It isn’t news to anybody that different breeds of dogs were bred for different functions. (Though there is a lot of variation within breeds, difference between breeds are considerable.) Nobody is surprised when a retriever loves to retrieve or a shepherd is a natural at herding. Dogs whose ancestors were bred for guarding, scent hunting, sight hunting or companionship have similarly predictable behavior in many cases. Though temperaments, behavior and cognitive abilities have been explored across breeds and breed groups, the neuroanatamincal (brain structure) basis of these differences has not been as well studied. A new research project investigated the links between brain structure and behavior.
Significant Neuroanatomical Variation Among Domestic Dog Breeds studied 62 dogs from 33 breeds and 10 major breed groupings. The scientists found that even when size of both brain and body as well as skull shape are accounted for, there are differences in the brains of dogs who have been bred for different functions. They studied the parts of the brain that show the most variation across breeds and correlated networks of brain pathways with specific functions. The shapes of these different networks matched up with the specific skills and behavior of different groups of dogs. One network associated with olfactory processing was significantly correlated with scent hunting. Another network of activity in the brain that was significantly correlated with sight hunting involved movement, eye movement and spatial navigation.
The majority of the differences in the brain were found to relate to the most recent evolutionary changes in dogs—the development of individual breeds. That suggests that at least some of that variation may have arisen due to selective breeding for skill at particular behaviors such as hunting, guarding and herding.
Though the study found differences in the brains of dogs bred for various tasks, the dogs were not engaged in those specific behaviors during the MRI imaging process. Additionally, the dogs in the study were pet dogs rather than working. Both of these factors may mean that the degree to which dogs’ brains are specialized may have been underestimated by the study.