Dogs could be using their sensitive noses to "see" as well as smell, according to a new study. Researchers have discovered an "extensive pathway" in the brain of domestic dogs that links the areas that manage smell and vision.
This allows dogs a remarkable sense of direction and awareness, even when they can't see, which explains how some blind dogs can play fetch. Dogs' strong sense of smell can help them detect and distinguish between different objects and obstacles, even if they are blind.
El new study provides the first evidence that dogs' sense of smell is integrated with their vision and other unique parts of the brain. Until now, this connection between the nose and the occipital lobe, functionally the visual cortex in dogs, had not been seen in any species.
The nose helps them orient themselves.
When we enter a room, we mainly use our vision to determine where the door is or where the table is. Whereas in dogs, this study shows that smell is actually integrated with vision in terms of how they learn about and orient themselves to their environment.
The new research corroborates Johnson's clinical experiences with blind dogs, which function very well despite not being able to see. They can still play fetch and navigate their surroundings much better than humans with the same condition. Knowing that there is an information connection that goes between those two areas could be very comforting to owners of dogs with incurable eye diseases.
However, it is not understood exactly how blind dogs use smell to see objects. Veterinarians have long wondered how totally blind dogs navigate their environment so well, even in new and strange surroundings. The olfactory connection we identified gives us an answer to this and shows that are less dependent on eyes alone and they probably use olfactory information to help them navigate their world.
Many people believe that this connection may be based on the behavior of trained dogs and detector dogs, but no one has been able to prove it.
Humans too?
The study revealed that the olfactory bulb connects to areas of the brain associated with memories and emotions. Humans also have this network, so smelling certain odors seems take us back in time. But what was surprising was a new information pathway leading from the olfactory bulb to the occipital lobe, the visual processing area of the brain.
The identification of new connections in the canine brain also opens avenues for further study, as in other mammalian species, possibly even humans. Seeing this variation in the brain allows us to see what is possible in the mammalian brain."
Perhaps there is a vestigial connection between those two areas from when we were more ape-like and scent-oriented, or perhaps other species have significant variations that we haven't explored.