Looking into the Brain and Mind of Human’s ‘Best Friend’
Celebrated for their loyalty, affection, and occasional acts of heroism, our faithful canine companions are often given attributes, and even some cognitive abilities, compatible with — if not exactly congruent with — our own. But how justified are we in ascribing to dogs (or any domesticated animal) thoughts and feelings similar to our own? How much can we really know about what dog’s are really thinking about (apart from food and “chasing rabbits”)?
Two recent studies are attempting to shed (no pun intended) some light on the cognitive capabilities of canines. The first, involving fMRI tests on fully awake dogs, and the second, focusing on dog empathy in the form of “contagious yawning”. Read on, oh dog-lovers, read on…
First Brain Scans of Non-Sedated Dogs
Researchers (Berns et al) from Emory University are reporting in the open journal PLoS ONE, the results of the first brain scans (using functional magnetic resonance imaging, or fMRI) of dogs while fully awake and aware.
Prior to these tests, most researchers had assumed that dogs could not stay still long enough to go through the claustrophobia-inducing fMRI machines. But after reading about a canine member of the Navy Seal team (that killed bin Laden) trained to jump from helicopters, the Emory U researchers realized that they could also be trained to sit still during an MRI session.
The experiment conducted here was rather simple, but revelatory: dogs were trained to recognize two different hand signals, the first being a left hand pointing down (signifying a hot dog treat would be given), and the second signal (both hands pointing toward each other), indicating no treat would be given. In humans, a brain region called the caudate (and the caudate nucleus) plays a central role in our reward “circuitry”. The researchers found that this same brain area in dogs would suddenly become active when given the first hand signal (the “treat” signal) but remained static when the “no treat” signal was shown. Quoting Gregory Berns in a recent SciAm article:
“These results indicate that dogs pay very close attention to human signals and these signals may have a direct line to the dog’s reward system.”
Exploring A Deep Connection from Our Evolutionary Past
Given the co-evolution of modern humans and dogs, the researchers hope to reveal the nature of our mutual connection with our canine companions (from the dog’s perspective), including how dogs decipher and represent human language and facial expressions. Their continued studies of dog cognition may offer us a “mirror” into the human mind, for, the dog’s brain is in many ways a product of human culture and evolution.
On the other hand (or paw), some recent research supports the notion that dogs have influenced human evolution — including our language and tool-making abilities — as much as we have influenced dog evolution.
Watch the video of the Dog brain scan experiment (article continues below):
Doggie Empathy? It’s All in the Yawn
You’ve no doubt seen it happen many times: someone yawns, and in short time, someone else yawns too. The phenomenon is referred to as ‘contagious yawning’ and apart from humans, the behavior is found in only a few other animals — mostly in primates, such as gelada baboons, stump-tail macaques, and chimpanzees…and it also occurs in “Man’s best friend.”
Most human yawning (apart from bored/sleep-deprived students in lecture halls) tends to occur around friends and relatives which has prompted some behaviorists to view the act as a form of empathy. It has been observed that dogs tend to yawn more after observing familiar and trusted humans yawning. But, whether this is the result of an empathetic response has remained in doubt. Perhaps, if the yawning response occurred in the absence of visual cues, that is, only through hearing, this might lend more credence to the theory.
Recently, a team of behavioral biologists led by Karine Silva at the University of Porto, Portugal, conducted a series of tests with 29 dogs who had lived at least six months with their owners. The tests were conducted in familiar rooms in their actual homes so as to to reduce any potential, laboratory-induced anxiety in the dogs. The canine subjects were tested in the presence of their owners, but without visual contact with them.
The researchers used recorded sounds of their owners yawning as well as an unfamiliar person (a woman yawning) and a computer-reversed yawn. Owners first listened to recording of other people yawning to induce their own, natural yawning. All 29 dogs were exposed to all the recordings in two different sessions conducted one week apart. The team then recorded the number of dog yawns in response to the yawn recordings of familiar and unfamiliar sources.
The results? Just under half (12) of the dogs yawned during the experiment. But of those that did so, they yawned five times more often when hearing a familiar person yawn, as opposed to any of the control yawns.
Speaking cautiously, Silva stated: “These results suggest that dogs have the capacity to empathize with humans.”
Given our long, entangled history, it would not be too surprising to learn that dog’s have developed some empathetic response to human behaviors. But is this what is really going on inside the canine cranium?
Empathy or Animal Mimicry?
Other researchers are more skeptical about the results, asserting that using behaviors (like yawning) as indicators of the dog’s internal ‘state of mind’ will only show similarities in behavior and do not tell us about what the dog is actually experiencing cognitively. Earlier tests with dogs who “looked guilty” failed to show that this emotion was actually being experienced by the dog.
Dogs can be very good imitators of human social interests and we humans, being given to personification of animals, may tend to believe that these imitations of human emotions are the result of the same mental processes.
Still, the results of these dog experiments indicate some type of connection between humans and canines that is operating even when the human is not in view.
Quoting from the paper’s (Auditory contagious yawning in domestic dogs (Canis familiaris): first evidence for social modulation) abstract:
‘The present study explored the ‘contagion-only’ hypothesis by testing whether the mere sound of a human yawn can be sufficient to elicit yawning in dogs, in a way that is unaffected by social–emotional factors. Unexpectedly, results showed an interesting interplay between contagion and social effects. Not only were dogs found to catch human yawns, but they were also found to yawn more at familiar than unfamiliar yawns. Although not allowing for conclusive inferences about the mechanisms underlying contagious yawning in dogs, this study provides first data that renders plausible empathy-based, emotionally connected, contagious yawning in these animals.’ [emphasis added]
Full results of the tests will be reported in the July, 2012 issue of Animal Cognition.