"Picking a dog" can be said to be a stress-relieving and pleasant experience in fast-paced urban life. After working hard for a day, dragging his tired body home. If a cute dog could come to greet him lively and enthusiastically, the workers would feel like they had received the "life-sustaining pistachio", and they were filled with vitality in an instant. If you don’t have the time and energy to raise your own dog, you will feel better even if you go to a pet shop or a pet cafe to play with the dogs for a while on weekends.
Dogs are not only the best and most loyal friends of human beings, but their abilities and talents have actually been used in many industries and have a long history. For example: guide dog, search and rescue dog, police dog. From the medical field, the therapeutic effect of dogs on psychological diseases such as depression and has been extensively studied.
It is not difficult to understand that with the increase of the population living alone, the emergence of negative emotions such as loneliness, social fear, and indifference have only increased and not decreased. The companionship that dogs can provide to these people is of great significance. In addition to these externally observed positive effects, what impact does interaction with dogs have on our brains? Or is this just a psychological comfort effect? From the perspective of neuroscience , what changes will happen to our brain function after interacting with dogs?
Recently, researchers from Swiss published a research paper titled Effects of contact with a dog on prefrontal brain activity: A controlled trial. To understand human-animal interactions from a neuroscience perspective, researchers explored changes in human frontal brain activity when in contact with dogs. Interaction stimulation with dogs caused more brain activity compared to control conditions, suggesting that interaction with dogs can activate stronger attention processes. Compared with non-living interaction stimulation, dog interactions can trigger more emotional arousal.
prefrontal cortex is a key area of social cognitive processing in different aspects, such as psychological theory/mentalization, understanding of self and others. Therefore, the activity of the prefrontal cortex is very important for studying the underlying mechanisms of human-animal interactions. In this study, the researchers studied brain activation in the prefrontal cortex of healthy subjects through functional near-infrared spectroscopy (fNIRS) in a controlled trial, comparing different interaction patterns with dogs and with stuffed animals.
study adopted controlled intra-subject cross-design and repeated measurements. The detailed steps and procedures are shown below. There are three types of interactions between subjects and dogs or plush toys: watching only, leaning on the body but not feeling, and stroking.
Figure Note: Research Overview Picture (Source: Marti, Rahel, et al. 2022)
O2Hb can reflect the neuronal discharge frequency, while HHb reflects the number of recruited neurons. O2Hb reflects task-related cortical activation more directly than HHb, so O2Hb was selected as the main result, and HHb, tHb and oxygen saturation were selected as the secondary result.
results found that with the increase of stimulation, oxygenated hemoglobin (O2Hb) in the prefrontal lobe significantly increased by 2.78 μmol/l from neutral phase 1 (baseline, participants looked directly at the white wall and relaxed) to the caressing period. After removing the stimulation of neutral phase 2 (again direct look at the white wall), O2Hb remained unchanged and was still significantly higher than that of neutral phase 1. The O2Hb of dogs is 0.80 μmol/l higher than that of stuffed animals (as shown below).
Figure Note: Effects of conditions and stages on O2Hb, HHb, tHb and oxygen saturation (left figure). Effects of conditions and contact times on O2Hb, HHb, tHb and oxygen saturation (right). (Source: Marti, Rahel, et al. 2022)
combined multiple measurement results and analysis, prefrontal activity increases with the increase in contact intensity with dogs or stuffed animals, that is, more stimuli are associated with higher brain activity. When participants interacted with dogs, their prefrontal brain activity was higher than when they interacted with stuffed animals.In the case of dogs, O2Hb, tHb and oxygen saturation were significantly higher compared to control conditions, while HHb tended to be lower, indicating that oxygen consumption in the prefrontal region increased, and therefore brain activation also increased in the presence of dogs.
The phenomenon of continuous increase in brain activity may be related to the participants' familiarity with the interaction object or social relationship. People can develop emotional connections with dogs and become more familiar with each other through repeated contacts. However, it is difficult to form such a relationship with non-living bodies such as plush toys. Therefore, interaction with stuffed animals does not continuously increase brain activity.
In summary, interaction with dogs may activate more attention processes, and particularly intimate and positive physical contact with a familiar dog may promote social attention in humans. This is especially important for patients who lack motivation, attention and socioemotional function, as interaction with dogs can increase learning and achieve treatment goals. Incorporating dogs into therapeutic interventions may be a promising approach to improving emotional engagement and attention.
I don’t know if the doctor will include “sucking a dog for half an hour, once a day” in the prescription list in the near future. However, I also hope that everyone can achieve freedom of dog petting as soon as possible, and do not wait until there is physical or psychological problems before going to a dog therapist.
