Dogs know if we’re happy, sad or scared just from our expressions, study suggests

It is a feeling every pet owner has experienced: you walk through the door after a long day, and your dog immediately mirrors your mood. While we have always suspected they can read us, scientists have now used MRI technology to peek inside the canine mind.

A team of researchers from the University of Vienna conducted brain scans on dogs to see how they reacted to various human expressions. The results, published in the journal iScience, show that dogs have developed sophisticated social tools to cooperate with humans despite our different evolutionary paths.

The Science of a Smile

The study involved scanning the brains of several dogs, including Border Collies and a Golden Retriever, while they viewed images of happy and neutral faces. When shown a smiling stranger, the dogs showed increased activity in the temporal cortex and caudate nucleus.

This is significant because the caudate nucleus is the area of the brain associated with rewards. According to lead researcher Laura Cuaya, this suggests that seeing a happy human face actually holds emotional value and serves as a positive signal for dogs.

Reading Negative Emotions

The research didn't stop at smiles. The team also showed the animals images of people looking angry, fearful, or sad. While these negative emotions didn't trigger the same reward centers as happiness, whole-brain analysis showed the dogs still processed these expressions using distinct neural patterns.

Raúl Hernández-Pérez, the study's first author, noted that dogs are exceptionally good at picking up small facial details. He explained that while we cannot know exactly what a dog is feeling, their brains clearly show they are processing our emotional states.

Trained for the Scanner

Getting a dog to sit still inside a loud MRI machine is no small feat. The dogs were specially trained to remain motionless, starting with just a few seconds and building up. Participation was entirely voluntary, and the dogs were free to leave the equipment at any time.

The researchers acknowledged that the study was small and focused heavily on Border Collies, a breed known for high intelligence. Future studies will look at whether all breeds are equally skilled at reading the room or if some dogs are more naturally tuned into our feelings than others.