How Dogs Love Us: A Neuroscientist and His Adopted Dog Decode the Canine Brain

  Text copyright © 2013 by Talking Dogs LLC

  All rights reserved.

  No part of this book may be reproduced, or stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without express written permission of the publisher.

  Published by Lake Union Publishing

  www.apub.com

  eISBN: 9781477850619

  For Lyra

  Contents

  Start Reading

  PROLOGUE Dress Rehearsal

  1 Dia de los Muertos

  2 What It’s Like to Be a Dog

  3 A Fishing Expedition

  4 Puppy Steps

  5 The Scanner Dilemma

  6 Resonant Dogs

  7 Lawyers Get Involved

  8 The Simulator

  9 Basic Training

  10 The Stand-In

  11 The Carrot or the Stick?

  12 Dogs at Work

  13 The Lost Wedding Ring

  14 Big Questions

  15 Dog Day Afternoon

  16 A New World

  17 Peas and Hot Dogs

  18 Through a Dog’s Eyes

  19 Eureka!

  20 Does My Dog Love Me?

  21 What’s That Smell?

  22 First Friend

  23 Lyra

  24 What Dogs Are Really Thinking

  Epilogue

  Notes

  Acknowledgments

  About the Author

  When the Man waked up he said, ‘What is Wild Dog doing here?’ And the Woman said, ‘His name is not Wild Dog any more, but the First Friend, because he will be our friend for always and always and always. Take him with you when you go hunting.’

  — RUDYARD KIPLING, JUST SO STORIES

  PROLOGUE

  Dress Rehearsal

  EMORY UNIVERSITY, ATLANTA, GEORGIA

  JANUARY 2012

  CALLIE WAS DANCING in the lab. Zooming from person to person, the little black village dog with the energy of a rocket knew that all the months of training had led to this moment. Her eyes sparkled with life, and her rat-tail wagged side to side with such intensity that her head moved in exactly the opposite direction. She was ready.

  Let’s get on with it!

  Callie’s excitement was infectious. Everyone in the lab wanted to see the experiment we were about to perform, mostly because nobody thought it would work. Could we really scan a dog’s brain to figure out what it was thinking? Would we find proof that dogs love us?

  With the team assembled and ten minutes until scan time, we headed to the hospital. Dogs, of course, were not allowed on campus, and here was a very special dog marching across the quad with a dozen people in her entourage. I carried the backpack full of treats and supplies, Andrew toted the computer that would record the timing of the experiment, and Mark hauled the plastic stairs that would let Callie walk up into the MRI—she would have to do that on her own. Everyone else tagged along, snapping photos and texting their friends: the Dog Project was actually going to happen.

  Students, stuck in their lectures, stared out classroom windows as Callie led us all to meet her destiny with a big-ass magnet.

  We entered the MRI room through a secret entrance to the hospital.

  Even though the Dog Project had already taken on a circuslike atmosphere, there was no need to alarm the patients by parading Callie through the hospital corridors. I pulled shut the massive door, which was clad in copper to keep out stray electrical signals. It made a tight seal, almost like an air lock. With the room secure, I let Callie off-leash.

  With nose to the ground and tail held high, she trotted around the MRI scanner, making several circuits. Curiosity satisfied, she exited the magnet room and checked out the control room. Despite the hospital setting, the floor was filthy. Several years earlier, a janitor had attempted to clean the MRI room. Imagine his surprise when the floor buffer levitated off the ground and crashed into the bore of the magnet. Ever since, the janitorial staff had been forbidden from entering the facility. The cleanliness had subsequently declined.

  Callie, of course, found every crumb of organic matter that had, at one time, been edible.

  Before we could do any brain scanning, Callie would have to go into the magnet. Normally, magnetic fields are imperceptible to us. But the MRI creates a field sixty thousand times stronger than Earth’s magnetic field. You definitely feel it. As you approach the center of the MRI, the magnetic field increases rapidly in intensity. If you moved a piece of metal through the field, an electrical current would be induced. The same thing happens when a person moves through the magnetic field. The field induces small electrical currents in your body. These currents are most prominent in the inner ear, creating a slight spinning sensation as you are moved into the center of the magnet. For some people, though, it can create a nauseating sense of vertigo.

  Up until that moment, the thought had not occurred to me that dogs might be more sensitive to the magnetic field than humans. We were about to find out.

  I placed the portable steps at the base of the patient table. Callie sniffed them but showed no interest in climbing them. She continued to trot around the room, curious about every nook and cranny. Time to bring out the hot dogs.

  That got her attention. Unable to resist the scent of hot dogs, she padded up to the top of the steps, but once there, she balked at climbing onto the patient table. Of course, I could have picked her up and put her there, but it was important to remain faithful to our ethical principle of self-determination. Callie had to do it of her own free will.

  The MR techs started laughing. How could we do an MRI if the subject wouldn’t even get on the table? But I knew Callie would eventually come around. The environment was new and exciting. Once she settled down, she would focus on what she had already learned.

  After five minutes of walking up the steps and jumping off, Callie tentatively placed her paw on the patient table. With great enthusiasm I encouraged her to keep going.

