Tag Archives: senses

Study finds new links between dogs’ smell and vision

Posted on August 8, 2022 | Leave a comment

Cornell researchers have provided the first documentation that dogs’ sense of smell is integrated with their vision and other unique parts of the brain, shedding new light on how dogs experience and navigate the world.

“We’ve never seen this connection between the nose and the occipital lobe, functionally the visual cortex in dogs, in any species,” said Pip Johnson, assistant professor in the Department of Clinical Sciences in the College of Veterinary Medicine and senior author of “Extensive Connections of the Canine Olfactory Pathway Revealed by Tractography and Dissection,” published July 11 in the Journal of Neuroscience.

“It makes a ton of sense in dogs,” she said. “When we walk into a room, we primarily use our vision to work out where the door is, who’s in the room, where the table is. Whereas in dogs, this study shows that olfaction is really integrated with vision in terms of how they learn about their environment and orient themselves in it.”

Erica Andrews, a former analyst in Johnson’s lab, is the paper’s first author and currently works in canine aging research.

Johnson and her team performed MRI scans on 23 healthy dogs and used diffusion tensor imaging, an advanced neuroimaging technique, to locate the dog brain’s white matter pathways, the information highways of the brain. They found connections between the olfactory bulb and the limbic system and piriform lobe, where the brain processes memory and emotion, which are similar to those in humans, as well as never-documented connections to the spinal cord and the occipital lobe that are not found in humans.

“It was really consistent,” Johnson said. “And size-wise, these tracts were really dramatic compared to what is described in the human olfactory system, more like what you’d see in our visual systems.”

Tractography, a 3D-modeling process, allowed Johnson and her team to map and virtually dissect the white matter tracts. The findings in the digital images were later confirmed by a co-author and white matter expert at Johns Hopkins University.

Johnson said the research corroborates her clinical experiences with blind dogs, who function remarkably well. “They can still play fetch and navigate their surroundings much better than humans with the same condition,” Johnson said. “Knowing there’s that information freeway going between those two areas could be hugely comforting to owners of dogs with incurable eye diseases.”

Identifying new connections in the brain also opens up new lines of questioning. “To see this variation in the brain allows us to see what’s possible in the mammalian brain and to wonder – maybe we have a vestigial connection between those two areas from when we were more ape-like and scent-oriented, or maybe other species have significant variations that we haven’t explored,” Johnson said.

Johnson plans to examine the olfactory system’s structure in the brains of cats and horses, which aligns with the broader goals of her research program – to leverage the most advanced imaging techniques, used commonly in human clinical research, to better understand animal brain physiology and disease.

Source: Cornell University Chronicle

A glimpse into the dog’s mind: A new study reveals how dogs think of their toys

Posted on June 17, 2022 | Leave a comment

Many dog lovers want to know what goes on in their furry friends’ minds. Now scientists are finally getting closer to the answer. In a new study just published in the journal of Animal Cognition, researchers from the Family Dog Project (Eötvös Loránd University University, Budapest) found out that dogs have a “multi-modal mental image” of their familiar objects. This means that, when thinking about an object, dogs imagine the object’s different sensory features. For instance, the way it looks or the way its smells.

The group of scientists assumed that the senses dogs use to identify objects, such as their toys, reflect the way the objects are represented in their minds. “If we can understand which senses dogs use while searching for a toy, this may reveal how they think about it” explains Shany Dror, one of the leading researchers of this study. “When dogs use olfaction or sight while searching for a toy, this indicates that they know how that toy smells or looks like”.

In previous studies, the researchers discovered that only a few uniquely gifted dogs can learn the names of objects. “These Gifted Word Learner dogs give us a glimpse into their minds, and we can discover what they think about when we ask them – Where is your Teddy Bear? –“ explains Dr. Andrea Sommese, the second leading researcher.

In the first experiment, they trained 3 Gifted Word Learner dogs and 10 typical family dogs (i.e., dogs that do not know the name of toys), to fetch a toy associated with a reward. During the training, dogs received treats and were praised for choosing this toy over a few distractor toys.

A picture of Gaia, one of the Gifted dogs (from Brazil) searching for her toy in the light (on the left) and in the dark (on the right)

The researchers then observed how the dogs searched for the targeted toy, always placed among 4 others, both when the lights were on and off. All dogs successfully selected the trained toys, both in the light and in the dark. However, it took them longer to find the toys in the dark. Only the Gifted Word Learner dogs participated in the second experiment. Here, the researchers aimed to find out what these dogs think about when they hear the name of their toys. “Revealing the senses used by the dogs to search for the named toys gave us the possibility to infer what these dogs imagine when they hear, for example, Teddy Bear explains Dr. Claudia Fugazza, co-author of the study.

The Gifted dogs were successful in selecting the toys named by their owners in the light and the dark. This reveals that, when they hear the name of a toy, they recall this object’s different sensory features and they can use this “multisensory mental image” to identify it, also in the dark. “Dogs have a good sense of smell, but we found that dogs preferred to rely on vision and used their noses only a few times, and almost only when the lights were off” clarifies Prof. Adam Miklósi, head of the Department of Ethology at ELTE University and co-author of the study. “Dogs sniffed more often and for longer in the dark. They spent 90% more time sniffing when the lights were off, but this was still only 20% of the searching time”.

To conclude, the dogs’ success in finding the toys and the different senses used while searching in the light and the dark reveals that, when dogs play with a toy, even just briefly, they pay attention to its different features and register the information using multiple senses.

Source: Eötvös Loránd University (ELTE)