Researchers have discovered that dogs, considered to be man’s best friend, can distinguish different emotional states on people’s faces.

According to researchers at the University of Vienna, this study, published in the Cell Press journal Eye Science, is the first scientific evidence of this ability.

The study used machine learning to analyze the brain scans of 12 dogs, the university said in a press release issued Tuesday. Meanwhile, the dogs were shown pictures of human faces with different emotions expressed.

According to the researchers, this is the first evidence that dogs can also distinguish specific negative emotions displayed on faces.

“Dogs have evolved with us to understand our emotions and cooperate with us, and recognizing this can change the way we interact with and care for them,” said the study’s lead author.

The researchers’ next goal is to examine how dogs integrate other cues, including body movements, vocal fluctuations and scents, to understand the humans around them.

The researchers clarified that all dogs in the study were family pets.

He warned that dogs raised outside of such an environment may react differently to human emotional cues.