It is absolutely amazing how quickly we perceive the elements of our environments. About a month ago, I went for a run near my home in southern York County, Pennsylvania, which I do on a (fairly) regular basis. We have the absolute best area for running/walking right near my home, as part of the road we live on is currently closed to traffic due to a bridge that is in desperate need of repair. I take full advantage of this free “track”, where I can run or walk with little worry of being run over by a car. It is a dirt road that goes through a forest, so there are plenty of sticks, twigs and leaves on the road and I frequently see deer, squirrels and chipmunks during my runs. This particular day, as I was running, I noticed something that caused me to stop. Amongst the twigs and gravel, there was a tiny snake. I had been moving at a pretty swift speed and this snake was only about 3-4 inches long and mostly black. If I had not spotted this snake, I would have most likely stepped on it.
Luckily, it was a very easily identifiable, non-venomous species of snake: the northern ring neck snake, Diadophis punctatus edwardsi (Vigil & Willson, n.d.). The part that I find most intriguing is that I was able to identify this creature as a snake, in spite of the fact that I was moving and it was small and well camouflaged amongst the twigs and leaves. This week’s lesson on perception brought this particular story to mind, causing me to evaluate how exactly I perceived this tiny snake and determined that it was a snake and not a twig.
Seeing the light reflected from the snake began the series of events that lead to my perception and identification of it. This reflection set off a chain of electrical signals sent from my eyes into my brain, causing the activation of specific neurons that are tuned to fire due to specific orientations of things that are seen (Goldstein, 2011). The shape of the snake consisted of geons, parts or shapes that can be observed and help us to identify the object being visually perceived (Goldstein, 2011). Even though I may not have seen the entire snake, just seeing the majority of geons allowed me to perceive and identify the object as a snake (Goldstein, 2011).
One aspect of perception that helped in identifying this snake is semantic regularities: this particular object is something that would normally occur in this type of setting (Goldstein, 2011). In this way, I used my previous experiences and knowledge to know that a snake is a normal item to find in a forest setting, so the object was, quite possibly a snake. Inside of my brain, I was using the what pathway from my striate cortex to the temporal lobe to identify what this object was in my environment and I used the where pathway from the striate cortex to the parietal lobe to determine where the snake was in the environment, allowing me to react appropriately (in this case, to step around the snake instead of on it) (Goldstein, 2011).
The most fascinating part of all of this is that all of these processes were engaged so quickly. In a matter of seconds, I was able to identify this tiny snake as a living creature and react. Our brains are incredible processing organs and we aren’t even consciously aware of what they are doing, even during such a mundane event as finding a snake while running through the woods.
Goldstein, E. B. (2011). Cognitive Psychology: Connecting Mind, Research, and Everyday Experience (3rd Ed.). California: Wadsworth, Cengage Learning.
Vigil, S & Willson, J.D. (N.D.). Species Profile: Ringneck Snake (Diadophis punctatus). Retrieved from http://srelherp.uga.edu/snakes/diapun.htm