“The dog should be calm,” Mark said. “And he should be unafraid of novel environments.”
I had no grant funding to do this. Everyone was volunteering, but it still cost $500 an hour to rent time on the MRI. I had a small amount of discretionary research funds, but to keep costs down, we couldn’t burn up scanner time just to let the dogs get used to the room. If we could find dogs that naturally remained calm in new situations, it would significantly boost our chances of success when it came time to actually do the scans.
“The most important trait,” Mark said, “is motivational drive.”
“What do you mean?” I asked.
“The dog has to enjoy the training. If he isn’t having fun, it is much harder to shape behaviors.”
Thorndike’s first law. The more the dog likes something, the stronger the S-R relationship.
“Do you know any dogs that meet all these criteria?” I asked.
“I know some that compete in agility trials,” he said. “But the owners can be a problem. If the owner isn’t motivated to do the training, then the dog won’t be either. A lot of people in the dog world have their own ideas about training. For this to work, we will want the training protocol to be consistent between dogs and owners.”
I hadn’t thought about the human side of the equation. Getting people to do what you want is a lot more difficult than getting dogs to. If Mark could do all the training, that would solve the problem, but he still had a business to run. What if I, or Andrew, learned how to train dogs? I wondered whether Callie could do this. She certainly wasn’t calm. But she was highly motivated by the prospect of hot dogs. The idea of training Callie to go into the MRI seemed unlikely, so I kept that thought to myself.
Mark had been in dog training for a long time, and he knew a lot of dogs and owners in Atlanta.
“I have a few people in mind,” he said. “Let me talk to them and get back to you.”
I was excited. I didn’t think anyone in the dog world would take the idea of scanning dogs’ brains seriously. But Mark was not your typical trainer. Much to my surprise, he was just as excited about the Dog Project as I was. After twenty years of dog training, he was feeling a bit burned out. The Dog Project, he later told me, renewed his enthusiasm for his work, opening up a whole new dimension in improving dog-human communication.
5
The Scanner Dilemma
WHILE ANDREW AND I WERE pretty sure we could figure out how to scan a dog’s brain, we had neglected to consider a minor, though important, detail: Where? The Dog Project needed a home.
The lab had been captivated with the “big question”—figuring out what goes on in a dog’s brain. Details like the type of brain scanner, or where to find it, were just that: details. Up until this point, I hadn’t been concerned. The best part of being a scientist is when the ideas are coming so fast and furious that you can’t even write them down. You don’t have time to worry about details. They just get in the way.
But eventually we had to confront the practical aspects of pulling this off. And the first detail was finding an MRI facility that would let us bring dogs into its scanner.
Yerkes National Primate Research Center, located about a mile from the main Emory campus, was our first choice for the MRI scanning. Nestled in a valley lined with southern pines, Yerkes seemed ideal. It was a short drive from the lab, so we could easily move our equipment there. And because it was off the main street, it was also quiet and peaceful. The last thing we wanted was to scare a potential canine subject with a trip through a busy intersection. From a dog’s perspective, I imagined Yerkes would look like a walk in the woods.
Yerkes also specialized in the study of animals—primarily monkeys. Andrew and I congratulated each other on our good fortune. We had come up with the idea of scanning the brain of a fully awake dog, and one of the premier facilities for the study of animals turned out to be right in our backyard. In fact, there are only eight such facilities in the United States. Yerkes even had an MRI scanner dedicated specifically to the study of animals. A friend and colleague of mine, Leonard Howell, was director of the Yerkes Imaging Center and invited us to take a look at how they scan monkeys’ brains.
Although the Yerkes MRI center is unusual in the sense that it was purposely built for the study of how primate brains function, it is actually not that unusual to have such a facility at a veterinary school or even at a high-tech veterinarian hospital. Any and all medical diagnostic tests performed on humans are now also done on animals. The challenge with obtaining an MRI of an animal, however, is that the subject must remain absolutely still. In a veterinary setting, this means sedating the animal with medication. But sedating an animal means that you can no longer study how the brain functions.
Leonard had pioneered a new approach to studying monkeys’ brains. Instead of sedating the monkeys, he had figured out how to scan their brains while fully awake. This was a big deal to neuroscientists. When you administer drugs that render the subject unconscious, you change brain function in a major way. How this happens is not really understood. While the unconscious state is interesting for its own sake, most neuroscientists spend their time trying to figure out how the conscious brain works. Having conscious subjects, animal or human, is critical.
Working with monkeys is a dangerous business. Monkeys are mean. Not if-you-don’t-give-me-food-I’ll-ignore-you mean. More like if-you-don’t-give-me-food-I-will-rip-it-from-your-hand-and-eat-your-finger-and-chew-off-your-face-for-dessert mean. This presents certain logistical problems for scanning their brains, especially if they are to remain fully awake.
