Neuroimaging Reveals How Animals Activate the Human Brain
Technology reveals how the human brain reacts to living animals.
Posted November 16, 2022 | Reviewed by Vanessa Lancaster
- Animal companions provide a wide range of benefits, but brain research on human-animal interactions is limited.
- Recently, researchers used fNIRS to measure blood flow in the prefrontal region of the human brain during dog interactions.
- The study suggests that living pets, but not stuffed animals, activate the human brain's prefrontal cortex.
We recently hosted a sweet-tempered Schnauzer-Poodle mix in our home while the dog’s primary guardian was out of town.
For several weeks, this dog kept me company and initiated interactions with me throughout the day – seeking a friendly scratch or communicating that it was “time for dinner” or “let’s take a walk.” These human-pup interactions made me fully appreciate just how comforting it is to share one’s space with a living four-legged companion.
Just how do pets affect us? There are so many ways we benefit from our animal friends. “Service animals” assist people with disabilities, and “pet therapy” involves guided treatments for human clients that employ animals during therapy. More commonly, we refer to “comfort animals” – a general term for pets who provide emotional support.
I previously posted about the possible future benefits of using robot pets as substitute comfort animals. Some people desire an animal companion but don’t have the capacity to care for a live pet. Will future technology provide AI-driven robotic pets, and will they ever substitute for the real thing?
To answer such questions, we must understand more about how and why pets affect us as they do. There is surprisingly limited research in this area. We know pets confer a wide range of benefits. For example, being with a pet can decrease stress hormones and lower blood pressure.1 People who adopt pets for five years or more show less cognitive decline as older adults.2 Animal companions appear to benefit our wellness, yet little is known about how our pets affect our brains. For this type of research, we need to use brain scans.
The noninvasive imaging of brain scans helps us study how our brains function. Not only can neuroscientists image brain anatomy – but the newest scans can measure brain metabolism while human subjects perform various tasks. This reveals which specific brain areas “light up” with enhanced activity during specific situations. One technology that maps brain metabolism and blood flow is known as human functional near-infrared spectroscopy (fNIRS). A recent study used NIRS to look at human brains during dog interactions.
Using fNIRS, researchers measured blood flow in the prefrontal region of the human brain. This prefrontal cortex area is of particular interest to neuroscientists studying social cognition. The researchers used fNIRS to observe that prefrontal activity increased when subjects interacted with a live dog but not when presented with a plush stuffed animal. Of course, we’d expect human brains to respond differently to a live animal than to a stuffed toy. Yet this result raises interesting questions: “Why does interacting with a live dog activate our prefrontal area?”
The research (above) suggests something special happens in our prefrontal area when interacting with a living pet – but not with a plush stuffed animal. Perhaps research with fNIRS can be expanded to compare the prefrontal activity of people interacting with living pets versus dynamic robotic pets instead of static stuffed animals.
The idea of robotic pets may make some cringe. (“It’s not natural!”) But robot pets offer some advantages for disabled or older people: They don’t require the care a live animal does, they can be built to monitor vital signs and call for help, and they don’t introduce germs into institutional settings. Future engineers will develop ever more realistic robot pets, simulating pet sounds, movements, breathing, eye contact, and the warmth of their natural counterparts. Perhaps these future robot pets will elicit a similar prefrontal brain “comfort response” in human companions.
Research with brain scans is beginning to reveal exactly how the human brain responds to interacting with animals. As technology helps explore the neurological basis for how pets affect us, perhaps we are closing in on the physical basis for why so many animal lovers say, “My therapist has a waggy tail.”
(1) Petersson M, Uvnäs-Moberg K, Nilsson A, Gustafson LL, Hydbring-Sandberg E, Handlin L. Oxytocin and Cortisol Levels in Dog Owners and Their Dogs Are Associated with Behavioral Patterns: An Exploratory Study. Front Psychol. 2017 Oct 13;8:1796. doi: 10.3389/fpsyg.2017.01796. PMID: 29081760; PMCID: PMC5645535.
(2) Shieu, Monica, Applebaum, Jennifer , Dunietz, Galit & Braley, Tiffany (2022, Feb) Companion Animals and Cognitive Health; A Population-Based Study. American Academy of Neurology 74th Annual Meeting: Cognitive Aging, Dementia, and Memory. U. Michigan Medical Center, Ann Arbor, MI and University of Florida, Gainesville, FL. Presented: February 23, 2022.
Marti R, Petignat M, Marcar VL, Hattendorf J, Wolf M, Hund-Georgiadis M, Hediger K. Effects of contact with a dog on prefrontal brain activity: A controlled trial. PLoS One. 2022 Oct 5;17(10):e0274833. doi: 10.1371/journal.pone.0274833. PMID: 36197880; PMCID: PMC9534402.