You might already know that dogs can smell far better than humans can. (The actual scientific estimate is that dogs can smell somewhere between 10,000 to 100,000 times better than we can!)
But there is still a lot to learn about exactly how powerful and accurate a dog’s sense of smell is. So a new study out of Cornell University has used MRI scans (like a brain X-ray) of different species to understand how their brains function. And results are leading to an exciting conclusion.
In a way, dogs use their noses like we use our eyes. Sort of.
The exact type of MRI scan used by researchers is called a diffusion MRI scan. Essentially, this scan lets scientists see how molecules flow inside a structure, like an organ such as the brain! By getting a map of how things move, they can see better how something works.
What were the researchers looking for here? Well, we already know that different parts of the animal brain are used for different things. For example, the olfactory bulb is a place where the sense of smell is processed, while the occipital lobe is for things that are seen.
Researchers wanted to know how things flowed through the brain of a dog.
Sniff, sniff! We see you!
In the 23 dogs that the Cornell researchers scanned, they noticed an incredible connection between the olfactory bulb and the occipital lobe.
Pip Johnson, who is one of the lead researchers at Cornell, described the findings this way.
“(The connections between the two parts of the brains were) really consistent,” she said in a press release. “And size-wise, these tracts were really dramatic compared to what is described in the human olfactory system, more like what you’d see in our visual systems.”
In other words, a dog’s sense of smell is wired up with their sight. So while a dog’s vision matters, the animals use their smell just as much, if not more, to understand their surroundings.
“It makes a ton of sense in dogs,” Johnson continued. “When (humans) walk into a room, we primarily use our vision to work out where the door is, who’s in the room, where the table is. Whereas in dogs, this study shows that olfaction is really integrated with vision in terms of how they learn about their environment and orient themselves in it.”
Maybe the best proof that Johnson and her team are on to something is the fact that dogs that are blind are still able to function extremely well—even when performing tasks that humans would find very difficult without vision.
“(Dogs) can still play fetch and navigate their surroundings much better than humans (without sight),” Johnson said. Go dogs, go!