Most dog owners think their own canine is the smartest in the world. In fact, some are more intelligent than others. When one points at an object, a toddler focuses on it, while the dog usually takes the gesture as a directional cue. In a recent study, researchers from the ethology department at Eötvös Loránd University in Hungary were able to explain this phenomenon. It appears that the discrepancy is not only due to how dogs see, but may, in fact, reflect how they think. For “smarter” dogs, the appearance of an object matters as much as its location, suggesting that their information processing is more similar to that of humans.
Spatial bias is the phenomenon of interpreting information in relation to distance, space or location when the same information could easily apply to an object. This is seen, for example, in the way dogs and children react to gestures when we show them the position of an object. Very early on, young children interpret the gesture as pointing to the object, while dogs take the pointing as a directional cue. In other words, regardless of the intention of the person giving the cue, the meaning for children and dogs is different.
This phenomenon has previously been observed in dogs using a variety of behavioral tests, ranging from simple associative learning to imitation, but it had never been studied per se,” said Ivaylo Iotchev, the first author of the study, which appears in the journal Ethology. They published the study under the title “Cognitive and sensory capacity each contribute to the canine spatial bias.” The researchers concluded that the spatial bias is an untapped opportunity to better understand how dogs think.
Previous research failed to determine whether dogs behave this way because they have inferior vision compared to humans or whether it is actually an information-processing bias in which the parameters of the space around them are more important to dogs than the specific, nearby objects.
The researchers measured spatial bias in two behavioral tests involving 82 dogs. In one task, the dogs had to learn over a maximum of 50 trials whether the treat was always on the right or left plate, so they learned a location. In the other task, two types of plates were used, a white round one and a black square one. These were always placed in the middle. A dog was always given only one type of plate to eat from but was exposed to each in a semi-random sequence. In this constellation, they were learning about the properties of the plate. Learning was measured by how fast the dogs ran to the correct plate.
Visual acuity in people and animals
The results showed that the animals learned faster when the treat was placed to the right or left, so they had to choose in which direction to go. It was harder for them to remember whether the treat was on the white round or black square plate. The “spatial-bias” measure described how much faster the dogs were at learning about the place than at learning about object features.
A more complicated task followed if the dogs had already learned where the treat was because then the situation was reversed – that is, if they had previously received the treat on the right, it was now on the left in the new position, and if it had been on the white plate, it was now on the black plate.
While people have a visual acuity of 20/20, dogs have an average visual acuity of only 20/75. This means that what a human can see clearly at 75 feet, a dog would need to be at 20 feet to see it with the same clarity. This lower visual acuity affects their ability to discern fine details and see objects clearly at a distance.
To find out whether spatial bias is sensory, cognitive, or mixed, the researchers needed to detect and measure differences between the visual and cognitive abilities of dogs. The researchers measured how short the dog’s head was, as this is correlated with visual acuity, and also measuring how efficiently they solve problem tasks.
The head shape was investigated by doctoral student and co-author Zsófia Bognár. “The visual abilities of dog breeds differ from each other, which indirectly results from their head shape. Dogs with shorter heads – known as brachycephalic breeds like French bulldogs, shi tzus, pugs, boxers, Boston terriers, pekingese, and Cavalier King Charles spaniels – develop human-like vision.
The structure of their retina implies sharper and more focused vision than their longer-headed counterparts. This has allowed us to use a measure of head shape (the “cephalic index”) as an approximate measure of the quality of vision in dogs. It is calculated by dividing the width of the skull by the length of the skull. The shorter the head, the higher the number, explained Bognár.
Spatial bias in dogs
To measure cognitive ability, the dogs took part in a series of tests. “We tested their memory, attention skills and perseverance and found that dogs with better cognitive performance in the more difficult spatial bias task linked information to objects as easily as to places,” the team said. “We also see that as children develop, spatial bias decreases with increasing intelligence. The study found that spatial bias is smaller in dogs with better visual acuity and who are “smarter.”
Dogs also have a different color perception compared to people. While humans have three types of color receptors (cones) that allow us to see a wide range of colors, dogs only have two types of cones. This means that canines have a limited color spectrum and see the world in shades of blue and yellow. They cannot distinguish between red and green, which are colors that humans perceive distinctly.
Giving dogs interactive toys, puzzles, and games that involve objects can help keep their minds active and prevent boredom. These activities can also strengthen the bond between dogs and their owners, as they work together to solve challenges and achieve goals.
"Spatial bias in dogs is not simply a sensory problem but also a mindset. We also found that “smarter” dogs are resilient in difficult learning situations and can overcome their biases,” Iotchev said.
While dogs may have different visual acuity and color perception compared to humans, their ability to prioritize and perceive objects in their environment is fascinating, the team concluded. “Smarter dogs tend to give more attention to objects that can be attributed to their problem-solving abilities and cognitive skills. Recognizing this aspect of their perception can lead to more effective training and enrichment strategies, ultimately enhancing their overall well-being.