It turns out that dogs really do love us -- in fact, they love us more than anything else in the world.
Magnetic Resonance Imaging of dog brains shows that one of the things that sets a dog's hear aflutter is the smell of their owners. From the good folks at Brain.mic
The most direct brain-based evidence that dogs are hopelessly devoted to humans comes from a recent neuroimaging study about odor processing in the dog brain. Animal cognition scientists at Emory University trained dogs to lie still in an MRI machine and used fMRI (functional magnetic resonance imaging) to measure their neural responses to the smell of people and dogs, both familiar and unknown. Because dogs navigate the world through their noses, the way they process smell offers a lot of potential insight into social behavior.
The scientists found that dog owners' aroma actually sparked activation in the "reward center" of their brains, called the caudate nucleus. Of all the wafting smells to take in, dogs actually prioritized the hint of humans over anything or anyone else....
Among other surprising findings, the study revealed marked similarities in the way dog and human brains process emotionally laden vocal sounds. Researchers found that happy sounds in particular light up the auditory cortex in both species. This commonality speaks to the uniquely strong communication system underlying the dog-human bond.
In short: Dogs don't just seem to pick up on our subtle mood changes — they are actually physically wired to pick up on them.