Author: cns18

Classical Conditioning

The definition of classical conditioning given in class is a type of learning in which an organism learns to associate stimuli; an automatic response to a stimulus. An example of this is thunder and lightning. We know that when we see lightning, we wince or get anxious because of the loud sound of thunder that follows immediately after we see this flash of light from the sky. This is because we learn by association, which allows our minds to connect events that occur in a sequence. Ivan Pavlov was a Russian physiologist primarily known for his work with classical conditioning. He conditioned dogs to salivate when hearing a bell. How? Well, Pavlov knew that dogs would naturally salivate when presented with dog food. Therefore, every time he would present a dog some food, he would ring a bell first, then give the dog food. After he practiced this experiment many times, every time he rang a bell the dog salivate, even when Pavlov did not have food for the dog.

Pavlov used four characteristics of classical conditioning for this experiment: Unconditioned stimulus (US), which naturally elicits a response, Unconditioned response (UR) which is a naturally occurring response, Conditioned stimulus (CS) which is an originally irrelevant stimulus, association with US that triggers CR, and Conditioned response (CR), which is a learned response. In this case, conditioning food (US) produces salivation (UR). The tone of the bell (neutral stimulus) does not. During conditioning, a neutral stimulus (bell) and the US (food) are paired resulting in salivation (UR). After conditioning neutral stimulus (now CS) elicits salivation (CR). 

There are other characteristics of classical conditioning such as acquisition, extinction, spontaneous recovery, generalization, and discrimination which can occur over time with this type of conditioning. Acquisition associates a neutral stimulus with the US. The neutral stimulus must come before an unconditioned stimulus. Extinction diminishes a conditioned response when the US no longer follows CS which will eventually lead the subject to quit responding. Spontaneous Recovery is the reappearance of an extinguished response after a break but will most likely become extinct again. Generalization is the tendency for similar stimuli to elicit similar responses. Pavlov conditioned salivation (CR) by using vibrations on high. Therefore, the dog responded strongest to high stimulation, but also to stimulation near high. And finally, discrimination is the ability to distinguish between a conditioned stimulus and other stimuli such as bells with different tones: one bell gets a response, one does not. 

A personal experience I’ve had involving classical conditioning would be when I had to babysit my 2-year-old nephew for a week. Every time I would wake him up from his mid-morning nap, he would cry. One morning before I woke up him up, I decided to make a pot of coffee which would sound off a quick “ping” when the coffee was ready. After one week of brewing coffee before waking him up, I would hear him cry immediately after the “ping” sounded, even though I did not physically wake him up yet. In this situation, the unconditioned stimulus would be me waking my nephew up from his nap and the unconditioned response would be him crying. After associating the sound of a ready coffee pot to me waking him up immediately after, the “ping”, conditioned stimulus, would make him cry, which is the conditioned response even though I did not physically wake him up.

Depth Perception: Monocular Cues

In Lecture 8, we talked about perceptual illusions, which help us understand how our perception is organized. Part of these illusions include depth perception, which enable us to judge distances. There are two types of depth perceptions: binocular cues (using both eyes) and monocular cues (using one eye). Focusing on monocular cues, this only requires one eye to obtain depth information. 

Examples of monocular cue perspectives include interposition, which allows one object to block our view of another, showing that the object that is blocking is closer. Aerial perspective, which shows that with more distant objects become fainter. An example of this could be to look at a picture of mountains with more “hazier” mountains in the background. Another example of a monocular cue is linear perspective, which involves parallel lines appear to converge with distance. The more the lines converge, the greater their perceived distance. With texture gradient, we see fewer details (texture) the farther an object is from us. Finally, motion parallax shows us that close objects appear to move more quickly than objects that are farther away. An example of this would be looking out a car window and seeing that the mountains in the back are moving at a slower pace than trees or other objects in front.

A personal experience I had when working with depth perception was when I was in art class in the 6th grade and was told to sketch a long street, with houses and stores on both sides. In order to create the illusion of depth, I needed to draw the street convergence in the distance. To do this, I had to use a linear perspective in which I created parallel lines that represented the street, that got closer or narrower as they appear farther away from the viewer. By doing this, it looked like my street was covering great distance as you looked up from the drawing. 

Selective Attention

In class, we learned that selective attention is the ability to deal with some stimuli and not others.  The world contains more information than our brains can handle, so we use selective attention to filter out what is most important to us. There are a few parts of attention that require specific efforts.  The mental effort allows the individual to mentally filter other stimuli to focus on one specific stimuli. An example of this would be if you were in class and there were peers whispering behind you in class while trying to focus on the teacher lecturing a lesson. You have the ability to mentally block that conversation to focus on the lecture. The natural effort is a sensory adaptation, like when you put a bandage on our arm. Initially, you will feel the stickiness of the bandage stick to your arm hairs, but eventually, you will adapt to the feeling and forget it is even there and you can focus on other stimuli. Effortless attention is when we automatically select our attention without thinking about it. An example of this would be if you heard a loud noise, like a book drop on the floor. Our attention would immediately go towards where that sound came from. 

An example of selective attention would be the “Monkey Business Illusion” shown in class. We were told to focus on the number of times a basketball was passed between people wearing white shirts, while changes were happening in the background (such as the gorilla being present, someone wearing a black shirt leaving the game, and how the curtain in the back changed from red to orange). We selected our attention towards the people wearing the white shirts passing the ball and were unaware of everything else happening in the background. 

Relating selective attention to personal experience, just recently I went to the grocery store and saw a huge stand for a popular brand of pumpkin flavored coffee as soon as I walked through the doors. Not only that, pumpkin candles were being burned and fake, orange leaves, and scarecrows were decorated all around this Fall display. My attention was immediately drawn to this brand of coffee, even though I usually buy a different, cheaper brand in the back of the store.  I ended up buying this brand of coffee because my attention was effortlessly drawn to it when I walked into the store. If it wasn’t for the huge stand, it was definitely the additions that triggered my senses (the sight of the decorations and smell of the candle) that attracted me to this display. This example of selective attention allowed me to process what was important to me, which was the name brand pumpkin coffee, and filter out other stimuli, in this case, the cheaper coffee in the back of the store.