Tag Archives: Professor Gregory Berns

Praise or food?

Given the choice, many dogs prefer praise from their owners over food, suggests a new study published in the journal Social, Cognitive and Affective Neuroscience. The study is one of the first to combine brain-imaging data with behavioral experiments to explore canine reward preferences.

“We are trying to understand the basis of the dog-human bond and whether it’s mainly about food, or about the relationship itself,” says Gregory Berns, a neuroscientist at Emory University and lead author of the research. “Out of the 13 dogs that completed the study, we found that most of them either preferred praise from their owners over food, or they appeared to like both equally. Only two of the dogs were real chowhounds, showing a strong preference for the food.”

food-or-praise

Praise Pooch: Most of the dogs in the experiments preferred praise over food, or liked them both equally. Kady, a Labrador-golden retriever mix, was the top dog when it came to the strength of her preference for praise.

Dogs were at the center of the most famous experiments of classical conditioning, conducted by Ivan Pavlov in the early 1900s. Pavlov showed that if dogs are trained to associate a particular stimulus with food, the animals salivate in the mere presence of the stimulus, in anticipation of the food.

“One theory about dogs is that they are primarily Pavlovian machines: They just want food and their owners are simply the means to get it,” Berns says. “Another, more current, view of their behavior is that dogs value human contact in and of itself.”

Berns heads up the Dog Project in Emory’s Department of Psychology, which is researching evolutionary questions surrounding man’s best, and oldest friend. The project was the first to train dogs to voluntarily enter a functional magnetic resonance imaging (fMRI) scanner and remain motionless during scanning, without restraint or sedation. In previous research, the Dog Project identified the ventral caudate region of the canine brain as a reward center. It also showed how that region of a dog’s brain responds more strongly to the scents of familiar humans than to the scents of other humans, or even to those of familiar dogs.

chowhound

Chowhound: Ozzie, a shorthaired terrier mix, was the only dog in the experiments that chose food over his owner’s praise 100 percent of the time. “Ozzie was a bit of an outlier,” Berns says, “but Ozzie’s owner understands him and still loves him.”

For the current experiment, the researchers began by training the dogs to associate three different objects with different outcomes. A pink toy truck signaled a food reward; a blue toy knight signaled verbal praise from the owner; and a hairbrush signaled no reward, to serve as a control.
The dogs then were tested on the three objects while in an fMRI machine. Each dog underwent 32 trials for each of the three objects as their neural activity was recorded.

All of the dogs showed a stronger neural activation for the reward stimuli compared to the stimulus that signaled no reward, and their responses covered a broad range. Four of the dogs showed a particularly strong activation for the stimulus that signaled praise from their owners. Nine of the dogs showed similar neural activation for both the praise stimulus and the food stimulus. And two of the dogs consistently showed more activation when shown the stimulus for food.

The dogs then underwent a behavioral experiment. Each dog was familiarized with a room that contained a simple Y-shaped maze constructed from baby gates: One path of the maze led to a bowl of food and the other path to the dog’s owner. The owners sat with their backs toward their dogs. The dog was then repeatedly released into the room and allowed to choose one of the paths. If they came to the owner, the owner praised them.

“We found that the caudate response of each dog in the first experiment correlated with their choices in the second experiment,” Berns says. “Dogs are individuals and their neurological profiles fit the behavioral choices they make. Most of the dogs alternated between food and owner, but the dogs with the strongest neural response to praise chose to go to their owners 80 to 90 percent of the time. It shows the importance of social reward and praise to dogs. It may be analogous to how we humans feel when someone praises us.”

The experiments lay the groundwork for asking more complicated questions about the canine experience of the world. The Berns’ lab is currently exploring the ability of dogs to process and understand human language.

“Dogs are hypersocial with humans,” Berns says, “and their integration into human ecology makes dogs a unique model for studying cross-species social bonding.”

Source:  Emory University media release

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How our dogs react to faces (vs other objects)

Dogs have a specialized region in their brains for processing faces, a new study finds. PeerJ is publishing the research, which provides the first evidence for a face-selective region in the temporal cortex of dogs.

“Our findings show that dogs have an innate way to process faces in their brains, a quality that has previously only been well-documented in humans and other primates,” says Gregory Berns, a neuroscientist at Emory University and the senior author of the study.

Dog in MRI machine at Emory University

The study involved dogs viewing both static images and video images on a screen while undergoing fMRI. It was a particularly challenging experiment since dogs do not normally interact with two-dimensional images, and they had to undergo training to learn to pay attention to the screen. Photo by Gregory Berns, Emory University

Having neural machinery dedicated to face processing suggests that this ability is hard-wired through cognitive evolution, Berns says, and may help explain dogs’ extreme sensitivity to human social cues.

Berns heads up the Dog Project in Emory’s Department of Psychology, which is researching evolutionary questions surrounding man’s best, and oldest, friend. The project was the first to train dogs to voluntarily enter a functional magnetic resonance imaging (fMRI) scanner and remain motionless during scanning, without restraint or sedation.

For the current study, the researchers focused on how dogs respond to faces versus everyday objects. “Dogs are obviously highly social animals,” Berns says, “so it makes sense that they would respond to faces. We wanted to know whether that response is learned or innate.”

The study involved dogs viewing both static images and video images on a screen while undergoing fMRI. It was a particularly challenging experiment since dogs do not normally interact with two-dimensional images, and they had to undergo training to learn to pay attention to the screen.

A limitation of the study was the small sample size: Only six of the eight dogs enrolled in the study were able to hold a gaze for at least 30 seconds on each of the images to meet the experimental criteria.

The results were clear, however, for the six subjects able to complete the experiment. A region in their temporal lobe responded significantly more to movies of human faces than to movies of everyday objects. This same region responded similarly to still images of human faces and dog faces, yet significantly more to both human and dog faces than to images of everyday objects.

