Tag Archives: 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 know when they don’t know

When they don’t have enough information to make an accurate decision, dogs will search for more – similarly to chimpanzees and humans.

Researchers at the DogStudies lab at the Max Planck Institute for the Science of Human History have shown that dogs possess some “metacognitive” abilities – specifically, they are aware of when they do not have enough information to solve a problem and will actively seek more information, similarly to primates. To investigate this, the researchers created a test in which dogs had to find a reward – a toy or food – behind one of two fences. They found that the dogs looked for additional information significantly more often when they had not seen where the reward was hidden.

Metacognition study

In this study, dogs showed some of the signs of metacognition, specifically that they searched for more information when they had not seen where a reward was placed. © Juliane Bräuer

In the field of comparative psychology, researchers study animals in order to learn about the evolution of various traits and what this can tell us about ourselves. At the DogStudies lab at the Max Planck Institute for the Science of Human History, project leader Juliane Bräuer studies dogs to make these comparisons. In a recent study published in the journal Learning & Behavior, Bräuer and colleague Julia Belger, now of the Max Planck Institute for Human Cognitive and Brain Sciences, explore whether dogs have metacognitive abilities – sometimes described as the ability to “know what one knows” – and in particular whether they are aware of what information they have learned and whether they need more information.

To test this, the researchers designed an apparatus involving two V-shaped fences. A reward, either food or a toy, would be placed by one researcher behind one of the two fences while another researcher held the dog. In some cases, the dog could see where the reward was placed, while in others the dog could not. The researchers then analyzed how frequently the dogs looked through a gap in the fence before choosing an option. The question was whether, like chimps and humans, the dog would “check” through the gap when he or she had not seen where the reward was placed. This would indicate that the dog was aware that he or she did not know where the reward was – a metacognitive ability – and would try to get more information before choosing a fence.

Experiment set up

The overall set-up of the experiment, showing the two V-shaped fences, the experimenter who places the reward, the experimenter holding the dog, and the dog in starting position, without a curtain to block the view. This dog was participating in the third variation, with a time delay. © DogStudies. Belger & Bräuer, 2018. Metacognition in dogs: Do dogs know they could be wrong? Learning & Behavior. DOI: 10.3758/s13420-018-0367-5.

Some researchers argue that some animals, such as dogs, may only look for extra information when searching as a routinized, instinctual behavior, and not as a result of a metacognitive process. To control for this, Bräuer and Belger tested whether dogs show the so-called “passport effect,” originally described by researcher Joseph Call. When humans are looking for something very important, for example, a passport, they will engage in more active searching and will check for it more often than if they are looking for something less important or generic. Great apes display this same behavior – they will search more for a high-value food. Thus, Bräuer and Belger varied whether the dogs were looking for high- or low-value food, in order to test whether dogs also had the searching flexibility displayed in the passport effect. In another variation, they tested whether it made a difference to the dog when they had to search for a toy or for food.

The dogs “checked” more often when they did not know where the reward was hidden

The researchers found that the dogs did check significantly more often for the reward when they had not seen where it was placed. “These results show that dogs do tend to actively seek extra information when they have not seen where a reward is hidden,” explains Belger. “The fact that dogs checked more when they had no knowledge of the reward’s location could suggest that dogs show metacognitive abilities, as they meet one of the assumptions of knowing about knowing.”

Checking, however, did not always make the dogs very much more successful. In the first variation, with food or a toy as a reward, when dogs checked they were correct more often than when they did not check. However, in the second variation, with high-value or low-value food as the reward, even when dogs checked, they were not correct more than one would expect based on chance. The researchers theorize that this could be due to inhibition problems – the dogs get so excited about finding the reward, that they cannot stop themselves from approaching the closest fence even when they have seen that the reward is probably not there.

Additionally, the dogs did check more often for the toy than for the food in the first variation, suggesting that they do show flexibility in their searching and are not just engaging in a routine behavior. However, they did not check more often for the high-value food in the second variation, although they did look for it more quickly. Overall, the researchers concluded that the dogs, while showing some degree of searching flexibility, are not as flexible as primates.

In a third variation of the test, the dogs could always see where a food reward was placed, but were subject to a delay of 5 seconds to 2 minutes before being allowed to retrieve the reward. Interestingly, the dogs did not check more often with a longer time delay, even though they were slightly less successful. “It’s possible that this was due to a ‘ceiling effect,’ as dogs overall selected the correct fence in 93% of trials in this variation, so the pressure for seeking extra information was low,” suggests Belger.

