If you thought your pet dog keeps waiting at the door for your arrival every evening only in the hope of filling its stomach, think again! A new research has shown that all it really needs first is a little pat on the back.

Most canines prefer praise over food, suggests the study published in the journal Social, Cognitive and Affective Neuroscience. 

"Out of the 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,” said lead author of the research Gregory Berns, neuroscientist at Emory University in Atlanta, Georgia.

For the experiment, the researchers began by training the dogs to associate three different objects with different outcomes. 

A pink toy truck signalled a food reward; a blue toy knight signalled verbal praise from the owner; and a hairbrush signalled no reward, to serve as a control.

The dogs were then tested on the three objects while in a functional MRI machine. Each dog underwent 32 trials for each of the three objects as their neural activity was recorded.

All of the dogs showed a stronger neural activation for the reward stimuli compared to the stimulus that signalled no reward, and their responses covered a broad range. 

Four of the dogs showed a particularly strong activation for the stimulus that signalled 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.

The dogs then underwent a behavioural experiment. Each dog was familiarised with a room that contained a simple Y-shaped maze constructed from baby gates: One path of the maze led to a bowl of food and the other path to the dog's owner. 

The owners sat with their backs toward their dogs. The dogs were then repeatedly released into the room and allowed to choose one of the paths. If they came to the owner, the owner praised them.

"We found that the caudate response of each dog in the first experiment correlated with their choices in the second experiment," Berns said. 

"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," Berns noted.