Menus Subscribe Search

Findings

bulldog-face

(Photo: Annette Shaff/Shutterstock)

Who Loves His Master? Brain Scans Provide Clues to a Dog’s Inner Life

• March 11, 2014 • 4:00 AM

(Photo: Annette Shaff/Shutterstock)

New research suggests a region of a canine brain that is associated with rewards is uniquely activated by the scent of a familiar human.

Do you ever wonder where your dog’s true loyalty lies? Sure, you two are close. But as their urine smell-based information network regularly reminds us, canines communicate with their peers on a level we can’t possibly understand. So what takes precedence in a dog’s mind: His species, or his master?

Newly published research provides evidence that points to the primacy of a dog’s human handlers.

A first-of-its-kind study that measured activity in dogs’ brains finds a key region only lights up when the animal is exposed to the smell of a familiar human being. Other dogs—even familiar ones—do not produce the same response.

“It is tempting to conclude that (this) response represents something akin to a positive emotional response to the scent of a familiar human,” writes the research team led by Gregory Berns of Emory University. Their study—including their speculative discussion of whether that’s truly the case—is in the journal Behavioural Processes.

A first-of-its-kind study that measured activity in dogs’ brains finds a key region only lights up when the animal is exposed to the smell of a familiar human being. Other dogs—even familiar ones—do not produce the same response.

Berns and his colleagues trained a dozen dogs “to remain motionless while unsedated and unrestrained” in an MRI machine—the same device used to determine what parts of the human brain are activated when certain activities are thought about or performed.

The researchers specifically looked at two areas of the dogs’ brains: the “olfactory bulb,” which indicates the animal’s sense of smell has been activated, and the caudate. “A vast literature on the caudate in humans, monkeys, and rats points to this region’s role in positive expectations, including social rewards,” they note.

While standing or sitting quietly in the brain-scanning device for about a half-hour (good dogs!), the 12 canines were exposed to five distinct smells, all collected that same morning on sterile gauze pads. The odors were from the dog itself; a different dog who resided in the same household; an unfamiliar dog; a familiar human; and a human the dog had never met.

The familiar human was either a member of the dog’s household or a close friend (but not the person handling the animal that day). For 11 of the 12 animals, it was “either the handler’s husband or their child.”

The researchers found the olfactory bulb “was activated to a similar degree” when the dog was exposed to each scent. Crucially, however, the smell of the familiar human led to the greatest activation of the caudate. Responses to the other four scents did not significantly differ from one another.

This suggests that “not only did the dogs discriminate that scent from the others—they had a positive association with it,” the researchers write. “This speaks to the power of the dog’s sense of smell, and it provides clues about the importance of humans in dogs’ lives.”

Berns and his colleagues note that the caudate is associated with positive emotions, but they can’t be sure that is an accurate description of the dog’s experience. They note caudate activation could indicate a “motivational state”—specifically, “a marker to approach the stimulus,” which in this case would be a desire to make contact with the person in question.

Of course, the easiest way for a human to pique a dog’s interest is to offer it food. This raises the possibility that the brain response noted here simply reflects the fact the dog associates the smell of this person with dinner.

“Although possible, we think this unlikely,” the researchers write, “because most of the familiar humans were not the dogs’ primary caregivers. Most of the handlers reported that they were the ones who fed the dog.” The person who provided the scent played with the dog, perhaps took it for walks, but seldom fed it.

Berns and his colleagues don’t know whether this human-centric response is the result of selective breeding, or perhaps socialization. (All 12 dogs were raised from puppies as family pets, and four were service animals.)

Regardless, they write, this research suggests dogs uniquely associate their humans with rewards, and act accordingly. Whether to call that “love” is a subjective decision.

There’s no question, however, that in your dog’s eyes, you are very special.

Tom Jacobs
Staff writer Tom Jacobs is a veteran journalist with more than 20 years experience at daily newspapers. He has served as a staff writer for The Los Angeles Daily News and the Santa Barbara News-Press. His work has also appeared in The Los Angeles Times, Chicago Tribune, and Ventura County Star.

More From Tom Jacobs

A weekly roundup of the best of Pacific Standard and PSmag.com, delivered straight to your inbox.

Recent Posts

September 15 • 4:00 PM

The Average Prisoner Is Visited Only Twice While Incarcerated

And black prisoners receive even fewer visitors.


September 15 • 2:00 PM

Gambling With America’s Health

The public health costs of legal gambling.