Do dogs have metacognitive abilities?

The results did not allow the researchers to say definitively whether dogs possess metacognition, although they displayed some evidence for it. “For humans, vision is an important information gathering sense. In this case our experiment was based on a ‘checking’ action relying on sight – but the dogs probably also used their sense of smell when checking through the gap. We know that smell is very important for dogs and we could see that they were using it,” states Bräuer. “In future, we would like to develop an experiment investigating under what circumstances dogs decide to use their sense of smell versus sight. This may give us additional insights into their information seeking abilities.”

Source:   Max Planck Institute for the Science of Human History

Yes, your pet can tell time

Are you taking your time when feeding your pet? Fluffy and Fido are on to you — and they can tell when you are dawdling.

time dog

A new study from Northwestern University has found some of the clearest evidence yet that animals can judge time. By examining the brain’s medial entorhinal cortex, the researchers discovered a previously unknown set of neurons that turn on like a clock when an animal is waiting.

“Does your dog know that it took you twice as long to get its food as it took yesterday? There wasn’t a good answer for that before,” said Daniel Dombeck, who led the study. “This is one of the most convincing experiments to show that animals really do have an explicit representation of time in their brains when they are challenged to measure a time interval.”

The research was published online this week in the journal Nature Neuroscience. Dombeck is an associate professor of neurobiology in Northwestern’s Weinberg College of Arts and Sciences.

When planning the study, Dombeck’s team focused on the medial entorhinal cortex, an area located in the brain’s temporal lobe that is associated with memory and navigation. Because that part of the brain encodes spatial information in episodic memories, Dombeck hypothesized that the area could also be responsible for encoding time.

“Every memory is a bit different,” said James Heys, a postdoctoral fellow in Dombeck’s laboratory. “But there are two central features to all episodic memories: space and time. They always happen in a particular environment and are always structured in time.”

To test their hypothesis, Dombeck and Heys set up an experiment called the virtual “door stop” task. In the experiment, a mouse runs on a physical treadmill in a virtual reality environment. The mouse learns to run down a hallway to a door that is located about halfway down the track. After six seconds, the door opens, allowing the mouse to continue down the hallway to receive its reward.

After running several training sessions, researchers made the door invisible in the virtual reality scene. In the new scenario, the mouse still knew where the now-invisible “door” was located based on the floor’s changing textures. And it still waited six seconds at the “door” before abruptly racing down the track to collect its reward.

“The important point here is that the mouse doesn’t know when the door is open or closed because it’s invisible,” said Heys, the paper’s first author. “The only way he can solve this task efficiently is by using his brain’s internal sense of time.”

By using virtual reality, Dombeck and his team can neatly control potentially influencing factors, such as the sound of the door opening. “We wouldn’t be able to make the door completely invisible in a real environment,” Dombeck said. “The animal could touch it, hear it, smell it or sense it in some way. They wouldn’t have to judge time; they would just sense when the door opened. In virtual reality, we can take away all sensory cues.”

But Dombeck and his team did more than watch the mice complete the door stop task over and over again. They took the experiment one step further by imaging the mice’s brain activity. Using two-photon microscopy, which allows advanced, high-resolution imaging of the brain, Dombeck and Heys watched the mice’s neurons fire.

“As the animals run along the track and get to the invisible door, we see the cells firing that control spatial encoding,” Dombeck said. “Then, when the animal stops at the door, we see those cells turned off and a new set of cells turn on. This was a big surprise and a new discovery.”

Dombeck noted these “timing cells” did not fire during active running — only during rest. “Not only are the cells active during rest,” he said, “but they actually encode how much time the animal has been resting.”

The implication of the work expands well beyond your impatient pooch. Now that researchers have found these new time-encoding neurons, they can study how neurodegenerative diseases might affect this set of cells.

“Patients with Alzheimer’s disease notably forget when things happened in time,” Heys said. “Perhaps this is because they are losing some of the basic functions of the entorhinal cortex, which is one of the first brain regions affected by the disease.”

“So this could lead to new early-detection tests for Alzheimer’s,” Dombeck added. “We could start asking people to judge how much time has elapsed or ask them to navigate a virtual reality environment — essentially having a human do a ‘door stop’ task.”

