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

July 25 • 4:00 PM

Flying Blind: The View From 30,000 Feet Puts Everything in Perspective

Next time you find yourself in an airplane, consider keeping your phone turned off and the window open.


July 25 • 2:00 PM

Trophy Scarves: Race, Gender, and the Woman-as-Prop Trope

Social inequality unapologetically laid bare.


July 25 • 1:51 PM

Confusing Population Change With Migration

A lot of population change is baked into a region from migration that happened decades ago.


July 25 • 1:37 PM

Do Not Tell Your Kids That Eating Vegetables Will Make Them Stronger

Instead, hand them over in silence. Or, market them as the most delicious snack known to mankind.



July 25 • 11:07 AM

The West’s Groundwater Is Being Sucked Dry

Scientists were stunned to discover just how much groundwater has been lost from beneath the Colorado River over the past 10 years.


July 25 • 10:00 AM

Shelf Help: New Book Reviews in 100 Words or Less

What you need to know about Bad Feminist, XL Love, and The Birth of Korean Cool.



July 25 • 8:00 AM

The Consequences of Curing Childhood Cancer

The majority of American children with cancer will be cured, but it may leave them unable to have children of their own. Should preserving fertility in cancer survivors be a research priority?


July 25 • 6:00 AM

Men Find Caring, Understanding Responses Sexy. Women, Not So Much

For women looking to attract a man, there are advantages to being a caring conversationalist. But new research finds it doesn’t work the other way around.


July 25 • 4:00 AM

Arizona’s Double-Talk on Execution and Torture

The state is certain that Joseph Wood’s death was totally constitutional. But they’re looking into it.


July 24 • 4:00 PM

Overweight Americans Have the Lowest Risk of Premature Death

Why do we use the term “normal weight” when talking about BMI? What’s presented as normal certainly isn’t the norm, and it may not even be what’s most healthy.


July 24 • 2:00 PM

California’s Lax Policing of the Fracking Industry Has Put the Drought-Stricken State in a Terrible Situation

The state’s drought has forced farmers to rely on groundwater, even as aquifers have been intentionally polluted due to exemptions for the oil industry.


July 24 • 12:00 PM

What’s in a Name? The Problem With Washington’s Football Team

A senior advisor to the National Congress of American Indians once threw an embarrassing themed party that involved headdresses. He regrets that costume now, but knows his experience is one many others can relate to.


July 24 • 11:00 AM

How Wildlife Declines Are Leading to Slavery and Terrorism

As wildlife numbers dwindle, wildlife crimes are rising—and that’s fueling a raft of heinous crimes committed against humans.


July 24 • 10:58 AM

How the Supremes Pick Their Cases—and Why Obamacare Is Safe for Now

The opponents of Obamacare who went one for two in circuit court rulings earlier this week are unlikely to see their cases reach the Supreme Court.



July 24 • 9:48 AM

The People Who Are Scared of Dogs

While more people fear snakes or spiders, with dogs everywhere, cynophobia makes everyday public life a constant challenge.


July 24 • 8:00 AM

Newton’s Needle: On Scientific Self-Experimentation

It is all too easy to treat science as a platform that allows the observer to hover over the messiness of life, unobserved and untouched. But by remembering the role of the body in science, perhaps we humanize it as well.


July 24 • 6:00 AM

Commercializing the Counterculture: How the Summer Music Festival Went Mainstream

With painted Volkswagen buses, talk of “free love,” and other reminders of the Woodstock era replaced by advertising and corporate sponsorships, hippie culture may be dying, but a new subculture—a sort of purgatory between hipster and hippie—is on the rise.


July 24 • 5:00 AM

In Praise of Our Short Attention Spans

Maybe there’s a good reason why it seems like there’s been a decline in our our ability to concentrate for a prolonged period of time.


July 24 • 4:00 AM

How Stereotypes Take Shape

New research from Scotland finds they’re an unfortunate product of the way we process and share information.


July 23 • 4:00 PM

Who Doesn’t Like Atheists?

The Pew Research Center asked Americans of varying religious affiliations how they felt about each other.


July 23 • 2:00 PM

We Need to Start Tracking Patient Harm and Medical Mistakes Now

Top patient-safety experts call on Congress to step in and, among other steps, give the Centers for Disease Control and Prevention wider responsibility for measuring medical mistakes.


July 23 • 12:19 PM

How a CEO’s Fiery Battle Speeches Can Shape Ethical Behavior

CEO war speech might inspire ethical decisions internally and unethical ones among competing companies.


Follow us


Subscribe Now

Do Not Tell Your Kids That Eating Vegetables Will Make Them Stronger

Instead, hand them over in silence. Or, market them as the most delicious snack known to mankind.

The West’s Groundwater Is Being Sucked Dry

Scientists were stunned to discover just how much groundwater has been lost from beneath the Colorado River over the past 10 years.

How Wildlife Declines Are Leading to Slavery and Terrorism

As wildlife numbers dwindle, wildlife crimes are rising—and that's fueling a raft of heinous crimes committed against humans.

How a CEO’s Fiery Battle Speeches Can Shape Ethical Behavior

CEO war speech might inspire ethical decisions internally and unethical ones among competing companies.

Modern Technology Still Doesn’t Protect Americans From Deadly Landslides

No landslide monitoring or warning systems are being used to protect vulnerable communities.

The Big One

Today, the United States produces less than two percent of the clothing purchased by Americans. In 1990, it produced nearly 50 percent. July/August 2014

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