by Sam Kean
These pure category deficits, while rare, imply something important about the evolution of the human mind. Our ancestors spent a lot of time thinking about animals, whether furry, feathered, or scaly. The reason is obvious. We’re animals ourselves, and the ability to recognize and pigeonhole our fellow creatures (as food, predators, companions, beasts of burden) gave our ancestors a big boost in the wild. Eventually, we probably developed specialized neural circuitry that took responsibility for analyzing animals, and when those circuits crap out, the entire category can slip clean out of people’s minds. Our ancestors exploited fruits and vegetables, too, as well as small, tool-like objects. Probably not coincidentally, these are the two other categories of things that commonly disappear from people’s mental repertoire. Our brains are natural taxonomists: we cannot help but recognize certain things as special. But the danger of specialized circuitry is that if the circuits go kaput, an entire class of things can go extinct mentally.
The way we catalogue the world teaches us something else about mind-brain evolution. I hesitate to even evoke the m-word, since it’s such a contentious term. But after reading about fruit deficits and animal deficits and color deficits, it seems pretty clear that our brains do have modules on some level—semi-independent “organs” that do a specific mental task, and that can be wiped out without damaging the rest of the brain. Some neuroscientists go so far as to declare the entire brain a Rube Goldberg machine of modules that evolved independently, for different mental tasks, and that nature stuck together with gum and rubber bands. That “massive modularity” pushes things too far for some scientists: they see the mind-brain as a general problem solver, not a collection of specialized components. But most neuroscientists agree that, whether you call them modules or not, our minds do use specialized circuits for certain tasks, such as recognizing animals, recognizing edible plants, and recognizing faces.
In some sense we analyze faces the same way as other objects, by scribbling our eyes over the lines and shadows and contours we see, which causes certain ensembles of neurons to harmonize and hum. That said, analyzing faces requires more sophisticated brainware than analyzing other objects, both because social creatures like us need to read people’s thoughts and feelings on their visages, and also because—let’s face it—most people’s features look pretty darn similar overall.
As with any mental faculty, many different patches of gray matter contribute to analyzing faces. But certain patches near the brain’s south pole, like the fusiform face area, have special responsibilities. On brain scans the FFA lights up whenever people study faces, and disrupting it electrically causes faces to morph and stretch in funhouse ways. The most notable feature of the FFA is holistic processing. Instead of piecing together a face feature by feature—the way we seem to process regular objects—we read faces instantly, at a glance. In other words, a whole face is greater than the sum of the eyes and nose and lips in isolation.
To be sure, the FFA can light up in other circumstances. Ornithologists and auto aficionados and Westminster judges get lots of pings there when they study birds and cars and dogs, respectively. In other words, whenever we need to parse a narrow class of nearly identical things, our plastic brains might recruit the FFA to help out.
Still, the balance of evidence suggests we do have a specialized, if nonexclusive, face circuit. Even with object and animal aficionados, the FFA lights up strongest for faces. And beyond the FFA—which is just one component of a larger system—our brains also process faces in more complicated ways than other objects: we have circuits that light up only for certain emotional expressions or only when someone looks in a certain direction. Also unlike with cars or whatever, we constantly detect faces where they don’t exist, in bathroom fixtures and tortillas and random piles of rocks on other planets (a tendency called pareidolia). Anytime we see two dark spots hovering above a quasi-horizontal line, we can’t help but want to introduce ourselves. Seeing faces is mandatory.
At least for most people. The best evidence for a specialized face circuit comes from people who struggle to recognize faces because of damage to the FFA or faulty wiring there. Some face-blind people brush right past their dearest friends on the street without blinking. For birthday bashes, even their own, they might ask people to wear name tags; same for family reunions. To recognize people at all, they either listen to their voices; memorize how they walk; or scan for distinctive moles, scars, or haircuts. (The great portrait painter Chuck Close has severe face-blindness; this seems ironic at first, but his need to scrutinize faces probably enhances his talent.) Some face-blind people cannot even determine gender or age. A Welsh mining engineer who fell asleep after a few drinks and had a stroke woke up unable to tell his wife from his daughter. In another case, a lesion left an Englishman so bereft of face-recognition skills that he quit society and became a shepherd. After a few years he could tell most of his sheep apart by looks, but he never did get the hang of humans again.
