July 9, 2012
Dr. Ming Zheng
Concept of Classical Conditioning and Factors that Affect Classical Conditioning Classical conditioning is learning which has been acquired by experience (Terry, 2009). Pavlov was the first one to experiment classical conditioning by training dogs how to salivate when they heard a bell ring. In order for Pavlov to be able to do this, the first step was to show the dogs food. The showing of food would cause the dogs to salivate. Afterward, Pavlov would ring a bell whenever he brought food out. The experimenter continued to this many times. Eventually, by the time the dogs heard the bell ring, and sometimes even without giving them food, they would salivate immediately because they had associated the ringing of the bell with the food. Pavlov demonstrated how a simple reflex, like salivation, could become conditioned or habituated to an external stimulus, in this case the bell. All this created a conditioned response. Therefore, before conditioning would take place, the food was the unconditioned stimulus and the unconditioned response was the salivation. The bell was the neutral stimulus first, not causing the dogs to salivate. Later on, during the experiment, the bell and the food caused the dogs to salivate, becoming the unconditioned response. Following the conditioning, the bell became the conditioned stimulus causing salivation (learned behavior), and the dog’s salivation was the conditioned response (Terry, 2009). In other words, for there to be classical conditioning four major factors need to be present: the unconditioned stimulus (US) that is something that naturally happens that can incite a natural reflex (Terry, 2009); the unconditioned response (UR) is the reflex response; the conditioned stimulus (CS) is the new stimulus that comes to trigger the conditioned response (CR), which is a similar response as the UR. Other factors that affect classical conditioning are the number of pairings; the intensity of the unconditioned stimulus; how dependably the conditioned stimulus predicts the unconditioned stimulus; and the spacing of pairing (Clark, Manns & Squire, 2002). The number of pairing affects when there is repeated pairings (e.g. US+CS, US+CS…). When this happens, the learning is not present, there has to be more pairings in order for conditioned response to occur. The same thing happens with the intensity of the unconditioned stimulus. If a CS is paired with a strong US, then the CR will be stronger and it will be learned much faster (Clark et al., 2002). The other factor that affects classical conditioning deals with the conditioned stimulus reliability. The neutral stimulus has to be able to predict the occurrence of the US (Clark et al. 2002). Last but not least, the spacing of pairing affects classical conditioning if the pairing of CS+US happens too fast, resulting in a slower learning. Slower learning also occurs when CS+US are too far apart. These factors go hand in hand with the basic phenomena of classical conditioning.
Basic Phenomena of Classical Conditioning The basic phenomena of classical conditioning are based on the responses of the sequences of conditioning. As mentioned above, the four principles of conditioning include conditioned stimuli (CS), unconditioned stimuli (US), conditioned response (CR), and unconditioned response (UR) (Terry, 2009). The phenomena describe the relationship between stimuli and response in relation to how it is presented to the subject. The degree of conditioning is measured after the sequence has been presented to the subject. The four basic phenomena of classical conditioning will be described below. Acquisition
Acquisition is the phenomena where conditioned stimulus is followed by unconditioned stimulus. The conditioned stimulus and...