Source:   Northwestern University media statement

Scientists chase mystery of how dogs process words

When some dogs hear their owners say “squirrel,” they perk up, become agitated. They may even run to a window and look out of it. But what does the word mean to the dog? Does it mean, “Pay attention, something is happening?” Or does the dog actually picture a small, bushy-tailed rodent in its mind?

scanner_eddie

Eddie, one of the dogs that participated in the study, poses in the fMRI scanner with two of the toys used in the experiments, “Monkey” and “Piggy.” (Photo courtesy Gregory Berns)

Frontiers in Neuroscience published one of the first studies using brain imaging to probe how our canine companions process words they have been taught to associate with objects, conducted by scientists at Emory University. The results suggest that dogs have at least a rudimentary neural representation of meaning for words they have been taught, differentiating words they have heard before from those they have not.

“Many dog owners think that their dogs know what some words mean, but there really isn’t much scientific evidence to support that,” says Ashley Prichard, a PhD candidate in Emory’s Department of Psychology and first author of the study. “We wanted to get data from the dogs themselves — not just owner reports.”

“We know that dogs have the capacity to process at least some aspects of human language since they can learn to follow verbal commands,” adds Emory neuroscientist Gregory Berns, senior author of the study. “Previous research, however, suggests dogs may rely on many other cues to follow a verbal command, such as gaze, gestures and even emotional expressions from their owners.”

The Emory researchers focused on questions surrounding the brain mechanisms dogs use to differentiate between words, or even what constitutes a word to a dog.

Berns is founder of the Dog Project, 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. Studies by the Dog Project have furthered understanding of dogs’ neural response to expected reward, identified specialized areas in the dog brain for processing faces, demonstrated olfactory responses to human and dog odors, and linked prefrontal function to inhibitory control.

For the current study, 12 dogs of varying breeds were trained for months by their owners to retrieve two different objects, based on the objects’ names. Each dog’s pair of objects consisted of one with a soft texture, such as a stuffed animal, and another of a different texture, such as rubber, to facilitate discrimination. Training consisted of instructing the dogs to fetch one of the objects and then rewarding them with food or praise. Training was considered complete when a dog showed that it could discriminate between the two objects by consistently fetching the one requested by the owner when presented with both of the objects.

During one experiment, the trained dog lay in the fMRI scanner while the dog’s owner stood directly in front of the dog at the opening of the machine and said the names of the dog’s toys at set intervals, then showed the dog the corresponding toys.

Eddie, a golden retriever-Labrador mix, for instance, heard his owner say the words “Piggy” or “Monkey,” then his owner held up the matching toy. As a control, the owner then spoke gibberish words, such as “bobbu” and “bodmick,” then held up novel objects like a hat or a doll.

The results showed greater activation in auditory regions of the brain to the novel pseudowords relative to the trained words.

“We expected to see that dogs neurally discriminate between words that they know and words that they don’t,” Prichard says. “What’s surprising is that the result is opposite to that of research on humans — people typically show greater neural activation for known words than novel words.”

The researchers hypothesize that the dogs may show greater neural activation to a novel word because they sense their owners want them to understand what they are saying, and they are trying to do so. “Dogs ultimately want to please their owners, and perhaps also receive praise or food,” Berns says.

Half of the dogs in the experiment showed the increased activation for the novel words in their parietotemporal cortex, an area of the brain that the researchers believe may be analogous to the angular gyrus in humans, where lexical differences are processed.

The other half of the dogs, however, showed heightened activity to novel words in other brain regions, including the other parts of the left temporal cortex and amygdala, caudate nucleus, and the thalamus.

These differences may be related to a limitation of the study — the varying range in breeds and sizes of the dogs, as well as possible variations in their cognitive abilities. A major challenge in mapping the cognitive processes of the canine brain, the researchers acknowledge, is the variety of shapes and sizes of dogs’ brains across breeds.

“Dogs may have varying capacity and motivation for learning and understanding human words,” Berns says, “but they appear to have a neural representation for the meaning of words they have been taught, beyond just a low-level Pavlovian response.”

This conclusion does not mean that spoken words are the most effective way for an owner to communicate with a dog. In fact, other research also led by Prichard and Berns and recently published in Scientific Reports, showed that the neural reward system of dogs is more attuned to visual and to scent cues than to verbal ones.

“When people want to teach their dog a trick, they often use a verbal command because that’s what we humans prefer,” Prichard says. “From the dog’s perspective, however, a visual command might be more effective, helping the dog learn the trick faster.”

