How Dogs Love Us: A Neuroscientist and His Adopted Dog Decode the Canine Brain
by Gregory Berns
New Harvest, 2013

In How Dogs Love Us, Emory University neuroscientist Berns recounts the death of Newton, his pet pug of 15 years. With age, Newton's spinal cord deteriorated, and the dog lost control of his hind legs, bowel and bladder. Berns recalls Newton's look of shame after his first accident inside the house and how he interpreted this look as Newton's plea to die. Berns laid him down and watched him snort one last time as he passed. It was then Berns realized he had never known what Newton was thinking or whether his pet loved him back.

That realization marked the beginning of the Dog Project, a research program to decode doggie thoughts and emotions with functional MRI. Scientists already employ fMRI, which uses changes in blood flow as a proxy for brain activity, to scan the brains of restrained monkeys, but Berns wanted to train dogs to willingly enter the machine and learn simple things, such as associating a hand signal with a reward of a hot dog, all the while staying still enough to collect interpretable brain scans.

The first half of the book details how Berns, his lab mates and two pooches worked together to accomplish this feat. It is an entertaining and inspiring inside look at the do-it-yourself aspect of science and a testament to Berns's passion. The latter half is a highly speculative analysis of brain scans collected from Berns's beloved terrier mix, Callie, and a border collie named McKenzie. He exposes Callie and McKenzie to the smells of familiar as well as unknown dogs and humans.

In Callie's scans, Berns observes activation in the caudate, a brain region involved in processing rewards, after exposing her to the smell of his daughter. He interprets this singular finding as evidence that dogs love their owners. In his excitement to describe Callie's brain activity as love, he sometimes forgets that fMRI is not a tool for mind reading and leaps to conclusions about dogs' abilities to mentalize human intentions.

What Berns lacks in hard data, he more than makes up for with scientific curiosity. He hopes his initial foray will spur future investigations into the mysteries of the canine brain, such as whether dogs have empathy. The book is as much a scientific exploration of how the canine brain might function as it is a deeply personal story about Berns's relationship with dogs as pets and colleagues. Ultimately that connection is what makes the book compelling.