Want to see some serious puppy dog eyes? Try spending more time near your pooch.

Sure, new toys and food are nice, but research from the University of Portsmouth shows that like most humans, what dogs really crave is attention.

In fact, scientists at the university's Dog Cognition Centre recently found that dogs are more likely to show facial expressions if humans are paying attention to them.

In the study — which was published in Scientific Reports —dog cognition expert Dr. Juliane Kaminski and a team tested how dogs' facial expressions changed in response to four different factors: a human facing them or turned away from them either with food or without.

After performing the experiment on 24 dogs of different breeds between the ages of one and 12, researchers studied the recorded expressions using DogFACS — a coding system that helps measure the muscle movement and structure of a dog's facial anatomy.

They determined that dogs were more expressive when a human was facing them as opposed to when their bodies were turned away, and found that while food, described as a "non-social but arousing stimulus," had no impact on their behavior.

By comparing how the animals reacted to both humans and food, the study ultimately confirmed that human attention impacts dog expressions, and that dogs don't simply use facial expressions to show they're excited — they also use them to communicate.

According to the research, eyebrow raising — which helps dogs achieve those lovable "puppy dog eyes" — was a common expression recorded on the animals when humans showed them attention.

"This study moves forward what we understand about dog cognition," Dr. Kaminski said in a news release, though she noted the behavior could be a result of the dogs being domesticated.

"We now know dogs make more facial expressions when the human is paying attention."