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The selective sparing of face circuits can also reveal a lot. In 1988, in Toronto, a man named C.K. was struck by a car while jogging and suffered a closed head injury. Aside from some emotional outbursts and memory problems, he more or less recovered and eventually completed a master’s degree in history with the help of a voice-activated computer. Still, one faculty never recovered: C.K. couldn’t tell any inanimate objects apart, even food. His neurologists recalled taking him to a buffet and watching him shuffle around, bewildered. Everything looked like “differently colored blobs,” and at the table he seemed to stab his fork at random and eat whatever he speared. At home he could no longer stage mock battles with his beloved toy soldier collections, since Greek and Roman and Assyrian armies all looked the same. He couldn’t recognize body parts, either: more than once he tried giving the heave-ho to a strange pink thing poking out from his sheets—his foot. Yet for all this blundering about, C.K. proved a savant with faces and learned them readily. He even startled his neurologist in the shower at the gym once by helloing the doctor well before the doctor could place him.
Intrigued by the purity of his deficit, neuroscientists ran C.K. through a battery of facial-recognition tests. He proved he could recognize celebrities easily, even with parts of their faces blacked out; he could also recognize celebrities when scientists superimposed disguises (e.g., Groucho glasses) on them. He could instantly pick out all the faces in those find-the-hidden-picture puzzles that conceal faces in, say, a forest scene. He could recognize Bugs Bunny, Bart Simpson, and other cartoon characters, and recognized caricatures of Elvis, Bob Hope, and Michael Jackson. (Caricatures often send people’s FFAs into a frenzy, because they exaggerate facial features. It’s like face porn.) Most impressively, C.K. could scan a stranger’s face in a photograph just once, then pick him out of a photographic lineup of near twins, even when the target was facing a different direction. On many of these tests C.K. scored higher than normal, control people did.
On the flip side, C.K. floundered on other tests. When shown upside-down faces, for instance, even faces he’d identified before, recognition always eluded him. Neuroscientists have long known that inverting any object hinders recognition, and that inverting faces hinders recognition even more than inverting animals, buildings, and other things. But while other people can usually puzzle through an upside-down face, C.K. was clueless. He couldn’t even identify upside-down cartoon faces, something most people found laughably easy. Splintering or scrambling a face, by exploding it into parts, also flummoxed him. And when shown an Arcimboldo—those odd, sixteenth-century “portraits” pieced together from fruits and vegetables—C.K. rarely saw anything but the overall mien; he was oblivious to the pear noses and apple cheeks and green-bean eyelids that make the rest of us gasp.
C.K.’s troubles imply that the brain can normally recognize faces through two channels. There’s the FFA circuit, which recognizes faces quickly and holistically. This system escaped damage in C.K. But the FFA circuit is picky: it needs to see the eye
s hovering above the mouth and needs to detect rough symmetry, or it fails to engage. In that case a backup system should take over. This backup system is slower, and probably pieces upside-down or fractured faces together feature by feature. In other words, it treats the face more like an object. In fact, it probably employs our general object-recognition brainware—which explains why C.K. suddenly floundered, since his object-recognition skills hovered in the bottom percentile. Dehumanize a face—turn it into a mere object—and the face savant became face-blind.
Naturally, the same circuits you use to recognize people around you also light up when you recognize your own features in the mirror. But seeing your own face also stirs up deeper associations—it taps into your id, your ego, your sense of self. And it was this aspect of the self that the facial wounds of World War I so threatened.
