By Kristel Tiburcio
At the end of the day, one of the things I get excited about coming home is being able to pet and hug my dog (even though at times, he rejects me for squeezing him too much). This becomes more apparent whenever I went through a stressful and hectic schedule within the day. There are also times wherein I would find myself stopping in the middle of reviewing for an exam, writing a major paper, or making a PowerPoint presentation for a report, just to pet my dog, even for a little bit. It would give me the energy to begin the work again. I can say that my dog (besides food) is my ultimate go-to happy pill! I would be one of those who would Facetime with my dog when I’m away from home for more than 24 hours.
Recently, in the city, dog and cat cafes have been a major hit, especially to the young population. I would see posts about visiting these cafes to destress or that visiting is the perfect way to take a break during finals or hell week. And everywhere, around the world, we see a lot of posts from pet owners, or even non-pet owners, who were saved by these little heroes. Dogs, and pets in general, have the power to calm (their) humans. They are heroes just because of what they are! How do they do this? Why is it that a simple touch (or for me, even just imagining touching and petting my dog) can make one happy and feel relaxed? Do dogs even feel the same with their owners? Why can’t we all just have pets, instead of stress balls, since they both fulfill the same function anyway (and for pets, even more!)?
It is not just for the reason that we simply love our pets that’s why we love them. There are also physiological changes inside our body that makes us want to touch, interact, and bond with our pets more. The study by Romero, Nagasawa, Mogi, Hasegawa, and Kikusui (2014) revealed that the human’s oxytocin levels produced within the body increases whenever a dog affiliates with its human partner. Similarly, when oxytocin is sprayed to dogs, they also affiliated with their human partners more, compared to other dogs who were sprayed with a placebo. In effect, this increase in affiliation with human partners will, again, increase the oxytocin levels within the body of its human partner. It’s a cycle that makes the pet and pet owner happy to be with each other! Oxytocin is the hormone known for its role in social affiliation and interaction. You might have encountered it as the “love”, “cuddle”, or “bonding hormone” (Stix, 2014). Despite the fact that interacting with dogs helps in reducing stress and anxiety, in the study by Romero et al. (2014), oxytocin does not function by reducing stress and anxiety. Oxytocin levels were shown to directly increase the motivation to affiliate which may help in reducing stress and anxiety.
Physiological changes due to human-dog interaction do not only include the increase in oxytocin levels. There are other studies made by researchers who are interested in the animal touch that further extends the benefits of petting based on these physiological changes. In a study by Baun, Bergstrom, Langston, and Thoma (1984), blood pressure was shown to experience changes when interacting with dogs. When a person interacts with a dog, especially with a dog they have already established a bond with, his/her blood pressure goes down. This lowering of the blood pressure creates a calm feeling for the human.
Vormbrock and Grossberg (1998) further showed that the “touching” part of interacting with dogs is the major factor of decreasing one’s blood pressure. In their study, they grouped a set of people by type of interaction with the dog: verbally, tactually, or visually. They found that blood pressure was lowest in the group who tactually interacted with the dog – petting the dog – and that heart rates were lower when a person touches or talks to the dog rather than touching and talking to the dog at the same time.
Besides the magic touch of human-dog interactions, it is also interesting to see how pets recognize the voices of their owners. When I say “Come here, Cloud” whenever I hear his foot (paw?) steps outside my door, he comes in without hesitation. However, once he hears a stranger inside the house (usually guests and relatives), he becomes alert – his ears perk up, he stands up immediately, and shifts his attention to (probably) gathering more sensory information about the guest.
A recent study by Andics, Gacsi, Farago, Kis, and Miklosi (2014) shows that just as we have a region in our brain that is sensitive to voices, dogs also have a similar area in their brains. They were able to arrive at this conclusion by testing dogs’ brains through functional magnetic resonance imaging or fMRI.
Dr. Andics (as mentioned in Hughes, 2014) mentioned that dogs and humans probably have an easier time understanding each other and getting along well because of their similarities in processing social and emotional information. This researchers think that this similarity signifies an evolutionary trait across mammals; however, others believe that it may be due to convergent evolution of man and dogs.
In their study, 11 border collies and golden retrievers were trained to rest in a machine. Since getting inside an fMRI machine may be greatly uncomfortable, training was a necessity in order to properly conduct the experiment and protect the dogs. Once inside the scanner, the dogs and 22 people were exposed to 200 different audio stimuli – “dog vocalizations (whining, playful barking, aggressive barking), human vocalizations (crying, cooing, laughing), and non-voice environmental sounds (cars, ringing phones)” (Hughes, 2014, par. 12).
It was found that 48% percent of the auditory cortex of dogs responds to non-voice sounds. On the other hand, only 3% of the human auditory cortex responds to non-voice sounds. This means that dogs respond more to non-voice sounds. The researchers explain that human brains are wired to process more voice or speech sounds since we use language to communicate everyday! They were also able to observe that both dogs and people have an area in their brains which respond more to positive emotions than negative emotions. The type of vocalization – whether human or dog – was not a factor; it will respond even if it was a positive bark or happy tone of human voice. Furthermore, there is an area in the human brain called subcortical medial geniculate body (MGB) which responds more to dog sounds than any other sounds.
The video abstract of the study can be found here.
All these studies show the beautiful companionship of dogs and humans. Dogs are not called “man’s best friend” for no reason; their existence becomes a factor in the plasticity and evolution of humans. A simple touch or bark/call can trigger physiological, emotional, and other psychological processes and changes in the human body. So for all dog owners out there, do not take your dog for granted. Love him/her and you will certainly get more love in return.
Andics, A., Gacsi, M., Farago, T., Kis, A., & Miklosi, A. (2014). Voice-sensitive regions in the dog and human brain are revealed by comparative fMRI. Current Biology, 24(5), 574-578. DOI: http://dx.doi.org/10.1016/j.cub.2014.01.058
Baun, M. M., Bergstrom, N., Langston, N. F., & Thoma, L. (1984). Physiological effects of human/companion animal bonding [Abstract]. Nursing Research, 33(3), 126-129. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/6563527
Hughes, V. (2014). How voices tickle the dog brain. Retrieved from the National Geographic website: http://phenomena.nationalgeographic.com/2014/02/20/how-voices-tickle-the-dog-brain/
Romero, T., Nagasawa, M.,Mogi, K., Hasegawa, T., & Kikusui, T. (2014). Oxytocin promotes social bonding in dogs. Proceedings of the National Academy of Sciences of the United States, 111(25), 9085-9090. doi: 10.1073/pnas.1322868111
Stix, G. (2014). Fact or fiction: Oxytocin is the “love hormone”? In Scientific American. Retrieved from http://www.scientificamerican.com/article/fact-or-fiction-oxytocin-is-the-love-hormone/
Vormbrock, J. K. & Grossberg, J. M. (1998). Cardiovascular effects of human-pet dog interactions [Abstract]. Journal of Behavioral Medicine, 11(5), 509-517.