Dogs and Cats: Their Brains, Faces, Blinking Eyes, and Us
New research clarifies various aspects of how dogs and cats communicate with us.
Posted Oct 11, 2020
Two recent essays about dogs and cats caught my eye, and the results of these research projects are well worth considering. There is broad interest in how these very popular companion animals communicate with us, how we communicate with them, and the shared emotions that work like "social glue" to bond us together. Neither of the essays, which are available for free online, are especially easy reads for non-specialists, but both have been well covered in the popular press.
Are dogs hard-wired to respond to human faces?
It's known that dog watch us carefully and read our faces very well. This is why I was especially interested in an essay in The Guardian by science writer Nicola Davis — "Dogs’ brains ‘not hardwired’ to respond to human faces" with the subtitle ,"Study of brain activity shows no difference when dogs see back or front of a head." Davis' piece nicely summarizes a research paper by Nóra Bunford and her colleagues, titled COMPARATIVE BRAIN IMAGING REVEALS ANALOGOUS AND DIVERGENT PATTERNS OF SPECIES- AND FACE-SENSITIVITY IN HUMANS AND DOGS.1
The researchers used fMRI's to scan the brains of 20 family dogs and 30 humans who were shown videos of either the back or front of the head of a dog or of a human. While dogs showed more interest in videos of dogs and didn't display differences in brain activity when they saw the front or back of a dog or human head, humans displayed more of a response when they were showed faces when compared with when they were shown the backs of heads.
Because dogs show a great dependency on odors in social communication, and allowing them to sniff can help them think positively, the results aren't all that surprising. However, some researchers aren't all that convinced by these data because only half of the dogs displayed a dog-specific cortical area. Clearly more research is needed, and Emory University's Daniel Dilks, who studies the human visual cortex, notes, "It will be important to understand why half of the dogs exhibit such a cortex, while the other half does not." I agree. There are large individual differences in the behavior and personalities of dogs—there are no "universal dogs"—and it's essential to pay careful attention to individual differences not only in behavior but also in how their brains work. Of course, the same can be said about cats and numerous other nonhumans.
Cats' eyes and positive emotional communication
Cats are fascinating companions and there are many factors that influence how they communicate with us and how we communicate with them. This is why I was really interested in a piece by Hannah Sparks called "How to make a cat like you: Why science recommends slow blinking" that summarizes a research essay by Tasmin Humphrey and her colleagues titled, "The role of cat eye narrowing movements in cat–human communication."2
Ms. Sparks begins, "Blink once if you love cats, but do it slowly. Animal behaviourists have revealed the most effective way to befriend a feline: the 'slow blink'.” To summarize the results of the first study to look at the role of slow-blinking in cat-human communication, the researchers write, "...our results suggest that slow blink sequences may function as a form of positive emotional communication between cats and humans."
I agree and there still is much to learn. For example, we still don't know if the slow-blink is an evolved adaptation or a learned response, or if it's used to interrupt a persistent stare that might be viewed as threatening. Cats also don't regularly initiate the slow-blink, but rather wait for humans to prompt it after which they respond. We're also told, "Cats were more willing to approach a human’s outstretched hand if they had also used the slow-blink technique to greet the cat, as opposed to participants who imparted a neutral expression." Humphrey wonders if cats "may have adopted the habit more regularly after noticing that humans were the ones who felt more relaxed after a cat’s slow blink."
There's also a welfare aspect to this research because as humans learn more about cat behavior, it may improve public images of these mysterious felines, about whom there is still much to discover about their rich cognitive and emotional lives.
Trainers also will be interested in these and similar studies, because so much of what they do depends on knowing the details of how humans and their companion animals interact with one another and how to use this information to offer the best lives possible for the nonhumans and humans. Positive force-free and successful training depends on being fluent in dog and cat and paying close attention to the details of reciprocal encounters between the nonhumans and humans and the context in which they occur.
Where to from here?
While there still much to learn about feline slow-blinks, this research opens the door for future studies on cat-human communication. Likewise, the study of dogs' brains and how they respond to human faces raises many questions about the nature of dog-human communication.
This is an exciting time to study all sorts of social interactions between humans and dogs, cats, and other companion animals, who plays the main role in initiating specific patterns of behavior and how they do it, and to learn if and how they're related to the process of domestication. I look forward to sharing these data as they emerge from detailed studies such as the ones discussed here. As we accumulate this much-needed information, it'll be a win-win for all.
1) The abstract for this essay reads, "Conspecific-preference in social perception is evident for multiple sensory modalities and in many species. There is also a dedicated neural network for face processing in primates. Yet, the evolutionary origin and the relative role of neural species-sensitivity and face-sensitivity in visuo-social processing are largely unknown. In this comparative study, species- and face-sensitivity to identical visual stimuli (videos of human and dog faces and occiputs) were examined using functional magnetic resonance imaging in dogs (n=20; 45% female) and humans (n=30; 50% female). In dogs, the bilateral mid suprasylvian gyrus showed conspecific-preference, no regions exhibited face-preference, and the majority of the visually-responsive cortex showed greater conspecific- than face-preference. In humans, conspecific-preferring regions (the right amygdala/hippocampus and the posterior superior temporal sulcus) also showed face-preference, and much of the visually-responsive cortex showed greater face- than conspecific-preference. Multivariate pattern analyses identified species-sensitive regions in both species, but face-sensitive regions only in humans. Across-species representational similarity analyses revealed stronger correspondence between dog and human response patterns for distinguishing con- from heterospecific faces than other contrasts. Results unveil functional analogies in dog and human visuo-social processing of conspecificity but suggest that cortical specialization for face perception may not be ubiquitous across mammals."
2) The abstract for this essay reads, "Domestic animals are sensitive to human cues that facilitate inter-specific communication, including cues to emotional state. The eyes are important in signalling emotions, with the act of narrowing the eyes appearing to be associated with positive emotional communication in a range of species. This study examines the communicatory significance of a widely reported cat behaviour that involves eye narrowing, referred to as the slow blink sequence. Slow blink sequences typically involve a series of half-blinks followed by either a prolonged eye narrow or an eye closure. Our first experiment revealed that cat half-blinks and eye narrowing occurred more frequently in response to owners’ slow blink stimuli towards their cats (compared to no owner–cat interaction). In a second experiment, this time where an experimenter provided the slow blink stimulus, cats had a higher propensity to approach the experimenter after a slow blink interaction than when they had adopted a neutral expression. Collectively, our results suggest that slow blink sequences may function as a form of positive emotional communication between cats and humans."
Bekoff, Marc. Dogs Watch Us Carefully and Read Our Faces Very Well. (Research shows dogs pay close attention to different human facial expressions.)
_____. How a Dog's Brain Processes Human Faces. (New research using fMRI shows the bilateral temporal cortex plays a key role.)
_____. Secrets of the Snout: A Dog's Nose Is a Work of Art. (What dogs' noses know and how they work.)
_____. "Bad Dog?" The Psychology of Using Positive Reinforcement. (A new study shows a human's emotional state and confidence are important.)
_____. Allowing Dogs to Sniff Helps Them Think Positively. (New research shows that allowing dogs to exercise their noses is good for them.)
_____. "My Own Dog Is an Idiot, but She’s a Lovable Idiot.” (A dog researcher has it all wrong!)
_____. Canine Confidential: Why Dogs Do What They Do. University of Chicago Press, 2018.
_____ and Jessica Pierce. Unleashing Your Dog: A Field Guide to Giving Your Canine Companion the Best Life Possible. New World Library, 2019.