The study of facial disfigurement really took off in the twentieth century, and not only because of modern war. The rise of handguns and especially cars produced plenty of accidents among civilians. Surprisingly, though, in all groups studied, many disfigured people rebounded quite well: even some of the most severely injured showed few psychological hang-ups. Like the mutilés who married their nurses, these people tended to brush the disfigurement aside and keep living life. Some also joked about their scars when they caught people staring, mentioning a botched bear-wrestling career or saying, “God hit me with a frying pan.”
Still, many victims reacted more predictably. They showed symptoms of mourning at first, grieving for their faces as for the dead. And they remained isolated long after their physical injuries had healed, suffering the gapes and double takes in silence. Years after the injury, a few were still startled by their reflections in plate-glass windows. A self-image is hard to let go of.
In the past decade psychologists have expanded their understanding of facial trauma by studying a new group of patients—the recipients of face transplants. A face transplant involves just what it sounds like, the surgical transfer of a nose, lips, cheeks, and other tissues from a dead person to a living one. In this way it combines the heroic reconstructive surgery of World War I with the lifelike masks of Anna Coleman Ladd and others. What’s more, because a face transplant involves a living mask, a mask that can speak and express emotions, psychologists could finally probe the question that Ladd’s work evoked so long ago: would the brain accept a new face as its own?
The first recipient of a face transplant, a thirty-eight-year-old Frenchwoman named Isabelle Dinoire, swallowed a mouthful of sleeping pills in May 2005 after an argument with her daughter. She didn’t expect to wake up again but did. Groggy, she put a cigarette in her mouth and found it wouldn’t stay. That’s when she noticed the pools of blood: her Labrador retriever had mauled her while she slept. Dinoire staggered to a mirror. Tousled, dirty-blond hair still ringed her face, but the dog had gnawed her nose down to two skeletal holes, and no lips covered her teeth or gums. Although emergency care stabilized her, in later months Dinoire became a recluse, hiding behind a surgical mask at all times.
In the years leading up to Dinoire’s injury, the medical world had worked itself into a froth over the ethics of face transplants. A few fear-mongering doctors actually suggested that donors’ families might start stalking transplant recipients, or that a black market in beautiful faces would spring up. Some activists proposed banning even the discussion of face transplants, to spare the feelings of the already disfigured. Less hysterical types opposed the surgery on medical grounds. Transplanting skin provokes an especially strong immune response, so transplant recipients would have to take heavy-duty immunosuppressants, increasing their risk for catching many diseases and probably shortening their lives.
Nevertheless, other doctors pursued the idea. They cited surveys suggesting that people would indeed trade many years of life to restore a damaged face. Surgeons favoring facial transplants also pointed out that naysayers had sown similar fears of identity crises before the first heart transplants, and none of those had come to pass. Doctors emphasized the limits of alternative treatments as well. Plastic surgeons could do clever things like fashion a new nose from a toe (really), but it often looked terrible and obviously didn’t function the same way. There’s just no substitute for facial tissue.
In examining the risks of face transplants, doctors turned to whatever approximations they could find. To determine whether the new face would look more like the donor (who would supply the skin and cartilage) or the recipient (who would supply the underlying bone structure), surgeons swapped faces on cadavers, then asked volunteers to judge before-and-after photographs. They concluded that (aside from certain features, like eyebrows) the face would look different than both the donor and recipient. It would be a new, unique face. Doctors examined the outcomes of other radical transplants as well, like tongue, larynx, and especially hand transplants. As with face transplants, hand transplants involved multiple kinds of tissue, so the demands on the patient’s immune system would be similar. Hand transplants also proved that the brain could integrate neurologically demanding tissues pretty easily. (It probably helps that, as with faces, we have specialized neurons that fire only in response to viewing hands—a legacy of hand gestures in prelanguage communication.
