Tag Archives: dog cognition

Do Bigger Brains Equal Smarter Dogs?

Bigger dogs, with larger brains, perform better on certain measures of intelligence than their smaller canine counterparts, according to a new study led by the University of Arizona.

bigger vs smaller

Bigger dogs have better short-term memory and self-control than more petite pups. Credit: © alexzizu / Fotolia

Larger-brained dogs outperform smaller dogs on measures of executive functions – a set of cognitive processes that are necessary for controlling and coordinating other cognitive abilities and behaviors. In particular, bigger dogs have better short-term memory and self-control than more petite pups, according to the study published in the journal Animal Cognition.

“The jury is out on why, necessarily, brain size might relate to cognition,” said lead study author Daniel Horschler, a UA anthropology doctoral student and member of the UA’s Arizona Canine Cognition Center. “We think of it as probably a proxy for something else going on, whether it’s the number of neurons that matters or differences in connectivity between neurons. Nobody’s really sure yet, but we’re interested in figuring out what those deeper things are.”

Canine brain size does not seem to be associated with all types of intelligence, however. Horschler found that brain size didn’t predict a dog’s performance on tests of social intelligence, which was measured by testing each dog’s ability to follow human pointing gestures. It also wasn’t associated with a dog’s inferential and physical reasoning ability.

The study’s findings mirror what scientists have previously found to be true in primates – that brain size is associated with executive functioning, but not other types of intelligence.

“Previous studies have been composed mostly or entirely of primates, so we weren’t sure whether the result was an artifact of unique aspects of primate brain evolution,” Horschler said. “We think dogs are a really great test case for this because there’s huge variation in brain size, to a degree you don’t see in pretty much any other terrestrial mammals. You have chihuahuas versus Great Danes and everything in between.”

Horschler’s study is based on data from more than 7,000 purebred domestic dogs from 74 different breeds. Brain size was estimated based on breed standards.

The data came from the citizen science website Dognition.com, which offers instructions for dog owners to test their canines’ cognitive abilities through a variety of game-based activities. The users then submit their data to the site, where it can be accessed by researchers.

Short-term memory was tested by dog owners hiding a treat, in view of their dog, under one of two overturned plastic cups. Owners then waited 60, 90, 120 or 150 seconds before releasing their dog to get the treat. Smaller dogs had more difficulty remembering where the treat was hidden.

To test self-control, owners placed a treat in front of their seated dog and then forbade the dog from taking it. Owners then either watched the dog, covered their own eyes or turned away from the dog. Larger-breed dogs typically waited longer to snag the forbidden treat.

Horschler and his colleagues controlled for whether or not the dogs had been trained. They found that larger-brained breeds had better short-term memory and self-control than smaller dogs, regardless of the extent of training the dogs had received.

In the future, Horschler said he’d like to do comparative studies of cognitive abilities in different breed varieties, such as the miniature poodle and much larger standard poodle, which are essentially the same except for their size.

“I’m really interested in how cognition evolves and how that arises biologically,” Horschler said. “We’re coming to understand that brain size is in some way related to cognition, whether it’s because of brain size specifically or whether it’s a proxy for something else.”

Source:  University of Arizona media release

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Dogs are more expressive when someone is looking

Dogs produce more facial expressions when humans are looking at them, according to new research from the University of Portsmouth.

Scientists at the University’s Dog Cognition Centre are the first to find clear evidence dogs move their faces in direct response to human attention. Dogs don’t respond with more facial expressions upon seeing tasty food, suggesting that dogs produce facial expressions to communicate and not just because they are excited.

Brow raising, which makes the eyes look bigger – so-called puppy dog eyes – was the dogs’ most commonly used expression in this research.

Puppy dog eyes

Puppy dog eyes

Dog cognition expert Dr Juliane Kaminski led the study, which is published in Scientific Reports.

She said: “We can now be confident that the production of facial expressions made by dogs are dependent on the attention state of their audience and are not just a result of dogs being excited. In our study they produced far more expressions when someone was watching, but seeing food treats did not have the same effect.

“The findings appear to support evidence dogs are sensitive to humans’ attention and that expressions are potentially active attempts to communicate, not simple emotional displays.”KAMINSKI-dog-eyes

Most mammals produce facial expressions – such expressions are considered an important part of an animal’s behavioural repertoire – but it has long been assumed that animal facial expressions, including some human facial expressions, are involuntary and dependent on an individual’s emotional state rather than being flexible responses to the audience

Dr Kaminski said it’s possible dogs’ facial expressions have changed as part of the process of becoming domesticated.

The researchers studied 24 dogs of various breeds, aged one to 12. All were family pets. Each dog was tied by a lead a metre away from a person, and the dogs’ faces were filmed throughout a range of exchanges, from the person being oriented towards the dog, to being distracted and with her body turned away from the dog.

The dogs’ facial expressions were measured using DogFACS, an anatomically based coding system which gives a reliable and standardised measurement of facial changes linked to underlying muscle movement.

Co-author and facial expression expert Professor Bridget Waller said: “DogFACS captures movements from all the different muscles in the canine face, many of which are capable of producing very subtle and brief facial movements.

“FACS systems were originally developed for humans, but have since been modified for use with other animals such as primates and dogs.”

Dr Kaminski said: “Domestic dogs have a unique history – they have lived alongside humans for 30,000 years and during that time selection pressures seem to have acted on dogs’ ability to communicate with us.

“We knew domestic dogs paid attention to how attentive a human is – in a previous study we found, for example, that dogs stole food more often when the human’s eyes were closed or they had their back turned. In another study, we found dogs follow the gaze of a human if the human first establishes eye contact with the dog, so the dog knows the gaze-shift is directed at them.