Source:  Emory University

Dog intelligence ‘not exceptional’

Note from DoggyMom:

This research hit mainstream media at the beginning of the month.  It’s an important part of the research process to have results peer reviewed and it is also common for reviews of this nature – across multiple pieces of research.

I don’t necessarily think that dogs must be exceptional, however.  And so the results of cognition research that have been published so far shouldn’t be discounted because of this review.  Rather, the cognition research undertaken with dogs helps to prove that they are sentient (very important for animal welfare laws) and more intelligent than many people (and policy makers) believe.

I certainly don’t expect my dogs to be Einstein, but I do see that they have intelligence and emotions – both of which we should respect.


Scientists reviewed evidence that compared the brain power of dogs with other domestic animals, other social hunters and other carnivorous (an order including animals such as dogs, wolves, bears, lions and hyenas).Dog intelligence photo

The researchers, from the University of Exeter and Canterbury Christ Church University, found the cognitive abilities of dogs were at least matched by several species in each of these groups.

The study examined more than 300 papers on the intelligence of dogs and other animals, and found several cases of “over interpretation” in favour of dogs’ abilities.

“During our work it seemed to us that many studies in dog cognition research set out to ‘prove’ how clever dogs are,” said Professor Stephen Lea, of the University of Exeter.

“They are often compared to chimpanzees and whenever dogs ‘win’, this gets added to their reputation as something exceptional.

“Yet in each and every case we found other valid comparison species that do at least as well as dogs do in those tasks.”

The review focussed on sensory cognition, physical cognition, spatial cognition, social cognition and self-awareness.

“Taking all three groups (domestic animals, social hunters and carnivorans) into account, dog cognition does not look exceptional,” said Dr Britta Osthaus, of Canterbury Christ Church University.

“We are doing dogs no favour by expecting too much of them. Dogs are dogs, and we need to take their needs and true abilities into account when considering how we treat them.”

The paper, published in the journal Learning & Behavior, is entitled: “In what sense are dogs special? Canine cognition in comparative context.”

Source:  University of Exeter media release

Dogs understand what’s written all over your face

Dogs can understand

Dogs can understand emotional expressions of humans. Credit: © ZoomTeam / Fotolia

Dogs are capable of understanding the emotions behind an expression on a human face. For example, if a dog turns its head to the left, it could be picking up that someone is angry, fearful or happy. If there is a look of surprise on a person’s face, dogs tend to turn their head to the right. The heart rates of dogs also go up when they see someone who is having a bad day, say Marcello Siniscalchi, Serenella d’Ingeo and Angelo Quaranta of the University of Bari Aldo Moro in Italy.

The study in Springer’s journal Learning & Behavior is the latest to reveal just how connected dogs are with people. The research also provides evidence that dogs use different parts of their brains to process human emotions.

By living in close contact with humans, dogs have developed specific skills that enable them to interact and communicate efficiently with people. Recent studies have shown that the canine brain can pick up on emotional cues contained in a person’s voice, body odour and posture, and read their faces.

In this study, the authors watched what happened when they presented photographs of the same two adults’ faces (a man and a woman) to 26 feeding dogs. The images were placed strategically to the sides of the animals’ line of sight and the photos showed a human face expressing one of the six basic human emotions: anger, fear, happiness, sadness, surprise, disgust or being neutral.

The dogs showed greater response and cardiac activity when shown photographs that expressed arousing emotional states such as anger, fear and happiness. They also took longer to resume feeding after seeing these images. The dogs’ increased heart rate indicated that in these cases they experienced higher levels of stress.

In addition, dogs tended to turn their heads to the left when they saw human faces expressing anger, fear or happiness. The reverse happened when the faces looked surprised, possibly because dogs view it as a non-threatening, relaxed expression. These findings therefore support the existence of an asymmetrical emotional modulation of dogs’ brains to process basic human emotions.

“Clearly arousing, negative emotions seem to be processed by the right hemisphere of a dog’s brain, and more positive emotions by the left side,” says Siniscalchi.

The results support that of other studies done on dogs and other mammals. These show that the right side of the brain plays a more important part in regulating the sympathetic outflow to the heart. This is a fundamental organ for the control of the ‘fight or flight’ behavioural response necessary for survival.

Source:  Springer.com

Which are smarter, cats or dogs?

This debate among pet owners can still get quite heated.

In this short video, a scientist explains why she concludes that dogs have the greater cognitive capabilities:

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