Functional magnetic resonance imaging was used in order to understand how dogs' brains see in a new study published last week.
Recent advancements in the fields of machine learning and functional magnetic resonance imaging (fMRI) have helped to decipher visual stimuli in human and nonhuman brains. However, this research, which provides new understandings of the nature of visual perception, has not yet been meaningfully applied to non-primates. That is, until the study was published in the peer-reviewed Journal of Visualized Experiments.
"We showed that we can monitor the activity in a dog's brain while it is watching a video and, to at least a limited degree, reconstruct what it is looking at," says Gregory Berns, Emory professor of psychology and corresponding author of the paper. "The fact that we are able to do that is remarkable."
Canines present a unique opportunity to study a species evolutionarily distant from primates. Dogs, by virtue of their domestication and co-evolution with humans over the last 15,000 years, receive a lot of the same visual stimuli that humans do on a daily basis - including screens which are the preferred method of showing visual stimuli during an fMRI. However, they process the information differently.
"We humans are very object oriented. There are 10 times as many nouns as there are verbs in the English language because we have a particular obsession with naming objects. Dogs appear to be less concerned with who or what they are seeing and more concerned with the action itself."
Gregory Berns
What can dogs show us about visual perception?
"While our work is based on just two dogs it offers proof of concept that these methods work on canines," says Erin Phillips, first author of the paper, who did the work as a research specialist in Berns' Canine Cognitive Neuroscience Lab. "I hope this paper helps pave the way for other researchers to apply these methods on dogs, as well as on other species, so we can get more data and bigger insights into how the minds of different animals work."
Previous fMRI studies showed that dogs have face- and object-processing regions in their brains that are architecturally similar to those in primates - although it is unclear how detailed their discernment is (e.g. when perceiving a head, determining if it is a dog head or human head by visuals alone).
"We humans are very object-oriented," Berns says. "There are 10 times as many nouns as there are verbs in the English language because we have a particular obsession with naming objects. Dogs appear to be less concerned with who or what they are seeing and more concerned with the action itself."
Methods and conclusions
Study participants were shown a series of naturalistic videos while undergoing an fMRI scan. Over three sessions, 90 minutes of fMRI data were obtained from each dog's responses to 256 individual video clips. This procedure was repeated on human volunteers.
"It makes perfect sense that dogs' brains are going to be highly attuned to actions first and foremost," he says. "Animals have to be very concerned with things happening in their environment to avoid being eaten or to monitor animals they might want to hunt. Action and movement are paramount."