Specific breeds of dogs, like border collies, can learn the verbal names of their favorite toys, but what is going on in the dog's mind when it's told to fetch a given toy? According to a recent paper published in the journal Animal Cognition, these dogs store key sensory features about their toys—notably what they look like and how they smell—and recall those features when searching for the named toy.
"If we can understand which senses dogs use while searching for a toy, this may reveal how they think about it," said co-author Shany Dror, a biologist at Eotvos Lorand University in Budapest, Hungary. "When dogs use olfaction or sight while searching for a toy, this indicates that they know how that toy smells or looks like."
Prior studies suggested that dogs typically rely on vision, or a combination of sight and smell, to locate target objects. A few dogs can also identify objects based on verbal labels, which the authors call "gifted word learner" (GWL) dogs. "Just like humans, GWL dogs not only recognize the labeled objects—or categories of objects—as stimuli they have already encountered, but they also identify them among other similarly familiar named objects, based on their verbal labels," the authors wrote. They wanted to investigate whether GWL dogs have an enhanced ability to discriminate and/or recognize objects compared to typical dogs.
To find out, they conducted two separate experiments. The first involved 14 dogs, three of which were GWL dogs (all border collies): Max, Gaia, and Nalani. All three had participated in prior studies and demonstrated they knew the names of more than 20 dog toys. Most of the dogs were tested in the lab; three were tested in their homes using the same experimental setup. The experimenter and the dog's owner stood with the dog in one room. An adjacent room held dog toys. The rooms were connected by a corridor and separated by heavy curtains. All the windows were covered with dark nylon sheets.