Dog and human brains process faces differently

Hungarian researchers discover striking similarities and differences in how dog and human brains process visual information about others. 

Do dogs process faces the same way humans do? Researchers in the Department of Ethology at Eötvös Loránd University, Hungary, set out to answer this question using a functional magnetic resonance imaging (fMRI) experiment. Faces are central to visual communication in humans, who possess a dedicated neural network for face processing. Although domesticated dogs also excel at eye contact and reading facial emotion, they also rely on additional bodily signals to communicate.

In the first directly comparative, non-invasive visual neuroimaging study of a non-primate and primate species, 20 dogs and 30 humans viewed short movies of canine and human faces and, for comparison, the backs of their heads.

The study identified brain areas in both dogs and humans that differentially responded to the videos depending on whether or not they showed an individual from their own species.

“Earlier, our research group showed a similar correspondence between dog and human brains for voice processing,” says Attila Andics, senior author of the study. “We now see that species-sensitivity is an important organizing principle in the mammalian brain for processing social stimuli, in both the auditory and the visual modality.”

Regarding differences, the study found no brain areas in dogs that encode whether the viewed image is a face or the back of a head – whereas in humans, this is a crucial distinction. While the human brain is better at distinguishing faces from non-faces, the dog brain is more focused on discriminating dogs from humans.

The findings, which were published in The Journal of Neuroscience, advance our understanding of how social brain functions, specifically visuo-social processing, are organized and how they evolved in both dogs and humans.

To watch a video abstract about the research, visit youtu.be/VO3YxGQ3P5M.