontal damage, and often leaves a victim unable to get beyond step one or two and complete a task.
Finally, Elliot’s personal life unraveled. After his inevitable firing, he drifted between jobs, working in a warehouse one season, preparing tax returns the next. Neither gig lasted. A shady local character then convinced him to invest his nest egg in a house-building scheme. When the investment got wiped out, Elliot shrugged. He fooled around on his wife of seventeen years, too, and after their divorce he married a prostitute, a union that fell apart six months later.
The strange thing was that Elliot’s memory, language, and motor skills remained intact, and his IQ remained in the 120s. He could discuss economic news and domestic policies in detail, as well as foreign affairs in Poland and Latin America. Most oddly, he could reason just fine in controlled settings. When presented with hypothetical scenarios about people’s social lives and asked to predict which choices would lead to happiness and which to ruin, Elliot could predict that, say, marrying a hooker maybe wasn’t the best idea. Nevertheless, he never bothered steering clear of such disasters in his own life. Why? Because disasters didn’t bother him—he didn’t sweat the big stuff.
Neuroscientist Antonio Damasio has written about Elliot at length. And although it’s a subtle case, Damasio argues that Elliot’s lack of emotional distress provides the key to understanding him. The human brain normally has strong neural connections between the emotional limbic circuits and the rational prefrontal areas, and we normally think about this relationship in master-slave terms, with the rational brain defusing our emotions and suppressing our impulses. But there’s more to their relationship, Damasio says. Emotions also advise the rational brain, and allow it to take past experiences into account when making decisions. Emotions do this by, once again, tagging any choices we face, A or B, as good or bad, based on how similar choices turned out in the past. Sometimes these tags even produce “gut feelings,” allowing the wisdom embodied in our bodies to bend back and influence our minds. Overall, Damasio argues, this is the basic evolutionary purpose of emotions: to nudge us toward “good” options by associating them with positive fee
lings and deter us from “bad” options by stirring up unease.
Elliot’s tumor destroyed key connections between his prefrontal lobes and limbic center, so the Socratic dialogue between reason and emotion never took place. This doomed him in small life choices, because choosing paisley over plaid or Chinese over country buffet depends little on ratiocination. Instead, it’s emotion—what do I feel like?—that nudges us toward A and away from B. And minus emotions, Elliot’s frontal lobes literally could not decide. Logic cannot make us make a choice.
The lack of dialogue also doomed him in big life choices. Elliot’s prefrontal damage wouldn’t have changed his basic drives and appetites, whether biological (e.g., for sex) or cultural (e.g., for money). In fact, those urges were probably normal, no stronger or more perverse than the urges the rest of us have. It’s just that in most human beings, the prefrontal area curbs these urges and redirects them in socially appropriate ways; that’s one of the most important jobs of the frontal lobes. And without the frontal lobe influence, Elliot’s immediate drives and impulses (me want sex) always won out, hijacking his mind and forcing him into the same gimme-now decisions an animal would make. Perhaps worse, his lack of frontal–limbic interaction ensured that he couldn’t tag his decisions emotionally as good or bad and thereby avoid similar mistakes in the future.
Notice that Damasio’s work here
* upends the traditional thinking about reason “versus” emotion. Emotions can cloud our reasoning, certainly. And again, abstract reasoning can proceed quite well without emotion: when presented with hypothetical scenarios in the lab, Elliot could foresee the disastrous consequences of certain decisions. It’s the next step that flummoxed him. To most of us the next step seems so obvious that it feels stupid to spell it out—avoid the decisions that lead to ruin, you idiot. Even after outlining all the negative consequences, however, Elliot would typically grin and admit that in real life, “I still wouldn’t know what to do.” It seems daft, the antithesis of common sense. But as we learned with regard to fear, it’s probably emotions that produce common sense. And when none of his possible options were marked as scary or dangerous or joyful, Elliot floundered. Overall, then, while reasoning without emotions might seem ideal in the abstract, in practice—in Elliot—it looks like irrationality incarnate. This is one of the hardest truths of neuroscience to swallow: that no matter how much we want to believe otherwise, our rational, logical brains aren’t always in charge. We crowned ourselves Homo sapiens, the wise ape, but Homo limbus might have been more apt.
Elliot’s struggles bring up another point, a deeply ethical point, about how much responsibility we have for our actions. Brain damage can release some dark and primitive impulses, and Elliot had particular trouble choosing right over wrong in the grip of an immediate temptation. Imagine, though, that instead of investing poorly or ruining his marriage, Elliot had embezzled money or murdered his wife. Our entire legal system is built on the premise that people who understand right and wrong are accountable for their actions. But in the light of neuroscience, jurists have struggled with in-between cases—cases where someone understands right and wrong, and even understands the need to choose right over wrong, yet lacks the power to.
One case involved a teacher from Virginia. Although he had a penchant for pornography, he lived a fairly vanilla life until around age forty, when he started soliciting happy endings at massage parlors. More troublingly, he started collecting smutty videos of underage girls, and even though he tried to resist these urges, he soon approached his eight-year-old stepdaughter for sex. She informed his wife, who found the kiddie porn stashed on his computer. Arrested and tried, the man couldn’t explain himself in court. He’d never lusted after children before and knew he shouldn’t now, but he couldn’t help it. Citing the lack of even a whiff of criminal activity in the man’s past, a judge sentenced him to attend rehab in lieu of jail. Things didn’t work out there: he kept asking the nurses to mount him; even after pissing himself one afternoon, he kept propositioning them, the Romeo. The center expelled him, so off to prison. But the night before his sentence began, he complained of a massive headache and checked into a hospital. You guessed it: he had an egg-sized tumor in his brain.
