How Dogs Respond To Words

Dogs are often told to “fetch!”, or “sit down!”, and almost all owners use auditory cues to train them to do so. However, various studies from Emory University indicate that dogs recognize objects in a different way than humans once expected, and also reveal dogs actually process commands through visual and tactile cues.

Gregory Berns, the founder of the Dog Project at Emory University, aims to explore fundamental questions about dogs using functional magnetic resonance imaging (fMRI). In this project, dogs are trained to lay under fMRIs for scanning in brain imaging to examine responses to odors, sounds, smells, food, and more.

In the study regarding dogs’ understanding of specific commands, 12 dogs of different breeds were trained to recognize the names of two different objects—one smooth and one rough to help with distinguishing between them—and were placed in the fMRI for scans. During the scans, owners would hold up the objects they trained their dogs to recognize and say the corresponding words, and would also hold up objects that the dogs have never seen before and say gibberish.

The results showed that dogs, like humans, can distinguish between known and unknown words. However, surprisingly, the study found that brain activity increased when dogs heard the new words. This is completely opposite from humans, where activity increases for known words in comparison to unknown. Researchers explain this result by noting that dogs try to understand what their owners are saying in order to “please their owners” for praise, treats, and food. The “heightened activity” in these 12 dogs was found in the left temporal cortex, caudate nucleus, the thalamus, and the parietotemporal cortex. Around half the dogs experienced it in the parietotemporal cortex, responsible for recognizing numbers and quantities. This indicates that dogs can distinguish the differences of two commands in a similar part of the brain than humans—the research team hypothesizes that the parietotemporal cortex in dogs is parallel to human’s angular gyrus.

Knowing that dogs can distinguish between words, a question is raised; how can we train dogs to best recognize differences? The Dog Project also looked at visual, olfactory, and verbal stimuli in dogs, and compared the most effective through looking at brain activity. There were three tests, each designated to one stimulus. The control in each set of scans was that after one stimulus that the dog had never encountered, the dog would receive a food reward. After another never-encountered stimuli, the dog would receive nothing.

The different objects/stimuli designated to each part of the study (visual, olfactory, and verbal) were two objects, two odors, or two spoken words. There were a total of 88 trails per one session because there were 4 runs, and 22 trials.

The results indicated that dogs “prioritize gestures over verbal commands when presented with conflicting signals”. This is probably because dogs use visual cues for communication between themselves; namely tail wagging, postures, expressions, etc. The study also found that dogs might prefer olfactory over visual cues. These two results determine visual and olfactory cues far more effective than auditory commands.

This photo of the brain scans reveals that brain activity is significantly lower in response to verbal cues than visual and olfactory in the caudate, amygdala, and parietotemporal cortex.

A question that may be raised in response to these studies is how dogs, despite their automatic preference for olfactory and visual cues, learn commands through auditory stimuli so effectively. Berns and other researchers think that it is in response to a reward presented by humans, whether a treat or petting.

In all, auditory commands can be used to train dogs and research confirms that dogs can differentiate between objects and sounds. However, using a reward system may be the most effective when using these spoken orders. Yet, using a specific motion, expression, or having a specific smell to present to dogs when you want them to follow your commands is proven to be the most effective and efficient.

Bibliography

Clark, Carol. "Scientists Chase Mystery of How Dogs Process Words." Emory News Center, 15 Oct. 2018, news.emory.edu/stories/2018/10/esc_dogs_process_words/campus.html. Accessed 15 Oct. 2020.

Emory Health Sciences. "Scientists Chase Mystery of How Dogs Process Words." Science Daily, 15 Oct. 2018, www.sciencedaily.com/releases/2018/10/181015120901.htm. Accessed 15 Oct. 2020.

"Fast Neural Learning in Dogs: A Multimodal Sensory fMRI Study." Scientific Reports, www.nature.com/articles/s41598-018-32990-2.