September 15 • 12:23 PM

The Scent of a Conservative

We are attracted to the body odor of others with similar political beliefs, according to new research.


September 15 • 12:00 PM

2014: A Pretty Average Election

Don’t get too worked up over this year’s congressional mid-terms.


September 15 • 10:00 AM

Online Harassment of Women Isn’t Just a Gamer Problem

By blaming specific subcultures, we ignore a much larger and more troubling social pathology.


September 15 • 8:00 AM

Atheists Seen as a Threat to Moral Values

New research attempts to pinpoint why non-believers are widely disliked and distrusted.


September 15 • 6:12 AM

To Protect Against Meltdowns, Banks Must Map Financial Interconnections

A new model suggests looking beyond balance sheets, studying the network of investment as well.


September 15 • 6:00 AM

Interview With a Drug Dealer

What happens when the illicit product you’ve made your living off of finally becomes legal?


September 15 • 4:00 AM

A Feeling of Control: How America Can Finally Learn to Deal With Its Impulses

The ability to delay gratification has been held up as the one character trait to rule them all—the key to academic success, financial security, and social well-being. But willpower isn’t the answer. The new, emotional science of self-regulation.



September 15 • 2:04 AM

No Innovation Without Migration: Do Places Make People?

We know that people make places, but does it also work the other way?


September 12 • 4:00 PM

Life, Liberty, and the Pursuit of Plastic Bags

California wants you to pay for your plastic bags. (FYI: That’s not an infringement on your constitutional rights.)


September 12 • 2:00 PM

Should We Trust the Hearts of White People?

On the 50th anniversary of the Civil Rights Act, revisiting a clip of James Baldwin on the Dick Cavett Show.


September 12 • 12:00 PM

Big Government, Happy Citizens?

You may like to talk about how much happier you’d be if the government didn’t interfere with your life, but that’s not what the research shows.


September 12 • 10:00 AM

Whispering in the Town Square: Can Twitter Provide an Escape From All Its Noise?

Twitter has created its own buzzing, digital agora, but when users want to speak amongst themselves, they tend to leave for another platform. It’s a social network that helps you find people to talk to—but barely lets you do any talking.


September 12 • 9:03 AM

How Ancient DNA Is Rewriting Human History

We thought we knew how we’d been shaped by evolution. We were wrong.


September 12 • 8:02 AM

Give Yourself a Present for the Future

Psychologists discover that we underestimate the value of looking back.


September 12 • 8:00 AM

I Walked Through the Financial Crisis

Why are former Wall Street employees guiding tourists around the Financial District? Paul Hiebert signed himself up and tried to find out.


September 12 • 7:05 AM

Scams, Scams, Everywhere


September 12 • 6:17 AM

In Soccer as in Art, Motifs Matter

A new study suggests a way to quantitatively measure a team’s style through its pass flow. It may become another metric used to evaluate potential recruits.


September 12 • 4:00 AM

Comfort Food Is a Myth

New research finds that, contrary to our beliefs, such foods don’t have any special ability to improve our moods.



September 11 • 4:00 PM

Reading the Camouflage Uniforms in Ferguson: ‘You Are Now Enemy Combatants’

Why are police officers wearing green or desert camouflage in a suburban environment?


September 11 • 2:00 PM

Wage Theft: How Two States Are Fighting Against Companies That Categorize Employees as Independent Contractors

New York and Illinois have passed hard-nosed laws and taken an aggressive tack toward misclassification.


September 11 • 11:03 AM

Yes, I’m a Good Person. But Did You Hear About Her?

A new study tracks how people experience moral issues in everyday life.


Follow us


To Protect Against Meltdowns, Banks Must Map Financial Interconnections

A new model suggests looking beyond balance sheets, studying the network of investment as well.

Big Government, Happy Citizens?

You may like to talk about how much happier you'd be if the government didn't interfere with your life, but that's not what the research shows.

Give Yourself a Present for the Future

Psychologists discover that we underestimate the value of looking back.

In Soccer as in Art, Motifs Matter

A new study suggests a way to quantitatively measure a team’s style through its pass flow. It may become another metric used to evaluate potential recruits.

Searching for Everyday Morality

Experimenters use text messages to study morality beyond the lab.

The Big One

One in three drivers in Brooklyn's Park Slope—at certain times of day—is just looking for parking. The same goes for drivers in Manhattan's SoHo. September/October 2014 new-big-one-3

Copyright © 2014 by Pacific Standard and The Miller-McCune Center for Research, Media, and Public Policy. All Rights Reserved.