  “That’s it, Callie! Good girl! Want more hot dogs?”

  She got it. Once up on the table, she saw it wasn’t scary at all and that there was a ready supply of hot dogs. Now she had to go into the bore of the MRI.

  I had already secured the foam chin bar in the head coil, located dead center in the magnet tube. Now I placed, Hansel and Gretel style, a trail of hot dogs leading from the entrance of the MRI to the head coil. Without a thought, Callie continued walking down the patient table into the bore, lapping up hot dogs as she went.

  My colleague Lisa, who was filming the event, gasped in excitement at the sight of a dog walking into the MRI.

  I quickly circled the scanner so I could face Callie from the other end of the bore. She was crouched down in a sphinx position just short of the head coil. Her tail was swishing back and forth. I reached in with a hot dog in my hand and immediately felt the room spin.

  Callie saw the hot dog and scooted forward into the head coil.

  “Good girl!” I said with my highest, most excited voice.

  She took the hot dog and backed up a little bit, but she didn’t leave the bore. With a steady stream of hot dogs, Callie quickly adapted to the new environment and was soon happily eating treats while nestled in the head coil. There was no indication that the magnetic field bothered her.

  With Callie comfortable in the magnet, we had accomplished the first goal of the session. Since that had been relatively easy, it was time to see how she would react to an actual scan.

  The scanner
software was created for human subjects, so it had no way of knowing that Callie was a dog. Inputting an accurate weight of the subject was the most important piece of information because that determined how much radio power the scanner would emit.

  Too much power would cook her like so much meat in a microwave.

  With hot dogs, I once again coaxed Callie into the MRI. When she was comfortably settled in the head coil, I gave a thumbs-up. The scanner made a series of clicks and hums as it revved up.

  Callie’s eyes narrowed.

  Then, like the onslaught of a thousand bees, the scanner started buzzing. This was the initial preparation phase, called shimming. The scanner automatically adjusts the magnetic field to compensate for the distortion caused by whatever is placed inside. Normally, shimming takes a few seconds, but with Callie inside, the buzzing continued. Even though she was wearing earmuffs, she wanted no part of it and headed for the exit.

  I waved my arms back and forth, signaling the MR tech to abort the scan.

  “What was that noise?” I asked.

  “Shimming,” he said.

  “Why was it going on for so long?”

  “The scanner was having trouble compensating,” he explained. “Probably because it expects a human.”

  We hadn’t thought of this. We hadn’t even recorded the shimming noises for our training sessions. We had assumed they would take only a few seconds, a minor blip compared to the lengthy functional scans that would follow. Callie reacted to these novel sounds as any dog would: she got scared.

  We tried a dozen times, but Callie scooted out as soon as the scanner started buzzing. We even tried starting the scan before she went in, figuring that if she got used to the ambient noise, I could coax her into the head coil. Eventually, with enough repetitions, the scanner was able to cobble together a crude compensation for her canine form.

  Next up were the functional scans. These are a series of scans that individually take about two seconds to capture the brain. By continuously acquiring these functional scans while Callie was in the MRI, we could measure changes in her brain activity and figure out what she was thinking. At least, that was the plan. Finally, we would do a structural scan, which is a high-resolution picture of the brain used to identify brain anatomy.

  It was tough for her. The earmuffs kept sliding back, exposing her ears to the full onslaught of the noise. Even so, Callie managed to hold her head in position for a few seconds at a time. We stopped the scanner after three minutes’ worth of scanning. That, we felt, would be enough to evaluate the quality of the data.

  Before she got too tired, we decided to make one attempt at a structural image. The structural scan takes thirty seconds, and Callie would have to hold still the entire time. After the scan, she bounded out of the magnet and pawed off her earmuffs. She jumped up and licked my face and then ran over to Lisa, who gave Callie a big hug.

  “What a good girl!” she exclaimed.

  We all went into the control room to see what the images looked like.

  The structural image looked remarkably good. There were ghost images throughout, which occur when the subject moves, but it was clearly recognizable as a dog’s brain. The functional images were a different story. Out of 120 images, only one contained anything that looked like a brain. Mostly they were jumbles of digital snow with an occasional eyeball peeking into the field of view.

  I hugged Callie and said, “I’m so proud of you.” But in reality, I didn’t know if this was going to work.

  The next scan—with Callie, the other dog, McKenzie, and the whole entourage—was in three weeks. I hoped we could figure it out before then. If we didn’t, I would have to pull the plug on the Dog Project and acknowledge that the naysayers had been right: you can’t scan the brain of an awake dog.

  1

  Dia de los Muertos

  TWO YEARS EARLIER

  EVERY NOVEMBER 1, I push aside the remains of the Halloween candy and erect a shrine on the dining room table.

  I begin with a vase that Kat and I bought in Mexico on our honeymoon. It’s a cheap thing, with a stylized owl painted on one side, but the vase has somehow survived multiple moves across the country, and I have come to value it for its resiliency rather than its beauty. It also provides the necessary ethnic authenticity for the ritual and functions as an ideal centerpiece to prop up photographs.

