Are you someone who smiles at the sight of a dog? Do you believe that dogs will react to your kindness and joy? A recently published study provides an answer to these questions.
The brain scanning study published in the journal “iScience” confirms a fact that most dog lovers firmly believe in: our canine companions are incredibly adept at interpreting and responding to human emotions.
They can sense whether we are happy or sad, and they perform better than expected in distinguishing negative emotions such as fear, sadness, and anger. Researchers claim that dogs’ ability to interpret our emotions is even better than that of chimpanzees.
In particular, when dogs see happy human faces, their brains become active; even a smile from a stranger can activate the region in a dog’s brain that responds excitedly to toys and rewards.
This study was conducted in Hungary and Mexico. Researchers Dr. Raul Hernandez-Perez and Dr. Laura Cuaya sought out calm and well-trained dogs in the park, engaged with their owners, and invited these dogs to participate in the research.
They recruited a total of 14 dogs, including Border Collies, Golden Retrievers, Labrador Retrievers, and mixed breeds.
The most challenging part came next. Even humans find magnetic resonance imaging (MRI) intimidating. How would dogs react in those noisy, claustrophobic cylinders during scans? Not to mention keeping still enough to complete the tests. Any movement over three millimeters during the scan renders the data useless.
In over 20 training sessions, researchers painstakingly trained the dogs to remain still in the scanner, assuming a prone position with their chin resting on a rest, and encouraged them to stay still through treats and games as rewards.
They extended the stillness time from an initial 5 seconds gradually to a full 3 minutes, and fitted the dogs with special earmuffs to protect their hearing.
After the training was completed, researchers displayed images of human faces expressing happiness, sadness, anger, fear, or neutral emotions to the dogs while scanning their brains.
Happy human faces triggered activity in the temporal cortex, responsible for facial recognition and processing emotional cues; it also activated the caudate nucleus, responsible for processing rewards and motivation.
On the other hand, fear and sadness activated an area in the brain called the right rostral suprasylvian gyrus, responsible for processing visual and other sensory information, while anger activated the right ectosylvian gyrus and left splenial gyrus.
The research results indicate that dogs have a strong response to happy faces and, for the first time, prove that they can differentiate certain negative emotional facial expressions.
The activation of the temporal cortex and caudate nucleus by happy faces is what happens in our brains when we enjoy something or recall pleasant memories – like savoring delicious food or receiving praise – a sensation known as “pleasure” or “excitement.”
Previous studies on dogs have found that the same areas of the brain become active when dogs anticipate tasty treats or smell familiar scents.
Cuaya, in an interview with the BBC, said, “This [brain region mentioned above] determines our motivation – the desire to go and do something.”
“This finding suggests that happy faces – even from strangers – have positive meaning for dogs.”
“We can reward dogs with treats, but we can also reward them with joy. So, we should smile at dogs – even those we randomly encounter on the street.”
She noted that from a neuroscience perspective, “the brains of dogs are fascinating.”
“They are very good at understanding human emotions – despite humans being a completely different species.”
Dr. Mia Cobb, a canine expert from the University of Melbourne in Australia, told The Age that despite the small sample size, the study provides valuable confirmation of concepts.
She pointed out that the dogs in the study had stronger reactions to fear and anger than to sadness.
“If we feel afraid or angry, it’s crucial that dogs notice that. If a person is scared, it could signal danger nearby to the dog; and an angry person might pose a direct threat to the dog.”
“If we feel sad, it’s not as important for dogs because it’s unlikely to threaten their safety.”
Though the study tested dogs’ reactions to static images, in reality, they respond to various cues, including our tone of voice, body language, and crucially, smell.
“In recent years, there’s been increasing evidence that dogs are very sensitive to the smell of fear and anxiety,” said Cobb.
Therefore, one of the best things we can do for dogs’ well-being – besides smiling at them – is to slow down during walks and let them sniff around. Cobb stated that for dogs, taking the time to smell a patch of grass that carries unique scents is equivalent to people enjoying magnificent mountain views.
“They live in a smell-based world, so allowing them to pause and sniff that tree trunk or post where another dog has urinated is essential for them to lead a fulfilling life.”