Happy human faces light up dogs’ brains, study finds

Vienna: Ever had a dog greet your smile with a wagging tail? Scientists may now know why. Researchers from the University of Vienna have found that happy human faces trigger a distinct response in dogs’ brains.

The team scanned dogs’ brains while showing them pictures of strangers with happy or neutral expressions. Happy faces led to increased activity in parts of the temporal cortex extending into the caudate nucleus — a region associated with reward processing.

In further experiments using photos displaying fear, anger and sadness, only the happy images produced the same response. The results suggest dogs can specifically distinguish smiles from negative expressions.

Whole-brain scans also showed different patterns of activity for fear, anger and sadness, indicating dogs can tell those emotions apart too.Senior author Laura Cuaya said the research provides the first brain-scan evidence that happy human faces hold “emotional significance” for dogs.

The team now plans to expand the work to compare how human and canine brains respond to the same emotional signals.“I would like people to see dogs as emotional beings,” Cuaya said. “They have evolved with us to understand our expressions and cooperate with us, and recognising that can change how we communicate with and care for them.”