Study: Dogs' Brains React Differently to Human Fear, Sadness, Anger

Dogs are capable of distinguishing between specific negative human facial expressions, not just categorizing faces as positive or negative, according to a new brain-imaging study. The research, published in the journal iScience on August 10, 2026, provides the first evidence that the canine brain exhibits distinct neural patterns for emotions like fear, anger, and sadness.

The study, led by researchers at the University of Vienna, used functional magnetic resonance imaging (fMRI) to scan the brains of 14 trained pet dogs as they viewed photographs of unfamiliar human faces. The dogs, which included border collies, golden retrievers, and a Labrador, were trained over at least 20 sessions to lie still in the MRI scanner for up to 10 minutes.

In the first experiment, eight dogs were shown faces with either happy or neutral expressions. The researchers found that happy faces activated the temporal cortex, involved in processing complex visual information, and the caudate nucleus, a deep brain region associated with reward and motivation. This response suggests a smiling face carries positive emotional significance for dogs.

The team then expanded the experiment to 12 dogs, showing...