Until the past few decades, neuroscientists really had only one way to study the human brain: Wait for strokes or some other disaster to strike people, and if the victims pulled through, determine how their minds worked differently afterward. Depending on what part of the brain suffered, strange things might happen. Parents couldn’t recognize their children. Normal people became pathological liars. Some people lost the ability to speak — but could sing just fine.
These incidents have become classic case studies, fodder for innumerable textbooks and bull sessions around the lab. The names of these patients — H. M., Tan, Phineas Gage — are deeply woven into the lore of neuroscience.
When recounting these cases today, neuroscientists naturally focus on these patients’ deficits, emphasizing the changes that took place in their thinking and behavior. After all, there’s no better way to learn what some structure in the brain does than to see what happens when it shorts out or otherwise gets destroyed.
But these case snippets overlook something crucial about people with brain damage. However glaring their deficits are, their brains still work like ours to a large extent. Most can still read and reason. They can still talk, walk and emote. And they still have the same joys and fears — facts that the psychological caricatures passed down from generation to generation generally omit.
The famous amnesiac H. M., for instance, underwent radical brain surgery in 1953 and had most of the hippocampus removed on both sides of his brain; afterward, he seemed to lose the ability to form new long-term memories. Names, dates, directions to the bathroom all escaped him now. He’d eat two breakfasts if no one stopped him. Careful testing, however, revealed that H. M. could form new motor memories — memories of things like how to ride a bicycle — because they rely on different structures in the brain. This work established that memory isn’t a single, monolithic thing, but a collection of different faculties.
That much is well known from the lesson-plan summaries of his life. Far fewer people know that H. M. could still appreciate poetry and do crossword puzzles. Or that he was a firearm nut who loved talking about rifles and handguns. Or that, later in life, when another patient at his nursing home tormented him, he would sometimes grab his bed and shake it like a gorilla would its cage. These were moments of pure animal frustration — but they also show a real, complex person breaking through. He reacted the way we’d all want to if dealt his fate: He raged.
Then there’s the railroad construction foreman Phineas Gage, possibly the most maligned man in medical history. One afternoon in 1848, while Gage was packing gunpowder into a blasting hole with an iron rod, a spark went off and caused an explosion. The rod rocketed through his skull and mangled his frontal lobes. Gage survived, miraculously, but his mind didn’t, not quite. His doctor reported that Gage turned capricious after recovering, and began telling tall tales and “indulging ... in the grossest profanity.” Friends swore that Gage “was no longer Gage.”
Some sources claim that Gage became a drunk, a beggar or a hypersexed louche. One science writer turned him into a con man who sold the exclusive, posthumous rights to his skull to a medical school — then sold the same rights to another school, and another, pocketing the cash each time.
Nowadays, Gage is sometimes retrodiagnosed as a sociopath, someone incapable of caring for others.
But the evidence for these drastic transformations is thin. The psychologist Malcolm Macmillan in fact argues that Gage might have recovered somewhat and carved out a semi-normal life. For instance, he worked in South America for several years in the 1850s as a stagecoach driver, a fact hard to square with his being a psychopathic grifter. For whatever reason, past neuroscientists twisted the facts about Gage to their own ends, unwilling or unable to see the real man beneath.
I am guilty of promoting these distorted views as much as anyone, and in reflecting recently on why, I realized that I’d stumbled into a sort of “uncanny valley” of neuroscience. Freud popularized the idea of the uncanny, the blend of attraction and repulsion we feel for something we can’t quite categorize. A Japanese engineer adapted the notion in the 1970s for work in robotics, and the idea was later extended to animation. In short, it says that if artists created characters that were only vaguely human, like cars with faces or anthropomorphic ducks, viewers found them endearing. Similarly, if artists drew realistic characters of almost photographic quality, viewers also adored them.
Something funny happened between the two extremes, though. If a drawing or robot looked mostly human but not quite, it actually repelled people. Computer-generated characters in movies often tumble into this uncanny valley, not to mention zombies, clowns and celebrities with bad face-lifts. It seems that when something is, say, 50 percent human, our brains focus on the similarities and we embrace it. When it’s 95 percent human, we focus on the differences, and the unresolved conflict we feel — is that human or not-human? — creeps us out.
Something similar happens with famous neurological cases. In the quest for scientific understanding, we end up magnifying patients’ deficits until deficits are all we see. The actual person fades away.
While writing a book about history’s most fascinating brain injuries, however, I stumbled across an antidote to this tendency — stories. Neurologists such as Alexander Luria and Oliver Sacks wrote whole “neurological novels” about the patients they treated. I realized the same approach could illuminate many other cases throughout history as well.
When we read the full stories of people’s lives, fictional or non-, we have to put ourselves into the minds of the characters, even if those minds are damaged. Only then can we see that they want the same things, and endure the same disappointments, as the rest of us. They feel the same joys, and suffer the same bewilderment that life got away from them. Like an optical illusion, we can flip our focus. Tales about bizarre deficits become tales of resiliency and courage.
Science writers often get asked how to bridge the sciences and humanities, and frankly, I never know what to say. After all, math gets you much further in understanding quantum mechanics than sculpture or opera ever will. (Although an appreciation of Kafka helps.) Still, sometimes the humanities can inform science, even improve it. Science led me into an uncanny valley, and I learned a lot down there about how the brain works. But the humanities helped me scale my way out, and gain the kind of perspective that comes only from leaving a valley behind.
Sam Kean is the author of the forthcoming book The Tale of the Dueling Neurosurgeons: And Other True Stories of Trauma, Madness, Affliction, and Recovery That Reveal the Surprising History of the Human Brain.