In a recent study, it was found that dogs like their owner’s smell the best.
Neuroscientist Gregory Berns and his team at Emory University’s Center for Neuropolicy used advanced brain imaging to see if dogs recognize scents even when the source isn’t present.
The study published in the January 2015 issue of the journal Behavioral Processes revealed that the canine brains responded differently to the odor of unfamiliar dogs and humans compared to their own family.
Berns wanted to find out how a dog thinks when smelling, especially because much of their sensory information comes from odor.
“Since dogs are so much more olfactory than humans, their responses would likely be even more powerful than the ones we might have,” he told Jennifer Viegas of Discovery News.
According to the ScienceDirect website, twelve dogs were used in the study. All of those dogs were trained to remain completely still while undergoing an MRI. The dogs’ brains were then scannedwhile presented with five different scent smells:
- The dog’s own scent.
- A dog that lives with them.
- An unfamiliar dog.
- An unfamiliar human.
- A known human that lives with them.
Each scent was obtained from the source’s highly odiferous body parts like the rear and genital areas of the dogs and the armpits of the humans. Human participants were also not allowed to bathe or use deodorant for 24 hours before the sampling.
The sources of the smell were not present during the test and the study also therefore demonstrates sensory memory in dogs.
This study has found that all five scents demonstrated activity in the part of the brain associated with positive expectations. This indicated that the canines did have some recollection and association with each scent but the strongest emotional responses, those that come from the caudate nucleus, were reserved for scents from familiar humans, followed by the smell of familiar dogs.
This shows that dogs favor their own family’s scent. It was also found that dogs who are trained as service or therapy dogs have the greatest responses to human smells.
According to Viegas’ article, the reason behind this may be genetics since service dogs are selected because they possess these attributes or abilities. This may also be due to stronger bonds created through to their training. Dogs who have been trained as service dogs have experienced more human interaction – leading to greater recognition and positive feelings.
“Not only did the dogs discriminate the familiar human scent from the others, they had a positive association with it. While we might expect that dogs should be highly tuned to the smell of other dogs, it seems that the ‘reward response’ is reserved for their humans. Whether this is based on food, play, innate genetic predisposition or something else remains an area for future investigation,” Berns told Viegas.
The bottom line is dogs prefer the smell of their human families over other dogs.