Dogs understand human emotions through facial expressions: study

A glimpse inside dog’s brains suggests that our furry companions can identify certain emotions in people’s faces, according to a new first-of-its-kind study.

A team from the University of Vienna scanned the brains of several dogs to reveal how the animals’ brains respond differently depending on humans facial expressions, which was published in the Cell Press journal iScience.

Researchers first showed eight dogs — six border collies, a labrador and a golden retriever — images of strangers with either a happy or neutral expression, finding that the images with happy expressions triggered a stronger response in a region of a canine’s brain.

In addition, researchers showed 12 dogs — one mixed breed, three golden retrievers, and eight border collies — pictures of people feeling happy, angry, fearful or sad, with whole-brain activity patterns distinguishing sad faces from fearful ones, and angry faces from fearful ones.

There was no evidence that the dogs could distinguish angry faces from sad ones. Fearful expressions stood out from the other negative emotions.

The authors describe the findings as the first direct evidence that dogs’ brains can distinguish between two human faces showing different negative expressions.

“I would like people to see dogs as emotional beings,” senior author Laura Cuaya of the University of Vienna said in a press release .

“They have evolved with us to understand our expressions and cooperate with us, and recognizing that can change how we communicate with and care for them.”

In the first experiment, the researchers trained eight dogs to sit completely still for several minutes in a functional magnetic resonance imaging (fMRI) machine, showing the dogs strangers’ faces with either a happy or neutral expression.

The happy images “elicited a stronger response than neutral faces in a right temporal cluster extending to the caudate nucleus,” which the study states are also activated in dogs by representations of “food reward” and “familiar scents.”

These two areas of the brain were only activated when happy images were shown.

However, the study does note that just because a dog recognized a happy face, it does not conclude that the animal is in turn feeling happy.

“The expression labels (i.e., happiness, anger, sadness, and fear) used here were defined in human-validated stimulus databases, and thus should be interpreted as descriptors of the stimuli rather than descriptors of dogs’ subjective experience.”

When the 12 dogs were shown images of strangers that were either sad, fearful or angry, researchers found distinct activity patterns that “differentiate some specific negative human facial expressions, showing that dogs’ brains can distinguish between expressions.”