If the dogs’ response to faces was learned – by associating a human face with food, for example – you would expect to see a response in the reward system of their brains, but that was not the case, Berns says.

The researchers have dubbed the canine face-processing region they identified the dog face area, or DFA.

One hypothesis is that distinguishing faces is important for any social creature.

Source:  EurekAlert! media statement


Professor Berns’ group at Emory University is one of the leading research teams in the field of canine cognition.  Previous blog posts about his work include:

Scent of my human

The functional MRI research team led by Gregory Berns have done it again.  In research published in the journal Behavioural Processes, they show that an area of the canine brain associated with reward responds more strongly to the scents of familiar humans than it does to the scents of other humans, or even to those of familiar dogs.

Kady, a lab involved in the study, shown training for the experiment in a mock-up fMRI scanner.  Photo by Helen Berns

Kady, a lab involved in the study, shown training for the experiment in a mock-up fMRI scanner. Photo by Helen Berns

“In our experiment, the scent donors were not physically present. That means the canine brain responses were being triggered by something distant in space and time. It shows that dogs’ brains have these mental representations of us that persist when we’re not there.”

When humans smell the perfume or cologne of someone they love, they may have an immediate, emotional reaction that’s not necessarily cognitive, Berns notes. “Our experiment may be showing the same process in dogs. But since dogs are so much more olfactory than humans, their responses would likely be even more powerful than the ones we might have.”

The experiment involved 12 dogs of various breeds. The animals had all undergone training to hold perfectly still while undergoing an fMRI scan. As they were being scanned, the subjects were presented with five different scents that had been collected on sterile gauze pads that morning and sealed in Mylar envelopes. The scent samples came from the subject itself, a dog the subject had never met, a dog that lived in the subject’s household, a human the dog had never met, and a human that lived in the subject’s household.

The familiar human scent samples were taken from someone else from the house other than the handlers during the experiment, so that none of the scent donors were physically present.

The dog scents were swabbed from the rear/genital area and the human scents were taken from armpits.

The results showed that all five scents elicited a similar response in parts of the dogs’ brains involved in detecting smells, the olfactory bulb and peduncle. The caudate responses, however, were significantly stronger for the scents of familiar humans, followed by that of familiar dogs.

“The stronger caudate activation suggested that not only did the dogs discriminate the familiar human scent from the others, they had a positive association with it,” Berns says. “While we might expect that dogs should be highly tuned to the smell of other dogs, it seems that the ‘reward response’ is reserved for their humans. Whether this is based on food, play, innate genetic predisposition or something else remains an area for future investigation.”

An interesting twist: The dogs in the experiment that had received training as service/therapy dogs showed greater caudate activation for the scent of a familiar human compared with the other dogs. It is unclear whether this difference was due to genetics or had simply been fostered through the service/therapy training.

“We plan to do further research to determine whether we can use brain-imaging techniques to better identify dogs that are optimal to serve as companion animals for the disabled,” Berns says.

The training of service dogs is time-consuming and expensive, he says, and only about one-third of the animals that begin the process successfully complete it. Meanwhile, the waiting list for service dogs is long, and includes many wounded veterans.

“In addition to serving as companion animals for wounded veterans, dogs play many important roles in military operations,” Berns says. “By understanding how dogs’ brains work, we hope to find better methods to select and train them for these roles.”

Source:  Emory University media release

Read my other blogs about functional MRI research:

 

 

How dogs were trained for functional MRI research

I’m an absolute advocate for positive reinforcement training.  Here’s how Professor Gregory Berns and his research team trained dogs to remain still in a noisy MRI scanner.

You can also read my other blogs about functional MRI research and dogs:

 

Your dog’s (brain) reward center

Professor Gregory Berns of Emory University is at it again.  He’s expanded on his earlier research using functional MRI (magnetic resonance imaging) to show the brain activity in dogs.

“Now we’ve shown that the initial study wasn’t a fluke: Canine fMRI is reliable and can be done with minimal stress to the dogs. We have laid the foundation for exploring the neural biology and cognitive processes of man’s best, and oldest, friend.”  said Professor Berns.

Tigger, a Boston Terrier, was one of the 13 study subjects

Tigger, a Boston Terrier, was one of the 13 study subjects

The task requires dogs to cooperatively enter the small enclosure of the fMRI scanner and remain completely motionless despite the noise and vibration of the machine.  Only those dogs that willingly cooperated were involved in the experiments.

The canine subjects were given harmless fMRI brain scans while they watched a human giving hand signals that the dogs had been trained to understand. One signal indicated that the dog would receive a hot dog for a treat. The other hand signal meant that the dog would not receive a hot dog.

Most of the dogs showed a response in the caudate region of the brain when seeing the hand signal for a treat.  This area of the brain has the highest concentration of dopamine receptors, which are implicated in motivation and pleasure, among other neurological processes.

“Our goal is to map out canine cognitive processes” said Berns. The research team needs to increase the number of canine subjects that can be trained to stay within the MRI machine so it can validate its research.

See my other blogs about functional MRI and Professor Gregory Berns:

Source:  Emory University media release

Dogs are people, too

In this New York Times opinion piece, Professor Gregory Berns discusses the MRI findings of brain activity in dogs, the evidence for ‘sentience’ and the reasons why dogs’ rights should go beyond consideration of animals as property.

For anyone involved in animal welfare advocacy, it is essential to have animal welfare laws that recognise dogs as sentient beings – with the ability to experience emotions like love and grief – because abuse and harm done to sentient beings carries a higher penalty in law than if an item of property is damaged.  (In many areas, dogs are considered nothing more than property.)

Jane Evelyn Atwood/Contact Press Images

Jane Evelyn Atwood/Contact Press Images