I like to remind myself that I don’t experience the world around me the same way that my dog experiences the world. One of the biggest differences for us is that as a human I primarily experience the world by picking up on visual cues, whereas my dog primarily experiences the world through olfactory cues. My smelling ability isn’t very good, but my vision is pretty great. My dog’s vision isn’t very good, but her smelling is phenomenal. “Humans are better equipped for sight than for smell,” writes Mary Roach in Gulp: Adventures on the Alimentary Canal, “We process visual input ten times faster than olfactory.”
While we can smell, hear, and sense pressure changes on our skin, it is primarily our eyesight that helps us perceive and move about our world. We gain more information from looking at something than we do from smelling, tasting, and even feeling that same thing. That is why so much of our art is visual, why we paint our homes and cars, and why movies and videogames are able to keep our attention so well. Our brains pick up on and process visual stimuli much quicker than other stimuli.
In the human brain, a huge amount of space is dedicated to visual processing. Much more of our brains matter is dedicated to visual processing than olfactory processing, as Roach’s quote above indicates. This is why our brains are so much quicker at decoding and deciphering visual stimuli. In other animals, such as my dog, the part of the brain dedicated to visual processing is not as large relative to other brain regions. My dog has more brain space dedicated to olfactory processing than visual processing, relative to my brain, and thus perceives the world acting on different primary stimuli.
In the book The WEIRDest People in the World, Joseph Henrich shares research which suggests that certain visual activities, like reading, change the structure of the brain. In the case of reading, the brain space dedicated to processing visual symbols grows as one reads more and the brain tends to give up space related to facial recognition. We get better at reading quickly, but worse at remembering faces. In Gulp, Roach explains that this kind of process is likely taking place very early on in childhood development. She quotes a scientist who she interviewed that explains that parents of infants go out of their way to label and identify objects that can be visually observed, but parents do not go out of their way to label sounds, smells, or other stimuli. We can spend hours identifying and labeling the tiny differences that we can observe in everything from different species of bugs to 1000 piece puzzles, but we don’t often spend a lot of time differentiating between all the aromas in the smell of coffee, all the different flavors in a slice of chocolate cake, or all the different sounds in an orchestra. In these instances, we take all the different components and experience them as one, unless we train to identify all the different components.
Our visual processing is truly impressive, but it is worth recognizing how much we rely on what we can see, and why. The world is a lot bigger than just what our minds can process from the visual information that we take in. Remembering how much of our brain is dedicated to visual processing can hep us better contextualize our experiences of the world and recognize when we are being overly biased toward visual information. Malcolm Gladwell’s final podcast of his most recent season, all about the power and potential of dogs’ olfactory processing, is a great reminder of why we shouldn’t be too biased toward what we can see.