New York, March 19 (IANS): You love it when your pet dog jumps on you and licks you when you come home from office.

What you perhaps do not know is that your body odour lingers like perfume in your dog's brain even if you are not near him.

An area of the canine brain responds more strongly to the scents of familiar humans than it does to the scents of other humans, or even to those of familiar dogs, research has shown.

“The canine brain responses are triggered by something distant in space and time. It shows that dogs’ brains have these mental representations of us that persist when we are not there,” said Gregory Berns, director of Emory's Center for Neuropolicy in the US.

When humans smell the perfume or cologne of someone they love, they may have an immediate, emotional reaction that is not necessarily cognitive.

“Our experiment may be showing the same process in dogs. But since dogs are so much more olfactory than humans, their responses would likely be even more powerful than the ones we might have,” Berns explained.

Berns led the team that captured the first brain images of alert, unrestrained dogs, using harmless functional magnetic resonance imaging (fMRI).

He conducted the scent research with Andrew Brooks, also with Emory’s Center for Neuropolicy, and Mark Spivak, owner of Comprehensive Pet Therapy.

“Olfaction is believed to be dogs’ most powerful and perhaps important sense, making it an obvious place to explore canine social cognition,” Spivak said.

The experiment involved 12 dogs of various breeds.

They were presented with five different scents.

The scent samples came from the subject itself, a dog the subject had never met, a dog that lived in the subject’s household, a human the dog had never met and a human that lived in the subject’s household.

The familiar human scent samples were taken from someone else from the house other than the handlers during the experiment, so that none of the scent donors were physically present.

“The stronger caudate activation in the brain suggested that not only did the dogs discriminate the familiar human scent from the others, they had a positive association with it,” Berns observed.

It seems that the ‘reward response’ is reserved for their humans.

Whether this is based on food, play, innate genetic predisposition or something else remains an area for future investigation, he added in a report published in the journal Behavioural Processes.