Was this a coincidence? Statistically speaking, some percentage of pedophiles will have brain tumors, tumors unrelated to their vice. And if not a coincidence, did the tumor simply release his dark desires, or did it create desires that didn’t exist before?
When surgeons removed the tumor in December 2000, the pedophilia disappeared. For a while. The man started pursuing children again the next October. But because his headaches returned as well, his doctors scheduled another brain scan, and sure enough, as so often happens, the surgeons had missed a tiny root of the tumor, and it had grown back like a pernicious weed. When surgeons removed it a second time, the pedophilia once again disappeared. This seems to argue that the tumor somehow caused the pedophilia. But again, we don’t know whether the tumor simply released a pent-up desire or whether it actually changed his mental makeup. This is not an isolated case, either. One study from 2000 found at least thirty-four men whose pedophilia emerged after tumors, trauma, dementia, or other insults to their gray matter. To be sure, most pedophiles do not suffer brain damage, but clearly some percentage do.
There are a few key factors to weigh when judging whether or not you can blame criminal behavior (or other outré activities) on brain damage. One is the presence of additional trouble. When examined, the Virginia man failed multiple neurological tests, being unable to keep his balance or write a legible sentence; he also showed the same snout reflex that kuru victims did. Equally important considerations include how quickly the new behavior emerged and the contrast between the patient’s former behavior and his current behavior. Pedophilia normally emerges in adolescence and normally emerges gradually, in step with all the other sexual changes we go through. But when a sixty-year-old man with a hitherto staid sex life—as happened in one case—starts having sex with his underage daughter and recklessly pursuing prepubescent boys, a neurologist should probably take a look. (This man also began sodomizing cattle out of the blue and adorning his penis with red ribbons.) Even this criterion doesn’t cover every case, though. It wasn’t a crime, but S.M., the woman with amygdala damage, repeatedly propositioned her doctors for sex: in addition to losing all fear of snakes and muggers, she’d apparently lost all social fear as well. Yet her condition emerged slowly, over many years.
These cases not only raise difficult questions about culpability, they introduce quandaries about how to punish offenders. If brain damage caused the criminal behavior, you might be tempted to be lenient, since on some level it’s not someone’s fault. But some judges (and scientists) reason the exact opposite way: if someone has permanent brain damage that leaves him with horrendous impulse control and an appetite for young girls, rehabilitation might do no good. Perhaps better to toss him into a supermax.
There’s no doubt that neuroscience will change our judicial system, but no one quite knows how. Neuroscience can help us understand why someone like Harvey Cushing periodically erupted—why his anger overwhelmed his decency when he noticed that an assistant had missed the left parathyroid body. It can help us understand why S.M. lacked fear, or why a man might find a safety pin sexy. But if a brain-damaged person attacks someone because his frontal lobes can’t control a cascade of emotions, then even if we can trace the causes down to the last neuron, neuroscience alone cannot tell us what to do next. Determining that will require a lot of hard thought and careful reasoning—which means that it will require listening to our emotions, to supplement our reasoning and make it more humane. If emotion without reason is blind, it’s equally true that reason without emotion is lame: a world run by Elliots would be a disaster. So despite all the advances of neuroscience, all the fancy machines and illuminating insights, we still need our old, wet gray matter—the only place where emotion and reason come together and alchemize into what we call wi
sdom—to tell us how to act.
PART IV
BELIEFS AND DELUSIONS
CHAPTER EIGHT
The Sacred Disease
In this section we shift from the physical brain to the mental brain. Common sense tells us there’s a sharp distinction between the physical and the mental, but diseases like epilepsy show how fuzzy the boundaries are.
Neurosurgeon Wilder Penfield had waited days for the letter about his sister, and when it arrived, he felt stupid, so stupid. A telegram a few days before had said little, only enough to distress him: that his sister Ruth was ailing, and that she and their mother had boarded a train from Los Angeles to Montreal, to seek his professional opinion. The letter that arrived on December 1, 1928, explained more. It said that Ruth, then forty-three, had suffered an increasing number of seizures in the past decade. These had included one two-day barrage of fits and one giant convulsion that required CPR to revive her. Now fits shook her almost daily, and she seemed likely to die without treatment.
Neurosurgeon Wilder Penfield. (National Library of Medicine)
Reading this, Penfield’s mind flashed back to an ugly incident from their childhood in Wisconsin. He, fourteen, stood eavesdropping outside Ruth’s bedroom door; she, twenty, lay prostrate inside, rigid and immobile, her head and neck spasming and jerking. He couldn’t have known her diagnosis then, but by 1928 he’d become a world expert on epilepsy. And yet until he received the letter, Penfield had never put it all together, never realized that all Ruth’s “headaches” and “nervous spells” over the years had been seizures. How did I miss it? Their prim Presbyterian family never discussed illness, and for the past decade he’d been too busy to inquire much into Ruth’s health. Now he would have to confront her epilepsy directly: she was due to arrive in Montreal in a few hours.