  We keep the photos in a drawer all year long, only to be brought out on this day. Kat and I surround the vase with them: pictures of family members who have passed away over the years. Then, to complete the offering for their spirits, we scatter a cornucopia of the sweetest, most delicious baked goods.

  Our two daughters, Helen and Maddy, had never questioned why we did this. They had, after all, lived with the ritual all their lives. But when they achieved the age of enlightenment, preteen-hood, they realized that celebrating Dia de los Muertos—the Day of the Dead—was not a normal thing to do. At least not the way we did it.

  We included the dogs.

  Although I had grown up with dogs, it wasn’t until I finished medical school that I had the opportunity to acquire a dog that I could truly call my own.

  Kat and I had been married for five years, and we were putting off children until I completed my training. So, in celebration of completing my first year of medical internship—a grueling year of hundred-hour weeks—we answered an ad for puppies. Pug puppies, actually. I note this with some qualification, because to many, pugs are a grotesque distortion of the canine form. Of course, Kat and I didn’t see them that way. Their large heads, with pushed-in noses and bulbous eyes, were almost human—a sort of baby substitute.

  We named our new puppy Newton.

  Like all pugs, Newton’s face was brachycephalic, meaning short-nosed, but his was foreshortened in the extreme, with his nostrils forming mere slits. He was what breeders call an apple head because of the taper of his skull. His panoply of malformations only made him more endearing to us, and his constant snuffling and snoring became a welcome background noise to our lives. At night, he slept with his unusual dome nestled in my armpit.

  Newton was smart and energetic—and a prankster. He would chew the tags off our clothing only to vomit them up an hour later. Once, he got into a bag of chocolate-covered espresso beans, prompting a panicked call to poison control. I could hear laughter before they assured the newbie dog owners that their precious pug would be okay.

  We immersed ourselves in pug culture. We socialized with other owners, all of whom echoed the analogy between pugs and Lay’s potato chips: you can’t have just one. So it was no surprise that within a year we had adopted two more pugs. Six-year-old Simon was the opposite of Newton: simple, sweet, and dimwitted. Dexter tipped the scales at thirty-three pounds after a lifetime of being fed hamburgers by a truck driver who took him everywhere but could no longer care for him. He was like Jabba the Hutt, waddling his rolls of skin around the house. Mostly he just liked having his chin rubbed.

  Newton.

  (Gregory Berns)

  Dexter was the first to go. Helen was three years old and Maddy had just turned two. That was the year we started celebrating Dia de los Muertos. At first, Dexter was the only dog spirit, and Kat and I began the tradition of leaving dog treats for him. Simon followed the next year.

  As much as we loved Newton, the house just didn’t seem right with only one dog. It didn’t take long for the girls, especially Helen, to ask for a dog of their own. But they wanted a big, fluffy dog that they could play with. (Pugs in their later years don’t play very much.)

  Not long after Simon’s passing, a respected breeder in our neighborhood had a litter of golden retriever puppies become available. Only three were left when we visited. We took home the only female, a sweet bundle of light golden fur. We named her Lyra, after the protagonist of Philip Pullman’s wonderful book The Golden Compass.

  Lyra settled into the house easily. She epitomized the affability that has made golden retrievers such a popular breed. She never protes
ted when the girls’ friends climbed on top of her, and she got along with every dog in the neighborhood, even a pair of irascible Jack Russell terriers that lived down the street. In part because of her easygoing, submissive personality, and in part because of her flowing golden mane, Lyra became a popular fixture in the neighborhood. Kids would run up to her to embrace the walking teddy bear. And Lyra would just grin.

  Helen, Maddy, and Lyra.

  (Gregory Berns)

  With time, the jet-black muzzle of Newton’s youth faded completely to gray, only his ears retaining some dark pigment. Most of his teeth were rotted out from a lifetime of mouth breathing, and his fountain of energy dwindled to a trickle. By the time he was fifteen, he suffered from a slowly progressive deterioration of the spinal cord. Newton eventually lost the use of his hind legs, requiring a doggy wheelchair. He soon lost control of his bladder and bowels too. Never in his life had Newton had an accident in the house, and his look of shame, as he struggled to crawl away from his mess, told us that it was time.

  As I laid Newton in his grave, he gave one last snort. I knew it was the remaining air in his lungs being expelled, but I still like to think it was his soul crossing the Rainbow Bridge into the mythical land where pets and humans are reunited.

  Even though I didn’t know it at the time, the seed for the Dog Project was planted with Newton. It was Newton’s spirit that continued to hold the greatest power over me. We had shared fifteen years together, and I had never really known what he was thinking.

  What I really would have liked to know was whether he truly returned my feelings toward him. But I would have needed some sort of canine brain decoder to know whether he loved me.

  A few months after Newton’s death, the kids were on spring break. Kat and the girls decided to take a trip to the animal shelter.

  The first hint that something was afoot was a text message from Kat. She attached a blurry photo of a dog slung over her shoulder. It was a long, skinny thing with sticks for legs. It was so black I couldn’t make out any details except for its four white paws. Its head looked like an anvil with one ear pointing straight up and the other flopping over its face.