BRAIN GAINS
We’ve come a long way in understanding the mind since ancient neurosurgery.
The human brain has remained a medical puzzle for centuries. It has taken us years to understand that a brain injury to a hockey or football player could have severe, long-term consequences and that we shouldn’t send them back into the game right away. Remember when hockey players didn’t even have to wear helmets? Sam Kean, who specializes in science writing, takes a look at the history of our understanding of the human brain from the 16th century, when two barber/surgeons tried to perform a brain operation on France’s Henri II, to contemporary events like the shooting of U.S. Congresswoman Gabrielle Giffords who lost her speech and had to relearn how to talk.
The interview has been edited for length.
Tell me about the title of your book, The
Tale of the Dueling Neurosurgeons.
The title comes from one of the first stories in the book. It’s about two neurosurgeons [trained as barbers] who were rivals and were active in Europe in the mid-1500s. They banded together to help the king of France, Henri II, when he got injured in a jousting match. He had been clobbered in the face. Today, we would understand it as a pretty massive concussion.
I liked it as the title story because first of all you don’t think about neurosurgery going on in the 1500s but you see the origins of neurosurgery. After the king died, they did an autopsy and opened his skull, something that had rarely been done. We’re still dealing with a lot of these issues today. We hear about hockey players and football players who suffer from concussions and because they don’t have anything obviously wrong with them they go right back onto the ice or field. You hear about soldiers who don’t seem to have serious brain damage and who go back out into the battlefield. You write about presidential assassin Charles Guiteau, who killed (U.S.) president James Garfield in 1881. Guiteau was hanged and his brain became the subject of intense study. What did scientists learn about the brain of a criminal?
The idea that you could study someone’s brain and learn why they were a criminal was a hot idea at the time. At first, there were no obvious signs of damage or abnormality to Guiteau’s brain. It seemed normal.
It was on the microscopic level you could see the brain had damage due to neurosyphilis, that there was neural damage to the cells. This was a new idea, to look at brain cells for damage.
We understand today, after two world
wars, and Afghanistan and Iraq, the phenomenon of the phantom limb. But, two hundred years ago, doctors didn’t take it seriously when patients who had a limb amputated complained of pain or sensation in the limb that was no longer there. Doctors then began to understand that people can still feel limbs that had been amputated.
They realized these sensations are something that arose mostly inside the brain. In a lot of cases, people were feeling cramps or itching or shooting pains in these limbs that didn’t exist. If these limbs don’t exist the pain is largely a mental phenomenon. That doesn’t mean it wasn’t real but doctors realized there must be something going on in the brain.
They also realized how the brain used the body and how the brain map is organized. We have these territories in our brain that operate different parts of our body. So there is a hand area, a facial area, a leg area etc. When we have a hand amputated, that spot in the brain that governs the hand goes blank because there is no input from the hand anymore.
What doctors found later was that other parts of the body that were still intact can move in and encroach on the empty territory in the brain. They will use that territory for themselves. It can stir up memories, not full sensations, but ghostly sensations of the phantom limb. It is a combination of the brain expecting to find the limb there and also because other parts of the brain are using the brain territory and therefore stirring old sensations to life.
It was during the U.S. Civil War when a lot of this happened. There were so many amputations, doctors were confronted with more people talking about phantom limbs. That was the first time they realized it wasn’t a symptom of being crazy. Which of the medical stories that you uncovered do you find the most amazing? A couple stand out. The story of a woman who lost the ability to feel fear. She had an injury to the amygdala, the area of the brain that helps to process fear. She lost the ability to fear and consequently her life was transformed . . . It kept getting her into these sticky situations and she almost died because she lost that healthy sense of fear.
The other story was the Canadian twins who were conjoined at the brain and the incredible things we are learning about sensory information. If you tickle one girl, the other will laugh. One girl loved ketchup, the other hated it but could taste it when her sister ate some. That case is interesting because it gets into ideas about our sense of self, how we distinguish one person from another.
How did you get interested in the brain?
I read stories about people getting injured, their behaviour changing drastically afterwards, and I did not believe the stories and I set out to disprove them.
I not only found out the stories were true but they gave interesting insights into the way the brain works. One of the stories was about someone who got hurt in the temporal lobe. The person could tell human beings apart, they could tell plants apart. But they couldn’t tell animals apart. They couldn’t tell the difference between elephants, rats or dogs.
The other story I read was about people who lost all ability to speak but they could sing. I thought that doesn’t make any sense. How could you do one thing without being able to do the other? But the more I looked into this story the more I found it was true.
Gabrielle Giffords, the U.S. Congresswoman who was shot in the head, this actually happened to her. She lost the ability to speak but she could sing Cyndi Lauper’s “Girls Just Wanna Have Fun.” She retrained her brain to speak again by listening to songs. The language centres were damaged so the brain took a back alley to help repair them. I guess that makes sense since you see people learning how to walk again and reuse their limbs after an accident.
It’s exactly the same thing. The brain sets up new circuits, pathways. Did you find the topic of the brain a difficult one?
Yes, because when you are talking about neuroscience you are talking about subjects from tiny molecules to language to people’s belief in an afterlife or the supernatural. You are running the gamut of human experience.
On the other hand I was writing about things people with brain injuries have to deal with in their everyday life: when you hear a story about a parent who can’t recognize his children; or people who can’t recognize animals, that’s something anyone can relate to.
What would life be like if that happened to me?