What's More Important to Your Dog: Food or Praise?

According to a new study published in the journal Social, Cognitive, and Affective Neuroscience, more dogs prefer praise from their owners over food when being rewarded for good behavior. This is the first study that explores the reward preferences of “man’s best friend” through the combination of brain-imaging data and behavioral experimentation.

When speaking of the conducted study, Gregory Berns, MD, PhD, neuroscientist at Emory University and lead author of the research, said, in a press release, “We are trying to understand the basis of the dog-human bond and whether it’s mainly about food, or about the relationship itself. Out of 13 dogs that completed the study, we found that most of them either preferred praise from their owners over food, or they appeared to like both equally. Only two of the dogs were real chowhounds, showing a strong preference for food.”

Classical conditioning is a form of associative learning that pairs together two different stimuli in order to elicit a new learned response. This concept was first discovered by Ivan Pavlov in the early 1900s, according to the press release. In his research, a person (unconditioned stimulus) would come and bring the dogs food (unconditioned stimulus) and they would begin to salivate (unconditioned response). Eventually, the dogs began to associate the person who was bringing the food to them with being fed, and thus, would start to salivate at the mere sight of the person (conditioned response).

Discussing the two theories behind effective positive reinforcement, Dr. Berns said, “One theory about dogs is that they are primarily Pavlovian machines: They just want food and their owners are simply the means to get it. Another, more current view of their behavior is that dogs value human contact in and of itself.”

For the first step in the study, researchers trained all 13 dogs to associate three different objects with three different outcomes. When they saw a pink toy truck, they knew that there would be a food reward; when they saw a blue toy knight, they knew that they would receive verbal praise for their actions. To serve as a control in the experiment, the researchers used a hairbrush to signal no reward.

The researchers found that the reward stimuli, the toy truck and the toy knight, activated stronger neural reactions in all of the dogs compared to the hairbrush stimulus, that signaled no reward. However, the range of neural activation when it came to the reward stimuli was a little broader. According to the press release, “Four of the dogs showed a particularly strong activation for the stimulus that signaled praise from their owners. Nine of the dogs showed similar neural activation for both the praise stimulus and the food stimulus. And two of the dogs consistently showed more activation when shown the stimulus for food.”

Following this experiment, the dogs then underwent a behavior experiment. The dogs were introduced to, and became familiar with, a room that contained a simple maze constructed out of baby gates that had been set up in the shape of a “Y.” The gates branched out to either a bowl of food on one side, or the dog’s owner, sitting with her/his back towards the dog, on the other. Each dog was repeatedly released into the room, where they could choose which path they wanted to take. If they decided to go to the owner, the owner would praise them.

When speaking of the results of the behavioral experiment, Dr. Berns said, “We found that the caudate response of each dog in the first experiment correlated with their choices in the second experiment. Dogs are individuals and their neurological profiles fit the behavioral choices they make. Most of the dogs alternated between food and owner, but the dogs with the strongest neural response to praise chose to go to their owners 80 to 90 percent of the time. It shows the importance of social reward and praise to dogs. It may be analogous to how we humans feel when someone praises us.”

Dr. Berns is the head of the Dog Project in Emory University’s Department of Psychology, which is dedicated to researching evolutionary questions regarding dogs. The Dog Project was the first to train dogs to, without any kind of sedation or restraint, enter at their own volition into a functional magnetic resonance imaging (fMRI) scanner and remain still during scanning. Previously, the Dog Project had conducted research that identified the region where the reward center of a dog’s brain is and furthermore, were able to show how that ventral caudate region elicits a stronger response to familiar human scents than it would if met with the scents of other humans or even familiar dogs.

This study, as well as Emory University’s Dog Project is laying groundwork to better understand how dogs experience their world through continued exploration, research, and experimentation. Currently, Dr. Bern’s lab is seeking to further understand how dogs process and understand human language.

When speaking of the rewards of conducting canine research, Dr. Berns said, “Dogs are hypersocial with humans and their integration into human ecology makes dogs a unique model for studying cross-species social bonding.”