Introduction to Sensation
Take a look at that trippy picture above. You see the different colors and their funky motion. You probably feel your butt against your seat (unless you are standing and in that case you are probably a little strange). Ok, now take a whiff around the room- different odors are entering your nose (hopefully something pleasant). Now listen really closely, what do you hear? Probably the hum from the computer or some Justin Timberlake in the background (don’t be embarrassed, we are all friends here). Now try to taste what’s in your mouth. Maybe you can dig out a piece of that peanut butter sandwich from between your teeth you ate an hour ago. Or maybe you have that morning breath flavor funk going on. Regardless, at this moment, in some distorted way, you are using all of your senses.
Sensation can be defined as the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. What that means is when our body (through our senses) takes in information from everything around us, we are experiencing sensation. Perception is the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events. So basically sensation is taking the stuff from outside of us and bringing it inside our bodies and perception is our body trying to understand what we just took in. The difference is important. We are first going to talk about how we sense things and break down each one of our senses in more detail. We will then try to understand how we perceive the world. Note that this is under the Biological school of psychology because there is a physiological (bodily) root to these ideas and they are all directly linked to our nervous system. In fact, I want you to look at sensation as an extension of our nervous system (part of our peripheral nervous system). Think about it, all of the senses (except smell) go first to our thalamus and then to different parts of our brain (vision to the occipital lobes, hearing to the temporal lobes, touch to the sensory cortex in the parietal lobes etc…).
Let’s start off with an important term called transduction. Transduction is the process by which our body transforms light, sound, touch etc.. into neural impulses that our brain understands. If you want to play your Ipod on your car radio you need a special wire that will turn the Itunes music into something your car stereo will understand. The changing of the signals would be transduction.
Now constant stimulation causes a neat phenomenon called sensory adaptation. Do you feel the underwear you are wearing now? Probably not, unless it is a beaded thong and in that case you have other issues to worry about. For the most part, you feel your clothing when you first put it on in the morning, but then lose any sensation of it later in the day. This is called sensory adaptation and it works for ALL of our senses. If you play a constant humming sound for long enough, you will lose sense of it. It even will work for your vision. If you stare at something for a few minutes it will disappear. Now if you are trying it now and it does not work, here is the reason why. Your eyes are constantly moving and never standing motionless, thus it seems as if our eyes are not subject to sensory adaptation. But if you clamped your eye in one position (please do not try this at home) you would experience sensory adaptation.