In news that will be no surprise to dog-lovers (or anyone who has tried to hide something from a pup), scientists have discovered that dogs can "see" with their noses, according to a new study published in the Journal of Neuroscience. How? Dogs are unique for having their vision and smell connected in the brain, an ability that doesn't exist for any other animal. "I just kept finding these huge pathways," says veterinary neurologist Philippa Johnson. "They seem like information freeways running from the nose back into the brain." Read on to learn how dogs "see" with their noses
How Can Dogs See With Their Noses?
Johnson and her colleagues at Cornell University's College of Veterinary Medicine studied the MRIs of 23 dogs, discovering an extensive pathway between the olfactory bulb (for scent) and their occipital lobe (for vision). "The most interesting thing about this research are the connections from the nose up to the occipital lobe, which houses the visual cortex," Johnson says.
Dogs Vs. Humans
Unlike humans, dogs rely on scent to make sense of their surroundings. "When we 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," Johnson says. "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."
Even Blind Dogs Can Play Fetch
Research suggests that because dogs are so skilled at using scent, it can be hard to catch vision issues ahead of time. "One of the ophthalmologists at the hospital here said he regularly has owners that bring their dogs in, and when he tests their eyesight, they are completely blind — but the owners literally won't believe him," Johnson says. "The blind dogs act completely normally. They can play fetch. They can orientate around their environment, and they don't bump into things."
Dogs Can "Smell" Heat
Previous research shows dogs can actually "smell" thermal radiation, explaining how even dogs with impaired vision can hunt and fight. "It's a fascinating discovery," says ethologist Marc Bekoff, PhD, professor emeritus at the University of Colorado, Boulder. "[It] provides yet another window into the sensory worlds of dogs' highly evolved cold noses."
Hope For Blind Dogs
"Knowing there's that information freeway going between those two areas could be hugely comforting to owners of dogs with incurable eye diseases," Johnson says. "To see this variation in the brain allows us to see what's possible in the mammalian brain and to wonder — maybe we have a vestigial connection between those two areas from when we were more ape-like and scent-oriented, or maybe other species have significant variations that we haven't explored."