In an announcement that validates the testimonies and anecdotal evidence of dog lovers through the centuries, a team of researchers believe they have discovered the neurological pathways that allow dogs to understand basic human emotions. Using fMRI (functional magnetic resonance imaging) technology, researchers at Eötvös Loránd University in Hungary were able to track blood flow to various areas of a dog’s brain to visualize their response to voices and sounds.
Researchers have known for more than a decade how human brains respond to the sound of a voice versus non-vocal noise, and the differences in brain activity associated with emotions such as sadness and happiness. This new study involving the canine brain points to a very similar mechanism in humans and canines which processes social and emotional information. Researchers speculate that this similarity is likely the reason they are able to tune in to the feelings of their owners, and how owners experience such strong shared emotions with their dogs.
In both humans and canines, a specific area of the brain has been identified which is tuned to the “emotional valence” of voices. This area responds more strongly to positive emotions, like playful barking or laughter, than to negative emotional sounds like aggressive barking and crying. This finding in how dogs understand human emotions is the most exciting discovery in the study, not only because it is fun to prove we really do share sentiment with man’s best friend, but for the greater evolutionary implications.
Back in 2008, another lab performing experiments on macaque monkeys reported similar findings to the original human studies. The macaques were shown to respond more strongly to vocalizations of other macaques than to the voices of other species or sounds other than vocalizations. After the results of that study, the theory arose that these specific regions of the brain may not have originated in humans. Now, with the findings from Eötvös Loránd University, some researchers have speculated that this specific vocal processing originated in a common mammalian ancestor, possibly 100 million years back into our family tree.
If this is correct, it could give great insight into the key biological features that made mammals such a successful order. Could a particular sensitivity to emotional and social information have made mammals more efficient? While other experts in the field of neuroscience support the idea that a sophisticated sound-processing and emotional sensitivity was likely a fundamental trait in the evolution of mammals, some biologists disagree.
An alternative explanation was proposed by T. Ryan Gregory, associate professor of integrative biology at the University of Guelph. Gregory states that humans and dogs could have evolved this wiring independently. Known as convergent evolution, nature is full of examples including the various forms of venom in different species and the similarities in binocular vision between species as far separated as humans and squids.
Another point in the canine brain scan study which dog lovers might appreciate is the uniquely gentle manner in which the they were prepared for the scans. A group of 11 border collies and golden retrievers spent 20 weeks learning to enter the fMRI scanner voluntarily with positive reinforcement training. Impressively, the dogs were able to remain still inside the large, noisy, and intimidating machine for six minute sessions, a feat that has only been achieved in other animals with the use of anesthetics, helmets, or surgically implanted head posts. Even the ability for trainers to achieve such success with positive reinforcement confirms what researchers discovered in the machines; that dogs have an uncanny understanding of human emotions.
By Mimi Mudd