Interacting with dogs engages the social brain

Interaction with an animal is a social situation emotionally important for most people. Human contact with animals has been described as having positive effects on human mental health, but the neurophysiology of this process is yet to be understood. A lot of studies have reported that a positive interaction with a dog reduces stress levels and leads to an increase of neurochemicals associated with bonding and affiliation.

In this 2022 study, Marti et al, compared the prefrontal brain activity of healthy human adults during contact with a dog and contact with a plush animal. They investigated two hypotheses:
1. That more stimulation correlates with higher brain activity
2. That interaction with a dog would cause more brain activity than with a plush animal

For this, 21 healthy individuals participated in six sessions each. Three sessions with a dog, with increasing level of intensity, and three sessions with a plush animal with increasing lever of intensity. The researchers measured oxygenated, deoxygenated, and total hemoglobin and oxygen saturation of the blood in the frontal lobe with functional near-infrared spectroscopy to assess brain activity.

Prefrontal activity was augmented in sessions where subjects contacted with the dog and with sessions that subjects contacted with a plush animal. The activity grew in both cases with the increase in intensity. This confirmed Hypothesis number 1.

The subjects had greater levels of activity when interacting with the dog, than they had interacting with the plush animal. This confirmed Hypothesis number 2.
Interaction with a dog is known to support people coping with stress, anxiety and depression and more research on this topic is needed to help design a possible system for animal-assisted therapy. The prefrontal cortex is particularly interesting because of it regulates and processes social and emotional interactions.

Future studies are needed to better understand if this brain activity can increase with familiarity and to unravel if humans suffering from socioemotional deficits can experience the same results.

Marti, R, Petignat, M, Marcar, VL, Hettendorf, J, Wolf, M, Hund-Georgiadis, M, Hediger, K, Effects of contact with a dog on prefrontal brain activity: a controlled trial, 2022, PLOS ONE, 17 (10).
DOI: 10.1371/journal.pone.0274833