Inside the Brain’s Amazing Ability to Re-Map Your Body
Surgeons only have to go so far before the brain takes over and reconnects the nervous system
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Before the first face transplant surgery nearly a decade ago, doctors debated whether patients undergoing the procedure would end up with immobile masks of flesh. Would patients ever blush, blink or smile again? We now know the answer is yes, thanks to the brain’s remarkable ability to reactivate its internal maps of the body.
There are two such maps, each found within a vertical strip of gray matter that originates behind the ears and stretches to the top of the head. One strip, the sensory cortex, receives and responds to touch sensation; the other, the motor cortex, sends messages to move. Each contains an inverted map of the body—a leg area near the top to talk to the legs, a hand area a little farther down for the hands, and so on. The face appears near the bottom and has a disproportionate, Canada-size territory, to account for all its sensitivities and intricate movements. The lips, cheek, tongue and other parts all have provinces.
But in patients who suffer from disfiguring diseases or facial accidents like animal attacks, the face area goes silent. Take Richard Lee Norris, whose lower face including flesh and bone was mostly blown off in a shotgun accident in 1997. For 15 years, he would leave his home only at night and only with his face covered. Before the transplant, Eduardo Rodriguez, a plastic surgeon at New York University who recently reported on the first 28 facial transplants ever performed, put Norris in a brain scanner and asked him to try to smile and open his mouth. Because Norris had no lips or lower jaw, the corresponding brain regions remained devoid of activity on the scan. “It’s like part of the brain was asleep,” Rodriguez says.
Asleep but not dead. During transplant surgery, a grueling procedure that takes up to 36 hours, doctors attach nerves in the donor face to the patient’s own nerve stumps. The face comes from a deceased person whose family gave permission and who matches the recipient in age and skin tone. It arrives in the operating room chilled with ice and unfurls like raw pizza dough.
Even after doctors establish hard-wired nerve connections between the face and brain, communication is clumsy and slow at first: Nerves and neurons need practice working together. (This also explains why toddlers—whose brains are creating body maps for the first time—need practice to talk or walk fluently.) To help this process along, patients undergo therapy—making sounds, or opening and closing the lips. This “facial reanimation” helps the maps learn to respond to and send messages to the new face.
Among transplant patients studied so far, simple hot/cold sensation usually returned within a few months, while coordinated movements like biting and chewing took up to eight months; some patients couldn’t smile until two years later. But all patients recovered some movement and sensation. And when scientists rescanned patients’ brain maps afterward, it was clear the new face had awakened those dormant territories, which now crackled with activity.
For most of history neuroscientists would have believed a transformation like this to be utterly impossible. But the adult brain is incredibly plastic and can fairly quickly take command of a foreign face. Surgeons were also surprised to learn in the Norris case, where they had trouble reattaching every nerve, that nerves don’t necessarily need to touch. Getting the donor and transplant nerves close can still jump-start communication.
Victims of facial trauma often deny that what they see in the mirror is their “true” self. But psychological changes come alongside physical ones. After receiving a new face, “they think it’s themselves in the mirror,” Rodriguez says. “They’re restored.”