What’s more, because they are closely related to humans, diseases can pass between the species with ease. For instance, HIV, the virus that causes AIDS, is believed to have originated in African chimpanzees. Monkeys harbor a strain of the herpes virus that is fatal to humans, which can be passed along if, for example, one spits on you, which monkeys often do. The monkeys also have to be protected from us. If humans can catch diseases from monkeys, the opposite is also true. Monkeys are particularly susceptible to tuberculosis. For all of these reasons, scientists must take extraordinary safety precautions to work around monkeys.
Andrew and I made special arrangements to see how Leonard and his team scanned the brains of fully awake monkeys. After registering at the security desk, we were escorted through a series of keyed doors and deposited in a changing room.
“You need to gown up,” Leonard’s assistant instructed. “From this point forward, everyone must be fully protected. This means gown, face mask, and eye shield.”
The so-called eye shields covered our faces entirely and were claustrophobic. They also had a tendency to fog up. The face masks were the surgical type. The combination of shield and mask made speech about as effective as talking into a pillow.
Our first stop was the training lab. Three oven-sized stainless steel boxes lined one wall. They resembled small refrigerators, but the hasp-type handle suggested something akin to a pottery kiln.
“These are the training boxes,” the assistant said. Opening one revealed a sterile interior with white enameled walls and a cubby for devices allowing tubes and wires to snake out to various pieces of monitoring equipment.
On the other side of the room sat an upright tube constructed from PVC plumbing material. A foot in diameter and three feet tall, the top end was capped with clear Plexiglas. A four-inch slot was cut in the center of the cap, and a plastic shelf sat below the slot.
The assistant explained, “This is the restraint device. The monkey has a collar around its neck that fits into the slot. With its head poking through, it rests its chin on the shelf.”
Andrew pointed to a pair of hoses that were attached to the bottom of the device. “What are these for?”
“Waste drainage.”
Pushing the resulting image out of my mind, I asked, “How do you get the monkeys to go in there?”
The assistant pointed to a metal rod on the wall. “That affixes to
their collar, and then we can steer them into the device from a safe distance.”
So far, none of this was looking appropriate for the Dog Project. I kept silent, though, still eager to learn anything that might be useful for us. The device kept the monkey from escaping, but it wasn’t clear what would keep its head still.
The assistant pulled a pink block of foam from a shelf.
“This is how we immobilize the head,” he explained. “First, we make a mold of the monkey’s head, which is then used to make a positive cast with plaster. From that, we use a gel-type material to make a soft cast, which fits snugly around its head. We cut holes for the eyes, nose, and mouth. This gets clamped to the restraint device.”
“And the monkeys cooperate with this?” I asked.
“They learn,” he replied. “We shape their behavior through rewards. It takes about six months to train a monkey to go into the restraint device.”
“What are the boxes for?” Andrew asked.
“Those are conditioning boxes. Once the monkeys are trained to go into the restraint device, the whole rig is placed in the box. We then train them with lights and sounds.”
“Trained for what?” I asked.
“To get addicted to drugs.”
Right. Leonard’s research group was studying the biology of drug addiction. To understand addiction, you need to look at the whole process, from the first time somebody uses a drug to the point he becomes addicted. Because it is unethical, obviously, to get people addicted to drugs, Leonard uses monkeys as a stand-in.
The assistant continued. “Once they are trained to associate cues with drugs, we take the whole rig to the MRI scanner so we can see what is going on in their brains while they are craving drugs. Are you ready to go down to the scanner?”
I couldn’t wait to get out of there.
Because the MRI’s strong magnetic field affects computer equipment, the control room is partitioned from the main scanner room. When we entered, a young woman draped in a surgical gown was staring intently at a computer screen with several brain images.
She was not pleased to have visitors.
“Who are you?” she snapped at me. “Have you had a TB test?”
I honestly couldn’t remember when I had last been tested for tuberculosis. Fortunately, Andrew distracted her.
“I have!” he announced cheerfully.
Leonard’s assistant explained that we were there to observe MRI scans of monkeys. The monkeys being scanned that particular day were from a different research lab. Because they had not gone through Leonard’s behavioral training, these monkeys had received a heavy dose of sedation. One monkey, surrounded by three veterinary technicians, was in the scanner when we entered, attached to monitors that reported vital signs like heart rate, breathing, and body temperature. Another monkey was on a cart, recovering from anesthesia. I almost walked right by it, until it started twitching with muscle spasms as the sedation wore off.
We took the opportunity to explain what we were trying to do with the Dog Project. The vet techs were not enthusiastic.
“You’re going to have to monitor them,” one said. “Vital signs and core body temperature.”
“How do you do that?” Andrew asked.
“Rectal probe.”
“Why would we do that to a dog that isn’t even sedated?” I asked.
“It’s standard operating policy to fully monitor all animals undergoing a procedure,” she replied.
“But we’re not doing a procedure,” I protested. “The dogs will be trained to go into the scanner willingly.”
She wasn’t buying it. “Who is going to be with the dogs?”
“Us, the dog trainer, and the owner.”
She shook her head. “I suppose you two are okay because you’re university employees, but no outside visitors.”
Although it was clear there was no convincing this woman, I pressed on. “Look, would you volunteer your dog to be in an experiment without being present?”
