Many dog owners can confirm that jealousy sometimes shapes the behavior of “man’s best friend”. Researchers have now gained clues as to what goes on in a dog’s head when his caregiver greets another dog with joy. Activity patterns in the brain seem to reflect the fact that the test animals perceived the dogs shown in videos as a potential threat to their bond with their caregivers.
An astonishing relationship across species boundaries: There is no other animal that humans have such a close relationship with as they do with dogs. In the course of the long history of domestication, the four-legged friends became better and better understanders of people. That is why they have been the focus of cognitive and brain research for some time: Scientists want to gain insights into the abilities and experiences of dogs as well as into the neural processes on which these services are based. Among other things, it has already been shown that dogs can differentiate between emotional facial expressions and correctly interpret human gestures and behavior.
These animal gifts form a basis of the often strong bond between dogs and their human partners. The animal’s sensation is often interpreted as love or deep friendship. A typical feature of such a relationship is the particular sensitivity towards the partner’s behavior when dealing with others. An emotion that humans call jealousy can come into play. Behind this is the fear of losing the partner’s attention to a rival. Behavioral tests on dogs that have seen their caregiver befriend another dog confirm that the animals react accordingly – sometimes they even literally intervene.
Look into the dog’s head
As part of their study, the researchers led by Sabrina Karl from the University of Vienna investigated the question of which brain processes in dogs could be the basis for such sensations. To do this, they used the method of functional magnetic resonance imaging (fMRI), which can depict the activity of certain areas of the brain. The team has now also established this method for brain research in dogs at the University of Veterinary Medicine, Vienna. For this purpose, test animals were gradually accustomed to the system, so that they finally got into the scanner voluntarily and relaxed and stuck their heads into the coil. The animals can then look at pictures or videos on a screen.
The current study looked at the brain activity of twelve dogs while watching videos of people interacting with other dogs. Either the master or mistress of the dog lying in the scanner or a stranger to him could be seen. In the videos, these people dealt with a strange dog in two different ways: Either they greeted it happily and stroked it. In the other case it was not a question of a positive social interaction, but of a neutral one: the strange dog’s teeth and ears were checked in a kind of vet scenario.
Signature of jealousy?
As the team reports, the results of the brain scans basically showed that the animals interpreted the videos as real scenarios. The researchers interpreted the increased activity in the hypothalamus during social human-dog interactions with the owner as a sign that the animals recognized their caregiver in the videos. The scientists report that there were characteristic differences in brain activity between the various types of video. The most important result was: The positive social interactions with the other dog resulted in a noticeably strong neuronal excitation. If, on the other hand, a stranger greeted the dog happily in the video or if the caregiver only examined the animal without emotion, there was comparatively little neural activity.
In detail, when looking at the positive-emotional interaction between the caregiver and the other dog, there was an increase in activity in the amygdala and the insula, the scientists report. As they explain, these are two areas of the brain that are involved in evaluating stimuli and processing emotions. According to them, it stands to reason that the test animals perceived the dog shown in the video as a potential threat to the bond with their caregiver. This would reflect what is known from observations and experiences with human-dog interaction in similar situations on the neural level.
In conclusion, however, the researchers emphasize that the results so far are preliminary – a clear assignment of the dog’s emotions based on the scanner data remains difficult. Nevertheless, according to them, the study now offers a first glimpse into the emotional life of dogs when assessing the actions of their human caregivers. It will therefore be interesting to see what interesting insights the examination method now established at the University of Veterinary Medicine in Vienna will provide in the future.
Source: University of Veterinary Medicine, Vienna, specialist article: Cerebral Cortex Communications, doi: 10.1093 / texcom / tgab047