“This study moves forward what we understand about dog cognition. We now know dogs make more facial expressions when the human is paying attention.”

It is impossible yet to say whether dogs’ behaviour in this and other studies is evidence dogs have flexible understanding of another individual’s perspective – that they truly understand another individual’s mental state – or if their behaviour is hardwired, or even a learned response to seeing the face or eyes of another individual.

Puppy dog eyes is a facial expression which, in humans, closely resembles sadness. This potentially makes humans more empathetic towards the dog who uses the expression, or because it makes the dog’s eyes appear bigger and more infant-like – potentially tapping into humans’ preference for child-like characteristics. Regardless of the mechanism, humans are particularly responsive to that expression in dogs.

Previous research has shown some apes can also modify their facial expressions depending on their audience, but until now, dogs’ abilities to do use facial expression to communicate with humans hadn’t been systematically examined.

Source:   University of Portsmouth news

Link to publication

9 special abilities that show how smart dogs really are

I enjoy reading and sharing information about research involving dogs and their cognitive abilities.

Business Insider Malaysia has published a good synopsis of research in the area with references to the relevant studies.

2-dogs-make-eye-contact

The 9 special abilities are:

  1. Dogs feel empathy
  2. Dogs make eye contact
  3. With eye contact, they form a special bond with humans
  4. Dogs see humans as part of their family
  5. And they interact with us as if they were children
  6. Dogs understand gestures, like pointing
  7. Dogs brains react to human voices
  8. Some dogs can learn new words the way children do
  9. And some dogs have the ability to generalize

Kathleen Crisley, specialist in dog massage, rehabilitation and nutrition/food therapy, The Balanced Dog, Christchurch, New Zealand

The great escape – an example of dog intelligence

Any reader of my blog knows that I enjoy following research topics, and I’ve written a number of posts about dog cognition.

This video, of a German Short Haired Pointer, shows that dogs are smart and can work things out.

She’s working on her great escape…watch her as she works it out (don’t just jump to the end)

Kathleen Crisley, specialist in dog massage, rehabilitation and nutrition/food therapy, Canine Catering Ltd, Christchurch, New Zealand

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:

Adjusting stress levels for mellow vs hyper dogs

People aren’t the only ones who perform better on tests or athletic events when they are just a little bit nervous — dogs do too. But in dogs as in people, the right amount of stress depends on disposition.

A new study by researchers at Duke University finds that a little extra stress and stimulation makes hyper dogs crack under pressure but gives mellow dogs an edge.  (These findings will be relevant to any owner who is competing in agility or obedience with their dog.)

The findings appear online in the journal Animal Cognition.

According to an idea in psychology called the Yerkes-Dodson law, a little stress can be a good thing, but only up to a point.

A task that isn’t demanding or challenging enough can make it hard to stay engaged and perform at one’s peak. But when the pressure becomes too much to handle, performance is likely to suffer again.

The idea is the relationship between stress and performance follows a Goldilocks model:  Both people and animals function best when the level of stress is not too much, nor too little, but just right.

When you’re taking a test, for example, it helps to be a little bit anxious so you don’t just blow it off,” said study co-author Emily Bray, who was an undergraduate at Duke at the time of the study. “But if you’re too nervous, even if you study and you really know the material, you aren’t going to perform at your best.”

Researchers first observed this pattern more than a hundred years ago in lab rats, but it has since been demonstrated in chickens, cats and humans. In a new study, a Duke team consisting of Bray and evolutionary anthropologists Evan MacLean and Brian Hare of Duke’s Canine Cognition Center wanted to find out if the conditions that enable certain animals to do their best also depend on the animal’s underlying temperament.

In a series of experiments, the researchers challenged dogs to retrieve a meat jerky treat from a person standing behind a clear plastic barrier that was six feet wide and three feet tall. To get it right, the dogs had to resist the impulse to try to take the shortest path to reach the treat — which would only cause them to whack into the barrier and bump their heads against the plastic — and instead walk around the barrier to one of the open sides.

In one set of trials, an experimenter stood behind the barrier holding a treat and called the dog’s name in a calm, flat voice. In another set of trials, the experimenter enthusiastically waved the treat in the air and used an urgent, excited voice. (See YouTube video at https://youtu.be/j6bfo5IlCEY – the video has been protected and so I’m unable to link it directly to this blog post).

The researchers tested 30 pet dogs, ranging in age from an eight-month-old Jack Russell terrier named Enzo to an 11-year-old Vizsla named Sienna. They also tested 76 assistance dogs at Canine Companions for Independence in Santa Rosa, California, a non-profit organization that breeds and trains assistance dogs for people with disabilities.

The researchers studied video recordings of each dog and estimated their baseline temperament in terms of tail wags per minute. “The service dogs were generally more cool in the face of stress or distraction, whereas the pet dogs tended to be more excitable and high-strung,” Bray said.

Both groups of dogs were able to solve the puzzle. But the optimal amount of stress and stimulation depended on each dog’s disposition.

For the dogs that were naturally calm and laid-back — measured by how quickly they tended to wag their tails — increasing the level of excitement and urgency boosted their ability to stay on task and get the treat.

But for excitable dogs the pattern was reversed. Increasing the level of stimulation only made them take longer.

In one high-arousal trial, a two-year-old spaniel named Charlie Brown lost it and shut down, barking and zipping around crazily until she almost ran out of time.

“In the first five trials she did fine and solved the puzzle quickly with no problems,” Bray said. “Then when the high-arousal trials started she choked. She just couldn’t figure it out.”

“Adding more excitement pushed the pet dogs over the edge and impaired their ability to perform at their peak,” Bray said.

The results will help researchers develop better tests to determine which dogs are likely to graduate from service dog training programs, for example.

Source:  Duke University media release