“I suppose not. Even so, you’ll have to convince the review committees.”
Andrew and I had seen enough. It surprised me that one of the nation’s premier animal research facilities wasn’t more encouraging about the Dog Project. But we were more determined than ever to find the right home for it.
When I got home that night, Callie and Lyra greeted me with unusual attention. Instead of jumping up and down as they usually did, they sniffed my feet intently. As I walked through the house they trailed me from a respectable distance, focused on my feet.
They knew. I had tracked monkey stink home with me.
Logistical problems aside, I realized there was no way we could do the scanning at Yerkes with all those monkeys.
6
Resonant Dogs
WHEN HELEN AND MADDY started kindergarten, I began a tradition of visiting their classes every year to teach the kids about the brain and perhaps convey some of the excitement in figuring out how it works. The first time I did “Brain Day” at the school, the principal and I had a frank discussion of what I planned to discuss.
“Will you emphasize the importance of brain health?” she asked. “Tell the kids about wearing bike helmets and how drugs damage the brain?”
“Um, sure,” I said. “How do you feel about me bringing a brain to school?”
“You mean a plastic model?”
“No. A preserved human brain.”
“In a jar?” she asked.
“A bucket,” I explained. “We have a set of teaching brains at the university that I can check out. The kids can touch it.”
A look of fascination flashed across the principal’s face, immediately replaced with one of consternation.
“We’ll need to send home a permission slip.”
She needn’t have worried. Not a single parent objected.
The kids loved Brain Day. Even a few teachers snuck into the classroom to touch the brain. I’m not sure the students ended up remembering much of what I said that first time, but it certainly made an impression when I reached into the bucket and brought out a full-sized, dripping wet human brain. Half the class said, “Cool!” while the other half simultaneously said, “Gross!”
By the time of the Dog Project, I had done Brain Day seven years in a row. Maddy was in fifth grade, her final year in elementary school, and Helen had begun middle school. The questions the students asked always fell into a predictable pattern. The bright ones asked questions like “Where do dreams and emotions come from?” Others just wanted to jam their fingers as far into the brain as they could. The last year I did Brain Day at the elementary school, a small boy raised his hand and asked a question I had never heard before.
“Have you ever studied a dog’s brain?” he asked.
The teacher chided the boy for asking silly questions.
“As a matter of fact,” I interrupted, startled by the coincidence. “We are about to do just that.”
With Helen’s transition to middle school, there wouldn’t be an opportunity to bring the brains to her science class. Sixth-grade science was devoted to geology, meteorology, and astronomy, and biology wouldn’t return until the seventh grade.
Growing up, Kat and I had gone to public schools, and we believed strongly in public education. As is true in many cities, however, the quality of the public schools in Atlanta varies widely. The schools that Helen and Maddy attended were solid but had the difficult mission of fulfilling the needs of all the kids in a very diverse district. A large number of children couldn’t afford to buy lunch and many had special needs.
At the end of her first week of classes in middle school, Helen brought home her science textbook, one apparently compiled by a team of bureaucrats who had overdosed on their daily Ritalin. Every page was crammed with full-color pictures guaranteed to distract even the most focused student from the text. The text itself was nothing more than a litany of facts to be memorized. Although it was the neighboring school district that had made national headlines for banning the w
ord evolution from its textbooks, you could still detect a patronizing tone throughout. More than anything, it smacked of scientists-say-it-is-so (wink-wink).
Helen struggled. Although she was diligent with her homework, her test and quiz scores hovered in the mid-70s. Kat and I didn’t want to be helicopter parents, but we couldn’t let Helen flounder. It was time for a parent-teacher conference.
Helen’s science teacher was a pleasant man who bore a striking resemblance to Ed Helms. The classroom looked much like I’d expected it to: slate laboratory tables arranged in neat rows, a chemical sink with an eyewash station should any mishap occur, wall cabinets full of rock specimens, a large periodic table of the elements on the wall.
After an exchange of pleasantries, I moved on to the reason for our meeting. “We’re concerned about how Helen is doing in science.”
He pulled up a grade spreadsheet to show us.
“Helen’s a good student,” he said. “She turns in all of her homework.”
“Yes,” I said, “but she seems unclear on what material she will be expected to know.”
“The students get exposed to the material multiple times,” he explained. “They hear about it in class. They read it in the textbook. And then we review it.”
This may have been partly true, but having helped Helen with her homework and then heard what was on each test, I was skeptical. Helen was in fifth-period science, and I began to suspect that the teacher might have been confusing what he had gone over with the classes at the beginning of the day with those at the end.
“Helen said her class is noisy and that she has a hard time hearing what you’re saying.”
“By fifth period,” he replied, “the kids have a hard time sitting still.”
Kat and I had already heard about his method of making the kids walk laps around the hallway to burn off energy. Maybe this helped some students concentrate, but it took valuable time away from Helen actually learning science.
How Dogs Love Us: A Neuroscientist and His Adopted Dog Decode the Canine Brain Page 5
