We know that dogs are incredibly sensitive to their human companions' emotions. But what about dogs reading the emotions of strangers? Tests measuring dogs' brain activity show that it's far more than simple familiarity with humans that allows dogs to understand emotions like anger, fear, and sadness.
In fact, dogs can make those emotional distinctions on a far more sophisticated level than previously believed.
A study published in the journal iScience has found evidence that "dogs appear to be able to make such distinctions on a more sophisticated level" than previously imagined, writes Tom Hawking in Popular Science.
“Previous behavioral studies [in dogs] have compared faces expressing a negative emotion with faces expressing a positive emotion,” explains study co-author and psychologist Laura Verónica Cuaya-Retana from Mexico’s National Autonomous University.
The team looked at eight dogs, volunteered by their owners, under a functional magnetic resonance imaging (fMRI) machine. The dogs needed very little training to first become accustomed to the machine and then understand they had to stay absolutely still while in the "donut."
While in the machine, the dogs were shown three photos of the same person (a stranger) expressing fear, anger, and sadness, as well as one positive emotion, happiness. The researchers then examined the electrical activity in the dogs' brains to see which part of the brain "lit up" in response to the photos.
"They found that anger, fear, and sadness appeared to stimulate different areas of the dogs’ brains," writes Hawking. "Interestingly, while the dogs displayed differing responses to fear and anger, and to fear and sadness, they did not seem able to differentiate anger and sadness."
We already knew that dogs familiar with their human friends had developed a sophisticated way to "read" their companions' body language, smell, and tone of voice to discern their mood.
“We do know that experience influences dogs’ ability to discriminate emotions, and that familiarity is highly relevant to how the dog brain processes faces,” says Cuaya-Retana. “For this reason, we presented faces of strangers, allowing us to test whether brain responses differed according to facial expression rather than familiarity.”
Popular Science:
The results provide a tantalizing suggestion that our canine companions can identify our expressions for what they are—that their understanding seems to be more along the lines of, “This human is smiling, so they are in a positive emotional state,” than, “This human’s emotional state appears more happy than it was five minutes ago.”
However, Cuaya-Retana cautions against anthropomorphizing these findings since we can’t truly access a dog’s subjective experience.
“Our results suggest that dogs’ brains can differentiate between some facial expressions as distinct categories, rather than merely detecting that one expression is more positive or negative than another,” she explains. “The evidence goes beyond dogs simply detecting whether their caregiver is pleased or displeased with them. Still, we cannot conclude that dogs understand/experience emotions in the same conceptual way that humans do.”
Using three negative emotions and one positive one also raises an interesting question. Is it reasonable to expect that the same sorts of results would arise from multiple positive expressions? Cuaya-Retana says, “Yes, … but it still needs to be tested.”
Why confirm scientifically what we know instinctively and because of our deep emotional connection to our canine friends?
“Studying the dog brain can also help us understand the evolution of social brain networks,” Cuaya-Retana says. “Humans and dogs are evolutionarily distant species with very different brains, yet both are sensitive to human emotional signals. Comparing how each species processes these cues can reveal which neural solutions evolved independently and which may reflect more general principles of social cognition.”
Some animals are very smart. We're still trying to unlock the depth of a primate's intelligence (gorillas, chimps, orangutans, and bonobos). But dogs appear to possess an emotional intelligence that is, at once, familiar to us and on a different level from humans.
Yeah. And I wish they could tell us in their own words, too.