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Doctors also evaluated the psychology of transplants. First and foremost, people needed to accept the foreign tissue as part of them. With hands, doctors made sure to correct any Freudian slips, forcing patients to refer to “my hand,” not “the hand” in conversation. Doctors also emphasized the need to use the hands in daily activities, the more intimate the better: while the surgeons on one transplant team scowled to see a patient nervously chewing the nails on his new hand, his psychologists rejoiced—you don’t bite someone else’s fingernails. Unfortunately, those psychological safeguards didn’t always work. The first hand transplant, in 1998, for one Clint Hallam, had gone quite well surgically, and Hallam had felt sensation creeping back into his new hand at a rate of a few millimeters per day. But after twenty-nine months Hallam stopped taking immunosuppressants, saying that the hand now creeped him out. His immune system attacked it, and doctors had to amputate.
If something went wrong with a face transplant, amputation wasn’t an option. Nevertheless, French surgeons—who tempted fate by comparing themselves to Copernicus, Galileo, and Edmund Hillary—pushed ahead in 2005 with Isabelle Dinoire, the woman whose Labrador had mauled her. They picked Dinoire partly because she’d lost “only” her nose, lips, and chin (the facial triangle), which made for an easier surgery. A suitable donor turned up in November 2005, when a forty-six-year-old woman in a nearby town tried to hang herself and ended up brain-dead. She matched Dinoire in age, blood type, and skin tone, and Dinoire’s surgeons rushed into action. They spent hours “recovering” the hanged woman’s face—peeling away her skin and connective tissue along with blood vessels and nerves, leaving only a red mask of muscle behind. The transfer onto Dinoire then took the better part of a day.
During recovery, Dinoire’s new face swelled frightfully, and on day eighteen her body nearly rejected it. Meanwhile the media got pretty frenzied; British tabloids even outed the identity of the brain-dead donor. But Dinoire recovered better than anyone could have hoped. She was eating with her new lips within a week and talking shortly thereafter. Hot and cold sensation returned within a few months, as did most movement. Most important, she started leaving the house again, resuming her social life and meeting new people. The one facial movement that lagged was smiling—at ten months she could only half smile, like a stroke victim. But by fourteen months she could smile fully again. She had reason to.
Chinese surgeons performed the second face transplant in April 2006, and more soon followed, with remarkable results. Many patients could speak, eat, and drink by day four. Sensation usually returned within a few months. And brain scans revealed that their faces came back “online” quickly, much more quickly than hands did. (Patients in fact got a kick out of watching their once-dorman
t face territories “wake up” on the scans.) The psychological adjustment usually went smoothly as well. It seemed to help that, unlike with a hand, you don’t have to look at your face constantly. And when people did look in a mirror, they found it easy to accept the reflection. It wasn’t the old “them,” certainly. But the underlying bone structure was enough to evoke a feeling of “me, that’s me” in the mirror.
Bolstered by these early successes, a few teams have now performed the more demanding full-face transplant. One early recipient, the third full-facial, was Dallas Wiens. In November 2008 the twenty-three-year-old Wiens was painting some structures on the roof of a Fort Worth, Texas, church when he accidentally steered his hydraulic lift into some power lines. The air around his head reportedly glowed blue for fifteen seconds, and the current running through his face melted it into a blank mask, one writer noted, not unlike “Mr. Potato-Head without the features.”
* In March 2011 Wiens got a replacement. The new face arrived in a blue cooler in a slurry of ice water; it was the size and thickness of medium pizza dough when unfurled.
Surgeons first hooked the donor face up to Wiens’s blood supply through his carotid arteries. This took some creative suturing, since the donor had cigar-sized carotids, while Wiens’s vessels (which had atrophied) looked like drinking straws. The transplant team felt enormous relief when the face started to flush pink, a sign that it was taking blood. In all, the surgery ran seventeen hours, during which time Wiens’s new face smirked, winked, and grimaced as surgeons manipulated it to reattach various nerves and muscles. Afterward, doctors rolled him into the ICU to see if Wiens would be able to smirk, wink, and grimace on his own.