Menus Subscribe Search

Follow us


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

November 25 • 4:00 PM

Is the Federal Reserve Bank of New York Doing Enough to Monitor Wall Street?

Bank President William Dudley says supervision is stronger than ever, but Democratic senators are unconvinced: “You need to fix it, Mr. Dudley, or we need to get someone who will.”


November 25 • 3:30 PM

Cultural Activities Help Seniors Retain Health Literacy

New research finds a link between the ability to process health-related information and regular attendance at movies, plays, and concerts.


November 25 • 12:00 PM

Why Did Doctors Stop Giving Women Orgasms?

You can thank the rise of the vibrator for that, according to technology historian Rachel Maines.


November 25 • 10:08 AM

Geography, Race, and LOLs

The online lexicon spreads through racial and ethnic groups as much as it does through geography and other traditional linguistic measures.


November 25 • 10:00 AM

If It’s Yellow, Seriously, Let It Mellow

If you actually care about water and the future of the species, you’ll think twice about flushing.


November 25 • 8:00 AM

Sometimes You Should Just Say No to Surgery

The introduction of national thyroid cancer screening in South Korea led to a 15-fold increase in diagnoses and a corresponding explosion of operations—but no difference in mortality rates. This is a prime example of over-diagnosis that’s contributing to bloated health care costs.



November 25 • 6:00 AM

The Long War Between Highbrow and Lowbrow

Despise The Avengers? Loathe the snobs who despise The Avengers? You’re not the first.


November 25 • 4:00 AM

Are Women More Open to Sex Than They Admit?

New research questions the conventional wisdom that men overestimate women’s level of sexual interest in them.


November 25 • 2:00 AM

The Geography of Innovation, or, Why Almost All Japanese People Hate Root Beer

Innovation is not a product of population density, but of something else entirely.


November 24 • 4:00 PM

Federal Reserve Announces Sweeping Review of Its Big Bank Oversight

The Federal Reserve Board wants to look at whether the views of examiners are being heard by higher-ups.



November 24 • 2:00 PM

That Catcalling Video Is a Reminder of Why Research Methods Are So Important

If your methods aren’t sound then neither are your findings.


November 24 • 12:00 PM

Yes, Republicans Can Still Win the White House

If the economy in 2016 is where it was in 2012 or better, Democrats will likely retain the White House. If not, well….


November 24 • 11:36 AM

Feeling—Not Being—Wealthy Cuts Support for Economic Redistribution

A new study suggests it’s relative wealth that leads people to oppose taxing the rich and giving to the poor.


November 24 • 10:00 AM

Why Are Patients Drawn to Certain Doctors?

We look for an emotional fit between our physicians and ourselves—and right now, that’s the best we can do.


November 24 • 8:00 AM

Why Do We Elect Corrupt Politicians?

Voters, it seems, are willing to forgive—over and over again—dishonest yet beloved politicians if they think the job is still getting done.



November 24 • 6:00 AM

They Steal Babies, Don’t They?

Ethiopia, the Hague, and the rise and fall of international adoption. An exclusive investigation of internal U.S. State Department documents describing how humanitarian adoptions metastasized into a mini-industry shot through with fraud, becoming a source of income for unscrupulous orphanages, government officials, and shady operators—and was then reined back in through diplomacy, regulation, and a brand-new federal law.


November 24 • 4:00 AM

Nudging Drivers, and Pedestrians, Into Better Behavior

Daniel Pink’s new series, Crowd Control, premieres tonight on the National Geographic Channel.


November 21 • 4:00 PM

Why Are America’s Poorest Toddlers Being Over-Prescribed ADHD Drugs?

Against all medical guidelines, children who are two and three years old are getting diagnosed with ADHD and treated with Adderall and other stimulants. It may be shocking, but it’s perfectly legal.



November 21 • 2:00 PM

The Best Moms Let Mess Happen

That’s the message of a Bounty commercial that reminds this sociologist of Sharon Hays’ work on “the ideology of intensive motherhood.”


November 21 • 12:00 PM

Eating Disorders Are Not Just for Women

Men, like women, are affected by our cultural preoccupation with thinness. And refusing to recognize that only makes things worse.


November 21 • 10:00 AM

Queens of the South

Inside Asheville, North Carolina’s 7th annual Miss Gay Latina pageant.


Follow us


Geography, Race, and LOLs

The online lexicon spreads through racial and ethnic groups as much as it does through geography and other traditional linguistic measures.

Feeling—Not Being—Wealthy Cuts Support for Economic Redistribution

A new study suggests it's relative wealth that leads people to oppose taxing the rich and giving to the poor.

Sufferers of Social Anxiety Disorder, Your Friends Like You

The first study of friends' perceptions suggest they know something's off with their pals but like them just the same.

Standing Up for My Group by Kicking Yours

Members of a minority ethnic group are less likely to express support for gay equality if they believe their own group suffers from discrimination.

How Old Brains Learn New Tricks

A new study shows that the neural plasticity needed for learning doesn't vanish as we age—it just moves.

The Big One

One in two United States senators and two in five House members who left office between 1998 and 2004 became lobbyists. November/December 2014

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