Humans, at least those of us who have sight, are very visual creatures. We make sense of our world mostly from visual cues. That is, our brains, specifically the visual cortex, process visual data into a three-dimensional representation of our surroundings.
“Visual cortex” is actually a term that indicates our visual bias because it is a functionally a data processing centre that does not necessarily need visual information to serve its purpose.
I first became vastly intrigued by how we perceive the world when I read an article about whales that suggested their brains construct their three-dimensional representation of the world using sonar. In other words, their visual cortex, or the analogous part of their brain, processes aural information to map the environment.
Obviously, this is not an all-or-nothing situation. Whales have visual, olfactory and tactile senses as well, as do humans. We perceive the world as a combination of all of these, although, different species rely more heavily on some than others.
I remember talking to a dog trainer one time. He explained dogs’ sense of smell to me in similar terms as a whale’s hearing.
When a dog enters a space, she has to smell everything. She is mapping the environment, the trainer said. I imagine her brain creating a “vision” of the space based on what she smells.
I see this with my dog, Lady MacBeth all the time. When we go somewhere new, she is cautious about it at first, she smells everything, much as I look at everything. When it is a familiar place, she forges ahead, only stopping to sniff things that are new or different.
The other morning we were walking on the trails out near J.C. Beach in the new snow. There were tracks. I noticed smaller sized boot prints and paw prints of two medium sized dogs, one veering off here and there from the trail, the other steadily behind the human prints. I knew, based on my visual acumen, exactly who had been there before us.
I am sure Lady knew as well having thoroughly sniffed the prints.
People frequently say that when people are blind, their other senses become enhanced. That is more than likely incorrect. We all have the same capabilities of scent, touch and hearing, but we do not rely on them as much as a blind person would.
I recently read an article about a fascinating study using functional Magnetic Resonance Imaging (fMRI). The incredible thing about the way blind people “see” is that it is apparently very much how the rest of us see. Despite the fact the blind subjects’ visual cortices were not receiving visual data, they were firing as they were.
One subject who lived sighted before going blind said he perceives his environment much the same way he did before but without colour.
This is so intriguing to me, I have spent a significant amount of time trying to grasp it intellectually. The problem is, no matter how hard I try, I can’t “visualize” it.
I have started to experiment, however, with closing my eyes and clicking my tongue, a trick that some blind people use. Stick tapping is another technique that apparently provides robust auditory data that can be translated into that three-dimensional “view” of the world.
Shockingly, or perhaps not, it didn’t take me very long before I could start to hear beside an object or an empty space, when I am approaching an object in front of me or when I am about to enter a smaller space, such as a doorway.
I cannot distingiush between a car and a mailbox, a door or a wall, but I can now start to appreciate a little bit how, between all the other senses, my brain might be trained to function in a way that would allow me to “see” without seeing, so to speak.
Even an intellectual comprehension of it and a rudimentary experience of it, however, enhances greatly my appreciation of what and incredible apparatus the human brain is.
