If you’ve always thought that you and your dogs understand one another’s emotions, you increasingly have scientific evidence supporting your views. The use of MRIs allowed researchers to demonstrate that the brains of both dogs and people have a similar response to human voices, crying and laughter, among many other sounds. Researchers conclude that the brains of both dogs and people have similar reactions to the emotional cues in many sounds.
Eleven dogs and 22 people were subjected to the same MRI scans during which they had to remain still for up to 8 minutes while exposed to various sounds. (A lot of training went in to teaching dogs to remain motionless during the scans.) The study is called “Voice-Sensitive Regions in the Dog and Human Brain Are Revealed by Comparative fMRI” (only the abstract is available online) and it was published last week in the journal Current Biology. It is the first study to use this technique to compare the brain of humans to a non-primate animal species.
Over 200 different sounds were played to each participant in the study over a number of sessions. There were sounds such as whistles and car noises as well as dog vocalizations and human sounds. The responses to human sounds in both people and dogs occurred in similar regions of the brain. This study is the first time such a similarity to humans has been shown in an animal species that is NOT a primate. Both the people and the dogs also reacted in similar regions of the brain to emotional canine vocalizations such as whimpering and intense barking.
Along with the similarities, there were also differences in responses between the two species. Humans were better at distinguishing between the sounds of the environment and vocalizations than dogs were. Additionally, both species responded more strongly to vocalizations of their own species.
It is impossible to say from this study whether these vocal regions of the brain evolved in a more ancient lineage than was previously thought or whether the dogs have evolved this similarity during the period of domestication as a mechanism to allow better communication and understanding between dogs and people.
Future studies that investigate brains of additional species may be able to determine the reason for the similarity between dogs and people. These scientists next plan to study the response of dog brains to human language, which was not a part of this study.