Dogs Recognize Familiar Faces in Pictures

New research from the Faculty of Veterinary Medicine at the University of Helsinki suggests that dogs are able to recognize familiar faces when shown a series of images. Recognizing facial features has generally been a skill only humans perhaps primates are thought to possess, so the research puts our canine companions on a level that few species in the animal kingdom are on.

The role that faces play in communication between humans and dogs is well-studied, but the new research, published in the journal Animal Cognition, is the first to investigate facial recognition in dogs with eye movement tracking.

The researchers, led by University of Helsinki professor Outi Vainio, sought to test whether dogs not trained to recognize faces could tell familiar and unfamiliar faces apart when shown a series of images.

By analyzing the gazing behavior of dogs shown images of familiar and unfamiliar faces, the researchers determined that the dogs not only recognize the physical properties of the faces, but also the information presented in the image and its semantic meaning.

For the experiment, dogs were trained to lie still and face a screen. They were then shown a variety of images featuring humans and other dogs. Some of the human images were of the dog's master, while others were of humans the dog had never seem before. Images of dogs in the same family were also shown in the test, as were faces of dogs whom the test dogs had never met.

Since prior studies have reported that canines have a preference for conspecific images (images belonging to the same species), it was not surprising that the dogs in the study spent more time gazing at images of other dogs.

However, the researchers found that the dogs gazed at familiar faces longer; the dogs in the test studied images of both familiar humans and familiar dogs longer than they did unfamiliar images.

"This study shows that the gazing behavior of dogs is not only following the physical properties of images, but also the information presented in the image and its semantic meaning," Vainio wrote in a statement. "Dogs are able to see faces in the images and they differentiate familiar and strange faces from each other. These results indicate that dogs might have facial recognition skills, similar to humans."